Tropical Ocean-Global Atmosphere program
Encyclopedia
The Tropical Ocean Global Atmosphere program (TOGA) is a component of the World Climate Research Programme
(WCRP) aimed specifically at the prediction of climate
phenomena on time scales of months to years.
TOGA emphasizes the tropical
ocean
s and their relationship to the global atmosphere
. Underlying TOGA is the premise that the dynamic adjustment of the ocean in the tropics is far more rapid than at higher latitude
s. Thus disturbances emanating from the western Pacific Ocean
(such as El Niño) may propagate across the basin on time scales of weeks compared to years for corresponding basin-wide propagation at higher latitudes. The significance of shorter dynamic times scales near the equator
is that they are similar to those of highly energetic atmospheric modes. This similarity allows the formation of coupled modes between the ocean and the atmosphere.
In order to achieve the TOGA goals, a strategy of large-scale, long-term monitoring of the upper ocean and the atmosphere, intensive and very specific process-oriented studies, and modeling has been planned (WCRP, 1985) and enacted through a series of national, multinational and international efforts (e.g., NAS, 1986; WCRP, 1986). Modeling activities have been coordinated by TOGA Numerical Experimentation Group (TOGA NEG).
World Climate Research Programme
The World Climate Research Programme was established in 1980, under the joint sponsorship of International Council for Science and the World Meteorological Organization, and has also been sponsored by the Intergovernmental Oceanographic Commission of UNESCO since 1993. It is a component of the...
(WCRP) aimed specifically at the prediction of climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
phenomena on time scales of months to years.
TOGA emphasizes the tropical
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
s and their relationship to the global atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
. Underlying TOGA is the premise that the dynamic adjustment of the ocean in the tropics is far more rapid than at higher latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s. Thus disturbances emanating from the western Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
(such as El Niño) may propagate across the basin on time scales of weeks compared to years for corresponding basin-wide propagation at higher latitudes. The significance of shorter dynamic times scales near the equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
is that they are similar to those of highly energetic atmospheric modes. This similarity allows the formation of coupled modes between the ocean and the atmosphere.
Scientific objectives of TOGA
The specific goals and scientific objectives of TOGA are (WCRP, 1985);- To gain a description of the tropical oceans and the global atmosphere as a time dependant system in order to determine the extent to which the system is predictable on time scales of months to years and to understand the mechanisms and processes underlying its predictability.
- To study the feasibility of modeling the couple ocean-atmosphere system for the purpose of predicting its variation on time scales of months to years; and
- To provide the scientific background for designing an observing and data transmission system for operational predication, if this capability is demonstrated, by coupled ocean-atmosphere models.
In order to achieve the TOGA goals, a strategy of large-scale, long-term monitoring of the upper ocean and the atmosphere, intensive and very specific process-oriented studies, and modeling has been planned (WCRP, 1985) and enacted through a series of national, multinational and international efforts (e.g., NAS, 1986; WCRP, 1986). Modeling activities have been coordinated by TOGA Numerical Experimentation Group (TOGA NEG).