Ken Haapala On The RSS Saga
By Paul Homewood
There’s a very readable analysis by By Ken Haapala, President, Science and Environmental Policy Project (SEPP), regarding the recent debate about the RSS adjustments:
Atmospheric Data – Re-Analysis and Confirmation: An issue developed this week that illustrates the importance of proper re-analysis of data and independent confirmation. The issue regarding temperature trends in the middle troposphere was noticed by Anthony Watts, WUWT, discussed in several other posts, with an expanded discussion by Roy Spencer. Spencer and John Christy developed the method of measuring temperatures using data from satellites, for which they received significant recognition. Their findings are publicly posted monthly, with the data going back to December 1978. These data, known as the University of Alabama in Huntsville (UAH) data are the most comprehensive estimates of global temperatures in existence. The group is funded by NOAA.
A private group, publicly and privately funded, is headed by Frank Wentz, with Carl Mears the chief scientist, Remote Sensing Systems (RSS) provides the other well-known analysis. Some years ago, this group discovered that the UAH data, at that time, did not properly account for orbital decay of satellites, giving a cooling bias to the data. Once this bias became known and demonstrated, UAH adjusted for it. This is the way science works, correcting mistakes. Unfortunately, this incident led some global warming promoters to declare that the UAH data is discredited, which it is not.
This week, ahead of print, the Journal of Climate posted an article by Mears and Wentz stating that, in effect, UAH under-estimate global temperature trends. And the fun begins.
At issue are the readings from one satellite, NOAA-14, roughly between 1995 to 2005. Spencer and Christy noticed that this satellite gave higher readings than the prior satellites and the following satellite, NOAA-15. They considered the warming to be spurious and adjusted for in their latest data on the Lower Troposphere and the Middle Troposphere for several reasons. One, the new Advanced Microwave Sounding Unit (AMSU) instrumentation on NOAA-15 is far superior to the prior instrumentation. Second, the NOAA-14 satellite orbit was “drifting far beyond any of the other dozen satellites in the record, leading to warming of the instrument itself.”
Further, after Mears made the RSS data available, Christy calculated the level of agreement (variance) of the three satellite data sets (including NOAAv3.0) with eight sets of radiosonde data from weather balloons. The correspondence with the UAH dataset was far better than the other two satellite data sets, with the exception of the balloon dataset showing the greatest warming trend. Also, when Mears and Wentz first submitted their article to another journal for publication, Christy reviewed it and made certain recommendations, but did not recommend against publication.
All this was available to Mears and Wentz prior to publication in Journal of Climate. Why they treated data from superior instrumentation the same as data from inferior instrumentation on a satellite that was shown to give biased readings is known only to them. But the incident demonstrates the importance of careful reanalysis and independent confirmation of instrument data. See links under Challenging the Orthodoxy and Measurement Issues – Atmosphere.
UAH Atmospheric Data Discredited? As stated above, some global warming promoters claim UAH atmospheric data are discredited, even though UAH made the necessary adjustments decades ago. The atmospheric data used in the brief filed by some scientists in support of petitioners opposing the Administration’s power plan is for the Lower Troposphere (surface to 18 km (59,000 feet)). The data show no statistically significant trends, positive or negative, exist between 1979 to 2011. Further, the data show no tropical hot spot (an atmospheric warming trend centered at about 33,000 feet, 10km) with more a pronounced warming trend than surface warming trend. The Mears and Wentz study is for the middle troposphere, not the lower troposphere (there is some overlap). It will be interesting to see if they publish one for the lower troposphere and if they test their ideas against radiosonde data from weather balloons.
In the context of atmospheric data, the new paper needs to be considered. In the context of the prevailing theory of the influence of carbon dioxide (CO2) concentrations on the earth’s temperatures, it is less important. Since the 1979 Charney report, the prevailing concept is that a doubling of CO2 will result in an increase in the earth’s temperatures in the range 1.5 º C to 4.5 º C or a range of estimates of 3 º C.
As of now, the trend for RSS is 0.129 º C per decade and for UAH 0.072 º C per decade. The difference equals 0.057 º C per decade over the satellite record. Given the wide range of estimates being advanced by the Climate Establishment, a difference between UAH and RSS estimates of 0.57 º C per century is not particularly significant. Using this difference to claim the UAH data discredited is akin to claiming a bump on the rump of an elephant discredits the elephant’s existence.
[It should be noted that the 2007 Fourth Assessment Report (AR-4) of the UN Intergovernmental Panel on Climate Change (IPCC) had the estimate of warming at 2.0 º C to 4.5 º C. This report was current in the 2009 EPA finding that greenhouse gas emissions, primarily CO2, endanger public health and welfare (Endangerment Finding). The Fifth Assessment Report (AR-5) in 2013 went back to 1.5 º C to 4.5 º C. So the IPCC partially undermined the EPA Endangerment Finding.
SEPP thinks that the lower bound (from a doubling of CO2) is far too high. Based on observations and recent research it should be no more than 1 º C, or significantly less. Of course, such an estimate would render meaningless the bureaucratic science being performed on the social costs of carbon by certain government entities, such as the US Global Change Research Program. See Measurement Issues – Atmosphere and the February 27 TWTW at SEPP.org.
El Niño Influence: For some time, Roy Spencer, and others, have suggested that the current strong El Niño may increase atmospheric temperatures, showing that these data are influenced by events other than CO2 concentrations, including weather events and volcanoes. Spencer reports that this February is the warmest since full-year satellite measurements began in 1979. It should be remembered that the IPCC, and others, consider El Niños to be weather events, not climate events. Even the concept that frequent El Niños influence climate was not accepted by the IPCC.
Not systematically discovering the causes of El Niños, which result in warming, and La Niñas, which result in cooling, is a major deficiency in the funding of climate science by government entities. The emphasis on only human factors is greatly misplaced. Among other private researchers, Bob Tisdale has asserted that El Niños result from a lessening of the trade winds in the equatorial Pacific Ocean, resulting in a lessening of the overturning of the ocean and a warming of the surface water.
For months, private groups and government entities have been forecasting that this 2015-16 El Niño is a strong one. Also, some private groups, such as Weatherbell Analytics, have been stating that the current El Niño is significantly different than the 1997-98 El Niño. It is centered further westward, towards the central equatorial Pacific, rather than in the eastern Pacific, off the coast of Peru. The different location results in different weather patterns, particularly in the Americas.
As linked in last week’s TWTW, NASA finally recognized that the current El Niño is different than the 1997-98 one, and NOAA forecasts that it will fade quickly and be replaced by a strong La Niña this year.
The real question is what will happen after the La Niña. Will the temperatures roughly stabilize for a number of years, as in the past? Will the level be roughly the same as before, or will it be higher, as happened after the 1997-98 El Niño. Unfortunately, these unknowns are among the many problems in climate science.