EH4_OPYC_SRES_A2_VELPOT500

Project: IPCC Third Assessment Report ECHAM4/OPYC data sets
The project embrases the simulations with the coupled climate model ECHAM4/OPYC, relevant for the third assessment report (TAR, http://www.ipcc.ch/ipccreports/assessments-reports.htm) of the Intergovernmental Panel on Climate Change (IPCC).The IPCC has been established by WMO and UNEP to assess scientific, technical and socio-economic information, relevant for the understanding of climate change, its potential impacts and options for adaption and mitigation.
A more detailed description about the work of the IPCC can be found at the IPCC homepage ( http://www.ipcc.ch ) and at ( www.grida.no/climate/ipcc ). As a further development the Special Report on Emission Scenarios (SRES, http://www.grida.no/Climate/ipcc/emission/) have been constructed, to describe (potential) future developments in the global enviroment with special reference to the production of greenhouse gases and aerosol precursor emissions.
A set of four scenarios families (A1, A2, B1, B2) have been developed (see also http://www.grida.no/climate/ipcc/emission/index.htm ) The model output data are available at the World Data Center for Climate, Hamburg.( wdc-climate.de ). Projection of future trends based on selected emission scenarios are provided through this project for a great many model variables of ECHAM4/OPYC.
For a selected set of variables the IDCC-Data Distribution Center provides additional data sets from a multitude of models that contribute to the IPCC-TAR report (project: IPCC_DDC_TAR).
Summary: The SRES data sets were published by the IPCC in 2000 and classified into four different scenario families (A1, A2, B1, B2). SRES-A2 storyline describes a very heterogeneous world with the underlying theme of self-reliance and preservation of local identities. It results in this scenario a continous increasing population together with a slower economic growth and technological change.
The model consists of the atmospheric component which based on the weather forecast model of ECMWF. The atmospheric component is the standard model version of a 19-level hybrid sigma-pressure coordinate system.
The ocean component is a model which computes with isopycnal coordinates.
ECHAM4/OPYC3(http://cera-www.dkrz.de/IPCC_DDC/SRES/ECHAM4/echam4opyc3.html ).
This data set is an enlargement of the IPCC data set and provides additional meteorological parameters.
The run produces 6h values of the variables.
ECHAM4/OPYC3 (http://cera-www.dkrz.de/IPCC_DDC/SRES/ECHAM4/echam4opyc3.html ).
Changes of anthropogenic emissions of CO2, CH4, N2O and sulphur dioxide are prescribed according to the above mentioned scenario. The model run starts in 1990 from the results of the scenario run GSDIO (Experiment EH4OPYC_22723GSDIO) which has been run with observed conditions for the time periode 1860 to 1990.

项目：政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）第三次评估报告ECHAM4/OPYC数据集
本项目涵盖耦合气候模式ECHAM4/OPYC的模拟实验，相关成果服务于政府间气候变化专门委员会（IPCC）第三次评估报告（TAR，链接：http://www.ipcc.ch/ipccreports/assessments-reports.htm）。IPCC由世界气象组织（World Meteorological Organization, WMO）与联合国环境规划署（United Nations Environment Programme, UNEP）联合设立，旨在评估与气候变化、其潜在影响以及适应与减缓方案相关的科学、技术与社会经济信息。
有关IPCC工作的更详细说明，可访问IPCC官方网站（http://www.ipcc.ch）及（www.grida.no/climate/ipcc）查阅。作为后续研究进展，团队构建了《排放情景特别报告》（Special Report on Emission Scenarios, SRES，链接：http://www.grida.no/Climate/ipcc/emission/），用以描述全球环境的（潜在）未来发展趋势，重点聚焦温室气体与气溶胶前体物的排放情况。
研究人员共开发了四类情景集合（A1、A2、B1、B2，详见http://www.grida.no/climate/ipcc/emission/index.htm）。该模式的输出数据可在汉堡世界气候数据中心（wdc-climate.de）获取。本项目针对ECHAM4/OPYC的大量模式变量，提供基于选定排放情景的未来趋势预测数据集。
针对选定的变量集合，IPCC数据分发中心（IDCC-Data Distribution Center）将提供来自众多参与IPCC-TAR报告相关研究的模式的额外数据集（项目：IPCC_DDC_TAR）。
【摘要】《排放情景特别报告》数据集由IPCC于2000年发布，共分为四类情景集合（A1、A2、B1、B2）。SRES-A2情景的叙事框架描绘了一个高度异质性的世界，其核心主题为自给自足与本土身份的保留。该情景下，人口持续增长，但经济增长与技术变革速度相对平缓。
该模式由大气分量与海洋分量组成：大气分量基于欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts, ECMWF）的天气预报模式构建，采用标准的19层混合西格玛-压力坐标系模式版本；海洋分量则采用等密度坐标系（isopycnal coordinates）进行计算。
ECHAM4/OPYC3（链接：http://cera-www.dkrz.de/IPCC_DDC/SRES/ECHAM4/echam4opyc3.html）是IPCC原有数据集的扩展版本，额外提供了多项气象参数。该模式运行输出的变量数据时间分辨率为6小时。
本数据集对应的ECHAM4/OPYC3模式（链接：http://cera-www.dkrz.de/IPCC_DDC/SRES/ECHAM4/echam4opyc3.html）中，二氧化碳（CO₂）、甲烷（CH₄）、一氧化二氮（N₂O）与二氧化硫的人为排放变化将依据前述情景设定。该模式的模拟初始场取自情景实验GSDIO（实验编号EH4OPYC_22723GSDIO）的1990年结果，该实验以1860年至1990年的实测气象条件为驱动开展模拟。