6.28.06

HIRDLS high resolution temperature measurements show short vertical wavelength gravity waves, permitting assessment of gravity wave forcing in the stratospheric circulation.

The temperature cross-section (over S. America) and enlarged view (right) depicts an alternating series of + and - wave fronts propagating from mid-latitude tropopause toward the mid-stratosphere tropics.

This is a gravity wave with short vertical (~ 4 km) and horizontal (500 km) wavelength and small amplitude (1-2K) that can not be observed with other techniques.

Analyses of HIRDLS data allow determination of momentum input from small scale waves which can be used in global circulation models.