Influence of Anamalous Eurasian Spring Snow Cover on the Indian Summer Monsoon

欧亚春季积雪异常对印度夏季风的影响

• 批准号: 9114318
• 负责人: Anandu Vernekar
• 金额: $ 11.68万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 1994-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9114318&HistoricalAwards=false
• 关键词: Influence; Anamalous; Eurasian; Spring; Snow

There is strong empirical evidence that the areal extent of Eurasian spring snow cover is negatively correlated with the following summer rainfall over rainfall over India. The purpose of this research is to study the validity of this empirical relationship from a series of experiments with a general circulation model (GCM). The GCM is a global spectral model with rhomboidal truncation at wave number 40 horizontal resolution with 18 layers in the vertical. The physical processes include: surface biophysical processes, diurnal cycle, shallow and deep convection, cloud-radiation interaction and effects of large-scale and subgrid- scale orography. Three experiments are proposed with varying areal extent and depth of the Eurasian snow cover in the spring to study its influence on the summer monsoon circulations. All three experiments will simulate ensemble global circulations in an annual cycle mode from March 1 though September 30. The difference in these simulations are only due to the prescribed snow extent and depth over Eurasia on March 1. All other prescribed quantities will come from climatology. The first experiment is to determine the impact of a negative anomaly in the snow extent on the monsoon circulations by prescribing a minimum snow extent similar to that observed during the spring of 1970. In this experiment the PI will use average snow depth. The second and third experiments are designed to investigate the impact of a positive anomaly in the snow extent similar to that observed during the spring of 1972. In the second experiment the PI prescribe a minimum snow depth in order to isolate the effects of the surface albedo. In the third experiment he will prescribe a maximum snow in order to study the effects of albedo as well as the effects of melting and evaporation. The results of these anomaly experiments will be compared with the control simulations to test the statistical significance of these results..This research is important because it seeks to improve our understanding of relationships between important components of the climate system, surface boundary forcing and monsoons.

有强有力的经验证据表明， 欧亚大陆春季积雪与 印度夏季降雨量超过降雨量。 的目的 本研究旨在研究这一实证的有效性， 从一系列的实验与一般的关系 环流模式（GCM）。 GCM是一个全球光谱模型， 菱形截断波数40水平分辨率， 垂直方向18层。 物理过程包括：表面 生物物理过程、昼夜循环、浅层和深层对流， 云辐射相互作用和大尺度和次网格的影响， 比例尺地形学 针对不同的面积提出了三个实验 研究欧亚春季积雪的范围和深度 对夏季风环流的影响。 所有三 实验将模拟一年中的总体全球环流， 3月1日至9月30日期间为循环模式。 的差异 这些模拟仅仅是由于规定的积雪范围， 3月1日，欧亚大陆上空。 所有其他订明数量 将来自气候学。 第一个实验是确定 积雪范围的负异常对季风的影响 通过规定最小降雪量， 1970年春天观察到的。 在这个实验中，PI将 平均积雪深度。 第二和第三个实验是 旨在调查一个积极的异常的影响， 降雪量与1972年春季相似。 在 第二个实验，PI规定了最小雪深， 以隔离表面辐射的影响。 第三 他将规定一个最大的雪，以研究 的影响，以及融化的影响， 蒸发 这些异常实验的结果将是 与对照模拟相比， 这些结果的意义…这项研究很重要，因为 它旨在提高我们对人类与自然之间关系的理解， 气候系统的重要组成部分，地面边界 强迫和季风。