Originally Posted by PamlicoTraveler
The latest data reveal that Antarctica is losing ice pretty quickly. If he waits a while he might not need a steel
I realise this was tongue-in-cheek, and perhaps you meant specifically the Peninsula, but others might take the above statement literally. They would mislead themselves, because it is contrary to observed fact.
While the Peninsula is losing ice, (being the warmest part of Antarctica, and having warmed faster than anywhere else on earth) much of Antarctica is presently gaining
Paradoxically, it seems this is also due to warming.
For one thing, the temperatures elsewhere than the Peninsula are still way below zero, hence melting (in the air, and at atmospheric pressure) cannot happen. At least, not yet.
The temperatures are still so much below freezing that warming in these areas allows snowfall further south, where the precipitation rates were previously below desert levels. It was too dry to snow more than a few mm per year.
It's like situating a deep freeze inside a walk-in chiller: you will not need to defrost the deep freeze as you would if it were located out in the main kitchen.
Furthermore the increased temperature differential between the continent and the surrounding sea means the katabatic wind
, which blows northwards off the land all around the continent, blows more strongly.
This pushes sea ice off the 'factory floor' of the polynyas close to shore.
As these areas are cleared of ice, the (still very cold) wind
can immediately freeze the freshly exposed water
surface into ice, which in turn is pushed north. The throughput of sea ice is consequently increased, and will be for some time, due to warming temperatures.
The Arctic does not have a continent, hence no katabatics. The Arctic is not isolated by water
from all land masses, unlike the Antarctic which is insulated (by the unbroken belt of westerlies around the Southern Ocean) from warm tropical airmasses.
This is how the Antarctic (except for the Peninsula, which is almost connected to Sth America) comes to be SO much colder than the rest of the planet.
That's my understanding of why this mechanism does not apply in the North, and why ice loss is already so evident in the Arctic summer, where the temperature routinely gets above freezing.
It occurs to me that if the global climate is likened to a cheque account, Antarctica is in some ways like a massive deposit. (of coldness)
If the person operating the account doesn't know about this huge reserve, and doesn't track income
vs expenses, they will happily live well beyond their means without getting any warnings from the bank. Until one day the hidden deposit is all spent.
Seems to me we need to be more vigilant about 'hidden expenditure' of this stash of coldness.
It bothers me, for instance, that cold north-flowing currents appear to be increasing in volume, presumably due to meltwater. It is certainly the case that there have been massive increases of fresh meltwater originating from the Antarctic glaciers, and their rate of delivery
of ice into the oceans has increased faster than scientists predicted, but there's enough glacier ice for this to continue indefinitely.
Indefinitely, admittedly, only in terms of the lifespan of those who are already born....