Greenland ice sheet surface mass balance 1991 – 2000 : Application of Polar MM 5 mesoscale model and in situ data
Greenland ice sheet surface mass balance 1991 – 2000 : Application of Polar MM 5 mesoscale model and in situ data
复制标题
格陵兰冰盖表面质量平衡 1991 – 2000：Polar MM 5 中尺度模型和现场数据的应用
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
L. Bai
中科院分区：
文献类型：
--
作者：
J. Box;D. Bromwich;L. Bai
[1]1991-2000年，宾夕法尼亚州立大学-国家大气研究中心第五代中尺度模式（Polar MM 5）区域气候模式在北大西洋区域运行。我们分析了24公里的格陵兰冰盖的输出，以评估空间和时间的变化的表面质量平衡及其子组件。该模型的输出进行了比较，3年的自动气象站（AWS）的数据，从17个站点，以确定偏见。使用现场数据，我们推导出对融化能量和来自地表和吹雪的水蒸气通量偏差的简单修正。模拟的累积速率与AWS和雪坑观测结果一致。估计径流和冰盖的表面质量平衡分布使用模拟融化量和融水保留计划。从调查的十年中，地面物质平衡分量的年际变化的幅度初步建立。最大的变化集中在沿着冰盖边缘，在那里的积累和消融速率最大。模拟的年际波动表明一个大的绝对变率，±187公里的总冰盖表面质量平衡的年1。在模拟的平衡线高度的变化是暗示在南方的热变率的主导地位，随着纬度的增加，积累的变化越来越重要。提出了地表物质平衡对温度和降水异常敏感性的经验函数。提出了最大和最小地表能量通量和质量通量的精确位置和区域。使用冰山排放和底部融化的估计，总冰盖质量平衡估计为78公里/年，在1991-2000年的十年中产生2.2毫米的海平面上升，并对观测到的（1.5毫米/年）全球海平面上升贡献15%。更负的质量平衡是由于包括吹雪升华损失和区域变暖在20世纪90年代。
[1] The Polar Pennsylvania State University–National Center for Atmospheric Research Fifth-Generation Mesoscale Model (Polar MM5) regional climate model was run over the North Atlantic region for 1991–2000. We analyze 24-km output over the Greenland ice sheet to evaluate spatial and temporal variability of the surface mass balance and its subcomponents. The model output is compared with 3 years of automatic weather station (AWS) data from 17 sites to identify biases. Using the in situ data, we derive simple corrections for biases in melt energy and in water vapor fluxes from the surface and from blowing snow. The simulated accumulation rate is in agreement with AWS and snow pit observations. Estimates for runoff and the surface mass balance distribution over the ice sheet are produced using modeled melt volume and a meltwater retention scheme. From the decade investigated, the magnitude of interannual variability in surface mass balance components is tentatively established. The largest variability is concentrated along the ice sheet margin, where both accumulation and ablation rates are largest. The simulated interannual fluctuations suggest a large absolute variability, ±187 km yr 1 for total ice sheet surface mass balance. Variability in simulated equilibrium line altitude is suggestive of a dominance of thermal variability in the south with increasing importance of accumulation variability with increasing latitude. Empirical functions for the sensitivity of surface mass balance to temperature and precipitation anomalies are presented. The precise locations and regions of maximum and minimum surface energy and mass fluxes are suggested. Using an estimate for iceberg discharge and bottom melting, the total ice sheet mass balance is estimated be 78 km yr , producing 2.2 mm of eustatic sea level rise over the 1991–2000 decade and contributing 15% to the observed (1.5 mm yr ) global sea level rise. The more negative mass balance is attributed to including blowingsnow sublimation loss and to regional warming in the 1990s.