Greenland high-elevation mass balance: inference and implication of reference period (1961–90) imbalance
Greenland high-elevation mass balance: inference and implication of reference period (1961–90) imbalance
复制标题
格陵兰高海拔物质平衡：参考期（1961-90）不平衡的推论和含义
作者：
W. Colgan;J. Box;M. Andersen;X. Fettweis;B. Csathó;R. Fausto;D. van As;J. Wahr
摘要本文对北极区域气候评估项目（PARCA）评估的格陵兰冰盖高海拔地区的投入产出质量预算进行了重新研究。我们修订的参考期（1961 - 1990）的质量平衡为54±48 Gt a - 1，大大大于PARCA评估的0±21 Gt a - 1，但与最近完全独立的高海拔质量平衡的输入-输出估计（41±61 Gt a - 1）一致。总之，这些估计推断出参考时期高海拔比质量平衡为4.8±5.4 cm w.e. a - 1。与此相关联的概率密度函数（PDF）推断，在参考期间，高海拔比质量平衡为正的可能性为81% (>0 cm w.e. a - 1)，比平衡为>2 cm w.e. a - 1的可能性为70%。考虑到参考期的累积具有世纪和千年平均值的特征，并且原位质量平衡观测表现出对地表坡度的依赖，而不是对地表质量平衡的依赖，我们认为千年尺度的冰动力是微妙参考期高海拔质量增加的主要驱动因素。如果不考虑微妙的参考期动态质量增益，将导致对近期动态质量损失的低估约17%，对近期格陵兰岛总质量损失的低估约7%。
Abstract We revisit the input–output mass budget of the high-elevation region of the Greenland ice sheet evaluated by the Program for Arctic Regional Climate Assessment (PARCA). Our revised reference period (1961–90) mass balance of 54±48 Gt a–1 is substantially greater than the 0±21 Gt a–1 assessed by PARCA, but consistent with a recent, fully independent, input–output estimate of high-elevation mass balance (41±61 Gt a–1). Together these estimates infer a reference period high-elevation specific mass balance of 4.8±5.4 cm w.e. a–1. The probability density function (PDF) associated with this combined input–output estimate infers an 81% likelihood of high-elevation specific mass balance being positive (>0 cm w.e. a–1) during the reference period, and a 70% likelihood that specific balance was >2 cm w.e. a–1. Given that reference period accumulation is characteristic of centurial and millennial means, and that in situ mass-balance observations exhibit a dependence on surface slope rather than surface mass balance, we suggest that millennial-scale ice dynamics are the primary driver of subtle reference period high-elevation mass gain. Failure to acknowledge subtle reference period dynamic mass gain can result in underestimating recent dynamic mass loss by ~17%, and recent total Greenland mass loss by ~7%.
影响因子：
5.2
作者：
Bamber, J. L.;Griggs, J. A.;Steinhage, D.
通讯作者：
Steinhage, D.
影响因子：
5.2
作者：
Doyle, Samuel H.;Hubbard, Alun;Hubbard, Bryn
通讯作者：
Hubbard, Bryn