The Big Bog on the island of

Maui The island of Maui (; Hawaiian: ) is the second-largest of the islands of the state of Hawaii at 727.2 square miles (1,883 km2) and is the 17th largest island in the United States. Maui is the largest of Maui County's four islands, which ...

is the largest high-altitude bog in the

Hawaiian Islands The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...

. It is located on

East Maui Volcano East or Orient is one of the four cardinal directions or points of the compass. It is the opposite direction from west and is the direction from which the Sun rises on the Earth. Etymology As in other languages, the word is formed from the f ...

's east

rift zone A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. Believed t ...

, at the border between Hāna Forest Reserve and

Haleakalā National Park Haleakalā National Park is an American national park located on the island of Maui in the state of Hawaii. Named after Haleakalā, a dormant volcano within its boundaries, the park covers an area of , of which is a wilderness area. The land wa ...

. It is alleged to be one of the

wettest places on earth Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

, with a reported annual rainfall of for the period 1992-2018.

Climate

The Big Bog has a

tropical rainforest climate A tropical rainforest climate, humid tropical climate or equatorial climate is a tropical climate sub-type usually found within 10 to 15 degrees latitude of the equator. There are some other areas at higher latitudes, such as the coast of southea ...

(Köppen '' Af''), with no observable dry season and nearly constant torrential rainfall. Prior to the establishment of the station there in 1992, rainfall for Big Bog was estimated at around per year. However, the first full year of recorded data showed of rainfall, which is one of the highest annual rainfall totals measured in the Hawaiian Islands. Since then, the annual average has been recorded as . Clear days are essentially nonexistent, and even when it is not raining, it is almost certainly cloudy or foggy. The lack of adequate drainage has caused moisture to accumulate, forming the bog.

Causes

The Big Bog lies at , very close to the trade wind inversion layer, leading to persistent transport of moisture rich air by the northeast trade winds up the steep mountain slopes. These trade winds condense to form clouds and precipitation. Its moniker as the cloudiest place in the Hawaiian Islands is verified by the fact that its average solar radiation and potential

evapotranspiration Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpi ...

are the lowest amongst recorded locations, and relative humidity and cloud attenuation are the highest.

Comparison with Mount Waiʻaleʻale

While the summit of Mount Waiʻaleʻale has long been considered the wettest place in the Hawaiian Islands, and thus Oceania, the Big Bog has a higher 30-year average
NOAA
reports Wai’ale’ale's annual rainfall as , while the

University of Hawaiʻi at Mānoa The University of Hawaii at Mānoa (University of Hawaii—Mānoa, UH Mānoa, Hawai'i, or simply UH) is a Public university, public Land-grant university, land-grant research university in Manoa, Mānoa, a neighborhood in Honolulu, Hawaii. It ...

reports the Big Bog's as . This would make the Big Bog the wettest location in the Hawaiian Islands and in

Oceania Oceania (, , ) is a region, geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, Oceania is estimated to have a land area of ...

, although many amateur sources cite Mount Waiʻaleʻale's precipitation as higher. Big-Bog-Satellite

References

{{reflist Geography of Maui

Climate

Causes

Comparison with Mount Waiʻaleʻale

See also

References