Daily Global Brightness Temperature at 18GHz from AMSR2 Satellite

GCOM-W/AMSR2 L3 Brightness Temperature (18Ghz) dataset provides daily averaged microwave brightness temperature measurements at 18GHz from the AMSR2 sensor onboard the GCOM-W satellite. Japan Aerospace Exploration Agency (JAXA) produces this data, which is calculated as a simple arithmetic mean over a 0.25-degree global grid for each day. The satellite was launched in May 2012, and the dataset includes separate calculations for ascending and descending satellite tracks.

Use Cases

• Monitor sea surface temperature anomalies and ice concentration by analyzing Brightness_Temperature_(H) and Brightness_Temperature_(V) polarization differences over ocean and polar grids.
• Assess data quality and uncertainty for climate records by examining the Standard_Deviation field available in the monthly product.
• Identify regions with sparse observational coverage by checking the Total_Number and Average_Number columns per grid cell.
• Detect sensor errors or data gaps in the time series by filtering for the specific error values (65531 to 65534) and missing value (65535).
• Create composite global maps of microwave emissions by merging daily Brightness_Temperature data from the EQR (equi-rectangular) and PS (polar stereo) projection products.

Strengths

• Global spatial coverage with a 0.25-degree grid resolution.
• Separate data layers for horizontal (H) and vertical (V) polarization at 18GHz.
• Includes statistical metrics like standard deviation and sample counts for quality assessment.
• Data is part of a long-term record from a sensor launched in 2012, supporting climate studies.

Limitations

• Specific temporal coverage (start/end dates) and total row count are not provided in the input.
• Daily product lacks the Standard_Deviation column, which is only available in the monthly aggregated version.
• Data uses specific missing (65535) and error (65531-65534) values that require filtering during analysis.

Provenance

Source

Japan Aerospace Exploration Agency (JAXA)

Collection Method

Calculated from Level 1B and Level 2 sensor data from the AMSR2 microwave radiometer on the GCOM-W satellite, using a simple arithmetic mean for daily and monthly grids.

Time Range

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Freshness

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Geography

Global