AVHRR Interim Climate Data Record based on CLARA-A2 methods - Multimission

The Interim Climate Data Record (ICDR) AVHRR provides a routinely generated continuation of the product suite of the CLARA-A2.1 climate data record (CM SAF cLoud, Albedo and RAdiation products - AVHRR-based, edition 2.1, DOI: 10.5676/EUM_SAF_CM/CLARA_AVHRR/V002_01), which in turn is an update and extension of the CLARA-A2 climate data record. The ICDR products are generated and published within five days of the corresponding observations. The ICDR AVHRR features a range of cloud, surface albedo and surface radiation products derived from the AVHRR instruments onboard polar orbiting NOAA and METOP satellites, which are consistent with the heritage record CLARA-A2.1. The cloud products comprise cloud fraction, cloud top temperature/pressure/height, cloud thermodynamic phase, and (for liquid and ice clouds separately) cloud optical thickness, cloud particle effective radius and cloud water path. They are available as monthly and daily averages. Surface albedo is presented as monthly and pentad (5 day) averages of the broadband black-sky albedo and is derived using all available data during the studied period. Surface radiation is provided as monthly and daily averages for the downwelling shortwave component. All monthly, pentad and daily averages are available on a 0.25°x0.25° global grid. Surface albedo and cloud products are also provided in two equal area grids with a resolution of 25 km x 25 km covering the polar regions.临时气候数据记录（Interim Climate Data Record, ICDR）先进甚高分辨率辐射计（Advanced Very High Resolution Radiometer, AVHRR）数据集，是CLARA-A2.1气候数据记录（CM SAF云、反照率与辐射产品——基于AVHRR的2.1版，DOI: 10.5676/EUM_SAF_CM/CLARA_AVHRR/V002_01）产品系列的常规延续版本；而CLARA-A2.1本身又是对CLARA-A2气候数据记录的更新与扩展。ICDR产品将在对应观测数据生成后的五天内完成制作并发布。ICDR AVHRR数据集包含一系列基于极轨NOAA（美国国家海洋和大气管理局，National Oceanic and Atmospheric Administration）卫星与METOP（气象业务卫星，Meteorological Operational Satellite）卫星搭载的AVHRR仪器获取的云、地表反照率及地表辐射产品，其与前代CLARA-A2.1数据集保持一致性。云产品涵盖云量、云顶温度/气压/高度、云热力学相态，以及分别针对液态云与冰晶云的云光学厚度、云粒子有效半径与云水路径，该类产品以日平均与月平均数据形式提供。地表反照率以月平均与五日平均的宽带黑空反照率形式呈现，其推导基于研究时段内的全部可用观测数据。地表辐射则以日平均与月平均的下行短波辐射分量形式提供。所有月平均、五日平均与日平均数据均采用0.25°×0.25°的全球格网发布。此外，地表反照率与云产品还提供两种分辨率为25 km×25 km的等面积格网数据，覆盖极地地区。