The Atmospheric Side of the Freshwater Budget

目的：该项目的主要科学目标是提高对从温带风暴路径到热带雨带的大西洋降水区的平均状态和年际变化的了解。此外，该项目的目标是向海洋学小组提供淡水预算大气方面的全球数据，即蒸发量、降雨量和大气湿度会聚/发散数据。在开阔海域，蒸发减去降水是模拟海洋盐度的关键边界条件。该项目还将作为1740研究组和大气研究界之间的总纽带。背景：最近，与湿度有关的大气过程被指出是气候研究的“重大挑战”。挑战在于，它们将大尺度大气环流与对流和降水等小尺度过程联系在一起。降水模式受大尺度大气环流的强烈影响，但大尺度环流也受降水及其在对流区的自组织方式的影响。最近特别强调的一个问题是，哪些因素分别控制着热带雨带和温带风暴路径的位置、强度和可变性。方法：该项目的主要任务是：1.分析大西洋降水区的平均状态和年际变化。这包括与多年时间尺度上的动力现象的相关性分析，例如北大西洋涛动(NAO)和厄尔尼诺南方涛动(ENSO)。分析将使用迄今尚未获得的新数据来源，即作为全球海洋卫星数据集的HOAPS4，作为现场验证数据集的Ocean RAIN，以及关于海洋状况的最新可获得的全球环境变化二氧化碳数据(来自TP3.1)。根据新的观测数据，还将重新评估气候模型在多大程度上正确地涵盖了平均状态和可变性。2.利用计算的水汽输送，分析蒸发和降水固有的汇、源和时空变化模式。将评估预算结算情况以及降水/蒸发模式和水蒸气运输之间的一致性。这包括考虑HOAPS不确定性估计和GECCO2海洋再分析结果的水汽通量估计的误差预算评估。3.向研究组其他成员提供更新的蒸发量和降水量数据。对于HOAPS来说，这是由德国气象局DWD主办的EUMETSAT气候监测卫星应用基金提供的实物捐助，不是通过本申请提供资金的。对于Ocean RAIN，这是由CLSAP/汉堡大学提供的实物捐助，也不是通过这项申请提供的资金。

Objective: The main scientific objective of the project is to improve the understanding of the mean state and interannual variability of Atlantic precipitation areas from extratropical storm tracks to tropical rain belts. Besides this, the project has the objective to provide global data on the atmospheric side of the freshwater budget to the oceanographic groups, namely evaporation, precipitation, and atmospheric moisture convergence / divergence data. Over the open ocean, evaporation minus precipitation is the key boundary condition for ocean salinity modeling. The project will also act as general link between Research Group 1740 and the atmospheric research community. Background: Atmospheric processes related to moisture have recently been pointed out as "grand challenges" for climate research. The challenge is that they couple the large-scale atmospheric circulation to small-scale processes such as convection and precipitation. Patterns of precipitation are strongly influenced by the large-scale atmospheric circulation, but the large-scale circulation is also influenced by precipitation, and how it self-organizes in convective areas. A question that has been particularly highlighted recently is which factors control the position, strength, and variability of tropical rain belts and extratropical storm tracks, respectively. Approach: The key tasks of the project are: 1. Analyze the mean state and interannual variability of precipitation areas over the Atlantic. This includes an analysis of the correlation with dynamical phenomena on multi-annual timescales, such as the North Atlantic Oscillation (NAO) and the El Niño Southern Oscillation (ENSO). The analysis will use new data sources that have hitherto not been available, namely HOAPS4 as a global ocean satellite data set, OceanRAIN as an insitu validation data set, and the latest available GECCO2 data (from TP3.1) for the ocean state. It will also be reassessed, to what extent climate models correctly cover the mean state and variability, given the new observational data. 2. Analyze sinks, sources, and spatiotemporal variability patterns inherent to evaporation and precipitation, utilizing the calculated water vapor transports. The budget closure and consistency between precipitation/evaporation patterns and water vapor transports will be assessed. This includes an error budget assessment of moisture flux estimates, considering HOAPS uncertainty estimates and the results of the GECCO2 ocean reanalysis. 3. Contribute updated evaporation and precipitation data to the other research group members. For HOAPS this is an in kind contribution from the EUMETSAT Satellite Application Facility on Climate Monitoring, hosted by the German Meteorological Service DWD, not funded through this application. For OceanRAIN it is an in kind contribution from CliSAP / University of Hamburg, also not funded through this application.