SGER: Simple Indices of Climate Variability and Change

将使用五个简单的大尺度地表温度变化指数来评估若干气候模式在模拟世纪气候变率和变化方面的性能。这些指数基于温室气候变化的空间指纹，包括区域平均表面温度、陆地-海洋温度对比、北方半球纬向温度梯度、陆地温度年周期幅度和陆地温度日较差幅度。 将根据1880-2003年期间的观测数据计算全球范围和北美区域的指数，并与这一期间的模型模拟数据进行比较。要分析的模型包括所有三个美国模型的模拟（社区气候系统模型，位于科罗拉多博尔德的国家大气研究中心;普林斯顿的地球物理流体动力学实验室模型（GFDL）;和纽约市的戈达德空间研究所模型）提供给政府间气候变化专门委员会（气专委）第四次评估报告，与其他几个国际模型。将在三个不同时间尺度上比较观测和模式之间指数的变率和相关结构：年际变率、十年变率和50年和世纪时间尺度上的趋势。 这一评价将使人们更有信心利用这些模型进行气候变化探测和归因研究，并预测未来的气候变化。

Five simple indices of large-scale surface temperature variations will be used to assess the performance of a number of climate models in simulating climate variability and change during the 20th century. These indices are based on the spatial fingerprint of greenhouse climate change and include the area-mean surface temperature, the land-ocean temperature contrast, the meridional temperature gradient in the Northern Hemisphere, the magnitude of the annual cycle in temperature over land, and the magnitude of the diurnal temperature range over land. The indices will be calculated for the global domain and for the North American region from observational data for the period 1880-2003 and compared with data from model simulations for this period. The models to be analyzed include simulations from all three U.S. models (Community Climate System Model, at the National Center for Atmospheric Research at Boulder, Colorado; Geophysical Fluid Dynamics Laboratory model (GFDL) at Princeton; and Goddard Institute for Space Studies model (GISS) at New York City) being made available for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, together with several other international models. The variability and correlation structure of the indices will be compared between the observations and the models on three different timescales: interannual variability, decadal variability and trends on 50 year and century timescales. This evaluation will provide greater confidence in using these models for climate change detection and attribution studies and for projection of future climate change.