Kosrae
Kosrae’s climate is tropical oceanic. Located only 5° north of the equator, Kosrae experiences periods of heavy rainfall associated with the Intertropical Convergence Zone (ITCZ). In 2007, the average annual temperature is 81°F (27.2 °C) with only 0.5 °F departing from the 30-year mean temperature recorded between 1970 and 2000 [5]. Rainfall is relatively high, slightly over 200 inches (5,080 mm) in 2007, nearly 30 inches (762 mm) more than the 30-year average [5]. The precipitation is normally higher in the highlands. The state has experienced three severe droughts in recent times, in 1982-83, 1992-93 and 1997-98. All three were a result of El Niño. Kosrae is located to the south and east of the typhoon track and very rarely experiences a direct strike from a typhoon. However, Pacific typhoons often go through the development stage in the area causing severe local winds. During the rainy season of November through March frequent severe rainstorms are sometimes accompanied by damaging winds, which can damage transmission and distribution facilities [9]
Chuuk
From about November to June, the climate of Chuuk is influenced chiefly by northeasterly tradewinds with average monthly speeds of 8-12 mph (13-19 km/h). By about April, however, the trades begin to weaken, and by July give way to the lighter and more variable winds of the doldrums. Between July and November, the island is frequently under the influence of the ITCZ. This is also the season when moist southerly winds and tropical disturbances, many associated with the ITCZ, are most frequent, and when humidities often are oppressively high. Temperature in Chuuk is remarkably uniform; with the highs generally in the middle 80s, and lows in the middle 70s. In 2007 the average temperatures was 82.2 °F (27.9 °C) [5] The northern atolls receive about 80 inches of rainfall a year while the annual rainfall in Southern atolls is normally higher, about 160 inches (4,060 mm). Monthly rainfall ranges from 6 to almost 16 inches (152-406 mm). The least amount of monthly rainfall (6 to 9 inches/152-228 mm) occurs during the months of January through March as stronger northeasterly trade winds approach the state of Chuuk [9]. The total precipitation of Chuuk in 2007 was measured at 127 inches (3,226 mm) [5].
Although the major typhoon tracks of the western Pacific lie to the north and west of Chuuk, several of the storms have passed close enough to the island to cause widespread damage. Tropical storms generally occur between the months of July and November [9]. Severe typhoons with winds in excess of 100 mph (161 km/h) strike portions of Chuuk, including Supertyphoon Nina in November 1987 [7] and Typhoon Chata’an in July 2002. Chata’an brought heavy rainfall causing extensive flooding, mudslides, and landslides that resulted in deaths and required more than $10.6 million in federal assistance [2]. According to the 2007 PEAC staff visit with the Chuuk Weather Service Office (WSO), sea level rise, drought, and inundation are biggest threats to Chuuk. Most infrastructure is located close to the coastline, as the interior of the islands are mountainous. Taro patches in Chuuk State suffered great losses from an inundation event in March 2007 [4].
Drought in FSM
Parts of Situation Report No. 1 from the Office for the Coordination of Humanitarian Affairs (OCHA)
Federated States of Micronesia
El Niño - Drought
27 March 1998
Due to the ENSO-related prolonged drought in 1997 and 1998, many areas in the Federated States of Micronesia were either without water or on water rationing systems. Many schools and public facilities were without adequate water supplies. Rivers dried up and wells were dangerously low with increasing levels of salinity. The national authorities were concerned about a possible public health crisis due to the increase in bacteria and contaminants in any remaining water supplies. The lack of water increased substantially the risk of fire. The drought depleted food supplies by causing stress on staple crops, especially taro.
The FSM National Government and the States of Pohnpei and Chuuk declared a state of emergency. A number of El Niño task forces were established at the various government levels. Plans were devised and implemented to increase water catchment, reduce water consumption, purchase water equipment and deliver water. The outer islands of the States of Pohnpei, Chuuk and Yap were provided with water rations. About 28,800 people needed relief assistance.
Major appropriations were made at the national and state government levels. A National Congress bill for appropriations for water projects was raised from USD 3 million to USD 5 million. The President of the Federated States of Micronesia determined that this crisis was of such severity and magnitude that an effective response was beyond the capabilities of FSM. Assistance was requested from the United States Government and the United Nations system.
Source: Micronesia: Drought - OCHA-01: 27-Mar-98, http://cidi.org/disaster/98a/0051.html |
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Kosrae, Island of Sleeping Lady. Source: Yimnang Golbuu. |
Pohnpei
Pohnpei's close proximity to the equator, right in the middle of the intertropical convergence zone (ITCZ), substantially reduces seasonal weather change [9]. Average annual temperature since 1970 has been around 81° F (27 °C) [5]. The island’s highest point, at 2,540 feet (798 m), is the summit of Mount Nahnalaud, thought to be one of the wettest spots in the world, with an average annual rainfall exceeding 400 inches (10,160 mm) [8]. While it has been estimated that within Pohnpei’s high mountainous interior it can rain as much as 330 inches (8,384 mm) a year, the weather service in Kolonia Town measured total precipitation of 194 inches (4,928 mm) in 2007, approximately 9 inches (229 mm) more than the 30-year average [5]. Runoff from the rains feed numerous streams and rivers that originate in the interior highlands. Typically, Pohnpei’s interior is almost completely cloud covered, and the island’s residents can expect most days to be partly cloudy, with periods of sunshine, then overcast and rain [9].
Pohnpei is generally south and east of the typhoon belt, but periodically experiences short, severe tropical storms [9]. The northern part of Pohnpei is where tropical disturbances often form, though most develop into typhoons north and west of the state. The southernmost atoll in the state is Kapingamarangi, located 2° north of the equator, and subject to droughts, particularly during La Niña events [8]
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View of Chuuk atolls from the air. Source: Sarah Jones |
Yap
The ITCZ lies near Yap during the northern summer, particularly as it moves northward in July and southward again in October. At such times, showers and light, variable winds predominate, interspersed with heavier showers or thunderstorms, occasionally accompanied by strong and shifting winds. In 2007 the average annual temperature in 2007 is 80.5 °F (26.9 °C), and annual rainfall is 138 inches (3493 mm) [5]. Since the twenty-first century began, Yap has experienced two major typhoon disaster declarations, Typhoon Lupit in 2003 and Typhoon Sudal in 2004 [2].
Despite plentiful rainfall (Pohnpei is one of the wettest places on Earth), during extreme ENSO events, drought conditions do occur periodically throughout FSM, especially when the El Niño condition moves into the Western Pacific. At these times, groundwater supplies have dwindled to emergency proportions, with a major drought disaster declaration in 1998 and emergency declarations in 2007[2]. The states of Pohnpei and Chuuk declared drought emergencies in several islands in these states due to food and water shortages from climate variability [6, 7]. In addition, the FSM faces wildfires, extreme tides, sea level variation, and erosion. Tropical typhoons (June to December) constitute an annual threat, particularly to the low-lying atolls [1, 3]. Fisheries, a primary economic sector in the FSM, have high correlations of fish catch with sea surface temperatures (SST) and ENSO events. As pelagic fish leave the region, the FSM experiences severe economic setbacks. (Also see Stakeholder Dialogue page, Pohnpei, Federated States of Micronesia, April 18-19, 2006.)
With the current stresses on the environment, infrastructure, and economy in the FSM, more frequent extreme events and climate change could pose severe problems for the resilience of the island communities. To address these issues, several non-profit organizations working with the government have begun to identify marine protected areas and conservation areas to protect resources for food security. In addition, some of the low-lying atolls have made arrangements to secure tracts of land on higher islands for possible relocation. (Also see Stakeholder Dialogue page, Pohnpei, Federated States of Micronesia , April 18-19, 2006.)
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