....you could follow the link to The Official Record, that Woodlock so conscientiously provided, and look at the solar longitude parameter, which is defined thusly:

Solar longitude (Ls)
This is the position of Mars relative to the Sun measured in degrees from the vernal equinox (start of northern Spring). This number is used as a measure of martian seasons: Northern Spring/Southern Autumn start at 0°, Northern Summer/Southern Winter start at 90°, Northern Autumn/Southern Spring start at 180°, and Northern Winter/Southern Summer begin at 270°.

These images have an Ls of 180.andchange, they're in the southern hemisphere, ergo and presto-chango, it's very early southern spring.

Things are thawing...outgassing remains a viable explanation.

--Robert