The dynamical signal in stratospheric temperatures from satellites, 1979–2005: Long term changes and the pole-tropics out-of-phase relationship

We examine the dynamically-induced, tropical/high-latitude out-of-phase relationship in temperature, arising

from the large-scale stratospheric overturning circulation, using satellite-derived data from channel 4 of

the microwave sounding unit (MSU T4, lower stratosphere) and channels 25, 26 and 27 of the stratospheric

sounding unit (SSU, mid- to upper-stratosphere). We will also present the zo nal mean

cycles for the satellite channels and analyze the long-term changes in the data, between 1979-2005.

Analysis of the long-term changes suggests that the overturning circulation is strengthening in the SH in

August and in the NH during December and January, but perhaps weakening in the NH during March. Besides for

March, we show that these changes are deep and persist up from MSU T4 to SSU 27. The long-term changes in

the MSU T4 data and the lowest SSU channel (25) are compared against radiosonde observations, providing

independent qualitative support of the satellite data.