A multi-sensor, 6-hourly atmospheric water vapor product is scheduled to be released in late 2006.
Atmospheric water vapor is a measure of the total gaseous water contained in a vertical column of atmosphere. Similar to specific humidity, it is quite different from the more familiar relative humidity, which is the amount of water vapor in air relative to the amount of water vapor the air is capable of dissolving. Atmospheric water vapor is the absolute amount of water dissolved in air. When measured in linear units (milimeters), it is the height (or depth) the water would occupy if the vapor were condensed into liquid and spread evenly across the column.
It is important to measure water vapor carefully, as it is Earth’s primary greenhouse gas, and is fundamental to our planet’s hydrologic cycle.
Currently available water vapor products
| SSM/I |  www.remss.com/ssmi |
1987 – present |
| TMI | www.remss.com/tmi |
1997 – present |
| AMSR-E | www.remss.com/amsre |
2002 – present |
