November 22, 2024

New ICESat-2 Observations Show We’re Losing Arctic Sea Ice at a “Frightening” Rate

New estimates of snow depth, from a combination of lidar and radar, enhance sea-ice thickness quotes, according to a new research study in AGUs Geophysical Research Letters. Arctic sea ice has actually lost 16% of its density in the last three years, the study finds. Credit: NASA/Kathryn Hansen

The study was published in the AGU journal Geophysical Research Letters, which publishes short-format, high-impact documents with ramifications that span the Earth and area sciences.
” We werent really anticipating to see this decline, for the ice to be this much thinner in simply 3 short years,” said lead study author Sahra Kacimi, a polar researcher at the California Institute of Technologys Jet Propulsion Laboratory.
Snow can weigh ice down, altering how ice drifts in the ocean. The new study compared ice density utilizing brand-new snow depths from satellite radar and lidar to previous ice density and snow depth estimates from environment records.
” Arctic snow depth, sea ice thickness and volume are 3 really challenging measurements to acquire,” stated Ron Kwok, a polar scientist at the University of Washingtons Applied Physics Laboratory who co-authored the brand-new study. “The key takeaway for me is the amazing loss of Arctic winter sea ice volume– one-third of the winter ice volume lost over just 18 years– that accompanied a widely documented loss of old, thick Arctic sea ice and decline in end-of-summer ice level.”
” This is the very first time anybody has numerous years worth of information from the distinction between lidar and radar data for snow depth,” stated Robbie Mallett, a polar ice researcher at University College London who was not involved in the research study. “Its an actually helpful upgrade on how ICESat-2 is carrying out.”
The study used an 18-year record of sea-ice observations from ICESat and the newer ICESat-2 and CryoSat-2 satellites to catch month-to-month modifications in Arctic sea-ice density and volume, to offer context for sea ice density approximates from 2018 to 2021. The 18-year record revealed a loss of about 6,000 cubic kilometers of winter ice volume, largely driven by the switch from predominantly multiyear ice to thinner, seasonal sea ice.
Older, multiyear ice tends to be thicker and therefore more resistant to melting. As that “reservoir” of old Arctic sea ice is depleted and seasonal ice ends up being the standard, the general thickness and volume of Arctic sea ice is expected to decline. “Current models forecast that by the mid-century we can expect ice-free summers in the Arctic, when the older ice, thick enough to make it through the melt season is gone,” Kacimi stated.
” This is really old ice were losing at quite a frightening rate,” Mallett stated.
Referral: “Arctic Snow Depth, Ice Thickness, and Volume From ICESat-2 and CryoSat-2: 2018– 2021” by Sahra Kacimi and Ron Kwok, 10 March 2022, Geophysical Research Letters.DOI: 10.1029/ 2021GL097448.

Arctic sea ice has lost 16% of its density in the last three years, the study discovers. Researchers make satellite estimates of sea-ice density using snow depth and the height of the drifting ice above the sea surface. Snow can weigh ice down, changing how ice drifts in the ocean. The brand-new research study compared ice density using new snow depths from satellite radar and lidar to previous ice thickness and snow depth estimates from environment records. As that “tank” of old Arctic sea ice is depleted and seasonal ice ends up being the standard, the general thickness and volume of Arctic sea ice is anticipated to decrease.

End-of-season Arctic multiyear sea ice has to do with 1.5 feet thinner in 2021 than in 2019
Arctic Ocean sea ice lost one-third of its volume in the past 18 years
New pan-Arctic snow depth recommends previous quotes of sea ice density might have been overestimated

Over the previous two years, the Arctic has lost about one-third of its winter sea ice volume, mainly due to a decline in sea ice that continues over several years, called multiyear ice, according to a new research study. The research study likewise found sea ice is likely thinner than previous quotes.
Seasonal sea ice, which melts totally each summertime instead of collecting over years, is changing thicker, multiyear ice and driving sea ice thinning trends, according to the new research study.
Arctic sea ice snow depth is approximated, for the very first time, from a combination of lidar (ICESat-2) and radar (CryoSat-2) data. Using these estimates of snow depth and the height of sea ice exposed above water, the research study found multiyear Arctic sea ice has lost 16% of its winter season volume, or roughly half a meter (about 1.5 feet) of density, in the three years because the launch of ICESat-2.