Collaborative Research: Atmospheric Controls on Northern Hemisphere Cryosphere Variability

罗宾逊，David A. Rutgers University， New Brunswick标题：大气对北半球冰冻圈变异性的控制该奖项支持对大气变异性与北半球雪和海冰波动之间关系的综合研究。这项工作的主要目的是提供冰冻圈对大气环流区域变化敏感性的半球综合，并根据降水、温度、风和大尺度遥相关模式之间的相关相互作用诊断这种敏感性。pi将确定冰冻圈的那些区域，以保证对潜在的气候变化进行重点监测，以及冰冻圈未来对环流制度变化的可能反应。作为这些工作的一部分，他们将在当前和预估的未来气候条件下，对观测到的积雪模式与不同gcm模拟的积雪模式进行一系列的相互比较。这项研究将解决至少六个基本问题：1)北半球海冰范围的变化与陆地积雪覆盖之间的关系是什么？冰冻圈的哪些区域对大气环流变化表现出强烈或微弱的响应？为什么？3)哪些地区对北半球冰冻圈变率贡献最大？4)冰冻圈对大尺度遥相关模态的响应是什么？这些响应与天气活动、温度和降水的平行异常有何比较？5)不同的gcm对积雪的现今分布和变率的描述有多好？从模拟环流变化的角度来看，gcm预测的响应CO2增温的冰冻圈变化是否合理？6)冰冻圈可以作为气候变化的可靠指标吗？对于积雪和海冰的分析，网格化的NOAA北半球积雪范围图和海军/NOAA冰浓度数据将与现有的积雪深度、降雪量、降水和地表温度的台站记录相结合。在大气分析方面，pi将使用从20世纪60年代初至今每天一至两次的NMC地面和高空场，用于计算气旋和反气旋的频率、位置和强度、风暴路径和其他天气活动指数（例如正涡度平流）以及温度的格点和区域时间序列。来自现有档案的Rawinsonde数据将用于分析水汽通量辐合模式及其与北部高纬度地区积雪和降水变化的关系。从不同的GCMs输出将获得双倍的二氧化碳（平衡）运行，瞬态运行（其中二氧化碳不断增加），以及运行使用相同的当前边界条件。这项研究是由科罗拉多大学（University of Colorado）和美国科罗拉多大学(dr。Mark Serreze和Roger G. Barry)和Rutgers大学（David Robinson博士）。这项工作很重要，因为它试图澄清冰冻圈在气候变率中的作用。

Abstract ATM-9314721 Robinson, David A. Rutgers University, New Brunswick Title: Atmospheric Controls on Northern Hemisphere Cryosphere Variability This award supports comprehensive study of relationships between atmospheric variability and fluctuations in the snow and sea ice covers the Northern Hemisphere. The primary thrust of the work is to provide a hemispheric synthesis of the sensitivity of the cryosphere to regional changes in the atmospheric circulation, and to diagnose this sensitivity with respect to associated interactions between precipitation, temperature, winds and the modes of large-scale teleconnection patterns. The PIs will identify those regions of the cryosphere warranting focused monitoring for potential climate change, and possible future responses of the cryosphere to changes in circulation regimes. As part of these efforts, they will perform a series of intercomparisons between observed snow cover patterns and those simulated by different GCMs under present and project future climatic conditions. The study will address at least six basic questions: 1) What are the relationships between variations in northern hemisphere sea ice extent and terrestrial snow cover? 2) What areas of the cryosphere exhibit strong or weak responses to atmospheric circulation changes and why? 3) Which areas contribute most strongly to northern hemisphere cryosphere variability? 4) What are the responses of the cryosphere to the modes of Large-scale teleconnections patterns, and how do these compare with parallel anomalies in synoptic activity, temperature and precipitation? 5) How well do different GCMs depict the present day distribution and variability of snow cover, and are changes in the cryosphere projected by GCMs in response to enhance CO2 warming reasonable from the viewpoint of modeled circulation changes? 6) Can the cryosphere be used as a robust indicator of climate change? For the snow and sea ice analyses, gridded NOAA charts of Northern Hemisphere snow extent and Navy/NOAA ice concentration data will be combined with available station records of snow depth, snow fall, precipitation and surface temperature. For atmospheric analyses, the PIs will use once to twice-daily NMC surface and upper-air fields from the early 1960s to present, used to calculate grid- point and regional time series of the frequency, position and strength of cyclones and anticyclones, storm tracks, and other indices of synoptic activity (e.g, positive vorticity advection), as well as temperature. Rawinsonde data from an existing archive will be used to analyze patterns of moisture flux convergence and their associations with snow cover and precipitation variations at high northern latitudes. Output from different GCMs will be obtained for doubled CO2 (equilibrium) runs, transient runs (in which CO2 is continually increased), as well as for runs using identical present-day boundary conditions. The research is a collaborative effort between University of Colorado (Drs. Mark Serreze and Roger G. Barry) and Rutgers University (Dr. David Robinson). The work is important because it seeks to clarify the role of the cryosphere in climate variability.