Our paper showed that there is a fairy strong connection between
changes in the circulation of the stratosphere and the circulation
near the Earth's surface. One aspect of the connection that has
contributed to other research involves weather prediction. Our
studies showed that circulation anomalies tend to propagate downward—often
reaching Earth's surface—suggesting the possibility of improved
weather forecasts. Another aspect of our results involved global
climate change. Further research by climate modelers has suggested
that the existence of the stratosphere—which is poorly represented
in most
climate models—may be important in understanding changes in both
average surface temperature and shifts in weather patterns. The
importance of the stratosphere in understanding climate change and
in chemistry/climate interactions is still being debated.
Does
it describe a new discovery or new methodology that's useful to
others?
We used a straightforward methodology that characterizes the
hemispheric circulation at any level by a single number. We used
daily time resolution to show the time-height development of
the largest changes in atmospheric circulation. Our methodology made
the downward propagation clear, and has contributed to its use,
along with refinements and simplifications by others—including
NOAA's Climate Prediction Center.
Is
it a condensation of previous literature on the subject?
No, but our results build on earlier work showing that
circulation changes in the upper stratosphere tend to move slowly
poleward and downward toward the troposphere.
Could
you summarize the significance of your paper in layman's terms?
The stratosphere is the layer of the atmosphere that extends
roughly from the level traversed by commercial aircraft to an upper
range of 50 km. During winter, large changes in the wind patterns of
the stratosphere tend to precede weather pattern changes at Earth's
surface by approximately three weeks. These changes in weather
patterns tend to last several weeks, suggesting that there is the
potential to improve seasonal weather forecasts.
Mark P. Baldwin
Senior Research Scientist, Northwest Research Associates, Bellevue, WA
USA
Northwest Research Associates
14508 NE 20th Street
Bellevue, WA 98007-3713 USA
