Skip all navigation and jump to content Jump to site navigation
NASA Logo - Goddard Space Flight Center

+ NASA Homepage

    
Goddard Space Flight Center
About MODIS News Data Tools /images2 Science Team Science Team Science Team

   + Home
ABOUT MODIS
MODIS Publications Link
MODIS Presentations Link
MODIS Biographies Link
MODIS Science Team Meetings Link
 

 

 

Gao, BC, Kaufman, YJ (2003). Water vapor retrievals using moderate resolution Imaging spectroradiometer (MODIS) near-infrared channels. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D13), 4389.

Abstract
[1] At present, two Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on board the NASA Terra and Aqua Spacecraft platforms are operational for global remote sensing of the land, ocean, and atmosphere. In this paper, we describe an algorithm for water vapor derivations using several MODIS near-IR channels. The derivations are made over areas that have reflective surfaces in the near-IR, such as clear land areas, clouds, and oceanic areas with Sun glint. The algorithm relies on observations of water vapor attenuation of near-IR solar radiation reflected by surfaces and clouds. Techniques employing ratios of water vapor absorbing channels centered near 0.905, 0.936, and 0.940 mm with atmospheric window channels at 0.865 and 1.24 mm are used. The ratios partially remove the effects of variation of surface reflectance with wavelengths and result in the atmospheric water vapor transmittances. The column water vapor amounts are derived from the transmittances based on theoretical calculations and using lookup table procedures. Typical errors in the derived water vapor values are in the range between 5% and 10%. The daily pixel-based'' near-IR water vapor product, which is a standard MODIS level 2 data product, at the 1-km spatial resolution of the MODIS instrument, and the daily, 8-day, and monthly near-IR water vapor products, which are standard MODIS level 3 products, at a 1degrees by 1degrees latitude-longitude grid globally are now routinely produced at a NASA computing facility. We present samples of water vapor images and comparisons to ground-based measurements by microwave radiometers.

DOI:
10.1029/2002JD003023

ISSN:
0148-0227

FirstGov logo Privacy Policy and Important Notices NASA logo

Curator: Brandon Maccherone
NASA Official: Shannell Frazier

NASA Home Page Goddard Space Flight Center Home Page