One of the big problems of climate science is uncertainty. Some things that always seem to be in flux are historical datasets, partly because, well, they have so much inherent uncertainty built in. Such is the case of the Historical TSI plot presented on the University of Colorado SORCE web page. All of the sudden, with little fanfare, it changed, and not just a little. What is interesting are the drops during the Maunder Minimum as well as our current Solar Cycle 24
Readers may know that a controversy persists as to the actual TSI behavior in the late 80s/early 90s. The so called “ACRIM gap” was created when the Challenger shuttle was destroyed in a famous accident due to mismanagement combined with launch pressure. It caused by the delay of the shuttle-launched ACRIM2, a satellite that was to maintain continuity of TSI measurements. The debate over how to bridge the gap is relevant to the explanation of the warming that persisted into the 90s. The debate has been quite heated, with those invested in the IPCC forcing story claiming that the TSI decreased in the 90s and those (Willson and Scafetta) who argued that the TSI continued to increase in the 90s.
Some previous TSI reconstructions:
Now there’s even more tinkering from SORCE:
http://lasp.colorado.edu/home/sorce/data/tsi-data/#plots
The SORCE TSI reconstruction looked like this a month ago (word BEFORE added):
Here is what it looks like as of today (word AFTER added):
They say this about it today:
This historical reconstruction of TSI is based on that used in the IPCC AR5 Working Group’s Assessment Report and based on TSI reconstructions by Krivova et al. (JGR 2010) and Ball et al. (A&A, 2012). The values from their SATIRE model have been offset -0.30 W/m2 to match the SORCE/TIM measurements during years of overlap and then extended using SORCE/TIM annual averages from 2003 onward. The historical reconstruction provided here was computed by G. Kopp using TIM V.15 data in February 2014, and is updated annually as new TIM data are available.
Download the ASCII data file
Explore the data interactively with LISIRD
Since the previous dataset wasn’t available to me to plot to show differences and comparisons, here is an overlay of the 2013 and 2014 image versions of the plot, scaled to fit properly since the Y axis changed in 2014 to accommodate the greater range:
They have changed the last three solar maxima and now show a clear roll-off since about 1975. Those are enormous changes since last year’s dataset.
Of note is the drop of about 0.3 w/sqm during the last minimum. You’d think they have a measurement handle on that with our current satellite platform, so you have to wonder why that would need adjustment.
Also of note is a drop of about 0.2w/sqm during the Maunder Minimum.
Not only is global temperature adjusted and is a constantly moving target, now so it is with solar irradiance. With so much input data in flux, the “uncertainty monster” of climate modeling output keeps growing.
h/t to Gordon Fulks and Aaron Smith
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As an active licensed ‘ham’ radio operator, my aerials may extend to the edge of my property, but the areal extent of my property is not very extensive.
She sells sea shells by the sea shore. The shells she sells are surely seashells. …
How much wood would a woodchuck chuck If a woodchuck could chuck wood? …
She stood on the balcony, inexplicably mimicking him hiccoughing, and amicably welcoming him home. Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.
…
etc.
.
How did they work out that a sunspot number of 200+ before the maunder minimum has a TSI of 1360.4 w/m2 yet solar cycle 19 with a maximum sunspot number of 200 has a TSI of 1362.3 w/m2?
That is a very good question, looking forward to seeing it answered.
Hey Jim @ur momisugly 6:25, I manage menageries you people wouldn’t imagine.
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Thanks WillR,
“With Climate Science only the past is uncertain.” That gave me my laugh for today, and I think it’s worth a banner in my study room. You are Will Rogers, right!?
The several blogs , including WUWT,where well informed scientists discuss or defend their work against others who are well informed is a wonderful example of peer review in real time. With all the questionable things happening in climate science, we can be thankful for this and encourage more of it by refraining from the ad hominem, and showing some modesty that most of us are not experts in every field!
Dr. Svalgaard, do you agree? If so, how do we encourage more such participation?
@lsvalgaard-Do you have up to date monthly resolution data files for your TSI and HMF reconstructions?
This isn’t really on topic, I’d just like to know because it will be useful information for something I am working on.
Doug Allen says:
February 11, 2014 at 7:46 am
and showing some modesty that most of us are not experts in every field!
some people here have much to be modest about 🙂
Now, solar-terrestrial relations [as the field used to be called] does embrace several other [broad] fields so it can be difficult to achieve the right mix of expertise needed to discourse properly.
If so, how do we encourage more such participation?
By more severe moderation, both to discourage the personal attacks [e.g. a la Scafetta] and also to better filter out the peddling of less than half-baked pet ‘theories’. Now, this is a fine line to tread and one must, in addition, encourage questions [there are no dumb questions, only dumb answers] from non-scientists and scientists alike.
timetochooseagain says:
February 11, 2014 at 7:53 am
@lsvalgaard-Do you have up to date monthly resolution data files for your TSI and HMF reconstructions?
Those are hard to come by [and the noise would overwhelm the extra information that the higher resolution may give you] . Yearly data is about the best we can do when we go into the past. For the past 60 years we have daily resolution of both.
@lsvalgaard-I’d settle for annual resolution. So do you have the files?
timetochooseagain says:
February 11, 2014 at 8:07 am
@lsvalgaard-I’d settle for annual resolution. So do you have the files?
I make them up as I go. Give me a day or so to put together a package for you. Just watch my website http://www.leif.org/research in the next day or so for the latest version of the files.
@lsvalgaard-Thanks, you have my appreciation!
I always enjoy the solar postings where Leif provides and responds to comments. I read all of the comments because it’s refreshing to learn something from a scientist that knows his craft and can respond without the snark. Thanks Leif for your participation here.
Is it too much to ask these “scientists” to learn about version control? I would like to be able to download current (presumably politically correct) data, as well as an older (presumably less tinkered with) version.
The UN would probably de-fund any such effort. They prefer an Orwellian world.
lsvalgaard says:
February 11, 2014 at 8:12 am
“I make them up as I go…”
Perhaps ‘put them together as I go” would have been a better phrase, unless vuk, tallbloke, ashley et al are actually correct (sarc) 🙂
Leif Svalgaard, thank you for your informative comments.
The 0.25 reduction in TSI in the 1996-2013 period is what I find insufficiently explained.
WTH?? With billions of dollars of high-tech gizmos studying the sun from perches on and off the Earth, somehow the TSI is shifted by more than 10% of it’s decadal variability?
I can see why this was done with little fanfare. If you can’t trust TSI values directly from instruments designed for the purpose, why should we put faith into any proxy reconstruction?
Stephen Rasey says:
February 11, 2014 at 8:52 am
The 0.25 reduction in TSI in the 1996-2013 period is what I find insufficiently explained.
That reduction is now well-understood. To keep track of instrument degradation each spacecraft carries several identical sensors. The trick is to expose them [i.e. keep the shutter open so sunlight can reach the sensor] for different lengths of time. One sensor is exposed all the time [it degrades most], another one is only open, say, once a week, or less and degrades less. The assumption was that if a sensor was never open it would not degrade. This has now been found to be wrong. Sensors degrade [a bit] even if not exposed. Taking that into account, one finds that there is no 0.25 W/m2 reduction over the past cycle.
Tom in Florida says:
February 11, 2014 at 8:29 am
“I make them up as I go…”
Perhaps ‘put them together as I go” would have been a better phrase
‘I make them up as I go’ is the more correct [or at least more honest] phrase. The observables are sunspots [for TSI] and geomagnetic data [for HMF B]. Those are not made up, but ‘measured’ [and adjusted where needed] the best we can [with all the uncertainties that involves]. From the observables a model forms the link to TSI and B. The model is calibrated to the actual data during the spacecraft era of direct observations [which also are taken at face value], then projected into the past from the observables from the past. This is the ‘making up’ part as there is no guarantee that the assumptions in the model hold at all times. But in absence of good evidence to the contrary we must go along with the assumptions. There are a few anomalies. e.g. with the cosmic ray flux that are not fully understood [as they say], but those are active research areas, see e.g. http://www.leif.org/research/Svalgaard_ISSI_Proposal_Base.pdf in the process of being resolved as we speak.
Leif:
I could not help but notice….
lsvalgaard says:
February 11, 2014 at 8:12 am
timetochooseagain says:
February 11, 2014 at 8:07 am
@lsvalgaard-I’d settle for annual resolution. So do you have the files?
I make them up as I go. Give me a day or so to put together a package for you. Just watch my website http://www.leif.org/research in the next day or so for the latest version of the files.
I certainly do know what you mean, but, in this climate (ahem) your comment could be word-smithed into perhaps the greatest crisis of the 21st Century.
I can see the headline Now! Leif Says: I make them up as I go.
Just sayin’ 😉
Cheers!
WillR says:
February 11, 2014 at 9:12 am
I can see the headline Now! Leif Says: I make them up as I go.
Honesty is always the best course. But see my comment just above about ‘making up’.
‘Michael Moon says:
February 10, 2014 at 9:37 pm
Whenever records of data have been posted without immediate controversy, which marks the records as adequate, and subsequently altered as historical records, science has been abandoned and a scam is in progress.”
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Michael, do you believe we landed on the moon?
look here doctored photos. note the crosshairs..
http://www.fascinatingpics.com/wp-content/uploads/2013/11/666.jpg
There is only one perpendicular point on the planet that receives the fullest level of watts the sun’s TSI generates. Even though we see the disc as a flat surface, the reality is the increasing anlge of curvature reflects the TSI into space. If we assume the wattage to be constant (just for argumentation) then any long term change in cloud cover would seem to have a large affect on TSI input to the the surface raising and lowering the long term temperatures accordingly. Similar in effect is the coolness at the poles as the sun’s TSI is less effective to heat the surface. I don’t see the point in arguing over TSI change as much as is the importance of total cloud cover.
“That reduction is now well-understood. To keep track of instrument degradation each spacecraft carries several identical sensors. The trick is to expose them [i.e. keep the shutter open so sunlight can reach the sensor] for different lengths of time. One sensor is exposed all the time [it degrades most], another one is only open, say, once a week, or less and degrades less. The assumption was that if a sensor was never open it would not degrade. This has now been found to be wrong. Sensors degrade [a bit] even if not exposed.”
Thanks Leif. That is a wonderful example of how assumptions play a role in “measurement” and “raw” data.
….So, parking a satellite above the clouds may be well intended for a cleaner measurement of TSI, what counts is the TSI that actually heats the surface.
Steven Mosher says:
February 11, 2014 at 9:43 am
Thanks Leif. That is a wonderful example of how assumptions play a role in “measurement” and “raw” data.
But also a wonderful example of detecting an error and rightly correcting the ‘precious historical record’ when it should be.
Well ages ago I used the value 1353 W/m^2, but that was based on rockets and balloons, and not really extra-atmospheric. That also is the value suggested in my (somewhat dated) infra-Red Handbook.
Then I settled on 1366 after looking at some satellite numbers from several different satellites; and then recently someone Possibly Leif said NASA/NOAA had a new value more like 1362.
Well I don’t think it’s a big deal, I still get about a 0.1% cycle over the solar cycle, and as Leif mentions; mox nix compared to the annual change due to earth orbit.
I’m sure the numbers will keep changing as “better” data shows up; but I’m not looking for any holy grail in TSI numbers.
Looks like 1366 is a good number for me to remember to use in calculations.
But there isn’t any big revelation there in TSI numbers.