Showing posts with label AMSU temps. Show all posts
Showing posts with label AMSU temps. Show all posts

2011/11/05

Just How good Are Satellite Derived Temperatures (updated)

Many changes have been made to satellite derive temperatures ( I have asked Spencer to explain the differences and unrecorded adjustments on many blogs. BUT never has he bothered to explain).
With the current BEST surface temperature  slanging matches raging on the anti AGW blogs all eyes seem to be turning to the satellite record and opinions seem to suggest that these results are what everyone should be usingas the gold standard (mainly because they only show the last 8 year and these have a cooling trend!!)

What goes up must (in earth orbit) eventually come down.
NOAA-15 was once the satellite producing the temperature records (from 1998) however as the hardware progressively fails the data from the AQUA satellite has been used (data available from 2002)

This gave a 6 year overlap where the temperatures could be compared and corrected. This, according to Leif Svalgaard is what happens with the TSI measurements for solar activity.

My complaint is that there is a LARGE error in data between AQUA and NOAA-15 and no attempt to reconcile the differences is made or explanations given.
Indeed The UAH team handling the data seem to adjust data at a whim.
For example: for channel 05 AQUA between the dates of 2010-07-03 and 2011-10-01 data missing in the earlier plot suddenly appeared in the later plot  (from 2009-02-01 to 2009-02-03 and on 2010-11-25 and 2010-11-26 Why and how? Also in my data the earlier records were one day adrift !! (could have been me however)

People are quibbling about discrepancies of 0.12 K/decade  but looking at the comparison between NOAA-15 data and AQUA this 0.12K/decade is the discrepancies produced by the two satellites and modified by the same team.

Chan 05
.

From the above plot during the overlap period:
NOAA warming is 3.27e-5K/day = 0.119K/decade
AQUA warming is -1.95e-5K/day = -0.0712K/decade
Also of interest is the two plots for the same series but obtained at different times red and blue in the plot these seem to have been revised without explanation (by up to .08K)

Looking at CH 4 data, the current data on their web site runs from 2002 to 2008 (with the last 6 monts failing) The data that was available (NOAA?) went from 1998 to 2011 and despite this being the longer record  is not used on their Discover website.


Again the slope over the valid overlap period is:
AQUA 1.0404e-5K/day = 0.0380K/decade
NOAA 1.1879e-4K/day = 0.434K/decade


Another series CH06


AQUA -4.2323e-5K/day = -0.154K/decade
NOAA -1.7595e-4K/day = -0.642K/decade

Chan 10


AQUA -6.59e-5K/day = -0.2345K/decade
NOAA -9.58e-4K/day = -0.3411K/decade
Chan 13



AQUA -2.1174e-4K/day = -0.754K/decade
NOAA -1.4831e-4K/day = -0.528K/decade

Another plot shows that CHLT (NOAA defunct) and CH04 (recently AQUA defunct) had peaks and troughs occurring at the same time. However comparing CH04 to Sea Surface temperature the temperature of the sea changes BEFORE the air temperature by a couple of months. HOW?


Absolute temperature differences
CH4 NOAA) - (CH4 AQUA)=-2K
( CH5 NOAA) - (CH5 AQUA)=-0.11K
( CH6 NOAA) - (CH6 AQUA)=-0.99K
( CH10 NOAA) - (CH10 AQUA)=-0.279K
( CH13 NOAA) - (CH13 AQUA)=0.062K
Conclusion

There seems to be many more problems with satellite temperatures than with surface temperatures. Why then are these held up as being the golden standard???

2011/06/25

Revisionism in the satellite Temperatures

http://discover.itsc.uah.edu/amsutemps/
 Dr. Roy Spencer and Dr. Danny Braswell, NSSTC Control the data

No problem with this (it presumably corrects errors from an older satellite) But if this had been done by CRU/Giss etc. it would have headlined on WUWT and CA with statements that this proves that the data and its controllers cannot be trusted!

One interesting one is CH4 (final plot) thewhole of the last years data (not shown on plot) has been deleted - why?






2010/07/21

AMSU unrecorded modifications still not answered.

Some time ago I asked for an explanation from Spencer as to why some of the channels from amsu had been dropped (in particular CHLT which was rising at 1.2C/decade) but also why ch05 was changed to ch05 aqua and then modified to a new version of ch05 aqua. All this with no notes on the discover website.
No explanation was forthcoming.

The major changes have removed the rapidly rising trends. Why?


Note that all FEB 29ths have been removed!

Assuming The AMSU team have now stabilized on their plots ch04 is still showing an upward trend of almost 0.5C per decade

2010/06/17

AMSRE data and errors

Spencer has an odd new data series in AMSU series CH05 Aqua. It is especially strange because of the popularity of feb 29ths (6 in last 8 years)!
02/28 -999.000 252.457 252.505 252.329 252.323 252.400 252.249 252.196 252.732
02/29 -999.000 252.492 252.432 252.350 252.415 252.387 252.250 -999.000 -999.000
03/01 -999.000 -999.000 252.625 -999.000 -999.000 -999.000 252.276 252.156 252.647
03/02 -999.000 252.517 252.632 252.511 252.379 252.465 252.251 252.269 252.836



update 10-06-18:
02/28 -999 252.457 252.505 252.329 252.323 252.4 252.249 252.196 252.732
02/29 -999 -999 252.432 -999 -999 -999 252.25 -999 -999
03/01 -999 252.492 252.625 252.35 252.415 252.387 252.276 252.156 252.647
03/02 -999 252.517 252.632 252.511 252.379 252.465 252.251 252.269 252.836





Not only that but there is some large errrors in the data:

08/08/2002 231.674
12/09/2002 233.682
05/11/2003 235.799
25/10/2007 233.854

update 10-06-16 all errors now show -999

It is lucky that Spencer is a sceptic otherwise this would by now have banner headlines claiming that all amsu temperatures are corrupt, Spencer is corrupt, and the world must therefore be cooling!!!!


Unfortunately this completely replaces the old channel 5 data which was continuous from 1998 - the new series starts in 2002.

Of course the new data magically shows less warming (in fact - cooling) than the old.




see also:
http://climateprogress.org/2010/06/17/roy-spencer-satellite-data-website-uah-amsu/

2010/05/02

AMSU Temperature Change per year

plotting the variation in temperature per year for each day produces this plot:



Interestingly the t-rise is not a constant over the year but has a pronounced dip at the beginning of May for lower air temp.

The sea surface temperature is practically flat. There is a peak during the NH summer. Why is this? Isn't the SH ocean bigger and therefore more likely to show an increase during it's summer when averaged globally. Is evaporation producing a stabilising effect which is less effective over the NH?

2010/03/19

latest AMSU-A temperatures

AMSU Channel data from satellite data

Data from:
discover web page

Note that all data is used (there seems to be none before 1998 for these channels


near surface is warming at 1.21e-4C/day=4.4C/century
3300ft data (now discontinued) was warming at 12deg/century
sea surface is slightly cooling but only 8 years of data.

No problem there then!



4.3deg C/century



4.41degC/century

Amazing coincidence.