Inter-Annual Variability of the Hydrologic Cycle over North America

[2020800 . 9]本文提出的研究目标是更好地了解水文循环的大气和陆地分支之间的耦合，并确定其年际变化的物理基础。本研究的基本假设是，区域大气水汽输送受大尺度强迫和局地再循环共同支配，它们的相对贡献对水文循环的年际变化具有重要意义。平流和再循环水分的相对贡献可能取决于季节、离子和各种储存库（如大气）的记忆。近地表和次地表储存。本项目将处理两个具体的科学目标：目标一：确定观测到的水文循环年际变化的模式及其潜在的因果机制。目标2：确定陆地表面和地下储存（水和雪/冰）在调节水文循环年际变化中的作用。自然或人为引起的气候变率。有可能改变水分通量，这可能会产生重大的社会影响。例如，据推测，二氧化碳引起的全球变暖将导致全球水循环的加剧（全球水通量的增加），从而导致更大的全球降水。蒸发速度加快，极端天气和包括洪水和干旱在内的水文状况普遍加剧。此外，由于水文循环和环流模式之间的反馈变化，我们可能会看到运输的空间格局发生变化。水文制度的变化对水资源管理以及生态系统中的生物地球化学过程都有影响。更好地了解水文循环的动态和潜在的因果机制将对所有与水有关的过程产生重大影响。

0208009KumarThe goal of the proposed research is to develop a better understanding of the coupling between the atmospheric and terrestrial (land) branches of the hydrologic cycle and identifies the physical basis of their inter-annual variability. The underlying hypothesis of the proposed research is that the regional atmospheric moisture transport is governed by both the large scale forcing as well as local recycling, and their relative contributions have important implications in the inter-annual variability of the hydrologic cycle. The relative contributions of advected and recycled moisture may depend on the season, re-ion and the memory of the various reservoirs such as the atmosphere. near-surface and sub-surface storage. Two specific science objectives will be addressed in this project:Objective I: Identify the modes of the observed inter-annual variability of the hydrologic cycle and the underlying causal mechanism.Objective 2: Identify the roles of land surface and sub-surface storage (water and snow/ice) in regulating the inter-annual variability of the hydrologic cycle.Climate variability, natural or human induced. Have the potential to alter the moisture fluxes, which can have significant societal impact. For example, it is speculated that C02-induced global warming would lead to an intensification of global water cycle (an increase in global water fluxes), leading to greater -global precipitation. faster evaporation and a general exacerbation of extreme weather and hydrological regimes including floods and droughts. In addition we may see a shift in the spatial patterns of transport, resulting from the feedback between the changes in the hydrologic cycle and general circulation patterns. Changes in hydrologic regimes have implications for water resource management as well as biogeochemical processes in ecosystems. A better understanding of the dynamics of the hydrologic cycle and the underlying causal mechanism will have significant impact in all areas of water-related processes.