East Asian rainy season

Monsoon season in East Asia

East Asian rainy season
Chinese name
Hanyu Pinyin	méiyǔ
Bopomofo	ㄇㄟˊㄩˇ
IPA	měiɥỳ
Hakka
Romanization	mòi-yí
Yue: Cantonese
Jyutping	mui4 jyu5
IPA	mu̖ːy̯jy̗ː
Southern Min
Hokkien POJ	mûi-ú / bôe-í

Korean nameHangul장마Hanja長마

Transcriptions
Revised Romanization	jangma

Japanese nameKanji梅雨Kanaつゆ / ばいうHiraganaつゆ / ばいうKatakanaﾂﾕ / ﾊﾞｲｳ

Transcriptions
Revised Hepburn	tsuyu / baiu
Kunrei-shiki	tuyu / baiu

Russian nameRussian

In China, the term "plum rain" was used for the rain in the fourth and fifth lunar month.[1]^[2] It specifically refers to the historical belief that, when the plums turn yellow and fall at the south of the Yangtze in the fourth and fifth months, the moisture that evaporates from the plant turns into rain.^[2]

The term appears in the following poem by Du Fu (fl. 8th century) of the Tang dynasty:

梅雨
南京犀浦道，四月熟黃梅。
湛湛長江去，冥冥細雨來。
茅茨疏易溼，雲霧密難開。
竟日蛟龍喜，盤渦與岸迴。

Plum rain
On the Xipu road from the Southern Capital [present-day Chengdu],
the fourth month ripens the yellow p[r]unus.
The long river goes off surging,
and, darkening, a fine rain comes.
Roof-thatch, loosely bound, is easily soaked,
clouds and fog are dense and will not lift.
All day long the dragons delight,
whirlpools turning with the bank.^[1]

Japan later adapted and transliterated the Chinese term "plum rain" to call the rainy season tsuyu (梅雨).

The season is instead commonly called Jangma (장마) in Korea, which means "long rain". The term was originally spelled Dyangmah (댱맣) in 1500s, which was the mix of the hanja character 長 ("long") and the old native Korean word 맣 (mah, "rain"). The word Dyangmah eventually transformed from Jyangma (쟝마) in 1700s to the current form of Jangma after the 1900s.^[3]

Formation

An east-west zone of disturbed weather during spring along this front stretches from the east China coast, initially across Taiwan and Okinawa, later, when it has shifted to the north, eastward into the southern peninsula of South Korea and Japan.

The weather front forms when the moist air over the Pacific meets the cooler continental air mass. The front and the formation of frontal depressions along it brings precipitation to Primorsky Krai, Japan, Korea, eastern China, and Taiwan. As the front moves back and forth depending on the strength of cool and warm air masses, there is often prolonged precipitation and sometimes flooding in eastern China. However, in the years that it does not rain as much as usual, a drought might result. The rainy season ends when the warm air mass associated with the subtropical ridge is strong enough to push the front north and away.^{[citation needed]}

Effects

The high

The rains in the middle of November - early December are sometimes called the sazanka tsuyu, literally "rainy season of the camellia" on account of the timing with the blossoming of the seasonal flower.^{[citation needed]}

This period is generally avoided for tourism, but some sights are considered particularly atmospheric in the rain and fog, particularly mountain forests, notably Sacred Sites and Pilgrimage Routes in the Kii Mountain Range (including Mount Kōya).^[6] Vegetation, especially moss, is also rather lush at this time, and hence sights known for their moss, such as Saihō-ji (the moss temple) are also popular at this time of year.^{[citation needed]}

Korea

The rainy season is between June and mid-July. It is caused by hot and humid high pressure forming in the Sea of Okhotsk due to the North Pacific anticyclone combining with Asiatic continental high pressure. When the two meteorological events meet they form a long jangmajeonseon (Korean: 장마전선, from 장마; lit. rainy season and 전선; 前線; lit. weather front). Beginning in late-May, the North Pacific high pressure forces the weaker continental anticyclone south of Okinawa Island. This fall to the south then reverses and gradually strengthens as it moves northwards back towards the Korean peninsula. On landfall, heavy monsoon rains lead to torrential downpours and flooding. By August the system has weakened as the southern systems retreat towards the Philippine archipelago.^{[citation needed]}

By early autumn, the North Pacific high-pressure system is pushed away as Asiatic continental cold high pressure moves southwards. This produces inclement weather although not on the scale of the summer monsoons. Korea can, however, be struck by typhoons during this period.^{[citation needed]}

Timing

In some years, the rainy season's actual beginning and end are under debate. For example, in 2005, the subtropical ridge moved quickly northward in late June/early July. The weather front skipped the Yangtze region and there was no rainy season there. Then, the ridge retreated southward and there was significant rainfall in the region. This gave rise to the question of whether this was the summer-type rainfall pattern that is common after the first rainy season or the second rainy season. Some meteorologists even argued that the rainy period in late June was not a true rainy season.^{[7][8][9][10][11]}

See also

• East Asian Monsoon
• Meiyu front
• List of China-related topics
• List of Japan-related topics
• List of Taiwan related topics

References

Look up plum rain in Wiktionary, the free dictionary.