Support the Arctic Sea Ice Forum and Blog

Author Topic: What's new in Antarctica ?  (Read 213152 times)

kassy

  • Nilas ice
  • Posts: 2357
    • View Profile
  • Liked: 1134
  • Likes Given: 978
Re: What's new in Antarctica ?
« Reply #600 on: July 08, 2020, 10:11:14 AM »
Esa and Nasa line up satellites to measure Antarctic sea-ice

US and European scientists are about to get a unique view of polar ice as their respective space agencies line up two satellites in the sky.

Authorisation was given on Tuesday for Europe's Cryosat-2 spacecraft to raise its orbit by just under one kilometre.

This will hugely increase the number of coincident observations it can make with the Americans' Icesat-2 mission.

One outcome from this new strategy will be the first ever reliable maps of Antarctic sea-ice thickness.

Currently, the floes in the far south befuddle efforts to measure their vertical dimension.

Heavy snow can pile on top of the floating ice, hiding its true thickness. Indeed, significant loading can even push Antarctic sea-ice under the water.

But researchers believe the different instruments on the two satellites working in tandem can help them tease apart this complexity.

Nasa's Icesat-2, which orbits the globe at about 500km in altitude, uses a laser to measure the distance to the Earth's surface - and hence the height of objects. This light beam reflects directly off the top of the snow.

Esa's Cryosat-2, on the other hand, at around 720km in altitude, uses radar as its height tool, and this penetrates much more deeply into the snow cover before bouncing back.

and more on:
https://www.bbc.com/news/science-environment-53326490
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

vox_mundi

  • Young ice
  • Posts: 3811
    • View Profile
  • Liked: 2237
  • Likes Given: 298
Re: What's new in Antarctica ?
« Reply #601 on: August 24, 2020, 03:35:54 PM »
Japanese Expedition Identifies East Antarctic Melting Hotspot
https://phys.org/news/2020-08-japanese-east-antarctic-hotspot.html

Ice is melting at a surprisingly fast rate underneath Shirase Glacier Tongue in East Antarctica due to the continuing influx of warm seawater into the Lützow-Holm Bay.



... "Our data suggests that the ice directly beneath the Shirase Glacier Tongue is melting at a rate of seven to 16 meters per year," says Assistant Professor Daisuke Hirano of Hokkaido University's Institute of Low Temperature Science. "This is equal to or perhaps even surpasses the melting rate underneath the Totten Ice Shelf, which was thought to be experiencing the highest melting rate in East Antarctica, at a rate of 10 to 11 meters per year."

... The data suggests the melting is occurring as a result of deep, warm water flowing inward, toward the base of the Shirase Glacier Tongue. The warm water moves along a deep underwater ocean trough and then flows upward along the tongue's base, warming and melting the ice. The warm waters carrying the melted ice then flow outwards, mixing with the glacial meltwater.

The team found this melting occurs year-round, but is affected by easterly, winds alongshore that vary seasonally. When the winds diminish in the summer, the influx of the deep warm water increases, speeding up the melting rate.



Daisuke Hirano et al., Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica. Nature Communications (2020)
https://www.nature.com/articles/s41467-020-17527-4
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

baking

  • Frazil ice
  • Posts: 393
    • View Profile
  • Liked: 145
  • Likes Given: 9
Re: What's new in Antarctica ?
« Reply #602 on: September 11, 2020, 01:39:24 PM »
Discovery of new colonies by Sentinel2 reveals good and bad news for emperor penguins
https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1002/rse2.176

Lots of information on how to find Emperor Penguin colonies using Sentinel 2 imaging with a complete list of known and recently discovered colonies.  I stumbled across this while searching for info on when we can expect to find new Sentinel 2 images for this upcoming season.