The Tropical Ocean Global Atmosphere program (TOGA) was a ten-year study (1985-1994) of the World Climate Research Programme (WCRP) aimed specifically at the prediction of climate phenomena on time scales of months to years.
TOGA emphasized the tropical oceans 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 latitudes. 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. TOGA was instrumental in developing a comprehensive observing system for the equatorial Pacific Ocean and laid important groundwork for ENSO prediction, data assimilation and understanding of air-sea interaction.
The roots of the TOGA program can be traced back to the 1920s and the work of Sir Gilbert Walker on what became known as the Southern Oscillation, an apparent linkage between atmospheric pressure anomalies throughout the Pacific Ocean that appeared to be a major driver of weather patterns.This work was furthered by Jacob Bjerknes in the 1960s when he solidified the link between the El Nino phenomena, a winter warm anomaly in the normally cool water off the coast of Peru, with the southern oscillation. The combined El Nino – Southern Oscillation, or ENSO, turned out to be a major contributor to seasonal climate variability with both human and economic implications. Study of these linked phenomena continued through the 1970s and 1980s via a variety observational and modeling studies which included the discovery of equatorial kelvin waves, a potential precursor to the ENSO phenomena.
This in mind, the World Climate Research Programme began to plan a decade long research initiative intended to understand ocean-atmosphere interaction in the tropical ocean basins. The goals of this program were solidified when in 1982-1983 a major El Nino event, at the time the strongest to date, struck without prior prediction or detection.This particularly strong event was punctuated by drought, flooding, extreme heat events, and severe storms. These events clearly defined a need for better predictive mechanisms for ENSO and the need for reliable real time data to support prediction.
TOGA was launched in 1985 with the intent of studying ocean and atmospheric variability in all three tropical ocean basins. The focus of the United States was in the Pacific Basin with funding being provided by the National Oceanic Atmospheric Association (NOAA), the National Science Foundation (NSF), and the National Aeronautics and Space Administration (NASA). The specific goals and scientific objectives of TOGA were;
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 were planned and enacted through a series of national, multinational and international efforts. Modeling activities were coordinated by TOGA Numerical Experimentation Group (TOGA NEG).
The TOGA program established an advanced ocean observing system to support research and forecasting of ENSO warm cycles. While traditional methods such as ships of opportunity and inland tide gauges were employed, the crowning achievement was the deploying of the Tropical Atmosphere Ocean (TAO) Array.
The TAO Array was a joint NOAA and Pacific Marine Environmental Laboratory (PMEL) venture consisting of 70 moored buoys stationed along the equatorial Pacific Ocean providing real-time wind, sea surface temperature, and deep ocean temperature data using the Autonomous Temperature Line Acquisition System (ATLAS).
Further, scientists in the program made use of a host of satellite derived products even though they were not specifically created for the program. Of most importance was the NOAA Advanced Very High Resolution Radiometer (AVHRR) for sea surface temperature, the Topography Experiment (TOPEX)/Poseidon for sea surface height and various defense passive microwave satellites for wind speed measurements.
All together, the combination of both satellite and in situ data with real time access proved critical to the success of the program.
From 1992 to 1993, a special field project known as the Coupled Ocean Atmosphere Research Experiment (TOGA-COARE) was conducted. The four-month effort included 1200 people, over 16,000 ship hours, 125 aircraft flights and the release of 12,000 radiosondes. Its primary mission was to examine the western pacific warming pool region specifically for:
The TOGA-COARE experiment resulted in improved understanding of atmospheric and oceanic variability on interseasonal scales including phenomena such as the Madden–Julian oscillation and westerly wind bursts. Further, the COARE program provided improvements in model parameterization for cumulus clouds, ocean mixing, and air-sea fluxes.
The TOGA program directly resulted in improved theoretical understanding of the ENSO cycle, including interactions between trade wind variations and sea surface temperature. Further it helped explain the evolution, development, and decay of ENSO events.
As a result of TOGA, seasonal forecasts models (both statistical and dynamical) were developed. The improvement of which resulted in the first successful ENSO prediction in 1986 and yearly forecasts being produced before the end of the program.
The impacts of TOGA extended beyond purely scientific findings but changed the way work was conducted within the oceanography and meteorology fields. The TOGA program forged new cooperation between and oceanographers and meteorologists and fostered a new culture of open data access. Rather than each research collecting and using their own data, data was now freely available to all in real time.
Perhaps the greatest success of TOGA program was the successful prediction and monitoring of the 1997-1998 El Nino, one of the largest El Nino events in history. Only with the findings and data collection methods set forth during the TOGA program would such operational success be possible.
El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific, including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. El Niño phases are known to last close to four years, however, records demonstrate that the cycles have lasted between two and seven years. During the development of El Niño, rainfall develops between September–November. The cool phase of ENSO is La Niña, with SSTs in the eastern Pacific below average, and air pressure high in the eastern Pacific and low in the western Pacific. The ENSO cycle, including both El Niño and La Niña, causes global changes in temperature and rainfall.
La Niña is an oceanic and atmospheric phenomenon that is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. The name La Niña originates from Spanish for "the little girl", by analogy to El Niño, meaning "the little boy". In the past, it was also called an anti-El Niño and El Viejo, meaning "the old man".
Climatology or climate science is the scientific study of climate, scientifically defined as weather conditions averaged over a period of time. This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography, which is one of the Earth sciences. Climatology now includes aspects of oceanography and biogeochemistry.
El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. The Southern Oscillation is the accompanying atmospheric component, coupled with the sea temperature change: El Niño is accompanied by high air surface pressure in the tropical western Pacific and La Niña with low air surface pressure there. The two periods last several months each and typically occur every few years with varying intensity per period.
The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal time scales. There is evidence of reversals in the prevailing polarity of the oscillation occurring around 1925, 1947, and 1977; the last two reversals corresponded with dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California.
The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric Research (NCAR). It is a large-scale coupling between atmospheric circulation and tropical deep atmospheric convection. Unlike a standing pattern like the El Niño–Southern Oscillation (ENSO), the Madden–Julian oscillation is a traveling pattern that propagates eastward, at approximately 4 to 8 m/s, through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself most clearly as anomalous rainfall.
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
Upper-atmospheric models are simulations of the Earth's atmosphere between 20 and 100 km that comprises the stratosphere, mesosphere, and the lower thermosphere. Whereas most climate models simulate a region of the Earth's atmosphere from the surface to the stratopause, there also exist numerical models which simulate the wind, temperature and composition of the Earth's tenuous upper atmosphere, from the mesosphere to the exosphere, including the ionosphere. This region is affected strongly by the 11 year Solar cycle through variations in solar UV/EUV/Xray radiation and solar wind leading to high latitude particle precipitation and aurora. It has been proposed that these phenomena may have an effect on the lower atmosphere, and should therefore be included in simulations of climate change. For this reason there has been a drive in recent years to create whole atmosphere models to investigate whether or not this is the case.
Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which temperate cyclogenesis occurs. Tropical cyclogenesis involves the development of a warm-core cyclone, due to significant convection in a favorable atmospheric environment.
Sverdrup Gold Medal Award - is the American Meteorological Society's award granted to researchers who make outstanding contributions to the scientific knowledge of interactions between the oceans and the atmosphere.
The Atlantic Equatorial Mode or Atlantic Niño is a quasiperiodic interannual climate pattern of the equatorial Atlantic Ocean. It is the dominant mode of year-to-year variability that results in alternating warming and cooling episodes of sea surface temperatures accompanied by changes in atmospheric circulation. The term Atlantic Niño comes from its close similarity with the El Niño-Southern Oscillation (ENSO) that dominates the tropical Pacific basin. For this reason, the Atlantic Niño is often called the little brother of El Niño. The Atlantic Niño usually appears in northern summer, and is not the same as the Atlantic Meridional (Interhemispheric) Mode that consists of a north-south dipole across the equator and operates more during northern spring. The equatorial warming and cooling events associated with the Atlantic Niño are known to be strongly related to rainfall variability over the surrounding continents, especially in West African countries bordering the Gulf of Guinea. Therefore, understanding of the Atlantic Niño has important implications for climate prediction in those regions. Although the Atlantic Niño is an intrinsic mode to the equatorial Atlantic, there may be a tenuous causal relationship between ENSO and the Atlantic Niño in some circumstances.
The Tropical Atlantic SST Dipole refers to a cross-equatorial sea surface temperature (SST) pattern that appears dominant on decadal timescales. It has a period of about 12 years, with the SST anomalies manifesting their most pronounced features around 10–15 degrees of latitude off of the Equator. It is also referred to as the interhemispheric SST gradient or the Meridional Atlantic mode.
The Tropical Atmosphere Ocean (TAO) project is a major international effort that instrumented the entire tropical Pacific Ocean with approximately 70 deep ocean moorings. The development of the TAO array in 1985 was motivated by the 1982-1983 El Niño event and ultimately designed for the study of year-to-year climate variations related to El Niño and the Southern Oscillation (ENSO). Led by the TAO Project Office of the Pacific Marine Environmental Laboratory (PMEL), the full array of 70 moorings was completed in 1994.
The Tuvalu Meteorological Service (TMS) is the principal meteorological observatory of Tuvalu and is responsible for providing weather services to the islands of Tuvalu. A meteorological office was established on Funafuti at the time the islands of Tuvalu were administered as parts of the Gilbert and Ellice Islands colony of the United Kingdom. The meteorological office is now an agency of the government of Tuvalu.
Paul Rowland Julian, a Fellow of the American Meteorological Society, is an American meteorologist who served as a longtime staff scientist at the National Center for Atmospheric Research (NCAR), was co-author with Roland Madden of the study establishing the Madden–Julian oscillation (MJO), and contributed to the international, multi-institutional Global Atmospheric Research Program (GARP), Tropical Wind, Energy Conversion, and Reference Level Experiment (TWERLE), and Tropical Ocean-Global Atmosphere (TOGA) meteorology research programs. The MJO meteorologic phenomenon he co-discovered is the largest element of the intraseasonal variability in the tropical atmosphere, a traveling pattern arising from large-scale coupling between atmospheric circulation and tropical deep convection. Description of the MJO remains an important contribution to climate research with relevance to modern short- and long-term weather and climate modeling.
The 2014–16 El Niño was a warming of the eastern equatorial Pacific Ocean that resulted in unusually warm waters developing between the coast of South America and the International Date Line. These unusually warm waters influenced the world's weather in a number of ways, which in turn significantly affected various parts of the world. These included drought conditions in Venezuela, Australia and a number of Pacific islands while significant flooding was also recorded. During the event, more tropical cyclones than normal occurred within the Pacific Ocean, while fewer than normal occurred in the Atlantic Ocean.
A westerly wind burst is a phenomenon commonly associated with El Niño events, whereby the typical east-to-west trade winds across the equatorial Pacific shift to west-to-east. A westerly wind burst is defined by Harrison and Vecchi (1997) as sustained winds of 25 km/h (16 mph) over a period of 5–20 days. However, no concrete definition has been determined, with Tziperman and Yu (2007) defining them as having winds of 14 km/h (8.7 mph) and lasting "at least a few days". On average, three of these events take place each year, but are significantly more common during El Niño years. They have been linked to various mesoscale phenomena, including tropical cyclones, mid-latitude cold surges, and the Madden–Julian oscillation. Their connection with Kelvin waves also indicate a connection with the onset of El Niño events, with every major occurrence since the 1950s featuring a westerly wind burst upon their onset.
Axel Timmermann is a German climate physicist and oceanographer with an interest in climate dynamics, human migration, dynamical systems' analysis, ice-sheet modeling and sea level. He served a co-author of the IPCC Third Assessment Report and a lead author of IPCC Fifth Assessment Report. His research has been cited over 18,000 times and has an h-index of 70 and i10-index of 161. In 2017, he became a Distinguished Professor at Pusan National University and the founding Director of the Institute for Basic Science Center for Climate Physics. In December 2018, the Center began to utilize a 1.43-petaflop Cray XC50 supercomputer, named Aleph, for climate physics research.
During 2014, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 117 tropical cyclones had formed this year to date. 79 tropical cyclones had been named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC). The most active basin in 2014 was the Western Pacific, which documented 23 named systems, while the Eastern Pacific, despite only amounting to 22 named systems, was its basin's most active since 1992. Conversely, both the North Atlantic hurricane and North Indian Ocean cyclone seasons experienced the fewest cyclones reaching tropical storm intensity in recorded history, numbering 9 and 3, respectively. Activity across the southern hemisphere's three basins—South-West Indian, Australian, and South Pacific—was spread evenly, with each region recording seven named storms apiece.
Pacific Meridional Mode (PMM) is a climate mode in the North Pacific. In its positive state, it is characterized by the coupling of weaker trade winds in the northeast Pacific Ocean between Hawaii and Baja California with decreased evaporation over the ocean, thus increasing sea surface temperatures (SST); and the reverse during its negative state. This coupling develops during the winter months and spreads southwestward towards the equator and the central and western Pacific during spring, until it reaches the Intertropical Convergence Zone (ITCZ), which tends to shift north in response to a positive PMM.