ASI3 northern hemisphere swath brightness temperatures and gridded sea ice concentration

• Main Author: Lu, Junshen
• Format: Dataset
• Language: English
• Published: PANGAEA 2019
• Subjects: brightness temperatures; File format; File name; File size; sea ice concentration; Uniform resource locator/link to file; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.909683; https://doi.org/10.1594/PANGAEA.909683

Since the launch of the AMSR series satellites in 2002, brightness temperatures are observed at 89 GHz with a much improved spatial resolution at about 5 km. Ice concentration retrieval using measurements at this frequency can therefore reveal more detailed features such as leads. Brightness temperatures at 89 GHz are however more prone to atmospheric and surface influences from water vapor, liquid water path, wind and surface temperature, which leads to erroneous sea ice retrieval. We improve an 89 GHz sea ice retrieval method, the ARTIST Sea Ice (ASI) algorithm, by correcting the observed brightness temperatures for atmospheric influences before they are input to the algorithm. A new retrieval algorithm named ASI3 is developed based on the weather corrected brightness temperatures and newly identified open water (80 K) and sea ice (14 K) tie points. The most influencing component of this correction scheme is including liquid clouds, the largest weather influence contributor. The correction is carried out by simulating brightness temperatures through a radiative transfer model and geophysical data retrieved by an optimal estimation method. --- This data set contains the ASI3 swath weather corrected brightness temperatures and the ASI3 daily gridded sea ice concentration in the northern hemisphere above latitude 50N. The corrected brightness temperatures are based on the AMSR-E Level 2A spatially resampled data at the resolution of 18.7 GHz channel (21km). The sea ice concentration data are derived from the corrected 89 GHz brightness temperatures, gridded to polar stereographic projection at 6.25km resolution. Each swath corrected brightness temperature file is packaged with geolocation coordinates. The coordinates of the daily gridded ice concentration are packaged in one standalone file. File information - Format Data are in HDF5 format. The geolocaton data fields are in H5T_IEEE_F32LE format. All the other data fields are in H5T_IEEE_F64LE. - File Naming Convention 1. Corrected swath brightness temperature ...