ADEOS-II/GLI L2 Snow Grain and Impurities

Product Summary

ADEOS-II/GLI L2 Snow Grain and Impurities is obtained from the GLI (Global-Imager) sensor onboard ADEOS-II and produced by the Japan Aerospace Exploration Agency (JAXA). Global environment change has become a worldwide concern in recent years. In order to clarify these environmental changes, the Advanced Earth Observing Satellite (ADEOS-II, renamed "Midori II" after launch) has been developed for the purpose of monitoring the Earth environment using remote sensing technology from space. Midori II carries mission instruments that are particularly dedicated to clarify the water energy cycle and the carbon cycle, and is expected to be utilized for international climate change research programs.
GLI an optical sensor that observes the reflected solar radiation from the Earth's surface, including land, oceans and clouds and/or infrared radiation with a multi-channel system for measuring the biological content. The SGLI has a swath of 1600 km.
This product includes snow grain size retrieved with 865nm and 1640nm band, Snow impurities as soot, Snow surface temperature, Surface classification flag.
Snow grain size retrieved with 865nm is using GLI channels 5 (0.46 μm) and 19 (0.865 μm), is based on the principle that the reflectance of snow is known to be dependent on snow grain size in the near infra-red (NIR) range and pollution in the visible range. It can be applied at high latitude (polar) as well as mid-latitude regions. The physical quantity is micro meter.
Snow grain size retrieved with 1640nm is using GLI channel 28 (1.64 μm) independently to retrieve snow grain size at very top surface. The physical quantity is micro meter. Snow impurities applies lookup tables have been constructed by using atmospheric optical properties obtained from MODTRAN in conjunction with the DISORT radiative transfer code.
The bi-directional reflectance of snow is taken into account. In the lookup tables the radiances that would be measured by the satellite instrument are simulated as a function of snow grain size and mass fraction of soot mixed in the snow. The snow grain size and mass fraction of soot are obtained by requiring the simulated radiances to be consistent with the measured ones in both GLI channel 5 and 19. The physical quantity is ppmw.
Snow surface temperature is retrieving the sea surface temperature (SST) for an area consisting of a mixture of snow/ice and melt ponds, and the snow/ice surface temperature (IST) for ocean areas covered by snow/ice. This product is only for the polar regions and for the use with GLI channel 35 and 36. The physical quantity is Kelvin.
Surface classification flag uses L2A_LC data in channels 8,13, 17, 19, 24, 27, 30, 31, 34, 35 and 36 is used as input to this product. The output of the cloudy/clear and snow/sea-ice discriminator algorithm will be an 8-bit word for each field of view. It includes information about whether a view of the surface is obstructed by cloud and the surface type for each pixel. There are four levels of confidence to indicate whether a pixel is judged to be cloudy or clear. The physical quantity is dimensionless.
The provided format is HDF. Map projection is EQR and PS. Generation unit is zone. The spatial resolution is 1 km and the statistical period is 16 days. The current version of the product is "Version 2".

Platform

ADEOS-II

Sensor

GLI

Coverage

Temporal Coverage

2003-01-24 to 2003-10-25

Spatial Coverage

Bounding Rectangle
(90.0°, -180.0°, -90.0°, 180.0°)

Resolution

1 km

Location

• GEOGRAPHIC REGION > GLOBAL LAND