The influence of Antarctic ice loss on polar motion: an assessment based on GRACE and multi-mission satellite altimetry

• DOI: 10.1186/s40623-021-01403-6
• Publication Date: 2021-04-23T05:03:11Z
• Authors: Franziska Göttl; Andreas Groh; Michael Schmidt; Ludwig Schröder; Florian Seitz
• Keywords: Antarctic ice sheet; Polar motion

Abstract Increasing ice loss of the Antarctic Ice Sheet (AIS) due to global climate change affects orientation Earth’s spin axis with respect an Earth-fixed reference system (polar motion). Here contribution decreasing AIS excitation polar motion is quantified from precise time variable gravity field observations Gravity Recovery and Climate Experiment (GRACE) measurements changing sheet elevation altimeter satellites. While GRACE models need be reduced by noise leakage effects neighboring subsystems, volume changes observed satellite altimetry have converted into mass changes. In this study we investigate how much individual gravimetry solutions differ each other. We show that combination systematic random errors data processing can robustness geodetic derived excitations increased. interannual variability functions means piecewise linear trends. find long-term behavior three subregions: EAIS (East Sheet), WAIS (West Sheet) APIS (Antarctic Peninsula quite different. no significant variations during period $$2003-2015$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>2003</mml:mn><mml:mo>-</mml:mo><mml:mn>2015</mml:mn></mml:mrow></mml:math> , trend increased in 2006 again 2009 while it started slightly decline 2013. explain about $$45\%$$ xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>45</mml:mn><mml:mo>%</mml:mo></mml:mrow></mml:math> magnitude vector (excluding glacial isosatic adjustment). They cause pole position drift along $$59^{\circ }$$ xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mn>59</mml:mn><mml:mo>∘</mml:mo></mml:msup></mml:math> East longitude amplitude 2.7 mas/yr. Thus has considered close budget geophysical motion.