Comparing satellite & balloon climate data corroborates slower rate of global warming

HUNTSVILLE, Ala. (May 1, 2003) -- A detailed comparison of atmospheric temperature data gathered by satellites with widely-used data gathered by weather balloons corroborates both the accuracy of the satellite data and the rate of global warming seen in that data.

Using NOAA satellite readings of temperatures in the lower atmosphere, scientists at The University of Alabama in Huntsville (UAH) produced a dataset that shows global atmospheric warming at the rate of about 0.07 degrees C (about 0.13 degrees Fahrenheit) per decade since November 1978.

"That works out to a global warming trend of about one and a quarter degrees Fahrenheit over 100 years," said Dr. John Christy, who compiled the comparison data. "That's a definite warming trend, which is probably due in part to human influences. But it's substantially less than the warming forecast by most climate models, and it isn't entirely out of the range of climate change we might expect from natural causes.

The UAH team's research is published in the May 2003 edition of the American Meteorological Society's "Journal of Atmospheric and Oceanic Technology."

"We know the climate is changing," said Christy, a professor of atmospheric science and director of UAH's Earth System Science Center. "Earth's climate has never been stable. What we don't know is the rate of natural climate change, which makes it really tough to say how much of the warming that we see might be due to things like adding greenhouse gases to the atmosphere."

The study published in the JAOT describes an updated global temperature dataset using NOAA satellite measurements of the atmosphere's microwave emissions, which change with the temperature. In this new version, the UAH team applied a more accurate accounting for temperature changes caused by the satellites' east-west drift.

To test the accuracy of the new dataset, Christy and his colleagues used independent data from 28 radiosonde weather balloon sites in an area bounded by eastern Canada, the Caribbean, Alaska and the Marshall Islands in the Western Pacific. They also used American, British and Russian composite datasets of hundreds of weather balloon sites around the world.

They used balloon data to test the satellite readings because balloon-borne thermometers and satellites both measure temperatures in deep layers of the atmosphere - comparing apples to apples.

"There is a 94 to 98 percent correlation between the satellite data and the different balloon datasets," said Christy. "The more difficult statistic to measure, the overall trend in the lower troposphere, agreed so well it was difficult to estimate the error bars."

Ultimately, the team calculated a 95 percent confidence in the satellite-based temperature trend within plus or minus 0.05 degrees Celsius per decade.

If the satellite data are reliable and accurate over the wide range of environments and climates represented by the balloon weather stations, Christy said, it is likely to be reliable over the rest of the globe.

Many climate models forecast that global warming should be happening at a rate much faster than that seen by either the UAH satellite dataset or the weather balloon data.

"But models don't provide scientific measurements," Christy said. "Climate models can be valuable for many scientific purposes, but models and their output shouldn't be confused with data or used as a standard for validating real data.

"If you have reliable data that disagree with a computer model, it's time to find out what's wrong with the model. To do anything else might lead you to conclude that your theories are correct and the real world is wrong."

Cogitator - Just a damn minute!

How in the hell do you explain this:

Winter in Big Cities of the East Ranked Among the Coldest Since 1950 -

HIGH LATITUDE BLOCKING AND RECORD SNOWCOVER A KEY TO THIS WINTER

Written March 10, 2003
by Joe D'Aleo
Chief WSI/INTELLICAST Meteorologist

In our winter outlook in the fall we showed why the oceans were in a mode, which favored enhanced high latitude blocking, which would make this El Nino colder than the ones we were used to in recent decades.

The degree of high latitude blocking is measured by two climate indices, the North Atlantic and Arctic Oscillations. In recent stories, we showed how the negative mode of both modes favored colder and often snowier than normal conditions in the eastern United States and Europe, even in El Nino winters. The indices were at or near the most negative values observed since 1950 especially during the early winter from October to December.

October to December Arctic Oscillation values were the most negative since 1950. This high latitude blocking helped generate large polar and arctic air masses that helped build deep snowcover and make the winter very cold for many areas in the hemisphere.

This high latitude blocking helped generate extensive polar and arctic air masses that brought extreme cold to places in the Northern Hemisphere. Here in North America, the flow pattern entrained frigid Siberian air to join with the cold high pressure building in Canada. The coldest air was focused on the eastern states.

With the large cold air masses came much more snow than normal across the hemisphere. In fact, according to the data compiled at the CPC, the extent of the Northern Hemisphere's snowcover from October through February was the greatest since records were started in 1973. It even exceeded the deep snowcover of the winters of the late 1970s.

October to February 2002/03 average snowcover for the Northern Hemisphere was at the highest level in the data set eclipsing the previous record set in the winter of 1976/77. From CPC: ftp://ftp.ncep.noaa.gov/pub/cpc/wd52dg/snow/snw_cvr_area/NH_AREA

PERSISTENT COLD WEATHER FROM OCTOBER TO FEBRUARY
El Nino winters are characterized dependably by a ridge in the western parts of North America and a trough in the eastern areas. With the productive Polar Regions and extensive snowcover, temperatures in the trough in the eastern states averaged persistently below normal. Temperatures during the October to February period ranked among the top ten winters since 1950 in many cities in the northeast.

In Boston, it was the second coldest such period just behind 1976/77.

BOSTON, MASSACHUSETTS

Year	Average Temperature
1976/77	35.42
2002/03	35.72

In New York City, the period ranked 4th coldest since 1950 behind the two memorable cold winters in the late 1970s (1976/77 and 1977/78) and the winter of 1967/68.

CENTRAL PARK, NEW YORK

Year	Average Temperature
1976/77	37.55
1967/68	38.25
1977/78	39.35
2002/03	39.70

In Rochester, New York, the winter ranked 7th coldest since 1950, tied with the winter of 1969/70 (our top analog year).

ROCHESTER, NEW YORK

Year	Average Temperature
1976/77	29.48
1993/94	30.38
1962/63	30.38
1981/82	31
1978/79	31.44
1969/70	31.56
2002/03	31.56

In Baltimore (BWI Airport), the winter ranked 3rd coldest behind 1976/77 and 1962/63.

BALTIMORE, MARYLAND

Year	Average Temperature
1976/77	37.04
1962/63	37.16
2002/03	38.63

What a difference a year can make. Many of these same locations during the same period last year found temperatures ranking among the warmest on record as resurgent solar activity produced a shrunken polar vortex and enhanced zonal flow, which in turn maximized the maritime influence on the continents and limited the extent of the snowcover. It also led to near record drought that lingered through the summer in many areas.

These two years demonstrate how many factors combine to choreograph the weather and climate as we march from season to season and year-to-year on our ride through time.

So this data can be used by both groups, as in "it's not warming very much" vs. "it's warming a lot more than they said two years ago".

Question has never been is it warming or cooling, the trend can be either both depending on your time frame.

The question's are quantitative, how much is due to mankind and under our control? And, is makind's impact sufficient to make a difference, if we were to change our techonolgies and economies sufficiently.

The answer for Greenhouse gases and the Greenhouse effect is clearly that mankind can affect the climate only negligibly, and it is even questionable if mankind could make a measureable difference in Climate at all:

Mankind's impact is only 0.28% of Total Greenhouse effect

for all emission control or other technical fixes politically feasible to apply:

" There is no dispute at all about the fact that even if punctiliously observed, (the Kyoto Protocol) would have an imperceptible effect on future temperatures -- one-twentieth of a degree by 2050. "

Dr. S. Fred Singer, atmospheric physicist

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