Geoscience Reference
In-Depth Information
Fig. 1. The time series of the zonal mean dust opacity at 9
µ
memployedinthe
simulations.
The zonal-mean dust opacity distribution at the surface used in the
simulations is shown in Fig. 1. Distributions of this type are based on
observations,
16
and are commonly accepted in GCM studies. Note that the
dust opacity values in Fig. 1 are affected by the topography with the global
north-to-south elevation. As the dust is not transported in this simulation,
no dynamical feedback is taken into account.
3. Model Results
At first, the model was spun up for 10 sols from the state of the rest and
a globally uniform temperature
T
= 160 K at the fixed
L
s
=160
◦
.After
reaching a practically equilibrium state, the model was run with
L
s
contin-
uously varying from 160
◦
to 240
◦
to cover the entire period of measurements
by SWAS. During the SWAS observations, the local time at the center of
the visible Martian disk varied significantly from early afternoons at the
start of the measurement sessions to mid-mornings at the end of these
sessions.
3
The sub-Earth latitude of the observation also varied around the
Martian equator,
3
although only slightly. Using the accurate ephemeris to
obtain the sub-Earth local time and latitude for any particular date, we
reconstructed the appearance of the planet's disk out of the model output.
Then, “disk average” temperatures were calculated from the GCM results
