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60-492: 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

120-683: A radio direction finder or GPS . The weight of a radiosonde is typically 250 g (8.8 oz). Sometimes radiosondes are deployed by being dropped from an aircraft instead of being carried aloft by a balloon. Radiosondes deployed in this way are called dropsondes . Radiosondes weather balloons have conventionally been used as means of measuring atmospheric profiles of humidity, temperature, pressure, wind speed and direction. High-quality, spatially and temporally “continuous” data from upper-air monitoring along with surface observations are critical bases for understanding weather conditions and climate trends and providing weather and climate information for

180-492: A radio frequency of 403 MHz or 1680 MHz. A radiosonde whose position is tracked as it ascends to give wind speed and direction information is called a rawinsonde ("radar wind -sonde"). Most radiosondes have radar reflectors and are technically rawinsondes. A radiosonde that is dropped from an airplane and falls, rather than being carried by a balloon is called a dropsonde . Radiosondes are an essential source of meteorological data, and hundreds are launched all over

240-501: A blind landing system for airplanes. The organization led by Diamond eventually (in 1992) became a part of the U.S. Army Research Laboratory . In 1937, Diamond, along with his associates Francis Dunmore and Wilbur Hinmann, Jr., created a radiosonde that employed audio-frequency subcarrier modulation with the help of a resistance-capacity relaxation oscillator. In addition, this NBS radiosonde was capable of measuring temperature and humidity at higher altitudes than conventional radiosondes at

300-499: A break in rainfall during mid-season when the Intertropical Convergence Zone or monsoon trough moves poleward of their location during the middle of the warm season; Typical vegetation in these areas ranges from moist seasonal tropical forests to savannahs . When the wet season occurs during the warm season, or summer , precipitation falls mainly during the late afternoon and early evening hours. The wet season

360-516: A computer that stores all the variables in real time. The first radiosondes were observed from the ground with a theodolite , and gave only a wind estimation by the position. With the advent of radar by the Signal Corps it was possible to track a radar target carried by the balloons with the SCR-658 radar . Modern radiosondes can use a variety of mechanisms for determining wind speed and direction, such as

420-617: 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

480-528: 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. Tropics The tropics are

540-521: A popular standard because of its simplicity and because it converted sensor readings to Morse code , making it easy to use without special equipment or training. Working with a modified Molchanov sonde, Sergey Vernov was the first to use radiosondes to perform cosmic ray readings at high altitude. On April 1, 1935, he took measurements up to 13.6 km (8.5 mi) using a pair of Geiger counters in an anti-coincidence circuit to avoid counting secondary ray showers. This became an important technique in

600-546: 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

660-494: 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

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720-414: 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

780-425: A small parachute on the radiosonde's support line may slow its descent to Earth, while some rely on the aerodynamic drag of the shredded remains of the balloon, and the very light weight of the package itself. A typical radiosonde flight lasts 60 to 90 minutes. One radiosonde from Clark Air Base , Philippines, reached an altitude of 155,092 ft (47,272 m). The modern radiosonde communicates via radio with

840-566: Is a battery-powered telemetry instrument carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Modern radiosondes measure or calculate the following variables: altitude , pressure , temperature , relative humidity , wind (both wind speed and wind direction ), cosmic ray readings at high altitude and geographical position ( latitude / longitude ). Radiosondes measuring ozone concentration are known as ozonesondes. Radiosondes may operate at

900-500: Is a time when air quality improves, freshwater quality improves and vegetation grows significantly due to the wet season supplementing flora, leading to crop yields late in the season. Floods and rains cause rivers to overflow their banks, and some animals to retreat to higher ground. Soil nutrients are washed away and erosion increases. The incidence of malaria increases in areas where the rainy season coincides with high temperatures. Animals have adaptation and survival strategies for

960-585: Is that the tropics represent a ' Garden of Eden ', a heaven on Earth, a land of rich biodiversity or a tropical paradise. The alternative is that the tropics consist of wild, unconquerable nature. The latter view was often discussed in old Western literature more so than the first. Evidence suggests over time that the view of the tropics as such in popular literature has been supplanted by more well-rounded and sophisticated interpretations. Western scholars tried to theorise why tropical areas were relatively more inhospitable to human civilisations than colder regions of

1020-612: Is – according to Article 1.50 of the ITU Radio Regulations (RR) – defined as "A radiocommunication service used for meteorological, including hydrological, observations and exploration. Furthermore, according to article 1.109 of the ITU RR: A radiosonde is an automatic radio transmitter in the meteorological aids service usually carried on an aircraft , free balloon , kite or parachute, and which transmits meteorological data. Each radio transmitter shall be classified by

1080-589: The Andes as far south as the northernmost parts of Chile and Perú . The climate is changing in the tropics, as it is in the rest of the world. The effects of steadily rising concentrations of greenhouse gases on the climate may be less obvious to tropical residents, however, because they are overlain by considerable natural variability. Much of this variability is driven by the El Niño-Southern Oscillation (ENSO) . The Tropics has warmed by 0.7–0.8 °C over

1140-552: 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

1200-639: The National Oceanic and Atmospheric Administration (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

1260-703: The Pantropic . The system of biogeographic realms differs somewhat; the Neotropical realm includes both the Neotropics and temperate South America, and the Paleotropics correspond to the Afrotropical , Indomalayan , Oceanian , and tropical Australasian realms . Flora are plants found in a specific region at a specific time. Some well-known plants that are exclusively found in, originate from, or are often associated with

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1320-722: The Soviet Union 's Vega program , the two Venus probes, Vega 1 and Vega 2 , each dropped a radiosonde into the atmosphere of Venus . The sondes were tracked for two days. Although modern remote sensing by satellites, aircraft and ground sensors is an increasing source of atmospheric data, none of these systems can match the vertical resolution (30 m (98 ft) or less) and altitude coverage (30 km (19 mi)) of radiosonde observations, so they remain essential to modern meteorology. Although hundreds of radiosondes are launched worldwide each day year-round, fatalities attributed to radiosondes are rare. The first known example

1380-568: The Tropical Atmosphere Ocean project (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). Scientists in the program made use of

1440-570: The Waterberg Biosphere of South Africa , and eastern Madagascar rainforests. Often the soils of tropical forests are low in nutrient content, making them quite vulnerable to slash-and-burn deforestation techniques, which are sometimes an element of shifting cultivation agricultural systems. In biogeography , the tropics are divided into Paleotropics (Africa, Asia and Australia) and Neotropics (Caribbean, Central America, and South America). Together, they are sometimes referred to as

1500-602: The World Meteorological Organisation which stated that "the situation in Africa shows a dramatic decrease of almost 50% from 2015 to 2020 in the number of radiosonde flights, the most important type of surface-based observations. Reporting now has poorer geographical coverage". Over the last two decades, some 82% of the countries in Africa have experienced severe (57%) and moderate (25%) radiosonde data gap. This dire situation has prompted call for urgent need to fill

1560-500: The atmosphere . The maximum altitude to which the balloon ascends is determined by the diameter and thickness of the balloon. Balloon sizes can range from 100 to 3,000 g (3.5 to 105.8 oz). As the balloon ascends through the atmosphere, the pressure decreases, causing the balloon to expand. Eventually, the balloon will expand to the extent that its skin will break, terminating the ascent. An 800 g (28 oz) balloon will burst at about 21 km (13 mi). After bursting,

1620-696: The axial tilt of the Earth . The Tropic of Cancer is the Northernmost latitude from which the Sun can ever be seen directly overhead , and the Tropic of Capricorn is the Southernmost. This means that the tropical zone includes everywhere on Earth which is a subsolar point at least once during the solar year . Thus the maximum latitudes of the tropics have equal distances from the equator on either side. Likewise, they approximate

1680-407: 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

1740-476: The radiocommunication service in which it operates permanently or temporarily. The allocation of radio frequencies is provided according to Article 5 of the ITU Radio Regulations (edition 2012). In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which

1800-455: The NBS radiosonde system included a pressure drive, which measured temperature and humidity as functions of pressure. It also gathered data on cloud thickness and light intensity in the atmosphere. Due to this and other improvements in cost (about $ 25), weight (> 1 kilogram), and accuracy, hundreds of thousands of NBS-style radiosondes were produced nationwide for research purposes, and the apparatus

1860-519: The Northern Hemisphere. A popular explanation focused on the differences in climate. Tropical jungles and rainforests have much more humid and hotter weather than colder and drier temperaments of the Northern Hemisphere, giving to a more diverse biosphere. This theme led some scholars to suggest that humid hot climates correlate to human populations lacking control over nature e.g. 'the wild Amazonian rainforests'. Radiosondes A radiosonde

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1920-521: The SE corner of Lough Neagh in Northern Ireland; Albemarle , (55.02, -1.88), NE England; and Lerwick , (60.139, -1.183), Shetland , Scotland . Raw upper air data is routinely processed by supercomputers running numerical models. Forecasters often view the data in a graphical format, plotted on thermodynamic diagrams such as Skew-T log-P diagrams , Tephigrams , and or Stüve diagrams , all useful for

1980-590: 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

2040-399: The angle of the Earth's axial tilt. This angle is not perfectly fixed, mainly due to the influence of the moon, but the limits of the tropics are a geographic convention, and their variance from the true latitudes is very small. Many tropical areas have both a dry and a wet season. The wet season , rainy season or green season is the time of year, ranging from one or more months when most of

2100-455: The average annual rainfall in a region falls. Areas with wet seasons are disseminated across portions of the tropics and subtropics , some even in temperate regions. Under the Köppen climate classification , for tropical climates , a wet-season month is defined as one or more months where average precipitation is 60 mm (2.4 in) or more. Some areas with pronounced rainy seasons see

2160-532: The data gap in Africa and globally. The vast data gap in such a large part the global landmass, home to some of the most vulnerable societies, the aforementioned call has galvanised a global effort to “plug the data gap” in the decade ahead and halt a further deterioration in the observation networks. According to the International Telecommunication Union , a meteorological aids service (also: meteorological aids radiocommunication service )

2220-494: The field, and Vernov flew his radiosondes on land and sea over the next few years, measuring the radiation's latitude dependence caused by the Earth's magnetic field . In 1936, the U.S. Navy assigned the U.S. Bureau of Standards (NBS) to develop an official radiosonde for the Navy to use. The NBS gave the project to Harry Diamond , who had previously worked on radio navigation and invented

2280-456: The geographic region; these usages ought not be confused. The Earth's axial tilt is currently around 23.4° , and therefore so are the latitudes of the tropical circles , marking the boundary of the tropics: specifically, ±23°26′09.8″ (or 23.43605°). The northern one is called the Tropic of Cancer , and the southern is the Tropic of Capricorn . As the Earth's axial tilt changes, so too do

2340-501: The interpretation of the atmosphere's vertical thermodynamics profile of temperature and moisture as well as kinematics of vertical wind profile. Radiosonde data is a crucially important component of numerical weather prediction. Because a sonde may drift several hundred kilometers during the 90- to 120-minute flight, there may be concern that this could introduce problems into the model initialization. However, this appears not to be so except perhaps locally in jet stream regions in

2400-955: The last century—only slightly less than the global average—but a strong El Niño made 1998 the warmest year in most areas, with no significant warming since. Climate models predict a further 1–2 °C warming by 2050 and 1–4 °C by 2100. Tropical plants and animals are those species native to the tropics. Tropical ecosystems may consist of tropical rainforests , seasonal tropical forests , dry (often deciduous) forests , spiny forests, deserts , savannahs, grasslands and other habitat types. There are often wide areas of biodiversity , and species endemism present, particularly in rainforests and seasonal forests. Some examples of important biodiversity and high-endemism ecosystems are El Yunque National Forest in Puerto Rico , Costa Rican and Nicaraguan rainforests, Amazon Rainforest territories of several South American countries, Madagascar dry deciduous forests ,

2460-467: The link to the ground. Gustave Hermite and Georges Besançon , from France, were the first in 1892 to use a balloon to fly the meteograph. In 1898, Léon Teisserenc de Bort organized at the Observatoire de Météorologie Dynamique de Trappes the first regular daily use of these balloons. Data from these launches showed that the temperature lowered with height up to a certain altitude, which varied with

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2520-426: 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 ,

2580-559: The observation times during the roughly two-hour ascent. Radiosonde observations are important for weather forecasting , severe weather watches and warnings , and atmospheric research. The United States National Weather Service launches radiosondes twice daily from 92 stations, 69 in the conterminous United States, 13 in Alaska, nine in the Pacific, and one in Puerto Rico. It also supports

2640-775: The operation of 10 radiosonde sites in the Caribbean . A list of U.S. operated land based launch sites can be found in Appendix C, U.S. Land-based Rawinsonde Stations of the Federal Meteorological Handbook #3, titled Rawinsonde and Pibal Observations, dated May 1997. The UK launches Vaisala RS41 radiosondes four times daily (an hour before 00, 06, 12, and 18 UTC) from 6 launch sites (south to north): Camborne , (lat,lon)=(50.218, -5.327), SW tip of England; Herstmonceux (50.89, 0.318), near SE coast; Watnall , (53.005, -1.25), central England; Castor Bay, (54.50, -6.34), near

2700-719: The overhead sun, the tropics receive the most solar energy over the course of the year, and consequently have the highest temperatures on the planet. Even when not directly overhead, the sun is still close to overhead throughout the year, therefore the tropics also have the lowest seasonal variation on the planet; "winter" and "summer" lose their contrast. Instead, seasons are more commonly divided by precipitation variations than by temperature variations. The tropics maintain wide diversity of local climates, such as rain forests , monsoons , savannahs , deserts , and high altitude snow-capped mountains . The word "tropical" can specifically refer to certain kinds of weather , rather than to

2760-513: The regions of Earth surrounding the Equator , where the sun may shine directly overhead . This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's axial tilt ; the width of the tropics (in latitude) is twice the tilt. The tropics are also referred to as the tropical zone and the torrid zone (see geographical zone ). Due to

2820-502: The season, and then stabilized above this altitude. De Bort's discovery of the tropopause and stratosphere was announced in 1902 at the French Academy of Sciences. Other researchers, like Richard Aßmann and William Henry Dines , were working at the same times with similar instruments. In 1924, Colonel William Blaire in the U.S. Signal Corps did the first primitive experiments with weather measurements from balloon, making use of

2880-421: The stratosphere. This issue may in future be solved by weather drones , which have precise control over their location and can compensate for drift. Lamentably, in less developed parts of the globe such as Africa, which has high vulnerability to impacts of extreme weather events and climate change, there is paucity of surface- and upper-air observations. The alarming state of the issue was highlighted in 2020 by

2940-625: 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

3000-451: The temperature dependence of radio circuits. The first true radiosonde that sent precise encoded telemetry from weather sensors was invented in France by Robert Bureau  [ fr ] . Bureau coined the name "radiosonde" and flew the first instrument on January 7, 1929. Developed independently a year later, Pavel Molchanov flew a radiosonde on January 30, 1930. Molchanov's design became

3060-413: The time due to the use of electric sensors. In 1938, Diamond developed the first ground receiver for the radiosonde, which prompted the first service use of the NBS radiosondes in the Navy. Then in 1939, Diamond and his colleagues developed a ground-based radiosonde called the “remote weather station,” which allowed them to automatically collect weather data in remote and inhospitable locations. By 1940,

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3120-516: The tropical and polar circles . The tropics constitute 39.8% of Earth's surface area and contain 36% of Earth's landmass . As of 2014 , the region was home also to 40% of the world's population , and this figure was then projected to reach 50% by 2050. Because of global warming , the weather conditions of the tropics are expanding with areas in the subtropics , having more extreme weather events such as heatwaves and more intense storms. These changes in weather conditions may make certain parts of

3180-464: The tropics include: Tropicality refers to the image of the tropics that people from outside the tropics have of the region, ranging from critical to verging on fetishism. Tropicality gained renewed interest in geographical discourse when French geographer Pierre Gourou published Les pays tropicaux ( The Tropical World in English), in the late 1940s. Tropicality encompassed two major images. One,

3240-550: The tropics uninhabitable. The word "tropic" comes via Latin from Ancient Greek τροπή ( tropē ), meaning "to turn" or "change direction". The tropics are defined as the region between the Tropic of Cancer in the Northern Hemisphere at 23°26′09.8″ (or 23.43605°) N and the Tropic of Capricorn in the Southern Hemisphere at 23°26′09.8″ (or 23.43605°) S; these latitudes correspond to

3300-431: The welfare of societies. Reliable and timely information underpin society’s preparedness to extreme weather conditions and to changing climate patterns. Worldwide, there are about 1,300 radiosonde launch sites. Most countries share data with the rest of the world through international agreements. Nearly all routine radiosonde launches occur one hour before the official observation times of 0000 UTC and 1200 UTC to center

3360-708: The wetter regime. The previous dry season leads to food shortages into the wet season, as the crops have yet to mature. However, regions within the tropics may well not have a tropical climate. Under the Köppen climate classification, much of the area within the geographical tropics is classed not as "tropical" but as "dry" ( arid or semi-arid ), including the Sahara Desert , the Atacama Desert and Australian Outback . Also, there are alpine tundra and snow-capped peaks, including Mauna Kea , Mount Kilimanjaro , Puncak Jaya and

3420-432: The world daily. The first flights of aerological instruments were done in the second half of the 19th century with kites and meteographs , a recording device measuring pressure and temperature that would be recovered after the experiment. This proved difficult because the kites were linked to the ground and were very difficult to manoeuvre in gusty conditions. Furthermore, the sounding was limited to low altitudes because of

3480-692: Was officially adopted by the U.S. Weather Bureau. Diamond was given the Washington Academy of Sciences Engineering Award in 1940 and the IRE Fellow Award (which was later renamed the Harry Diamond Memorial Award) in 1943 for his contributions to radio-meteorology. The expansion of economically important government weather forecasting services during the 1930s and their increasing need for data motivated many nations to begin regular radiosonde observation programs In 1985, as part of

3540-545: 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

3600-411: Was the electrocution of a lineman in the United States who was attempting to free a radiosonde from high-tension power lines in 1943. In 1970, an Antonov 24 operating Aeroflot Flight 1661 suffered a loss of control after striking a radiosonde in flight resulting in the death of all 45 people on board. A rubber or latex balloon filled with either helium or hydrogen lifts the device up through

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