I am confused too... The article is behind a paywall, unfortunately. But what are we looking at here? If this was a shadow zone, the temperature would obviously have to be much lower. So it's in the sun. At which point I'd have expected the temperature to be much higher. Though it's the pole, so I guess the sun comes in a lot flatter. Still, the sunlit period would also be a lot longer, so it'll build up more heat, right?
So a 20 degrees C estimate intuitively seems much too low, except for early in the day maybe. Even the measured temperature of 70 doesn't seem very high. But of course I know almost nothing about the matter, while I'm sure the people who made that estimate know quite a lot. I'd just like to understand what they're going on. Can somebody explain to me what expected situation the original estimate was based on? Is it based on a specific time, considering how much sunlight there would have been received by the surface? Also, what is depth in that diagram? I would assume it's depth of the soil, but I'm confused by the scale going from negative to positive. Negative depth seems rather pointless if there's no atmosphere?
Yeah... confused just about says it, I guess.