Improved Earth Oblateness Rate Reveals Increased Ice Sheet Losses and Mass-Driven Sea Level Rise

Loomis, B D ; Rachlin, K E ; Luthcke, S B

关键词: ANTARCTIC REGIONS;    EARTH GRAVITATION;    ESTIMATING;    GRACE MISSION;    GRACE-FO MISSION;    SATELLITE LASER RANGING;    SEA ICE;    SEA LEVEL;   

RP-ID  :  GSFC-E-DAA-TN70257

学科分类：海洋学与技术

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Satellite laser ranging (SLR) observations are routinely applied toward the estimation of dynamic oblateness, C(sub 20), which is the largest globally integrated component of Earth's time-variable gravity field. Since 2002, GRACE and GRACE Follow-On have revolutionized the recovery of higher spatial resolution features of global time-variable gravity, with SLR continuing to provide the most reliable estimates of C (sub 20).We quantify the effect of various SLR processing strategies on estimating C(sub 20) and demonstrate better signal recovery with the inclusion of GRACE-derived low-degree gravity information in the forward model. This improved SLR product modifies the Antarctic and Greenland Ice Sheet mass trends by -15.4 and -3.5 Gt/year, respectively, as compared to CSR TN11, and improves global mean sea level budget closure by modifying sea level rise by +0.08 mm/year. We recommend that this new C(sub 20) product be applied to RL06 GRACE data products for enhanced accuracy and scientific interpretation.