A decade of sea level rise slowed by climate-driven hydrology and its implicaitons on the land-atmosphere interaction

▎主講：羅敏輝助理教授 (台大大氣科學系)
▎時間：2016.12.23（五） 12:20～14:00
▎地點：臺灣大學全球變遷研究中心前棟2樓202會議室（近台大醉月湖畔）

 Abstract
While the ice sheets and mountain glaciers continue melting, changes in climate over the past decade have led to Earth's continents to store an extra 3.2 trillion tons of water in land (over soils, lakes and underground aquifers), temporarily lowering the rate of sea level rise by about 20% that is called “climate-driven sea level changes”.
 
The climate-driven sea level rise has been absent from IPCC sea level budget owing to lacking of observations. Recent advances in satellite measurement of time-variable gravity combined with reconciled global glacier loss estimates enable a disaggregation of continental land mass changes and a quantification of this term. To illustrate the importance of including climate-driven changes in land water storage in decadal sea level budgets, we place our estimate of climate-driven land water storage uptake in the context of other mass contributions to sea level change as estimated by using GRACE data (Launched in 2002, NASA's Gravity Recovery and Climate Experiment (or, GRACE) provided the land water storage trends by measuring the distance between the two GRACE satellites.).
 
Over the past decade, climate-driven land water storage uptake is of opposite sign and of magnitude comparable with ice losses from glaciers and ice sheets and nearly twice as large as mass losses from direct human-driven changes (groundwater withdrawal and dam) in land water storage. It is found that between 2002 and 2014, climate variability resulted in an additional 3200 ± 900 gigatons of water being stored on land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 mm per year.