Collaborative Research: Quantifying the impacts of atmospheric and land surface heterogeneity and scale on soil moisture-precipitation feedbacks

合作研究：量化大气和地表异质性和规模对土壤湿度-降水反馈的影响

• 批准号: 1035843
• 负责人: Pierre Gentine
• 金额: $ 22.93万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1035843&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; impacts; atmospheric

This project studies the potential feedback between soil moisture and precipitation. A positive feedback would mean that enhanced soil moisture leads to enhanced precipitation, as a wetter surface provides a source of evaporation for subsequent rainfall. In that case, precipitation would lead to wetter soil, which would in turn lead to further precipitation, while a lack of precipitation could lead to a lack of soil moisture and hence further reductions in precipitation leading to prolonged drought. This study assesses the influence of atmospheric and land surface heterogeneity and spatial scale on soil moisture-precipitation coupling, principally at daily timescales, through two interconnected approaches: 1) diagnostic analysis of available observations, reanalysis products, and global climate model (GCM) output; and 2) conceptual modeling of land-atmosphere interactions using process-based idealized models expresed as analytic equations as well as atmospheric column models coupled to simple soil models (eg "bucket" models). A primary objective of this activity is the development of robust, physically-based metrics for quantifying and comparing intraday soil moisture/precipitation coupling in models and observations.The issues addressed in this project have relevance to society as well as science, as drought duration and intensity have substantial consequences for agriculture. In addition, the project will support and train a postdoctoral researcher, thereby helping to support and train the next generation of scientists.

该项目研究了土壤水分和降水之间的潜在反馈。 积极的反馈将意味着增强的土壤水分会导致降水增强，因为湿润的表面为随后的降雨提供了蒸发来源。 在这种情况下，降水会导致潮湿的土壤，进而导致进一步的降水，而缺乏降水可能会导致缺乏土壤水分，从而进一步减少降水，从而导致长时间干旱。这项研究通过两种相互联系的方法评估了大气和陆地表面异质性和空间尺度对土壤水分湿度耦合的影响，主要是在日常时标：1）对现有观察结果，重新分析产物和全球气候模型（GCM）的影响； 2）使用基于过程的理想化模型以及大气柱模型与简单土壤模型（例如“桶”模型）结合的大气柱模型，对土地大气相互作用进行概念建模。该活动的主要目的是开发稳健的，基于物理的指标，用于量化和比较模型和观察中的盘中土壤水分/降水耦合。该项目中解决的问题与社会以及科学相关，与干旱持续时间和强度有关，对农业产生了实质性的影响。 此外，该项目将支持和培训一名博士后研究人员，从而帮助支持和培训下一代科学家。