In this paper,we present the results of a comprehensive assessment and analysis of five major Antarctic grounding line(GL)products from remote sensing data.The systematic assessment of this large amount of GL data was...In this paper,we present the results of a comprehensive assessment and analysis of five major Antarctic grounding line(GL)products from remote sensing data.The systematic assessment of this large amount of GL data was performed using a new two-step framework and implementation strategy,in which 84.4%of the product data were processed effectively by using a set of developed assessment metrics,with the remaining 15.6%handled by a comprehensive manual processing procedure aided by additional multisource data.The radar GL product shows a high quality(inconsistency of 0.3%)and is recommended for use wherever available.Meanwhile,the optical image GL products show a lower quality(inconsistency of 3-12%)but offer complete coverage,particularly in areas of weak tides.The GL analysis based on the assessed products(1992–2009)showed that 9.5%of the entire Antarctic GL were retreating or advancing,classified as a dynamic state.At the basin scale,the highest retreat rate was−1544±51 m a^(-1) in Basin 22(including Pine Island Glacier)and the highest advancement rate was 304±16 m a^(-1) in Basin 14(including Mertz Glacier).The West Antarctic Ice Sheet(WAIS)and the East Antarctic Ice Sheet(EAIS)showed the average GL change rates of−370±8 m a^(-1) and 5±7 m a^(-1),respectively,indicating that there was a clear trend of GL retreat in WAIS and a balanced to slightly advanced GL state in EAIS(except for the region around Totten).展开更多
基金supported by the State Key Research and Development Program of China(Grant No.2017YFA0603100)the National Natural Science Foundation of China(Grant Nos.41822106,41571407,41631178&41730102)+1 种基金the Shanghai Shuguang Program(Grant No.18SG22)the Fundamental Research Funds for the Central Universities.
文摘In this paper,we present the results of a comprehensive assessment and analysis of five major Antarctic grounding line(GL)products from remote sensing data.The systematic assessment of this large amount of GL data was performed using a new two-step framework and implementation strategy,in which 84.4%of the product data were processed effectively by using a set of developed assessment metrics,with the remaining 15.6%handled by a comprehensive manual processing procedure aided by additional multisource data.The radar GL product shows a high quality(inconsistency of 0.3%)and is recommended for use wherever available.Meanwhile,the optical image GL products show a lower quality(inconsistency of 3-12%)but offer complete coverage,particularly in areas of weak tides.The GL analysis based on the assessed products(1992–2009)showed that 9.5%of the entire Antarctic GL were retreating or advancing,classified as a dynamic state.At the basin scale,the highest retreat rate was−1544±51 m a^(-1) in Basin 22(including Pine Island Glacier)and the highest advancement rate was 304±16 m a^(-1) in Basin 14(including Mertz Glacier).The West Antarctic Ice Sheet(WAIS)and the East Antarctic Ice Sheet(EAIS)showed the average GL change rates of−370±8 m a^(-1) and 5±7 m a^(-1),respectively,indicating that there was a clear trend of GL retreat in WAIS and a balanced to slightly advanced GL state in EAIS(except for the region around Totten).
