NZCLIMATE & ENVIRO TRUTH NO 100
MAY 25TH 2006
TRENDS IN THE LOWER ATMOSPHERE
A new publication
on this subject by the NOAA ( US National Oceanic and Atmospheric
Administration), is now aviailable in full (9.2MB) or in part, from
The full title is
"Temperature Trends in the Lower Atmosphere: Steps for Understanding
and Reconciling Differences"
Its authors include
T.R.Karl, T.M.Wigley, J.R.Christy, T.C. Peterson, F.J.Wentz,
K.Y.Vinnikov, .R.W.Spencer, R.S.Vose, R.W. Reynolds, B.D.Santer, P.W.
Thorne, C.K. Folland and D. Parker. This includes most of the people
working on temperature records, with the notable exceptions of P.D.
Jones and J.E.Hansen
Part of the Abstract
is as follows "Specifically, (i.e. previously) surface data
showed substantial global average warming while early versions of
satellite and radiosonde data showed little or no warming above the
surface. This significant discrepancy no longer exists because errors
in the satellite and radiosonde data have been identified and
corrected. New data have also been developed that do not show such
Figure 1 of the
"Executive Summary" shows a comparison between the latest, corrected,
versions of four temperature records of global anomalies from
1958 to 2004. The top two, are Lower Stratosphere, and Mid Troposphere
and Lower Troposphere and I will ignore them.
The third one shows
the superposition of four separate records, two of
which, extending only from 1978 to 2004, are from satellite
data, (UAH :University of Alabama, Huntsville):and
RSS :Remote Sensing Syatems) and the other two, all the way
from 1958 to 2004, are from radiosondes (HadA2: Hadley Center,
University of East Anglia, and RATPAC :Radiosonde Atmospheric
Temperature Products for Assessing Climate). The agreement between all
four graphs is remarkably good, particularly for the satellite region,
1978 to 2004. .Discrepancies between them seem to have been
successfully removed. .
The fourth graph is
the surface record from 1978 to 2004 with superposition of records from
NOAA, NASA (Goddard Institute os Space Studies) and HadCRUT2v (Climatic
Research Unit, University of East Anglia) They also show close agreement
At first sight graphs
three and four appear almost identical. but one difference which the
abstract says existed only in the past, is still there. Despite all the
corrections, the temperature change in the lower troposphere, with all
four records is very near to zero from 1978 to 1997, whereas the
surface record shows a definite rise over that period. I showed this is
true in my Newsletter no 98 by magnifying the relevant
section of each record and comparing them.
The graphs all contain
dotted lines to show the influence of the volcanoes Agung in 1963, El
Chichon in 1982 and Pinatubo in 1993.. It is obvious that all these
depress the temperature for a short time after the eruption, so
they enhance a perceived upwards trend. The Report makes no
attempt to correct for this. They make a much greater error by ignoring
the many El Niño ocean events over the period which were greater
towards the end of the sequence, and enhance a perceived
upwards trend to a much greater extent. The 1998 El Niño
was so great that it masks the real differences between the two graphs
almost on its own, as soon as you draw a linear curve through the data.
This conclusion is
further confirmed by some of the other graphs in the report. In figure
3.3 of Chapter 3 the lower graph is a plot of the two radiosonde
records again, at a slightly higher scale. It is again evident that
there was no "global warming" in the 850-300 hPa region of the
atmosphere from1978 to 1997 despite El Chichon at the beginning and
Pinatubo halfway through.
Chapter 3, Figure 3.3a
shows a slightly larger graph of lower troposphere readings, but only
plots the UAH and RSS satellite data and one radiosonde, HadAT2.
It shows, once again, no warming from 1978 to 1997
Chapter 3 in Figure
3.1 has a better version of the three surface records from 1958 to 2004
and it is obvious that it shows a steady increase since 1978.
Appendix A on
"Statistical Issues Regarding Trends" by T.M. Wigley has Figures 1 and
2 from 1978 to 2004 where he indicates not only the
volcanoes El Chichon and Pinatubo, but also six El Niño episodes
over the period, at 1983, 1988. 1992, 1995, 1998 and 2003. Although
these are more or less evenly spaced over the sequence, the events
themselves increased in intensity, so they impose an obvious
upwards bias to the temperature record which is ignored by this report.
The 1998 eveny was particularly strong.
Wigley's Figure 2
shows all three satellite records with the derived trend lines. The UAH
record shows a negligible upwards trend even when the 1998 El
Niño is included, The RSS record shows only a slight trend with
the 1998 El Niño.but none without it. The third record, from UMd
(University of Maryland) was not plotted on the graph in the Executive
Summary. It shows a slight upwards trend even without the 1998 El
Niño, but this would probably disappear if the effects of the
two volcanoes are considered.
Chapter 3 in Table 3,3
Gives the results of linear regression for all the records
For the surface the
slopes are 0.16±0.04ºC (NOAA), 0.16±0.04ºC
(NASA) and 0.17±0.04º (HadCRUT2v), all per decade
For the radiosondes,
in the lower troposphere, they are 0.02±0.07ºC (RATPAD),
0.03±0.08ºC (HA\adAT2). all per decade
For the satellites,
they were 0.04±0.08ºC (UAH), 0.13±0.08ºC (RSS)
and 0.20±0.07ºC (UMd)
Then there are
"reanalyses" These are defined in the glossary as "a mathematically
blended record that incorporates a variety of observational data sets
(with adjustments) in an assimilation model."
The trends of these
reanalysis records, which are not plotted anywhere, are, for the
surface; 0.12±0.07ºC (NCEP50; National Centers for
Environmental Prediction) and 0.11±0.06ºC (ERA40; European
Center for Medium-range Weather Foirecasts). per decade.
The linear trends from
reanalysis for the lower troposphere are -0.04±0.10ºC
(NCEP50) and 0.07±0.10ºC (ERA40).
These results show
that the discrepancies between the temperature records of the lower
troposphere and the surface have not disappeared. They have been
confirmed. The very thorough correction of the various instruments has
not changed the obvious contrast between the surface and the lower
troposphere, particularly for the period 1978 to 1997. The
absence of any warming trend in the lower troposphere over this period
by all of the instruments involved shows that the effects of increases
iun greenhouse gases are not detected in the region where they are
thought to be most prominent for a period of ten years.
The agreement of
linear trends from 1978 to 2004 claimed in this report is not
confirmed for many of the individual records,notably for both
radiosondes, the best established of the satellite records (UAH) and
both of the reanalysis records.
When the disturbing
effects of the 1998 El Niño are considered, all records except
one (UMd) show neglibible warming between 1978 and 1997, and even this
single exception would probably go down to a negligible
trend if the effects of volcanic eruptions are consodered,
The information from
this report is the best evidence we have so far that the supposed
effects of increasing greenhouse gases on global temperature are
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