Water vapor is a small but significant constituent of the atmosphere, warming the planet due to the greenhouse effect and condensing to form clouds which both warm and cool the Earth in different circumstances. A key feature of global atmospheric water vapor convection is the Intertropical Convergence Zone, the low pressure region within five degrees of the equator where the trade winds converge and solar heating of the atmosphere forces the water-laden air to rise in altitude, form clouds, and then precipitate as rain in the afternoon. This visualization shows the global water vapor distribution in gray and white and the global precipitation in yellow every hour from August 30, 1998 to September 20, 1998. The afternoon thunderstorms in the tropics are seen as a flashing yellow region that moves from east to west, following the sun. This is a La Nina period, when the water to the west of South America is cooler than normal, forcing the atmosphere there to cool down and hold less water. Strong east-to-west winds can be seen in this region, contributing to the high water vapor region that forms further to the west over southeast Asia, the Philippines, and Indonesia, causing increased humidity and rainfall in that region. This data is from the Goddard Earth Modeling System, a coupled land-ocean-atmosphere model which uses earth and satellite-based observations to simulate the Earths physical system during events such as La Nina.

An animation of sea surface temperature, sea surface height, and sea temperature at depth in the Pacific Ocean from July 1997 through November 1998 as measured by NOAA AVHRR, TOPEX Poseidon, and the TAO TRITON Array

Sea surface temperature anomaly in color, sea surface height anomalies in height

An animation of sea surface temperature anomaly, sea surface height anomaly, and sea temperature anomaly at depth in the Pacific Ocean from January 1997 through December 1999 as measured by NOAA AVHRR, TOPEX Poseidon, and the TAO TRITON Array

An animation of sea surface temperature anomaly, sea surface height anomaly, and sea temperature anomaly at depth in the Pacific Ocean from January 1997 through February 1999 as measured by NOAA AVHRR, TOPEX Poseidon, and the TAO TRITON Array

An animation of sea surface temperature anomaly, sea surface height anomaly, and sea temperature anomaly at depth in the Pacific Ocean from July 1997 through November 1998 as measured by NOAA AVHRR, TOPEX Poseidon, and the TAO TRITON Array

Sea Surface Height Anomaly for the Equatorial Pacific region from June, 1997, to June, 1998.

An animation of sea surface height anomaly in the Pacific Ocean from December, 1997, to April, 2000, as measured by TOPEX-Poseidon

An animation of sea surface height anomaly in the Pacific Ocean from January 1997 to December 1999 as measured by TOPEX-Poseidon

An animation of sea surface height anomaly in the Pacific Ocean from January 1997 to February 1999 as measured by TOPEX-Poseidon

An animation of sea surface height anomaly in the Pacific Ocean from January 1997 to November 1998 as measured by TOPEX-Poseidon

An animation of sea surface temperature, height, and wind anomalies in the Pacific for January 1997 through August 1998. (Wind anomalies stop at May 1998.)

An animation of sea surface temperature and height anomalies in the Pacific for January 1997 through August 1998 from NOAA AVHRR and TOPEX Poseidon

An animation of sea surface temperature and height anomalies in the Pacific for January 1997 through August 1998 from NOAA AVHRR and TOPEX Poseidon

Isomorphic view of El Nino. Sea surface temperature anomalies are colors, with red being warmer than normal and blue being colder than normal, and sea surface height anomalies are exaggerated heights.

An animation of sea surface temperature and height anomalies in the Pacific for January 1997 through November 1998 from NOAA AVHRR and TOPEX Poseidon

An animation of sea surface temperature and height anomalies in the Pacific for January 1997 through November 1998 from NOAA AVHRR and TOPEX Poseidon

A view of El Nino and La Nina through Pacific sea surface temperature anomalies from 1998 through 2001.

A comparison of the Pacific sea surface temperature anomaly during the El Nino of 1982-1983 with that of 1997-1998, as measured by NOAA AVHRR