GHRSST Level 2P Global Subskin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the MetOp-A satellite (GDS2 version) for 2016-05-21 (NCEI Accession 0154420)

A global 1 km Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in real-time from the Advanced Very High Resolution Radiometer (AVHRR) on the European Meteorological Operational-A (MetOp-A)satellite (launched 19 Oct 2006). The MetOp satellite program is a European undertaking providing weather data services for monitoring climate and improving weather forecasts. It was jointly established by the European Space Agency (ESA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) with a contribution by the US National Oceanic and Atmospheric Administration (NOAA) of an AVHRR sensor identical to those flying on the family of Polar Orbiting Environmental Satellites (POES). AVHRR instruments measure the radiance of the Earth in 5 (or 6) relatively wide spectral bands. The first two are centered around the red (0.6 micrometer) and near-infrared (0.9 micrometer) regions, the third one is located around 3.5 micrometer, and the last two sample the emitted thermal radiation, around 11 and 12 micrometers, respectively. The legacy 5 band instrument is known as AVHRR/2 while the more recent version, the AVHRR/3 (first carried on the NOAA-15 platform), acquires data in a 6th channel located at 1.6 micrometer. Typically the 11 and 12 micron channels are used to derive SST sometimes in combination with the 3.5 micron channel. The MetOp-A platform is sun synchronous generally viewing the same earth location twice a day (latitude dependent) due to the relatively large AVHRR swath of approximately 2400 km. The highest ground resolution that can be obtained from the current AVHRR instruments is 1.1 km at nadir. The production of the MetOp-A L2P SST data is done by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), Ocean and Sea Ice Satellite Application Facility (OSI SAF) at Meteo-France/Centre de Meteorologie Spatiale (CMS) in France. In the processing chain, global AVHRR level 1b data are acquired at CMS through the EUMETSAT/EUMETCAST system. A cloud mask is applied and SST is retrieved from the AVHRR infrared (IR) channels by using a multispectral technique. The MetOp-A SST L2P data consist of global coverage at 1.1 km (nadir) resolution separated into three minute observation granules, and are compliant with the GHRSST Data Processing Specification (GDS) version 2 format specifications.

本数据集为一套全球1公里分辨率的高分辨率海表温度工作组（Group for High Resolution Sea Surface Temperature, GHRSST）2P级数据集，其基于多通道海表面温度（Sea Surface Temperature, SST）反演结果，由搭载于欧洲气象业务-A（MetOp-A）卫星（2006年10月19日发射）的先进甚高分辨率辐射计（Advanced Very High Resolution Radiometer, AVHRR）实时生成。MetOp卫星计划是一项欧洲工程，旨在提供气象数据服务以支撑气候监测与天气预报优化。该计划由欧洲空间局（European Space Agency, ESA）与欧洲气象卫星应用组织（European Organisation for the Exploitation of Meteorological Satellites, EUMETSAT）联合发起，美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）提供了一套与极轨环境卫星（Polar Orbiting Environmental Satellites, POES）系列搭载的同款AVHRR传感器。AVHRR仪器可在5（或6）个相对较宽的光谱波段内测量地球辐射亮度：前两个波段分别以红光（0.6微米）和近红外（0.9微米）波段为中心，第三个波段中心位于3.5微米附近，最后两个波段分别采样11微米和12微米附近的热辐射。经典的5波段仪器被称为AVHRR/2，而最新的AVHRR/3（首次搭载于NOAA-15卫星平台）则新增了1.6微米的第6波段。实际反演SST时，通常会利用11微米和12微米波段，有时也会结合3.5微米波段。MetOp-A卫星平台为太阳同步轨道，由于AVHRR的刈幅宽度约为2400公里，因此通常每天可两次观测到同一地球位置（观测频次随纬度变化）。当前AVHRR仪器在星下点处可获得的最高地面分辨率为1.1公里。MetOp-A的L2P级SST数据由法国国家气象局/空间气象中心（Centre de Meteorologie Spatiale, CMS）内的欧洲气象卫星应用组织（EUMETSAT）海洋与海冰卫星应用设施（Ocean and Sea Ice Satellite Application Facility, OSI SAF）负责生产。在数据处理流程中，空间气象中心通过EUMETSAT/EUMETCAST系统获取全球AVHRR 1b级数据，随后执行云掩膜处理，并通过多光谱技术从AVHRR红外（Infrared, IR）波段反演得到SST。MetOp-A SST L2P级数据采用全球覆盖模式，星下点分辨率为1.1公里，数据被分割为3分钟时长的观测分块，且符合GHRSST数据处理规范（GHRSST Data Processing Specification, GDS）2.0版本的格式要求。