Daily Global Brightness Temperature at 89GHz from AMSR2

Brightness temperature measurements at 89GHz are derived from the AMSR2 sensor aboard the JAXA GCOM-W satellite. Data represents daily statistical mean values on a 0.1-degree global grid, calculated separately for ascending and descending satellite tracks. The Japan Aerospace Exploration Agency (JAXA) produces this dataset, with observations beginning after the satellite's launch in May 2012.

Use Cases

• Analyzing daily brightness temperature trends for horizontal (Brightness_Temperature_(H)) and vertical (Brightness_Temperature_(V)) polarizations to study surface emissivity changes.
• Mapping global sea ice concentration by utilizing the 89GHz brightness temperature channel, which is sensitive to ice surface properties.
• Detecting precipitation events over oceans by identifying specific signatures in the 89GHz brightness temperature data within the observation swath.
• Validating atmospheric reanalysis models by comparing modeled microwave emissions with the observed daily statistical mean brightness temperature values.
• Studiating land surface temperature and soil moisture in arid regions using the differential response captured in the dual-polarization 89GHz data.

Strengths

• Global coverage with a 1450 km observation swath from the AMSR2 sensor.
• Data provided on a consistent 0.1-degree latitude/longitude grid for spatial analysis.
• Includes separate calculations for ascending and descending satellite tracks, allowing for diurnal cycle analysis.
• Clear data quality flags with defined missing (65535) and error (65531-65534) values.

Limitations

• The dataset's temporal coverage and recency are unspecified, potentially limiting analysis of recent events.
• The simple arithmetic mean used for daily and monthly aggregation may smooth out extreme events or sub-daily variability.
• The spatial resolution of 0.1 degrees (~11 km) may be too coarse for applications requiring fine-scale feature detection.

Provenance

Source

Japan Aerospace Exploration Agency (JAXA), from the AMSR2 sensor on the GCOM-W satellite.

Collection Method

Level 3 processing applies a simple arithmetic mean to one day's worth of Level 1B and Level 2 data to calculate daily statistical mean brightness temperature at each grid point.

Time Range

Observations began after the satellite launch on May 18, 2012; specific end date not provided.

Freshness

Daily statistical period; update frequency not specified.

Geography

Global coverage.