Discussion about this post

User's avatar
Christopher Game's avatar

I am still not clear in my mind as to the time scale or scales of Antarctic land ice accumulation and calving.

Exceptionally hot moist air radiates exceptional heat to outer space as it passes over the South Pole. But that exceptional cooling factor doesn't immediately cool the general atmosphere. Instead, it is stored as a weight of snow or ice that only with a delay presses down on the land ice. It takes time to squeeze out the ice to the edge of the land and into the sea, to melt and eventually cool the oceans.

One thought is that this ocean cooling might be continuous, so that this year's snow might trigger this year's ocean cooling, and we would have a negative feedback stabilising ocean temperatures on a one-year time scale. This would be slower than the tropical storm atmospheric circulatory convection temperature negative feedback stabilisation mechanism, that works on a time scale of hours or days.

Another thought is that this ocean cooling might take thousands or tens of thousands of years to proceed. What would trigger the calving on that time scale? Is this a dynamical factor in the hundred-thousand-year glaciation—deglaciation cycle of the current ice age?

Perhaps there are several time scales at work here?

Expand full comment
Jim Bannister's avatar

Ned Nikolov says the drop in cloud albedo over the last few decades does not correspond to a change in cosmic ray ionisation promoted by Henrick Svensmark. We don’t know why cloud albedo has decreased.

Expand full comment
1 more comment...

No posts