SGER: Evaluation of Surface Solar Irradiance in Coupled Climate Models

SGER：耦合气候模型中地表太阳辐照度的评估

• 批准号: 0446780
• 负责人: Beate Liepert
• 金额: $ 2.5万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0446780&HistoricalAwards=false
• 关键词: SGER; Evaluation; Surface; Solar; Irradiance

Observations from satellites and in situ measurements of surface downwelling irradiance will be analyzed and compared with global general circulation coupled model simulations of the late 19th century and 20th century runs to evaluate the model climatology, variability and cloud and aerosol effects. The incoming shortwave irradiance at the surface is one driving mechanism of the ocean/ice and land submodels and while it is directly affected by the physics in the atmosphere, such as clouds, aerosols, water vapor, ozone and other gases, it is only indirectly affected by the ocean/ice/land. Hence, aerosol and cloud variations have a strong direct signal on the downwelling shortwave surface irradiance, which can be easily interpreted. At the same time, surface solar irradiance and its link to clouds and aerosols represents one crucial part of the cloud feedback loop. Furthermore, there has been increased interest in the scientific community regarding the long-term variability of the surface incoming solar irradiance. Observations show that solar irradiance has recently been decreasing in stations worldwide by about 4% from 1961-1990, possibly due to changed aerosol concentrations and cloud variations. This has been described as a global dimming effect. Current research (from satellite observations) shows a reversal of this effect from the late 1980s and during the 1990s. The PIs will use two data sets, which represent two different classes of data retrieval methods, from satellites and in situ measurements. They will compare the observed climatology and variability of the surface downwelling shortwave flux to four coupled climate models, the Goddard Institute for Space Studies (GISS) model with two ocean submodels, the Geophysical Fluid Dynamics Laboratory (GFDL) model and the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM-3), on all resolved temporal and spatial scales. Since the models use different aerosol datasets and cloud parameterizations (some use indirect cloud-aerosol effects) the inter-model comparisons of the solar irradiance at the surface will be instructive of the quality of each models' representation of cloud and aerosol impacts. The PIs will a) assess the long-term variability and trend of the model downwelling shortwave flux at the surface and compare it to observations, b) assess the aerosol and cloud effects in the models and, c) examine the models' capability in simulating specific events (volcanic eruptions and El Nino conditions). Broader Impacts: This research is important because it has the potential to improve the quality of climate prediction models, which would be a benefit to societal activities, such as, environmental management and decision-making.This is a grant under the U.S. Climate Change Science Program's, Climate Variability and Predictability Program (CLIVAR).

将分析卫星观测和地面下流辐照度的现场测量结果，并将其与19世纪末和20世纪运行的全球环流耦合模式模拟结果进行比较，以评估模式气候学、变率以及云和气溶胶效应。地表入射短波辐照度是海洋/冰/陆地子模式的驱动机制之一，虽然它直接受到大气中云、气溶胶、水蒸气、臭氧等气体等物理因素的影响，但它只间接受到海洋/冰/陆地的影响。因此，气溶胶和云的变化对下行短波表面辐照度有很强的直接信号，这很容易解释。与此同时，地表太阳辐照度及其与云和气溶胶的联系代表了云反馈回路的一个关键部分。此外，科学界对地表入射太阳辐照度的长期变化越来越感兴趣。观测显示，1961-1990年间，全球站的太阳辐照度最近减少了约4%，这可能是由于气溶胶浓度和云的变化。这被称为全球变暗效应。目前的研究（来自卫星观测）表明，自1980年代末和1990年代以来，这种影响发生了逆转。pi将使用两个数据集，它们代表两种不同类型的数据检索方法，分别来自卫星和现场测量。他们将把观测到的气候学和地表下潜短波通量的变率与四种耦合气候模型进行比较，即戈达德空间研究所（GISS）模型和两个海洋子模型、地球物理流体动力学实验室（GFDL）模型和国家大气研究中心（NCAR）社区气候系统模型（ccsm3），在所有已分解的时空尺度上。由于模式使用不同的气溶胶数据集和云参数化（有些使用间接的云-气溶胶效应），模式间对地表太阳辐照度的比较将对每个模式对云和气溶胶影响的表征质量有指导意义。PIs将a)评估模式在地表向下的短波通量的长期变率和趋势，并将其与观测值进行比较；b)评估模式中的气溶胶和云效应；c)检查模式模拟特定事件（火山爆发和厄尔尼诺条件）的能力。更广泛的影响：这项研究很重要，因为它有可能提高气候预测模型的质量，这将有利于社会活动，如环境管理和决策。这是美国气候变化科学计划的气候变异和可预测性计划（CLIVAR）下的一项拨款。