Spatiotemporal variations of extreme events in surface mass balance over Greenland during 1958–2019
Spatiotemporal variations of extreme events in surface mass balance over Greenland during 1958–2019
复制标题
1958-2019年格陵兰岛表面质量平衡极端事件时空变化
DOI：
10.1002/joc.7689
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Q. Yan
中科院分区：
文献类型：
--
作者：
Ting Wei;B. Noël;M. Ding;Q. Yan
由于北极变暖加剧，格陵兰岛的表面物质平衡（SMB）正在发生巨大变化，更频繁的破纪录融化事件。为了全面了解格陵兰冰盖的行为，我们根据RACMO2.3p2模型的输出，开发了一套指数来研究1958-2019年格陵兰SMB极端事件的时空变化。我们说明了极端消融主导事件的气候分布（即，SMB < 0的极端值）在强度和频率方面与平均SMB有很大的相似性，显示出沿海到内陆的下降模式。这种模式适用于极端积累主导事件的强度（即，极端SMB > 0），但不是从沿海到内陆格陵兰岛的频率增加。在时间演化方面，格陵兰极端消融主导事件的强度和频率在1958-1978年期间呈下降趋势，而在之后的20年（2001-2019年）中，趋势有所增加。然而，这些趋势在GrIS的幅度和符号方面都存在区域性波动，最明显的变化发生在格陵兰西南部。相比之下，极端积累主导的事件在强度和频率方面平均显示出从1958年到2019年的长期增长趋势。然而，在1958-2019年期间，整个GrIS存在明显的空间波动，特别是在格陵兰西南部和东北部之间，观察到相反的趋势。此外，夏季SMB极值的变化与区域温度、降水及相关大气环流的变化有关，且主导因子随极值指数和时间间隔的不同而不同。我们的研究结果可能会促进我们对格陵兰岛SMB变化的理解，并有助于未来格陵兰岛观测网络的设计。
Greenland surface mass balance (SMB) is undergoing dramatic change due to the amplified Arctic warming, with more frequent record‐breaking melt events. To comprehensively understand the behaviour of the Greenland ice sheet, we develop a suite of indices to examine the spatiotemporal variations of extreme events in SMB over Greenland during 1958–2019 based on the RACMO2.3p2 model outputs. We illustrate that the climatological distributions of extreme ablation‐dominated events (i.e., extremes with SMB < 0) share large similarity with the mean SMB in terms of intensity and frequency, showing a coastal‐to‐inland decreasing pattern. This pattern holds for the intensity of the extreme accumulation‐dominated events (i.e., extremes with SMB > 0), but not for the frequency which increases from the coastal to inland Greenland. Regarding the temporal evolution, the intensity and frequency of extreme ablation‐dominated events show a decreasing trend over Greenland during 1958–1978, whereas the trend increases afterwards, especially during the last two decades (2001–2019). However, these trends fluctuate regionally across the GrIS both in terms of magnitude and sign, with the most pronounced variations occurring in southwest Greenland. In contrast, extreme accumulation‐dominated events show, on average, a long‐term increasing trend from 1958 to 2019 in terms of intensity and frequency. However, obvious spatial fluctuations exist across the GrIS during 1958–2019, especially between the southwest and northeast Greenland where an opposite trend is observed. Additionally, the variations of SMB extremes in boreal summer are linked with the changes in regional temperature and precipitation and the associated atmospheric circulations, and the dominating factor varies with different extreme indices and time intervals. Our results may advance our understanding on SMB variability over Greenland and contribute to the design of future Greenland observational networks.
前所未有的大气条件（1948
DOI：
10.5194/tc-14-1209-2020
发表时间：
2020
期刊：
The Cryosphere
影响因子：
--
作者：
Tedesco, Marco;Fettweis, Xavier
通讯作者：
Fettweis, Xavier
影响因子：
64.8
作者：
Golledge, Nicholas R.;Keller, Elizabeth D.;Edwards, Tamsin L.
通讯作者：
Edwards, Tamsin L.