GHRSST Level 3P North Atlantic Regional Subskin Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on NOAA-19 (GDS version 1)

A Group for HIgh Resolution Sea Surface Temperature (GHRSST) dataset for the North Atlantic Region (NAR) from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-19 platform (launched 6 Feb 2009). This particular dataset is produced by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), Ocean and Sea Ice Satellite Application Facility (OSI SAF) in France. The AVHRR is a space-borne scanning sensor on the National Oceanic and Atmospheric Administration (NOAA) family of Polar Orbiting Environmental Satellites (POES) having a operational legacy that traces back to the Television Infrared Observation Satellite-N (TIROS-N) launched in 1978. 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 sea surface temperature (SST) sometimes in combination with the 3.5 micron channel. The highest ground resolution that can be obtained from the current AVHRR instruments is 1.1 km at nadir. 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 NAR products are SST fields derived from 1km AVHRR data that are re-mapped onto a 0.02 degree equal angle grid. In the processing chain, global AVHRR level 1b data are acquired at Centre de Meteorologie Spatiale (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 NOAA-19 SST L3P data are compliant with the Group for High Resolution SST (GHRSST) Data Specification (GDS) version 1.7.

北大西洋区域（North Atlantic Region, NAR）高分辨率海表温度工作组（Group for High Resolution Sea Surface Temperature, GHRSST）数据集，其数据源自搭载于NOAA-19平台（2009年2月6日发射）的先进甚高分辨率辐射计（Advanced Very High Resolution Radiometer, AVHRR）。该数据集由法国欧洲气象卫星开发组织（European Organization for the Exploitation of Meteorological Satellites, EUMETSAT）下属海洋与海冰卫星应用设施（Ocean and Sea Ice Satellite Application Facility, OSI SAF）制作。AVHRR是美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）极轨环境卫星（Polar Orbiting Environmental Satellites, POES）系列搭载的星载扫描传感器，其业务运行历史可追溯至1978年发射的电视红外观测卫星-N（Television Infrared Observation Satellite-N, TIROS-N）。AVHRR仪器可测量地球在5（或6）个较宽光谱波段的辐射亮度：前两个波段中心波长分别位于红光（0.6微米）和近红外（0.9微米）波段，第三个波段位于3.5微米附近，最后两个波段则分别采样11微米和12微米附近的地球热辐射。传统5波段构型的AVHRR被称为AVHRR/2，而最新的AVHRR/3（首次搭载于NOAA-15平台）新增了1.6微米的第6通道以获取观测数据。实际业务中通常利用11和12微米波段，有时结合3.5微米波段反演海表温度（Sea Surface Temperature, SST）。当前AVHRR仪器在星下点可获得的最高地面分辨率为1.1千米。MetOp-A平台为太阳同步轨道，由于AVHRR的扫描幅宽约2400千米，该平台通常每天可两次观测同一地球位置（观测频次随纬度变化）。北大西洋区域产品为由1千米分辨率AVHRR数据生成的海表温度场，并将其重映射至0.02度等角网格。在处理流程中，全球AVHRR的1b级数据通过EUMETSAT/EUMETCAST系统由空间气象中心（Centre de Meteorologie Spatiale, CMS）获取；随后将应用云掩膜，并通过多光谱技术从AVHRR红外波段反演得到海表温度。NOAA-19搭载传感器生成的SST L3P级数据，符合高分辨率海表温度工作组（GHRSST）数据规范（Data Specification, GDS）1.7版本要求。