Re:Antarctic sea ice – rapid decreases, reduced to lowest ar...
by tremon on Tuesday July 02, 2019 @12:01PM
(#20336411)
The 40-year timespan marks the boundary of the current measurement regime (satellite multichannel passive-microwave measurements). This isn't the first time it happens, but earlier measurements may not be directly comparable.
From the article:
The one other several-year period during the time frame of modern instrumental records with an estimated loss of hemispheric sea ice coverage comparably as rapid as [the current one was] in the mid-1970s. Calculations based on a variety of datasets [..] show rates of decrease of ∼600,000 km2/y for the 4 y from the start of 1973 to the start of 1977 and for the 3-y subset from the start of 1974 to the start of 1977
The concluding remark is helpful to reproduce in full:
I hope that the 40-y record discussed in this paper will encourage further studies into the atmospheric and oceanic conditions that could have led to the extremely rapid 2014–2017 decline of the Antarctic sea ice cover, the comparably rapid decline in the mid-1970s, and the uneven but overall gradual increases in Antarctic sea ice coverage in the intervening decades. More broadly, the environmental datasets may be nearing the point where they are long enough and rich enough to enable the linking of several of the modes and dipoles and oscillations now spoken of separately, just as the El Niño and Southern Oscillation phenomena were linked together years ago as ENSO; once that further linkage happens, the understanding of Earth’s very interconnected climate system, including the sea ice cover, could be markedly enhanced.
From the article:
The one other several-year period during the time frame of modern instrumental records with an estimated loss of hemispheric sea ice coverage comparably as rapid as [the current one was] in the mid-1970s. Calculations based on a variety of datasets [..] show rates of decrease of ∼600,000 km2/y for the 4 y from the start of 1973 to the start of 1977 and for the 3-y subset from the start of 1974 to the start of 1977
The concluding remark is helpful to reproduce in full:
I hope that the 40-y record discussed in this paper will encourage further studies into the atmospheric and oceanic conditions that could have led to the extremely rapid 2014–2017 decline of the Antarctic sea ice cover, the comparably rapid decline in the mid-1970s, and the uneven but overall gradual increases in Antarctic sea ice coverage in the intervening decades. More broadly, the environmental datasets may be nearing the point where they are long enough and rich enough to enable the linking of several of the modes and dipoles and oscillations now spoken of separately, just as the El Niño and Southern Oscillation phenomena were linked together years ago as ENSO; once that further linkage happens, the understanding of Earth’s very interconnected climate system, including the sea ice cover, could be markedly enhanced.