Rain Rate, Water Vapor and 85 GHz Tb -- SSM/I

The rain rate over land and ocean is based on the 85 GHz scattering index as defined by Ferraro et al. The 85 GHZ scattering index (SI85) is defined by


Oceanic:

SI85=-174.4+0.715*TB19v+2.439*TB22v-0.00504*TB22v*TB22v-TB85v


Land:

SI85=451.9-0.44*TB19v-1.775*TB22v+0.00574*TB22v*TB22v-TB85v

when 100< TB19v <300 and 80< TB85v <300. Surfaces that have microwave signatures similar to that of rain need to be identified and removed for accurate rain rate retrieval. Over the ocean, the contamination from sea ice needs to be removed, while over land surfaces the problem is more complex. The highly variable nature of land surfaces requires checks for snowcover, deserts and semi-arid regions.

This data is considered to be of research quality, and the presented rain rates should not be considered absolute. Returned rain rates greater than 35 mm/hr were set to the maximum of 35 mm/hr.

Rain Rates

Today's Orbits Updated at 0600, 1200, 18:00, and 2400 GMT
Ascending passes for F10, F11 and F13 using data from update time - 18 hours
Rain rate -- 0600 GMT
Rain rate -- 1200 GMT
Rain rate -- 1800 GMT
Rain rate -- 2400 GMT


Descending passes for F10, F11 and F13 using data from update time - 18 hours
Rain rate -- 0600 GMT
Rain rate -- 1200 GMT
Rain rate -- 1800 GMT
Rain rate -- 2400 GMT

Water Vapor

Today's Orbits Updated at 0600, 1200, 18:00, and 2400 GMT
Ascending passes for F10, F11 and F13 using data from update time - 18 hours
Water Vapor -- 0600 GMT
Water Vapor -- 1200 GMT
Water Vapor -- 1800 GMT
Water Vapor -- 2400 GMT


Descending passes for F10, F11 and F13 using data from update time - 18 hours
Water Vapor -- 0600 GMT
Water Vapor -- 1200 GMT
Water Vapor -- 1800 GMT
Water Vapor -- 2400 GMT

85 GHz Brightness Temperature (vertical)

Today's Orbits Updated at 0600, 1200, 18:00, and 2400 GMT
Ascending passes for F10, F11 and F13 using data from update time - 18 hours
85 GHz Tb (v) -- 0600 GMT
85 GHz Tb (v) -- 1200 GMT
85 GHz Tb (v) -- 1800 GMT
85 GHz Tb (v) -- 2400 GMT


Descending passes for F10, F11 and F13 using data from update time - 18 hours
85 GHz Tb (v) -- 0600 GMT
85 GHz Tb (v) -- 1200 GMT
85 GHz Tb (v) -- 1800 GMT
85 GHz Tb (v) -- 2400 GMT

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