Eighteen-year record of circum-Antarctic landfast-sea-ice distribution allows detailed baseline characterisation and reveals trends and variability

• Published in: The Cryosphere
• Main Authors: A. D. Fraser, R. A. Massom, M. S. Handcock, P. Reid, K. I. Ohshima, M. N. Raphael, J. Cartwright, A. R. Klekociuk, Z. Wang, R. Porter-Smith
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Antarctic; The Antarctic; East Antarctica; Antarc*; Antarctica; Ice Sheet; Sea ice; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-15-5061-2021; https://doaj.org/article/7aa407daf1784738a54b1a15e7b29e9f

Landfast sea ice (fast ice) is an important though poorly understood component of the cryosphere on the Antarctic continental shelf, where it plays a key role in atmosphere–ocean–ice-sheet interaction and coupled ecological and biogeochemical processes. Here, we present a first in-depth baseline analysis of variability and change in circum-Antarctic fast-ice distribution (including its relationship to bathymetry), based on a new high-resolution satellite-derived time series for the period 2000 to 2018. This reveals (a) an overall trend of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">882</mn><mo>±</mo><mn mathvariant="normal">824</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="58pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="453c88ebba731e287b80a2e1ca09d1f2"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-5061-2021-ie00001.svg" width="58pt" height="10pt" src="tc-15-5061-2021-ie00001.png"/></svg:svg> km 2 yr −1 ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.19</mn><mo>±</mo><mn mathvariant="normal">0.18</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="ae39578bd83f0d4df3b4603b31a77636"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-5061-2021-ie00002.svg" width="64pt" height="10pt" src="tc-15-5061-2021-ie00002.png"/></svg:svg> % yr −1 ) and (b) eight distinct regions in terms of fast-ice coverage and modes of formation. Of these, four exhibit positive trends over the 18-year period and four negative. Positive trends are seen in East Antarctica and in ...