|
|
|
|
|
|
Planetary Waves, Planetary Waves (Figures)
The Cryogenic Infrared Spectrometers and
Telescopes for the Atmosphere (CRISTA) instrument
has flown on two shuttle missions providing
observations of constituents and temperature
throughout the stratosphere and mesosphere
at high vertical and horizontal resolution.
During the second mission (CRISTA 2: August
7-17, 1997) a wave two signature was observed
in the southern midlatitudes in the temperature
data between 17 and 80 km and in the ozone
data between 17 and 63 km (the limits of
ozone data availability for the current data
version). This signature has a period of
~12.5 days and a vertical wavelength of ~45
km. It is one of the few observational instances
showing vertical and equatorward propagation
of a planetary wave well into the mesosphere.
The relative phase of the signature in the
temperature and ozone varies with height
with the two being in phase below 30 km and
180 degrees out of phase above 40 km. These
signatures are consistent with those expected
from a migrating planetary wave with the
ozone signature being dynamically driven
at lower altitudes and photochemically driven
at higher altitudes. The CRISTA results above
the middle stratosphere show a greater agreement
with photochemical equilibrium calculations
than previous analyses. These results clearly
illustrate the penetration of a dynamical
feature from the tropopause into the mesosphere
and its effect on constituent distributions
throughout this height range.
The results have been published by Ward et al. [2000] (see publications section)
 |
Wave-2 temperature at 25 km for one day of CRISTA-2 measurements. Click on image for an animated view. |
 |
Polar views of the temperature field in the SH at 6 different altitudes. Shown are the results for one measuring day. Dark contours are plotted at 70% and light contours are plotted at 30% of the full contour interval. Click on image for larger figure. |
 |
Polar views of the ozone field in the SH at 6 different altitudes. Shown are the results for the same day as in the Figure above. Dark contours are plotted at 70% and light contours are plotted at 30% of the full contour interval. Click on image for larger figure. |
 |
Height versus latitude cuts of the amplitude and phase of the wave 2 temperature in the SH. The amplitudes are in grey scale and the phases (=wave maximum on day 220) are the labeled contours in degrees of longitude. Click on image for larger figure. |
 |
Height versuts latitude cuts of the amplitude (in % perturbation) and phase of the wave 2 ozone in the SH. Click on image for larger figure. |
 |
Plots of the value of theta derived from the SH data from August 14 with (solid lines), without (dashed line) feedback effects and from the photochemical equilibrium calculations of Froidevaux et al. [1989] (solid circles, left panel) and the associated correlation coefficient (right panel). The fit (without feedback effects) is according to the formula d[O3]/O3 = -theta * dT/T**2. For details see the paper by Ward et al. [2000]. Above 40 km altitude T and ozone are strongly anticorrelated due to the photochemistry. Click on image for larger figure. |