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The Central Arctic Sea ice area has plummeted in the last 2-3 days. Note that this is NOT reflected in any loss of sea ice EXTENT. Seems to be all about low concentration. But if this continues questions on the resilience of the Central Arctic Sea's ice might surface (again).
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Isn't loss of SIA, with no loss of SIE traditionally a sign of growing melt ponds 'confusing' the sensors?
Of course, extensive melt ponds across the CAB during the peak of summer would be disastrous for that bastion of stable ice.
But if there are growing meltponds, where would they be? The black 'dots' of low concentration on the AMRSR2 images have been skipping merrily around the Central Arctic Sea ice for the past week, as they so often do. Consistent low concentration has been showing up where there IS low concentration... the rapidly failing Chukchi, the ESS, the margins of the Laptev... Again (sigh} I am probably missing something... Maybe the effect is too subtle to register on the map?
The 89ghz channel on the AMSR2 can't see through clouds/fog. When obscure by these things it registers as near 100 percent concentration.
Jaxa uses channel 36 GHz and channel 18ghz as a filter. I don't believe jaxa uses channel 89ghz but they might for coastal edges. But I am unsure it's been a long time since I've read about the algorithms.
NSIDC keeps two long term data sets or at least one long term data set using the lower frequency channels on the ssmis instrument so the data is compatible with the ssmi data that iirc ran from late 78 to 88. And the data on the sat before that from 72-78.
However for their real time graphics they use channel 91 GHz I believe on the ssmis.
So the lower frequency channels like 18/36 GHz on the AMSR2 instrument can differentiate between between clouds, fog, water vapor, and cloud ice with open ocean, sea ice, snow, and wet ice.
The drawback is the resolution is like 3x worse than the channel 89ghz which is like 3-5km resolution.
This is why looking at the BREMEN OR HAMBURG HIGH A RES CONCENTRATION WONT ALWAYS MESH WITH NSIDC OUTPUT.
The TWO IMAGES BELOW ARE FROM JUNE 30TH AND JULY 4TH.
ON JUNE 30TH THE SOUTHERN CAB WAS CLEAR AND SUNNY.
ON JULY 4TH IT WAS INUNDATED BY DENSE FOG.
YOU CAN SEE THE LOWER CONCENTRATION THAT APPEARED MOSTLY DUE TO MAJOR MELTPONDING JUST VANISHED.
BUT IN REALITY IT'S STILL THERE.