Rows in the following table represent each of the 3 Antarctica test sites:
Dome C, Antarctica (74.5S 123.0E): pixel containing Automatic
Weather Station (AWS)
Siple, Antarctica (75.9S 84.0W): another AWS
"Coldsite", Antarctica (78.0S 24.5E): no AWS, very cold, topography
homogeneous
The two columns contain "warm pass" and "cold pass" time series at each
site, for SMMR from 1978 to 1987. In each plot, the colored symbols are
the warm and cold pass satellite overpass (local) time, and the black
symbols represent the time elapsed since the earliest time in the the
gridded data file. I am using this as an approximation to the time since
turn-on, since if the turn-on happened in the Northern hemisphere, the
actual turn-on could be as much as one-half orbit (~45 minutes) earlier
than the minimum time in the Southern hemisphere file. It assumes that
we've gotten the daily cycling correctly into the gridded data, but we
spent a considerable effort to do this during the EASE-Grid processing, and I have reasonable confidence that it was done correctly.
I expected to see low (i.e. within a couple of orbits, say less than 3
hours) differences from minimum file times for "warm" passes at DomeC,
thereby backing up a hunch I had that Dome C was just always unluckily
viewed during the thermal cycling. Not only are the majority of Dome C's
differences more than 5 hours from turn-on, but Siple's cold pass
differences are actually right at 3 hours. So I think that the thermal
cycling can't be affecting the TB behavior we're seeing. Further
evidence: "Coldsite"'s overpasses are all safely later than turn-on, but
we see odd behavior in the TBs there as well.
(Click on any thumbnail to see full resolution image.)
