CEOP CPPA SGP (Southern Great Plains) Reference Site

The Southern Great Plains (SGP) site was the first field measurement site established by DOE's Atmospheric Radiation Measurement (ARM) Program. Scientists are using the information obtained from the SGP to improve cloud and radiative models and parameterizations and, thereby, the performance of atmospheric general circulation models used for climate research. Deployment of the first instrumentation to the SGP site occurred in the spring of 1992, just 24 months after the program was approved. The site was dedicated in November 1992. Additional instrumentation and data processing capabilities have been incrementally added in the succeeding years. The site was recently rededicated in the name of Dr. Frederick Luther (1943-1986), who made outstanding contributions to the field of atmospheric research and furthering our understanding of atmospheric radiation and its interactions with clouds, aerosols, and gases. The SGP was chosen as the first ARM field measurement site for several reasons including its relatively homogeneous geography and easy accessibility, wide variability of climate cloud type and surface flux properties, and large seasonal variation in temperature and specific humidity. It also already had a large, existing network of weather and climate research and instrumentation. The SGP site consists of in situ and remote-sensing instrument clusters arrayed across approximately 55,000 square miles (143,000 square kilometers) in north-central Oklahoma. The ARM SGP site is the largest and most extensive climate research field site in the world and can be viewed as a real "laboratory without walls." The heart of the SGP site is the heavily instrumented central facility located on 160 acres of cattle pasture and wheat fields southeast of Lamont, Oklahoma. A staff of 30 scientists and technicians collect and monitor data from the central facility instruments and from smaller, unstaffed facilities throughout the site. The instruments throughout the site automatically collect data on surface and atmospheric properties, routinely providing data to the Site Data System, which is linked by high-speed communications to the ARM Archive and Data Center. The Data Center acquires additional data from other sources, such as National Weather Service satellite and surface data, and provides tailored data packages to ARM Science Team members. More than 30 instrument clusters have been placed around the SGP site, at the central facility and at boundary, extended, and intermediate facilities. The locations for the instruments were chosen so that the measurements reflect conditions over the typical distribution of land uses within the site. The continuous observations at the SGP site are supplemented by intensive observation periods, when the frequency of measurements is increased and special measurements are added to address specific research questions. During such periods, approximately 2 gigabytes or more of data (two billion bytes) is generated daily. Both during intensive observation periods and at other times, scientists bring their own specialized instruments to the SGP site, typically for several weeks.

南大草原站点（Southern Great Plains, SGP）是美国能源部（Department of Energy, DOE）大气辐射测量计划（Atmospheric Radiation Measurement, ARM）建立的首个野外测量站点。科学家们利用SGP站点获取的信息，改进云与辐射模型及参数化方案，进而提升用于气候研究的大气环流模式（Atmospheric General Circulation Model）的性能。1992年春季，即该计划获批仅24个月后，首批仪器便部署至SGP站点；同年11月，站点正式投入使用。此后数年，站点逐步新增了更多仪器设备与数据处理能力。近日，该站点以弗雷德里克·路德博士（Dr. Frederick Luther, 1943-1986）之名重新命名，以纪念他在大气研究领域的卓越贡献——他深化了人类对大气辐射及其与云、气溶胶和气体相互作用的理解。

SGP被选为ARM首个野外测量站点的原因有多个：其一，其地理环境相对均一且易于抵达；其二，气候、云型及地表通量特性具有广泛变异性；其三，温度与比湿的季节变化显著。此外，该区域已拥有成熟的天气与气候研究及仪器网络。

SGP站点由原位（in situ）和遥感仪器集群组成，这些集群分布在俄克拉荷马州中北部约55,000平方英里（143,000平方公里）的区域内。ARM SGP站点是全球规模最大、覆盖最广的气候研究野外站点，堪称真正的“无墙实验室”。

SGP站点的核心是仪器密集的中央设施，该设施位于俄克拉荷马州拉蒙特市东南部，占地160英亩，涵盖牧场与麦田。30名科学家与技术人员组成的团队负责收集和监测中央设施及站点内各小型无人设施的仪器数据。

站点内的仪器自动收集地表与大气特性数据，并定期将数据传输至站点数据系统（Site Data System）。该系统通过高速通信链路连接至ARM档案与数据中心（ARM Archive and Data Center）。数据中心还从其他来源（如美国国家气象局的卫星与地面数据）获取补充数据，并为ARM科学团队成员提供定制化数据包。

SGP站点周边已部署超过30个仪器集群，分布于中央设施、边界设施、扩展设施及中间设施。仪器位置的选择旨在确保测量结果能够反映站点内典型土地利用分布下的环境条件。

SGP站点的持续观测辅以强化观测期（intensive observation periods）——在此期间，测量频率会提高，并增加特殊测量以解决特定研究问题。强化观测期内，每日生成的数据量约为2吉字节（GB，即20亿字节）或更多。无论在强化观测期还是平时，科学家们通常会携带自己的专用仪器前往SGP站点，停留时间一般为几周。