The Korea Meteorological Administration (KMA) has announced that Atmospheric Motion Vector (AMV) and Clear Sky Radiance (CSR) products from the Geostationary Earth Orbit–Korea Multi-Purpose Satellite–2A (GK-2A)’s observation data will be released on the Global Telecommunication System (GTS) from 25 June 2020. The file format of the AMV and CSR output is the Binary Universal Form for the Representation of meteorological data (BUFR). Preliminary results from our test on the KMA’s Numerical Weather Prediction (NWP) system have shown that the GK-2A’s AMV and CSR data have positive effects.

The GK-2A is Korea’s second geostationary meteorological satellite launched on 4 December 2018. It has an Advanced Meteorological Imager (AMI) with 16 channels. KMA has been officially operating the GK-2A since July 2019. KMA wanted to distribute the AMV and CSR products first, and in the future All Sky Radiance (ASR) product will also be added on the GTS.

Please refer to the following sections for a brief explanation of the AMV and CSR data.

For more information, please contact JaeGwan Kim (kimjgwan@korea.kr).

1. GK-2A’s AMV data

The GK-2A’s AMV product is defined as the output of the atmospheric movement obtained by tracking clouds or water vapor fields with the satellite. To calculate the motion vectors, consecutive three images are used in a time series.

■ GK-2A AMV product information for BUFR file

▷ WMO BUFR Master table version: 32 (Table Reference: 310077)

▷ Channels: VIS (0.6 ㎛), SWIR (3.8 ㎛), WV (6.3, 6.9, 7.3 ㎛), IR (10.5, 11.2 ㎛)

▷ Spatial Resolution: 24 x 24 km² for VIS, 32 x 32 km² for SWIR, WV, and IR

▷ AMV Product Temporal Resolution: 30 minutes

▷ Observation Mode: Full Disk

▷ Satellite Orbit: 128.2E GEO

▷ Valid Output Area: Satellite (Viewing) Zenith Angle within 70 degrees

▷ Major Components of Subset: Wind Direction, Wind Speed, Height Assignment Method, Pressure, QI Index, Satellite Zenith Angle, Solar Zenith Angle, etc.

▷ File Division

1. Classified by channels

2. Bulletin header: INVN##_RKSL for northern hemisphere,

INVS##_RKSL for southern hemisphere

■ Sample images