Rapid ablation zone expansion amplifies north Greenland mass loss: modelled (RACMO2) and observed (MODIS) data sets ...

Since the early 1990s, the Greenland ice sheet (GrIS) has been losing mass at an accelerating rate, primarily due to enhanced meltwater runoff following an atmospheric warming of ~1ºC. Here we show that a pronounced latitudinal contrast exists in the GrIS response to recent warming. The ablation are...

Full description

Bibliographic Details
Main Author: Noël, Brice P Y
Format: Dataset
Language:English
Published: PANGAEA 2019
Subjects:
Online Access:https://dx.doi.org/10.1594/pangaea.904428
https://doi.pangaea.de/10.1594/PANGAEA.904428
Description
Summary:Since the early 1990s, the Greenland ice sheet (GrIS) has been losing mass at an accelerating rate, primarily due to enhanced meltwater runoff following an atmospheric warming of ~1ºC. Here we show that a pronounced latitudinal contrast exists in the GrIS response to recent warming. The ablation area in north Greenland expanded by 46%, almost twice as much as in the south (+25%), significantly increasing the relative contribution of the north to total GrIS mass loss. This latitudinal contrast originates from a different response to the recent change in large-scale Arctic summertime atmospheric circulation, promoting southwesterly advection of warm air towards the GrIS. In the southwest, persistent high atmospheric pressure reduced cloudiness, increasing runoff through enhanced absorption of solar radiation; in contrast, increased early-summer cloudiness in north Greenland enhanced atmospheric warming through decreased longwave heat loss. This triggered a rapid snowline retreat, causing early bare ice ...