BOM disappears rainfall data, “no trend” becomes “downtrend”

UPDATE: Thanks to a reader who pointed out where to find the 2008 version of BOM rainfall data, I’m able to plot the two data sets. There are differences. See addendum below. – Anthony

BOM loses rainfall

by Tom Quirk on Quadrant Online

Shock Murray-Darling Basin discovery

Analysts at the Australian Bureau of Meteorology have some explaining to do.

In the last two years some 900 mm of rainfall have been removed from the rainfall record of the Murray-Darling Basin. This startling discovery was made by comparing the annual Murray-Darling Basin rainfall reported on the Bureau of Meteorology website in August 2008 and the same report found yesterday.

The annual rainfall figures are shown as reported in October 2010:
Yearly rainfall in the Murray-Darling Basin from 1900 to 2009 as reported in October 2010 with a mean value of 467 mm (solid line).

There is no significant trend in rainfall through this period but there is large variability with rainfall extremes of a 257 mm minimum and a 787 mm maximum.

The comparison with the August 2008 report is revealing. The difference is a decrease of 900 mm rainfall in the 2010 report. The significant decrease occurs after 1948:


Changes to Bureau of Meteorology record of Murray-Darling Basin rainfall. Data downloaded August 2008 and October 2010

The Bureau is already on record adjusting Australian temperature measurements and they now appear to have turned to rainfall, making the last 60 years drier than previously reported.

One can understand that adjustments might be made to a few of the most recent years as records are brought up to date but a delay of forty or fifty years seems a little long.

This raises the question how certain is the data that is used by policy makers?

When we are confronted by apparently definitive forecasts of our future with rising temperatures and less rain, are we living through a period that brings to mind the Polish radio announcement of Soviet times?:

The future is certain only the past is unpredictable.

============================================

WUWT Reader Charlie A writes:

The Wayback machine comes to the rescue!

http://web.archive.org/web/*/http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rain/0112/mdb/latest.txt is the Murray Darling basin annual rainfall archived by archive.org on January 30th, 2008.

The current series can be found at http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rain/0112/mdb/latest.txt

The query form for data and graphs is at http://www.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=mdb&season=0112&ave_yr=0

So, now having the older data, I decided to run a quick plot to see the difference. I fired up my Dplot program and came up with this in about a minute:

 

click to enlarge

 

There are differences in the two data sets. The 2010 data has lower values, starting around 1950, just like the Quadrant article. WUWT?

- Anthony

Addendum: I notice the peaks post 1950 seem to be reduced, but the lows are not. Strange.

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133 Responses to BOM disappears rainfall data, “no trend” becomes “downtrend”

  1. Robinson says:

    Why would you need to adjust rainfall?

    (I mean apart from to get a government grant….)

  2. rxc says:

    Those who control the present control the past. Those who control the past control the future…..

  3. gerard says:

    The BoM, pro AGW advocates and politicians have taken advantage of the 13 year drought to promote their cause to a naive public. As we currently sit through one of the coldest October days in living memory today with occasional snow flurries I wonder how long they can play this game. This La Nina winter has seen rains return to above average. At this time, we are 150mm above average for the year to date and the current temperature in Kyneton at the very top of the Murray Darling catchment in central Victoria is 2.5 celsius and falling

  4. Tim F says:

    “Analysts at the Australian Bureau of Meteorology have some explaining to do.”

    So have they been asked to comment? What did they say? Where is their reply?

    I can think of several explanations:
    * some radical analysts decided to adjust the measurements to make climate change seem more dramatic.
    * some sloppy analysts made a mistake somewhere.
    * instruments changed over the years, and they were adjusting the readings to reflect corrections
    * The Murray-Darling Basin covers over 1,000,000 km^2. They might be using a different averaging algorithm to get a more accurate average for this extended area.

    Before speculating or accusing further, it might be prudent to actually get some facts. That is, after all, how science (and reporting for that matter) is supposed to be done.

  5. Latimer Alder says:

    Evaporation?

    All that hot air about AGW in Australia influencing the samples?

    Import of the Fidllethenumbers virus from NZ?

    Global cooling causing the water samples to contract?

    I’m sure that there is an entirely innocent and satisfactory explanation.

    In UK we have a Prof. Jones at UEA who might be able to help in any investigation. He has lots of expertise in this area.

  6. Patrick Davis says:

    We’re getting some rain in NSW, below average temps, snow on the hills down to 500m, but it is just weather. It will be a hotter than average October, of course! (Yeah right BoM, Sept was colder than it was 16 years ago…apparently. Some “papers” report this event as being the coldest Sept in 5 years. Who to believe eh?).

  7. kevin oram says:

    [snip]. How long do they and others like them really believe they will be allowed to get away with this sort of thing? Desperate stuff really.

  8. michael hammer says:

    I am confused. The second graph seems to be labelled “2000 – 2008 difference of yearly rainfall mm”. There is a point plotted for each year suggesting this is not averaged data but unsmoothed raw data yet look at the data from 1910 to about 1945. The difference is about 10mm peak to peak. Would anyone in their right minds accept that for about 35 years the total annual rainfall was consistent within 10 mm year over year. Then again, over the entire record the variation is no more than about 40mm. Any thinking person in Victoria Australia would know with 100% certainty from personal experience that that was inconceivable. Now look at the 2008 data. The variation year over year is up to 500mm (and typically more than 200 mm) . We all know that this is what happens in reality. Have I missed something? Because if not, the 2010 graph even in isolation screams “manipulation” to a degree that makes the data obviously worthless. Surely the people who drew this up would realise their data could not survive the most casual scrutiny – they could not be so dumb. There has to be something more to it. Again, what have I missed?

  9. pRadio says:

    I’ll bet it was “Rotten rain” so they culled it!
    Probably smells bad too……..

  10. Robert of Ottawa says:

    Weren’t people sailing yachts on Lake Eyre last year?

  11. Robert of Ottawa says:

    I like your reason, Latimer: “The evidence just evaporated, honest your honour”

  12. David W says:

    Why does it seem like every adjustment that is ever made to weather records is in support of AGW. I understand errors can be made and improved methodology over time can allow scientists to achieve a more accurate result but it simply beggars belief that correction of every single error in historical measurements shows a stronger warming trend or lower rainfall.
    You can’t help but see this occurring and hake your head in disbelief. Do the people who make these adjustments have any comprehension of how bad they look?
    I actually hope there turns out to be an innocent explanation for this particular adjustment because it looks terrible at face value.
    So much so that it shreds the credibility of the bureau’s climate scientists.
    If this ones true it makes me incredibly angry.

  13. Latimer Alder says:

    Have there been any recorded instances of ‘adjustments’ to the raw data which have led to an underestimate of the effect of AGW? To this naive mind, accidental errors should work equally in both directions.

    I just wondered…. :-)

  14. stephen richards says:

    Tim F says:
    October 15, 2010 at 5:00 am
    * some radical analysts decided to adjust the measurements to make climate change seem more dramatic. Probable
    * some sloppy analysts made a mistake somewhere. In 194x. How difficult it is to read a rain gauge?
    * instruments changed over the years, and they were adjusting the readings to reflect corrections. It’s a rain gauge for christ sake. How can you change a tube with a scale which you just read.
    * The Murray-Darling Basin covers over 1,000,000 km^2. They might be using a different averaging algorithm to get a more accurate average for this extended area.

    Average in maths is an average. You take all the rain gauge measurements, add them together and divide by the number of rain gauges.

    How difficult can it get. And how does that change the data for 60 yrs ago.

  15. Jack Jennings (aus) says:

    It’s probably got to do with a very expensive desalination plant, renewed rainfall after the15 yr drought and an election in a few weeks time.
    JJ

  16. Mike S. says:

    michael – I think it’s labelled “2010-2008 difference of yearly rainfall mm”. The second graph appears to me to be the difference between the 2008 data and the revised 2010 data. The “decrease in 900mm rainfall” mentioned appears to be the cumulative amount removed from the 2008 report to the 2010 report. Since (as was observed) most of that was after 1948, the average decrease is around 12-15mm/yr (1948-2008).

    I agree with Tim F – while this does look like the alarmist’s standard M.O., there could be a relatively innocent explanation, and we just don’t have enough information right now to be sure.

  17. kramer says:

    Why would you need to adjust rainfall?

    As far as I’m concerned, to tie it to AGW and then scare the public into accepting their leftist political solutions.

  18. A C Osborn says:

    michael hammer says:
    October 15, 2010 at 5:14 am
    What you have missed is that that graph is the values by which the old readings have been altered.

  19. Jimmy Haigh says:

    I reckon they removed the rainfall to make the figures agree with their models’ hindcasts.

  20. Bill in Vigo says:

    Looking at graphs I wonder if they might have possibly substituted the “temperature” chart inverted for the rainfall graph. Just a slip of the finger on the computer keys, simple mistake, could have happened to any one. Surely just an innocent error. Hmmm would make their projections fit the dogma better.

    Just wondering,
    Bill Derryberry

  21. tty says:

    “Weren’t people sailing yachts on Lake Eyre last year?”

    This year too. It’s almost full to the brim:

    http://www.lakeeyreyc.com/Status/latest.html

  22. Douglas Dc says:

    This is like the Cascade snowpackl not dropping but increasing, but the various Climatologists in Washington and Oregon (for example, George Taylor) being
    declared anathema, and sent into outer darkness by the State….

  23. Chris in Queensland says:

    The “why” is pretty simple really.

    The Greens are now in coalition with the Labor Party governing Australia.

    The Greens want to return the Murray Darling river system to as it was prior 1788.

    Farmers, (say the greens) take all the water from the system.

    The government wants to take the water off the farmers and return it to the rivers.

    The MDBA (Murray-Darling Basin Authority) report came out in the last day or so recommending the return of irrigation water back to the system.

    BOM is just helping out the government in saying we are getting less rain so the farmers have to give back the water.

    Farmers are in revolt.

    There you are, simple !!

  24. Roger Knights says:

    Tim F says:
    October 15, 2010 at 5:00 am

    “Analysts at the Australian Bureau of Meteorology have some explaining to do.”

    So have they been asked to comment? What did they say? Where is their reply?

    I can think of several explanations:
    ………
    * instruments changed over the years, and they were adjusting the readings to reflect corrections
    * The Murray-Darling Basin covers over 1,000,000 km^2. They might be using a different averaging algorithm to get a more accurate average for this extended area.

    Before speculating or accusing further, it might be prudent to actually get some facts. That is, after all, how science (and reporting for that matter) is supposed to be done.

    Scientists are also supposed to publish explanations when making changes in the underlying technique of publicly reported data. When that isn’t done, a public outcry is justified.

  25. RoyFOMR says:

    Someone left the lid off the jar and the data dog drank it?

  26. GeorgeGr says:

    Michael Hammer,
    I believe the second graph shows the adjustments made by BoM. They have “increased” rainfall in th early years and then “decreased” rainfall in the later years. The opposite of their usual adjustments to temperatures.

    Thus, the picture BoM is painting with their combined adjustments is that it was colder and wetter (less droughts) in earlier years, and increasingly hotter and drier in later years. All consistent with the AGW predictions…

  27. John Kehr says:

    This is why we keep having to download the data and archive it. The problem is then your data doesn’t match the source at a later period. That is very frustrating.

    Messing with the data is real blasphemy.

  28. Jimbo says:

    Farmonline – 19 Aug, 2009
    “Murray chief goes against the climate flow
    As speculation grows that consecutive years of dry conditions could be a permanent climate “step change”, Murray-Darling Basin Authority chief Rob Freeman has expressed confidence that wetter times will return………..”Some commentators say this is the new future, I think that is an extreme position and probably a position that’s not helpful to take,” he said.”
    http://tinyurl.com/3ax53jy

    ——————–

    The Australian – March 06, 2010
    Record falls to flush Lake Eyre, Murray-Darling
    The Bureau of Meteorology estimates that, over the 10-day period ending March 3, 403,000 billion litres of rain fell across the Northern Territory and Queensland – the biggest fall since April 1990……..Records have tumbled with the rain. The bureau reports rainfall of over 100mm across 1.7 per cent of Australia on March 1, and over 1.9 per cent of the country the following day, setting a record for a single day. The previous record was set on December 22, 1956.”
    http://tinyurl.com/yh2sv5f

    ————————————
    2009 – Near Bellingen on the northern NSW coast ;O)
    http://www.abc.net.au/reslib/200902/r340495_1548650.jpg

  29. Michael Larkin says:

    I’m somewhat confused by the graphs.

    The first shows annual rainfall figures since 1900 as at Oct 2010.

    Am I right that what is not shown is the corresponding graph as at Aug 2008?

    Then, would the second graph shown be the difference between the Oct 2010 and Aug 2008 graphs, revealing a series of adjustments with a downwards trend?

    If so, what might be helpful is the inclusion of the missing 2008 graph. I’m also unsure what is meant by “a decrease in 900mm rainfall”. Would that be the sum of the downwards adjustments over the 1900-2010 record?

  30. Mike says:

    Tim F wrote: “Before speculating or accusing further, it might be prudent to actually get some facts. That is, after all, how science (and reporting for that matter) is supposed to be done.”

    Tim, people don’t come to WUWT for facts. They come for confirmation bias. http://www.skepdic.com/confirmbias.html

    Got’a keep the costumer satisfied.

  31. tarpon says:

    So the rainfall just evaporated?

  32. CGTG says:

    Is it possible to have the Aug 2008 graph also ? … perhaps a blink comparator ?
    I always like to have the most “raw” info possible.

  33. Tom_R says:

    >> michael hammer says:
    October 15, 2010 at 5:14 am
    I am confused. The second graph seems to be labelled “2000 – 2008 difference of yearly rainfall mm”. There is a point plotted for each year suggesting this is not averaged data but unsmoothed raw data yet look at the data from 1910 to about 1945. <<

    The second graph shows the adjustments made to the rainfall data. It's the difference between the graph/data published in 2008 and the graph/data published in 2010. Perhaps showing the two years with a blink-comparison would have made that clearer.

  34. son of mulder says:

    The missing rainfall has been included in the sealevel rise record;>)

  35. Jimbo says:

    OT – but related to trends
    NASA funded peer reviewed paper says basically there has been no trend in global hurricane activity (1965–2008)
    http://www.agu.org/journals/ABS/2010/2010GL042487.shtml

  36. DesertYote says:

    If we are entering into a cooling phase, then rainfall is going to decrease. The greenies are just getting ready for the next change in their narrative. When it is Hot-Wet they talk about the heat. When it is Cold-Dry, they will talk about the drought. They have already convinced the public that Hot = Dry, i.e. Global Warming creates deserts.

  37. gcb says:

    michael hammer says:
    October 15, 2010 at 5:14 am
    I am confused. The second graph seems to be labelled “2000 – 2008 difference of yearly rainfall mm”. There is a point plotted for each year suggesting this is not averaged data but unsmoothed raw data yet look at the data from 1910 to about 1945

    I believe that the second graph is just a subtraction of the numbers in the first graph (2010, not 2000) from some other (unsupplied) historical dataset that was captured in 2008. So, for example, the 1960 data point in the second graph really represents the 2010 historical data point for 1960 minus the 2008 historical data point for 1960.

    This second graph shows that, after the data point for 1948, the values gathered in 2010 are pretty much uniformly below the values gathered back in 2008, as the result of the subtractions are all below zero. As such, yes, it appears someone has been fiddling with the data, although the reasons are unclear.

  38. Matt says:

    The more they lie and cheat like this the more discredit they bring on themselves. If it can be found that they lied to get funding then naturally prosecutions for fraud should follow.

  39. amicus curiae says:

    After I saved a BoM page with 1930s heat wave data and then it vanished some 3 weeks later..I started to twig that we also had the AGWbug at work on out weather data.
    It is NO Mistake!
    they are trying to remove massive amounts of water allocated to our rural ag areas.
    this is a Purposeful atempt to make it look like its worse than it is to ram home this policy.
    Our farmers have battled drought and debt for 10 years in many areas, and this is likely to ruin thise we have left!
    they are among the BEST! farmers in the world coping with conditions that would have made many walk away, they battled on, finally! a good season even with Locust issues, and this lunatic labor/green cadre is trying to Gut the survivors!
    IF Joolyabrown, hadnt blocked the report released this week, before the election..
    she would be sending her Xmas cards from antarctica as thast where she and her green buddy would have ended up..
    OUT in the cold.
    its 2c here in spring?
    the dry we have had is NO different to any I have tracked back in local settlers journals since the 1800s.
    ABC radio the Bom and CSIRO are all in collusion with Govt and a definite agenda!
    as an Aussie taxpayer I am wildly angry and disgusted with the lot of them.
    they have ruined any credibility they had, and I will Never accept a damn thing they publish now without some serious checking and wanting supporting evidence..and somehow? I reckon thats going to be scarce.
    I thank you again most sincerely Anthony and co, as without your checking these mongrels would be a lot more likely to get away with the Murder! of our society, which is..what the AGW con is all about.

  40. nandheeswaran jothi says:

    is the second graph a moving average, over a number of months? like 72 months or something like that with the y axis being a percentage of the mean over a period?

    otherwise the graph makes no sense at all. generally precipitation vary from a 1/3 to 3 times the mean.

  41. James Sexton says:

    Robinson says:
    October 15, 2010 at 4:31 am

    “Why would you need to adjust rainfall? ”
    ========================================================

    Because it fits the alarmist narrative. Remember, it is now climate disruption, complete with simultaneous floods and droughts. If you don’t have a handy drought, well, you can just make one!

  42. Doug in Seattle says:

    My first observation is that the two graphs show different things and do not match the text very well. I can still digest some information from them though.

    There appears in both graphs some kind of post 1940′s change in either precipitation or how it is measured/recorded. More info is needed to explain the shift, which does not appear to be something that occurred recently.

    Without explanation of the shift, I would be skeptical of any interpretation of the data.

  43. JEM says:

    AGW is not the only political cause shaping science in Australia; the supposed shortage of future rainfall was used to justify building a hugely expensive desalination facility instead of a dam to provide water in Vic state.

  44. Henry chance says:

    Can’t report too much rain. It could scare people.

  45. Ecotretas says:

    This is also happening in Portugal. Several stations are not recording rainfall in days when it happened. I’ve documented it, in Portuguese, here:

    http://ecotretas.blogspot.com/2010/10/chuva-mal-contada.html

    Ecotretas

  46. Herbie Vandersmeldt says:

    Global dimming adjustment? The evaporation pans in Australia are the most famous ones.

    Silly that the reasons for changes and method weren’t included in the release. Irresponsible.

  47. Jeff says:

    Tim F …

    since no accusations where positied in the post what are you talking about ?

  48. Gordon Ford says:

    Jullia, Here’s the new rainfall numbers. It’s now “worse than we thought!”
    Sod the farmers.
    BoM

  49. Ian W says:

    It would appear that these meteorologists and climatologists have no concept of quality management and quality control in keeping and maintaining records. If they were to have shown this ill disciplined behavior in commercial industry they would have been sacked.GHCN

    All changes should be openly documented with a reason for the change, how it was made, who authorized the change, how it was checked and accepted as correct and who carried out the acceptance test. The changes, their documented procedures and change records should be open book to the public who pay for the BOM.

    Their approach to data matches the approach to GHCN sites – do what you can get away with. I’ll disciplined and slap dash. Yet based on this poorly collected and maintained data global political decisions are being made.

  50. John F. Hultquist says:

    stephen richards says: at 5:33 am

    “ . . . add them together and divide by the number . . . ”

    The link below shows three (3) [also spelled “Tree”] boxes with dots and labeled as Three types of spatial distribution

    http://home.comcast.net/~sharov/PopEcol/lec3/3distrib.html

    Have a look. Assume each dot is a measuring station. The right-most box has a cluster of dots in the upper-right and lets assume a storm stalls over the five dots nearest the corner and much rain falls. The other very close by places show no rain – thus showing the local nature of the storm.

    The left most box has only two (2) dots, or measurement stations, in the same corner where the other has 5.

    Perhaps the mean is not the best statistic to describe the rainfall for the entire area:

    http://www.microbiologybytes.com/maths/1011-18.html

  51. Gary Pearse says:

    Tim F 5:00am.
    Re BoM have some explaining to do – whether or not one asks for an explanation (which, if you are not trying to hide your changes, you should give along with the update) the statement stands. There is nothing here but a statement that they should be obliged to explain such a half century change. This is not an acusation. Tell me that you don’t want to have an explanation.

  52. kalsel3294 says:

    The Murray-Darling Basin covers a large area. I wonder if they have redefined it and changed the stations that provide the rainfall data?

  53. ZT says:

    Nothing to see, please move along…

    There is just a missing addition to the label for the second plot – “(homogenized value added rainfall)”.

  54. TomRude says:

    Truly looks like Australia is run like Zimbabwe…

  55. Stephan says:

    Save all that stuff it will be useful for upcoming litigation, NZ, BOM and others take note

  56. Tim F says:

    Jeff says:
    “since no accusations where positied in the post what are you talking about ?”

    I was talking about the three posts immediately before mine, all of which imply a nefarious intent behind the adjustments. I was talking about any number of subsequent posts that specifically state that is this is a result of AGW activitists trying to manipulate the data.

    Even the title of this blog is inaccurate, creating a rather clear accusation. “BOM disappears rainfall data, “no trend” becomes “downtrend” “. But, no! That is not what the article says at all. Look within the post – “There is no significant trend in rainfall through this period.” The article specifically states that the ADJUSTED data shows no significant trend!

    Let me repeat – the data in the graph AFTER the adjustments were in 2010 made STILL show no downward trend. Yes, the trend will be a little bit more downward than it would have been with the previous numbers. Without the raw data it is hard to be certain, but I suspect that there is no statistically significant change in the slope before and after adjustment. If someone wants to post results of that statistical analysis, I’d love to see it.

  57. An Inquirer says:

    Mike says: “. . . people don’t come to WUWT for facts. They come for confirmation bias.”

    Actually, I came to WUWT (and Climate Audit) because I was stymied at Real Climate looking for facts. WUWT matches the world I live in — a world in which there is both an Antarctica was well as an Arctic. A world that continues even after 2007 in the Arctic and after 2005 in the Carribean. A world which did not start in 1979 — or even 1750. A world where the droughts and heat of the 1930s still scorched my grandfather’s farm no matter what 21st century computer gymnastics tell us now. A world where hurricanes existed before satellites did. A world where outcomes are not determined by wishful intentions but rather by consequences of incentives.

  58. RockyRoad says:

    Tim, without raw data it is impossible to be certain about anything. Adjusted data is pretty much worthless unless the exact adjustments are included along with justification/methodology so you can obtain the raw data.

  59. Charlie A says:

    The Wayback machine comes to the rescue!

    http://web.archive.org/web/*/http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rain/0112/mdb/latest.txt is the Murray Darling basin annual rainfall archived by archive.org on January 30th, 2008.

    The current series can be found at http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rain/0112/mdb/latest.txt

    The query form for data and graphs is at http://www.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=mdb&season=0112&ave_yr=0

    Lots of WUWT enthusiasts are skeptics. duh. And and we like to verify claims independently.

  60. Trevor says:

    It was determined that it was never rain to begin with, rather the higher amounts of water were caused by people sweating excessively due to higher temperatures.

  61. 899 says:

    tty says:
    October 15, 2010 at 6:13 am
    “Weren’t people sailing yachts on Lake Eyre last year?”

    This year too. It’s almost full to the brim:

    http://www.lakeeyreyc.com/Status/latest.html

    Yes, but you see? It’s all ‘pretend’ rain, and pretend water, and that makes it possible for people to ‘pretend’ to sail with pretend yachts.

    That’s all made possible by the same pretentious folks who brought you pretend CAGW/CC/CD.

    Remember this, and remember it well:
    The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.
    ~ H. L. Mencken ~

  62. sHx says:

    Mike says:
    October 15, 2010 at 6:54 am

    Tim, people don’t come to WUWT for facts. They come for confirmation bias.

    Well, with regard to global warming issue more facts can be gleaned from WUWT than any other website or mainstream media outlet. I visit here regularly precisely because of that. Like it or not, this is a fact.

  63. Tim F says:

    stephen richards says: October 15, 2010 at 5:33 am

    “Average in maths is an average. You take all the rain gauge measurements, add them together and divide by the number of rain gauges.”

    Averaging is actually a bit of a challenge, as anyone who tries to come up with a “global average temperature” will tell you.

    In this particular case, i hypothesize that sometime around 1910, and again around 1950, more stations were added to the system.

    Let me make up some numbers to illustrate my point (and no, these are NOT the actual results, but the principle still applies).

    Suppose in 1900 there were 10 gauges for the region, and they have averaged 450 mm of rain since they were installed with no detectable trends over that time.
    Then, in 1910, 10 more were installed, and they have been averaging 470 mm. (they were installed in areas that happen to get a little more rain on average than the first 10.)
    Then in 1950, 10 more were installed, and they have been averaging 490 mm.

    Following your method — “You take all the rain gauge measurements, add them together and divide by the number of rain gauges.” — you find that
    * from 1900 – 1910, the average rainfall was 450 mm/yr
    * from 1910 – 1950, the average rainfall was 460 mm/yr
    * from 1950 – now, the average rainfall was 470 mm/yr

    No individual rain gauge shows a trend, but the data shows an increase! Clearly we should not conclude that rainfall has increased. The more accurate conclusion is that the rainfall was 470 mm/yr the whole time. Thus the only real choice is to add 20 mm/yr to the numbers before 1910 and and 10 mm/yr to the numbers between 1910 and 1950.

    Is this what really happened? I don’t know! But to me it is a much simpler explanation than a vague conspiracy. Until there is specific evidence of improper conduct,

    Maybe we need a variation of the old saying “Never attribute to malice that which can be adequately explained by stupidity.”
    “Never attribute to malice that which can be adequately explained by correct and proper science.”

    As far as I can tell, no one (Quirk, nor Watt, nor posters) has made an effort to contact the BOM in Australia to get an explanation for the changes. Are fact really that unimportant to the discussion???

    (There is also the issue that the gauges are not evenly spaced, so even for a fixed set of gauges, you would want a weighted average, not the simple average you were advocating. )

  64. Dan S. says:

    OK – I’ve been looking for info on this Polish radio announcement
    “The future is certain only the past is unpredictable.” and I can’t find anything. Is there a certain event I can search for?

  65. Mike S. says:

    Is it possible to have the Aug 2008 graph also ? … perhaps a blink comparator ?

    CGTG – Problem is the scale. Since the scale of the differences is quite small compared to the scale of the raw values, the difference between graphs likely wouldn’t jump out at you.

    The article specifically states that the ADJUSTED data shows no significant trend!

    Good catch, Tim F., I missed that point entirely.

    Does anyone know if BoM has been pinged regarding an explanation for these adjustments? Their answer might be legitimate or it might be completely bogus, but I’d sure like to hear it, whatever it turns out to be.

  66. Latimer Alder says:

    Perhaps they have lost the fag packet on which the adjustments were made?

    Hence cannot provide an exact explanation of their reasoning? The technical term for this sort of adjustment is ‘the CRU method’.

  67. Person of Choler says:

    Also sprach Tim F, “Before speculating or accusing further, it might be prudent to actually get some facts. That is, after all, how science (and reporting for that matter) is supposed to be done.”

    How about this: When making adjustments to previously published data it behooves those making the changes to announce the adjustments and explain what they did and why.

    That is, after all, how science is supposed to be done.

  68. Mike Abbott says:

    The 2010 graph and the raw data used to generate it can be found at the BoM web site at http://www.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=mdb&season=0112&ave_yr=0.

    Click on the “About time series” link near the top and you’ll find a detailed description of their methodology. It appears that they may have started using a new methodology in 2009 (see the citation at the bottom.)

  69. Charlie A says:

    When looking at the trends of Jan 2008 data and the current data I didn’t find any significant change in trends. Perhaps I miscalculated, but it looks like it’s pretty close to “no trend” any way you look at it.

    Jan 2008 data 1900-2007 trend: +0.55mm/yr
    Jan 2010 data 1900-2007 trend: +0.38

    The level of variation in the data can be seen by the effect of adding or dropping a single year. The 1900-1949 trendline is -0.22mm/yr in the 2008 data, and -0.45mm/yr in the 2010 data.

    But changing the trendline period by just one year so it is 1900-1950 the results change sign.
    1900-1950 trendline is +0.6mm/yr using 2008 dataset, and +0.33mm/yr using the 2010 dataset.

    It all looks like a tempest in a teapot. Insignificant trends all around.

    It appears to be just yet another case of poor documentation of adjustments.

  70. Mike S. says:

    Dan – the quote is a translation, the more common form is “Only the future is certain; the past is always changing.” I’ve seen it ascribed to the Solidarity union, as a Polish or Russian proverb, etc., but almost always in the context of a commentary on the tendency of communist governments to revise history.

  71. morgo says:

    To TomRude: NO it is being run like Cuba. Our gov’t is the worst gov’t we have ever had, it is run by green looneys. As far as our Murry rainfall have a look at our weather at the moment: RAINING, FLOODING, COLD, SNOWING, WINDY SEAS. So much for global warming.

  72. Martin Hale says:

    Is it just me, or are the warmists increasingly resorting to using tactics spelled out in Orwell’s Nineteen Eighty-four as a playbook, instead of the dire warning they were intended to be? This instant story could have literally been ripped out of Winston Smith’s daily activity log sheet at the Ministry of Truth. Revising history to fit the narrative of today.

  73. Charlie A says:

    Mike Abbott says October 15, 2010 at 10:25 am:
    Click on the “About time series” link near the top and you’ll find a detailed description of their methodology. It appears that they may have started using a new methodology in 2009 (see the citation at the bottom.),

    I don’t see much detail. But reading between the lines, I infer that they have changed how they average or combine the stations. Perhaps the 2008 data is a simple average of all stations in the Murray Darling Basin. More likely, the 2008 data is some sort of simple gridded/weighted average. Now they have gone to a higher resolution grid.

    Jeff Id over at TheAirVent and various others bloggers and posters have done a lot of work with various methods of combining surface air temperatures to get a global average. Kind of like in this case, there are minor differences in the results, but the overall trends change very little.

  74. jorgekafkazar says:

    Tim F says: “…No individual rain gauge shows a trend, but the data shows an increase! Clearly we should not conclude that rainfall has increased. The more accurate conclusion is that the rainfall was 470 mm/yr the whole time. Thus the only real choice is to add 20 mm/yr to the numbers before 1910 and and 10 mm/yr to the numbers between 1910 and 1950…”

    Total nonsense, Tim, based on spurious assumptions.

  75. Paul Deacon, Christchurch, New Zealand says:

    Mike says:
    October 15, 2010 at 6:54 am

    Tim F wrote: “Before speculating or accusing further, it might be prudent to actually get some facts. That is, after all, how science (and reporting for that matter) is supposed to be done.”

    Tim, people don’t come to WUWT for facts. They come for confirmation bias. http://www.skepdic.com/confirmbias.html

    Got’a keep the costumer satisfied.
    ******************************
    Mike – there are no facts in the experimental and natural sciences, there are only observations. This article shows 2 differing sets of observations. The difference is unexplained, but it may be that as a result of the article a reader (or the BoM) might point us in the direction of possible explanation. A main reason I visit WUWT is to read this sort of discussion, especially as I live in a country, like Australia, where the officials (NIWA) are known to make significant adjustments to the historical temperature record, leaving no audit trail or explanation for their adjustments. They also rely on a decades old study by a PhD student, which has not been peer-reviewed. My judgment is not easily swayed, I visit WUWT because I like open discussion of these and other issues, which is not easy to find on the internet.

    Why do you visit WUWT?

    All the best.

  76. Tim F says:

    Person of Choler says:

    How about this: When making adjustments to previously published data it behooves those making the changes to announce the adjustments and explain what they did and why.

    That is, after all, how science is supposed to be done.

    Well, what do you know. That’s what they did!

    “Mean rainfall timeseries are calculated using a high-resolution gridded dataset developed for the Australian Water Availability Project (AWAP). The dataset uses topography-resolving analysis methods applied to all available monthly rainfall data passed by a series of internal quality tests. The resulting analyses have a resolution of approximately 5km x 5km and represent a substantial improvement on the grids previously used for operational rainfall monitoring.”
    http://www.bom.gov.au/climate/change/about/rain_timeseries.shtml

    So in conclusion:
    * they developed a better way to analyze the data
    * they presented the better data
    * they told us that they had presented better data.

  77. Mike S. says:

    Between the explanation Tim F found and Charlie A’s analysis of the difference in trends between the datasets, it seems to me like there really is nothing significant to look at here unless somebody starts trying to make some kind of unsupportable point from it about global warming climate change climate disruption.

    REPLY: The central question is: Why do rainfall records need to be adjusted at all? -Anthony

  78. DesertYote says:

    Tim F
    October 15, 2010 at 11:53 am
    ” The dataset uses topography-resolving analysis methods applied to all available monthly rainfall data passed by a series of internal quality tests.”

    So in conclusion:
    * they developed a better way to analyze the data
    * they presented the better data
    * they told us that they had presented better data.
    #

    Cool. Probably one of the internal quality tests is to reject monthly readings that are outside a given threshold. So have we seen this sort of filtering before that just happens to have only rejected readings on the contra-narrative side?

  79. Mike Abbott says:

    Anthony, regarding your Update, you should be able to use the Wayback machine to get at the 2008 data for the other regions and for Australia as a whole. Were they all adjusted downward, or was the Murray Darling Basin a fluke? In particular, how does the current total for Australia compare to the 2008 data?

  80. Tim F says:

    Mike S. says:
    October 15, 2010 at 12:19 pm

    Between the explanation Tim F found and Charlie A’s analysis of the difference in trends between the datasets, it seems to me like there really is nothing significant to look at here unless somebody starts trying to make some kind of unsupportable point from it about global warming climate change climate disruption.

    Too late! There have already been dozens of unsupportable points made. The motivations and abilities of good scientists were assumed to be flawed by people making unsupportable points because of anti global warming climate change climate -climate disruption ideology.

    “The central question is: Why do rainfall records need to be adjusted at all? -Anthony”

    To me, the central question is “Why were so many people ready to believe an unchecked, unvetted opinion from an unknown author?”

  81. kalsel3294 says:

    Across Australia generally, the second half of the 1900′s were wetter than the first half and that is reflected in the Murray-Darling Basin records. Although official records have not been reconciled for the 1800′s, there are sufficient indications that the 1800′s were drier and more drought prone then the 1900′s which indicates, that despite the latest drought that may have been etched in peoples TV memories, the trend is not as dire as many would have us believe.

  82. Latimer Alder says:

    Anthony asks the faux naif question

    Why do rainfall records need to be adjusted at all?

    But the answer is clear. They do not fit with the theory. And we simply must not have theory and experiment disagreeing – it would be entirely unscientific.

    So a few minutes work to make corrections to some old unimportant records and voila everything is back in order once more.

    We can all sleep easy in our beds again. AGW re-confirmed..now with even more evidence of its correctness!

  83. E O'Connor says:

    After a day of continuous rain yesterday, there is intermitment snow here in Canberra this morning. Occasional morning frosts in October are normal, but not snow!

  84. Stephen Brown says:

    As far as I am concerned rainfall simply … IS.
    If more stations have been added, if conditions in hitherto unmetered areas are such that an overall change is noted why is this not given along with the raw data?
    The “alteration” of rainfall figures cannot, under any circumstances, be tolerated.

  85. mILLrAT says:

    If you get the “new improved” data and put it alongside the old data and plot the difference year by year you observe 3 stages of data improvement.
    From 1900 to 1910 the new data averages 6.3 mm extra rainfall per year. With zero negative adjustments over that period.
    From 1911 to 1945 the new data averages 3.4 mm less rainfall per year, with only 3 out of 35 readings showing a positive adjustment. This gives the combined average for 1900 to 1945 only 1.3 mm less rainfall per year.
    From 1946 to 2007 the new data averages 14.1 mm less rainfall per year than the old data. There is only one positive correction out of the 62 readings.
    So from 1911 to 2007, of the 97 annual readings there are only 4 positive adjustments.
    I would love to hear the BOM’s rational for the changes but I doubt they will see the light of day.

  86. Neville says:

    The time series graphs from BOM has a toggle above that allows a trend line to be drawn like here.

    http://www.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=mdb&season=0112&ave_yr=T

  87. John Cooper says:

    Anthony writes:

    The central question is: Why do rainfall records need to be adjusted at all?

    The only reason I can think of is to…dare I use the word?…homogenize the data over a wider area. A rain gauge measures rainfall at a certain location over a certain period of time. Maybe some genius is trying to extrapolate the history at a single location over a wider area and a longer time.

    I’ve always wondered about those weather forecasts that estimate a “40% chance of rain” in my area. Do that mean that at my location there will be a 40% chance of rain over the next 24 hours, or 100% chance of rain during the next 24 hours over 40% of the forecast area? Or maybe they do a root-mean-square calculation or something?

    Sometimes I sits and thinks, and sometimes I just sits…

  88. Jan of Perth says:

    The Queensland Government used to produce a chart of Australia’s variable rainfall from 1890 – discontinued in 2004 but still to be seen on this site. It would be great if a private company could reproduce them again because it is very instructive looking at the chart because you can see clearly that while droughts have occurred, the trend in Australia appears to have been for more rain over the 20th century, not less. Each home in Australia should have one of these on the wall!!

  89. Stilgar says:

    Tim F says:
    October 15, 2010 at 1:17 pm

    To me, the central question is “Why were so many people ready to believe an unchecked, unvetted opinion from an unknown author?”

    Generally, if data from the past is adjusted, there are 2 big reasons why:
    1. purely scientific – better methods than were used in the current system and to get the most scientific answer the best methods must be used.
    2. purely political – the old answer goes against political will so someone is tasked with producing something that better fits with what the politicians want to be done (politics can be governement of corporate).

    Commenters have posted that there is political interest over the area so it is at least plausable that something else is going on. Is there no point in wondering exactly why/how it was changed? Or is it just no point in posting it on a blog for others to read?

  90. Stilgar says:

    oops… (politics can be governement OR corporate)

  91. Dr A Burns says:

    More on the non-existent decline in NSW rainfall
    http://www.warwickhughes.com/sydwater/sydrain.htm

  92. Michael Jankowski says:

    One of my first posts at RC years ago was countering someone from Australia railing on-and-on about the decline of rainfall on the continent in the 20th century, particularly in her area. Her proof was a BoM article with comments to the effect. The funny thing was that you could go to the BoM site and both download the data and have the website generate graphs for the continent as a whole or specific regions…and the results showed the trend was basically flat.

  93. Terry says:

    The second graph looks more like a step change at about 1950 or so. Equipment change? location change ?

  94. Andrew says:

    As we shiver through a cold / wet October day in south-eastern Australia, with major flooding in numerous parts of the Murray / Darling basin, it is interesting to look at today’s (16/10/10) rainfall figures for the Canberra area and note how variable they are. Canberra airport (new station) 15.8mm, Canberra airport (old station) 17.0mm. These are 500 metres apart. Tuggeranong 48.8 mm (13km S of the airport) and Mt Ginini 73.4mm (41km SW of the airport). And our state of the art plastic guage on the back deck (5km SE of the airport) 33mm.

    Try coming up with a ‘high resolution 5km x 5km gridded dataset’ with figures like this.

  95. kalsel3294 says:

    Rainfall can vary widely, as discussions between neighbouring farmers often shows, ;-) however over a period of time things do tend to average out, over a year as well as over decades. There are still however areas that are in rain shadows or the like that consistently are either higher or lower than surrounding areas

  96. David W says:

    Tim F says:
    October 15, 2010 at 1:17 pm
    ……..
    “The central question is: Why do rainfall records need to be adjusted at all? -Anthony”

    To me, the central question is “Why were so many people ready to believe an unchecked, unvetted opinion from an unknown author?”

    Thats a very good question Tim F. Why don’t you actually go away and think about it. What is it that has caused such a massive amount of distrust in the data presented by climate scientists.

    If what was being presented was a sound and incontrevertible as the AGW movement has been trying to tell us, there is absolutely no way there should be the level of mistrust and scepticism in climate “data” that we see today.

    Just as trust is earned so is mistrust.

  97. David W says:

    Ooops typo. Incontrevertible should be incontrovertible.

  98. DavidS says:

    Data can dissapear but the rain won’t. I have a friend who just emigrated to Queensland from Scotland. He says he feels right at home.

  99. Chris in Queensland says:

    DavidS says:
    October 15, 2010 at 5:08 pm
    Data can dissapear but the rain won’t. I have a friend who just emigrated to Queensland from Scotland. He says he feels right at home.

    ===================================================

    Would have to agree, only 17.1c at the Hervey Bay Airport at 10:30 AM and where I am, 100meters from the beach, it is only 16.5c.

    This time of the day here in the tropics, it should be around the 27 / 28c.

  100. Richard says:

    Anthony, you asked:
    REPLY: The central question is: Why do rainfall records need to be adjusted at all? -Anthony.

    Possibly because the government and the greens who helped get them into power want the Murray River to flow more than it ever has in the past. They are putting the farmers and food production as a low priority. Most countries are planning for 40 years ahead and food requirements. Not Queensland, we are selling out to the greens and AGW warmists.

    In Griffith, Yoogali Hall was nowhere near large enough to hold the more than 7000 angry farmers and residents who turned up for yesterday’s public consultation about the scaling back of water rights.

    While some cried, children as young as five held up signs saying “Keep my family on the farm”, while others wore animal costumes to protest against the plans by the authority. It has proposed an average basin-wide water cut of 27 to 37 per cent – even higher in some regions – which would return between 3000 and 4000 gigalitres of water to the stressed river.

  101. John of Cloverdale WA says:

    As ever Tony, Warwick Hughes has an interesting article on the plot of South Australian rainfall vs wheat production (Australian not South Australian unfortunately) on his blog http://www.warwickhughes.com/blog/?p=678
    Contrary to what the media and green-socialist lobby would have you believe about food production and “global warming” (sorry worst drought ever).

  102. Ted Annonson says:

    Sure, an intelligent person could see the flaws in this, but this was made for politicians.

  103. John of Cloverdale WA says:

    More from the weather department down under, during what will probably be reported as the hottest ever October globally (in their own minds).
    SNOW, WIND AND RAIN WHIP EASTERN AUSTRALIA
    http://www.weatherzone.com.au/news/snow-wind-and-rain-whip-eastern-australia/15216

  104. Bob_FJ says:

    I don’t see that these small changes 2008 versus 2010 are significant in terms of trends, although they do seem to be very strange. Has anyone asked for an explanation from the BOM?
    Whatever, there seems to be plenty of evidence that there is nothing unusual in periods of severe drought in the Murray-Darling basin, and also wide volatility.

    For instance, how about this first photo: “Dry river bed of the Murray River at Myall near Kerang, Victoria, 1914. During the Federation drought it stopped flowing for about 6 months.” Or, secondly, upstream at Mildura, camels crossing. Nowadays of course, this is the realm of houseboats, and deaths in boating and water sports reportedly exceed those on the roads in the region.
    http://farm5.static.flickr.com/4018/5079020859_ef8d51b35e_b.jpg

    And, on a more romantic but highly relevant note, check out this magnificent poem of 1904 by Dorothea MacKellar, describing horrible drought, a decade before those photos
    http://www.lancescoular.com/my-country-by-dorothea-mackellar.html

    I also feel that the following anomaly graph (13 October 2010) from the BOM is perhaps an easier-to-see portrayal, showing the BOM/CSIRO preferred 11-year smoothing.
    http://farm5.static.flickr.com/4133/5084763699_59bb331d8b.jpg

    Incidentally, I’m currently making a complaint of bias in the ABC’s “The Science Show” (21 Aug 2010) using in part the info above.
    Also, will be doing something concerning the recent proposals by the Murray Darling Basin Authority, to make, massive cuts to water allocations to farmers. (There is uproar)
    http://www.abc.net.au/local/stories/2010/10/15/3039023.htm?site=rural&microsite=murraydarling&section=latest

  105. Tim Folkerts says:

    “Maybe some genius is trying to extrapolate the history at a single location over a wider area and a longer time.”

    Yes, I EXACTLY agree with you. The graph is indeed an extrapolation over a wide area — namely the 1,000,000+ km^2 Murray-Darling Basin.

    The simple (perhaps naive) answer is that they found a better way to extrapolate the data and presented the new results.

    The conspiracy answer is that someone intentionally adjusted the calculations downward.

    I’m willing to be skeptical of BOTH options. Convince me that YOUR position is correct. Go over the data. See what algorithms they use. I’d love to hear your report with appropriate statistical analysis. It you find something incorrect, I’ll be the first to congratulate you. If you find something underhanded, I’ll be the first to join you demanding that someone get fired!

    Skepticism must go both ways. If one is only skeptical of one side, that is worse than no skepticism at all.

    On a different front …
    jorgekafkazar says: October 15, 2010 at 11:27 am
    Tim F says: “…No individual rain gauge shows a trend, …
    Total nonsense, Tim, based on spurious assumptions.

    I don’t think you read what I wrote. I specifically hypothesized a plausible situation where such corrections could have legitimately been applied. I never assumed this was what ACTUALLY happened.

    I suppose I should have written “In this hypothetical situation, no rain gauge would have shown a trend … “. Does that clarify my hypothetical situation?

    And finally …
    I am skeptical of the hypothesis that “data were changed”.

    I hypothesize that only the algorithm for analyzing the records was changed (whether that change was intentional malfeasance or an honest mistake or a true improvement). My hypothesis 1) fits the information available and 2) is simpler than the hypothesis that the algorithm AND the records were both changed. I would argue that by Occam’s razor, my hypothesis a better starting point.

    But I would be happy to be shown wrong. Can anyone present specific evidence (even circumstantial evidence) that rainfall records that go into the calculated average rainfall for Murray-Darling Basin were changed? That the rainfall amounts a given station were adjusted downward to make the overall average lower? (Guilt by association is not a legitimate argument.)

  106. Cirrius Man says:

    Tim F says:
    October 15, 2010 at 5:00 am
    “Analysts at the Australian Bureau of Meteorology have some explaining to do.”

    So have they been asked to comment? What did they say? Where is their reply?

    Tim F – The point here is that if the BOM makes these adjustments without explanation hoping that no one will notice (except that someone almost always does), then the trust factor will move accordingly. When you drill the BOM for explanation they come up with something along the lines of done in the interests of producing high quality data. It’s a complete joke, so why try and defend the fools only to become one in the process ?

    What I find so ammusing here is that the Murray is now experiencing floods following another rain event yeasterday. The Hume Weir is now expected to overflow next week and there is now a risk of major flooding downstream if we have further rain as all the upstream catchments are at capacity. Not to mention all the unseasonal snow and cold weather that accompanied…. (Is somone upstairs trying to send a message ?)
    http://www.abc.net.au/news/stories/2010/10/16/3040181.htm

    Recently, a link between the Indian Ocean dipole and rain in SE Australia was discovered, and the cause between the past decade of MIA drought was resolved. Now with La Nina cranked up at full throttle and the Indian Ocean dipole finally in the negative phase we can expect more of the same for months to come. Of course the recent big rains in this area of Australia have come at a very inconvenient time for our left wing political parties trying to basically legislate farmers off this land to allow water to flow out to sea.

    My advise to the BOM – Please act very quickly to remove all this rain in your database records via your high quality homoginisation process – before somone notices !
    :)

  107. PlainJane says:

    For those outside Australia if you want a link to a site discussing how cogent this issue is in current Australian politics try starting with Andrew Bolts blog. http://blogs.news.com.au/heraldsun/andrewbolt/

    There might be a reasonable reason for the changes to the BOM rainfall information.

    Perhaps by pure coincidence there happens to be extremely current political reasons for showing there is less water in the Murray-Darling than there used to be. The Government want to remove water rights that it sold to farmers decades ago. Now the Govt wants the water back to buy green votes. This will bankrupt countless farms and associated businesses and towns will die. Unlike in the USA the rural vote is not strong all.

    The Australian Federal Government has already used the Rio Earth summit and Kyoto summit targets as a reason to remove use rights from farmers to their lands to meet carbon targets. (Native Vegetation act – trees and native grasses cant be touched and ploughing need a permit if not done for 10 years) Since under the Federal constitution the goverment cannot do this without compensating property owners the Feds got the States to do it for them where there is no constitutional requirement for compensation.

    Having confiscated land use the Government is also working on water rights.

    Showing that rainfall has fallen is used as supporting information by the Government in the argument to remove extremely valuable assets from the people who currently own them, most likely without compensation.

    I am not saying the BOM staff have definitely changed their data to suit their employers, just that the changes are very coincidental.

  108. John of Cloverdale WA says:

    Thanks for that post “Dr A Burns says:
    October 15, 2010 at 3:16 pm”. Shows you how alarmists, media and politicians ignore historical data.

  109. BS Footprint says:

    The scientific world (especially climate-related) really ought to keep data in version-controlled archives. It turns out in this case that archive.org saved the day, but you got lucky. Archive.org isn’t always reliable.

    Professional software developers use proper revision control systems to protect themselves from lost work. What do researchers and scientists use? When the aren’t trying to cover their tracks, that is…

  110. Rattus Norvegicus says:

    You might have overstated your claim. The Mark I eyeball would seem to indicate no trend for both data sets. However, there does seem to be more interannual variability in the latter part of the record. I notice that nobody did a trend analysis on the two data sets. Run one and give us the results. Are they statistically significant?

  111. David Joss, Australia says:

    Someone asked “why would you need to adjust rainfall?”
    Maybe to promote the decline in line with the preachings of one of Australia’s high priests of AGW, Tim Flannery, whose predictions, somewhat battered by recent rainfall, are found here:
    http://www.science.org.au/nova/newscientist/105ns_001.htm
    He is perhaps partly right in claiming a decline in the past 50 years but if you go back further it seems not:
    http://reg.bom.gov.au/cgi-bin/climate/change/timeseries.cgi?graph=rain&area=seaus&season=0112&ave_yr=0
    Although the BoM seems not to show any records prior to 1900, the great Federation drought actually began in the late 1890s. There is historical documentation of another great drought from the mid 1830s to 1842 too.

  112. There’s nothing unusual about how the BoM handles its rainfall records. In November last year they increased the temperatures for August by about half a degree …

    http://www.waclimate.net/bom-bug-temperatures.html

  113. MikeA says:

    I like conspiracy theories; however since I live on the edge of the catchment I have to face reality. Annual rainfall means squat, you need rainfall at the right time for crops and catchments and in the right places. Falling water tables, rising salt and environmental degradation (think dust) plague the catchment. The rainfall has shifted north, this is not noticeable over a million square km, but the soil is drying out and the river is short of water. One La Nina does not mean the drought is over, major catchments are less than half-full and may never fill. This is all fairly normal for the Australian climate but the northerly rain shift and the decrease in frosts may well be symptoms of AGW. What’s in the future? Well, with or without AGW, drought.

  114. David Joss, Australia says:

    MikeA says “major catchments are less than half-full and may never fill. ”
    What major catchments are you talking about? Hume is currently at 88% with much more water to come down (in April it was 15%), Burrinjuck is full, Blowering almost full, Burrendong is full, Eildon (near empty for the last couple of years) was 60+ when I looked before the most recent storms. In short the Murray-Darling basin is awash. Any more rain will mean major floods.
    If you look at the major flood records, they happen on a roughly 17-20 year cycle which happen to coincide with big La Nina years. That’s going back to 1853 using historical documents as the BoM doesn’t provide figures before 1900.

  115. Bob_FJ says:

    MikeA, Reur October 15, 2010 at 11:28 pm
    “…however since I live on the edge of the catchment I have to face reality… …What’s in the future? Well, with or without AGW, drought.”

    Cheer up old boy, at least you didn’t have to live there during the disastrous droughts of the late 1800’s and early 1900’s.
    What’s in the future? Well, with or without AGW; probably also floods, because the basin has long been historically very volatile.

    Check out:
    http://wattsupwiththat.com/2010/10/15/bom-disappears-rainfall-data-no-trend-becomes-downtrend/#comment-508827
    That’s October 15, 2010 at 6:49 pm above

    You should put aside your emotions, open the links therein and carefully study them, together with some more recent posts.

    David Joss,
    The “Melbourne reserves” were also dramatically improved BEFORE the recent heavy rains. Even 50% full would be adequate for a good few years of drought, providing sensible irrigation is allowed,

  116. gerard says:

    I have annual rainfall figures for Kyneton in the Murray Darling Basin dating back to 1874. I do not detect any real trend.

  117. Cirrius Man says:

    gerard says:
    October 16, 2010 at 1:08 am
    I have annual rainfall figures for Kyneton in the Murray Darling Basin dating back to 1874. I do not detect any real trend.

    Remember, you need to get your raw data adjusted by BOM’s high quality homoginizing algarithm before it can be used as a valid reference. Then the trend becomes obvious.

  118. gerard says:

    MikeA says:
    October 15, 2010 at 11:28 pm
    I like conspiracy theories; however since I live on the edge of the catchment I have to face reality. Annual rainfall means squat, you need rainfall at the right time for crops and catchments and in the right places. Falling water tables, rising salt and environmental degradation (think dust) plague the catchment.

    One of the advantages of falling water tables (due to drought) is that rising salt is less of an issue. Salinisation (dryland salinity) requires rising water tables. Most land degradation issues in the Murray Darling Basin are due to past land management issues such as extensive land clearance and over grazing by sheep and cattle during drought of deep rooted perennial native grasses. Clearing of low quality marginal country is still occuring in Queensland exacerbating problems in the basin.

  119. julie says:

    The unreliable Australian BOM has been chosen to ‘peer review’ New Zealand’s latest attempt at an official/unofficial temperture record. I’ve got a feeling the New Zealander’s have chosen the right people.

  120. We know Jim Hansen has his thumb on the temperature scale at NASA GISS.

    The question is: who has unfurled the umbrella over the rain gauges at BOM?

  121. Bob_FJ says:

    MikeA, Reur October 15, 2010 at 11:28 pm
    You twice mentioned a northerly rain shift in Oz, apparently with some concern, re AGW climate modelling. The suggestion is of doubtful scientific logic, for instance:

    If you look at the BOM rainfall record, there was an increase in rainfall in Southern Australia between about 1972 and 2002
    http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rranom/0112/saus/latest.gif

    In Northern Oz, there was a somewhat similar period of increase, but far more volatile. (Monsoonal variations?)
    http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rranom/0112/naus/latest.gif

    Here is Victoria, the worst affected state in recent and past drought which somewhat bucks the similar trends above:
    http://www.bom.gov.au/web01/ncc/www/cli_chg/timeseries/rranom/0112/vic/latest.gif

    However, an interesting aspect is that the notably “wet” period between about 1950 and 1975, corresponds to a period of global cooling. (All rather volatile though). Do you remember the global cooling scare of the 70’s?

    There is other stuff too, but this could be a thought starter for you.

  122. An Inquirer says:

    There’s that interesting statement from the IPCC, paraphrased: “Observational data do not conform to model results. Therefore either the data are wrong or the models are wrong. We tend to believe the former.”
    When a body is governed by such a belief, it is natural to be suspicious when its analysts come around a couple of years later saying, “We have a adjusted in an improved process, and now it matches the models better.” To be trustworthy, there needs to be a clear and honest explanation of the new process. By “honest,” I mean a discussion of the pros and cons of the old as well as the pros and cons of the old. Otherwise, it is not science; it is politics.

  123. R. Craigen says:

    Tim F:
    Jeff says:
    “since no accusations where positied in the post what are you talking about ?”

    I was talking about the three posts immediately before mine, all of which imply a nefarious intent behind the adjustments.

    I’m probably wasting my time as Tim’s behavior marks him as a troll. Even so, for the millionth time: DON’T CONFUSE POSTS BY THE OWNER OF A BLOG SITE WITH COMMENTS BY GUESTS AND ANONYMOUS VISITORS! In your original comment you clearly addressed the poster — in this case, Anthony who is cross-posting Tom Q’s piece from Quadrant Online — and as part of those comments you say “Before speculating or accusing further…

    Embarrassed by being called out (Anthony’s post contains neither speculation nor accusations of any sort), you scan the comments for something that supports your statement.

    What’s that behavior called again? Oh, yes, “confirmation bias”. Thanks for the reminder Mike!

    Incidentally, you ask whether Anthony/Tom has asked for an explanation. What the h*&# do you think this post (which begins with the assertion that BOM has some explaining to do) is, if not a call for an explanation?

    Anthony has often publicly called for experts to answer for this or that action or statement, and always provides space to publish their responses when these are made available. Challenge for Mike: find me an alarmist site with a similar profile that habitually does the same with off-narrative submissions. Until you can do so please don’t lecture us about “confirmation bias”.

  124. R. Craigen says:

    Mods: isn’t there a way to add commenter self-editing or a preview stage for comments so we can catch or fix problems like the run-on link in my above comment? Anyway, please fix for me. Thx

    REPLY: Fixed, but no preview available from wordpress.com I’ve asked many times -Anthony

  125. Bob_FJ says:

    Anthony,
    Reur reply comment just above.
    Over at Harmless Sky, it declares at the foot of their web pages:

    Harmless Sky is powered by WordPress | Using Tiga theme with a bit of Ozh + WP 2.2 / 2.3 Tiga Upgrade

    e.g. this thread of over 12,000 comments: http://ccgi.newbery1.plus.com/blog/?p=274&cp=16#comment-89222

    Marvellously this not only allows WORDPRESS preview, but easy formatting, AND insertion of images within the comments.

    I’m sure that TonyN would be happy to discuss with you. I have his Email address if you want.

  126. Cam says:

    There have been massive bouts of political contamination of the meterological and climatological disciplines (and data) in this country over the past 5-10 years to help justify a number of very expensive &/or highly controversial Government policy changes here relating to water (primarily). Each project to date has failed a cost-benefit analysis, however doctored or intentionally mis-interpreted data are used to make a ‘better case’ for a project or policy under the guise of ‘climate change’.

    Data and trends are taken out of context by Government (and their self-serving stooges like Steffen, Flannery, Garnaut, Connor and others) to justify their spending of tens of billions of dollars on de-sal plants throughout the country, pipelines from (now full) reservoir to (now full) reservoir, and changes to water allocation policies that now threaten entire agricultural regions.

    Climate is used as a ‘tool of fear’ in Australia more than just about anywhere else on the planet. It’s used to sell papers, sell books, approve projects, stop projects, justify public debt, employ thousands in the public sector, target specific sectors of the community, and justify ‘white elephant’ infrastructure.

    ‘Climate change’ is a politicians (and social engineers like the Greens) greatest weapon.

  127. Fool me once (shame on you) - fool me twice (shame on me) says:

    What pathetic sceptic drivel – a full apology is in order from Mr Watts. You’ll publish anything Anthony.

    • The Bureau of Meteorology updated its spatial analyses in 2009 as part of the Australian Water Availability Project (further details on the Bureau’s component can be found here (http://www.bom.gov.au/amm/docs/2009/jones.pdf). The new data are at a much higher resolution (~5km versus ~25km previously) and substantially more accurate. The analyses are described in a scientific paper (above), and draw on a partnership between Bureau of Rural Sciences, CSIRO, Australian National University and the Bureau of Meteorology.

    • A large area average (such as for the Murray-Darling Basin) is not a measurable quantity but rather is estimated from discrete values at stations. The estimate has most recently been improved by improving the quality of the underling algorithms used to convert station rainfall to gridded rainfall. The process of improving data and estimates is ongoing, through the use of new data (such as from satellites/radar), back digitisation of historical rainfall data and improvement to spatial analysis algorithms.

    • The difference between the old (Barnes) and new (Australian Water Availability) analyses is typically 0 to 5% by year – the mean difference is 1.8%. The newer analyses are very slightly drier overall than the Barnes analyses, in part, because earlier versions of the analyses tended to spread rainfall too widely from alpine/high altitude stations because they did not account for altitude. In both cases the linear trend in the area average Murray-Darling Basin rainfall data is for a very slight (non-significant) increase of rainfall over the last 110 years

    • A description of the data and methodology has been available publicly at http://www.bom.gov.au/climate/change/about/rain_timeseries.shtml

    Will Tom Quirk make an unreserved apology !?

  128. Bob_FJ says:

    Re: Fool me once … October 18, 2010 at 12:47 am
    It might have been more helpful and politic if you had referred us directly to the following paper:

    High-quality spatial climate data-sets for Australia.
    David A. Jones, William Wang and Robert Fawcett (2009)
    http://www.bom.gov.au/amm/docs/2009/jones.pdf

    However, upon a quick read, it does not seem to me to explain the step change discussed in the lead article here.

    The Jones paper in fact shows rainfall data per AWAP method all the way from 1900 to 2007, not from ~1950 to 2009, that being the suspected period of step change.
    See Fig. 11(b) and also the text below it, talking of AWAP data from 1900.

    I also don’t see that this change in itself is important, since it has only a slight effect on trends. However, it is interesting in the light of “adjustments” in other data sets, all in the “it’s worse than we thought” direction. For instance the recent NIWA episode.
    Of course some of the “adjustments” have been in gradual steps over a lengthy period, which is an interesting consideration, wot?

  129. Steve Short says:

    Farmonline – 19 Aug, 2009
    “Murray chief goes against the climate flow
    As speculation grows that consecutive years of dry conditions could be a permanent climate “step change”, Murray-Darling Basin Authority chief Rob Freeman has expressed confidence that wetter times will return………..”Some commentators say this is the new future, I think that is an extreme position and probably a position that’s not helpful to take,” he said.”

    20 Aug, 2010: Federal election results in hung parliament. Labor retains government with help of Greens……

    ABC News – 18 Oct, 2010
    “For Murray Darling Basin Authority chairman Mike Taylor, the week was mission near impossible. He delivered dire news to dozens of inland communities, in short telling them that they are living well beyond their means. Their water use must be drastically cut, in some cases by almost a half…..”

  130. Fool me once (shame on you) - fool me twice (shame on me) says:

    I see very little to get exited about BobFJ – number of stations change dramatically after 1950 – depends on where those stations are related to orographic effects in the new spatial analysis and amounts of rain in what part of the state in what years. The whole issue is a massive beat-up.

    But as always one could get all the rainfall data from BoM’s database ADAM and do your own spatial analysis and publish it.

  131. Bob_FJ says:

    Fool me once Reur October 20, 2010 at 1:06 am
    See: Fig. 1 (a) in the David Jones et al paper:
    http://www.bom.gov.au/amm/docs/2009/jones.pdf

    The number of rainfall stations plotted do not exhibit a step-change from ~1950 to 2009, which is the primary subject in the lead article here. There is a notable peak between ~1960 & ~1980, but it then drops away to a rough fit to a gradual linear increase from ~1915 to end. ( From around 5,400 to 6,600 stations)

    The AWAP change to spatial gridding is applied to all data from 1900 to 2007.

    Anthony’s comment at the foot of the lead article is also succinctly relevant:
    Addendum: I notice the peaks post 1950 seem to be reduced, but the lows are not. Strange.

    I agree that there is very little to get excited about because the step-change is small, but we will have to wait and see if it suffers from “creep” like as for example with the anti-clockwise rotation of GISSTEMP. As I said, it is strange how the cumulative “adjustments” of various surface station data are always in the “it’s worse than we thought” direction.

  132. Malcolm Souness says:

    I’m wondering if Quadrantonline has gone offline, or if it’s being filtered by the NZ firewall?

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