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:
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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Why would you need to adjust rainfall?
(I mean apart from to get a government grant….)
Those who control the present control the past. Those who control the past control the future…..
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
“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.
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.
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?).
[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.
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?
I’ll bet it was “Rotten rain” so they culled it!
Probably smells bad too……..
Weren’t people sailing yachts on Lake Eyre last year?
I like your reason, Latimer: “The evidence just evaporated, honest your honour”
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.
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…. 🙂
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.
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
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.
“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.
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.
I reckon they removed the rainfall to make the figures agree with their models’ hindcasts.
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
“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
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….
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 !!
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.
Someone left the lid off the jar and the data dog drank it?