2007難寧靜 預計出現5個超級颶風 | 環境資訊中心

2007難寧靜 預計出現5個超級颶風

2007年05月28日
摘譯自2007年5月23日ENS美國,華府報導;丁秋仁編譯;莫聞審校

聖嬰現象與反聖嬰現象的對照圖(照片來源:NASA)美國國家海洋暨大氣總署(NOAA)氣候預報中心22日表示,在太平洋海面溫度趨向降低的同時,大西洋卻背道而馳,平均溫度持續增高,因此2007年大西洋的颶風活動有7成5的機會高於平常。

大西洋在颶風季節中平均會產生11個風暴,其中約6個會轉變成颶風等級,並有2個屬於超級颶風。NOAA主管勞滕巴赫爾(Conrad Lautenbacher)指出,署內科學家們依海面溫度變化預測,2007年颶風季中,大西洋將可能出現13至17不等的風暴,其中10個將發展成颶風,而有3到5個颶風的威力恐怕達到3級以上。

海洋與大氣在特定的組合條件下,會加劇大西洋的颶風活動、海面溫度異常升高,以及影響太平洋聖嬰與反聖嬰現象的週期。由於氣候變化的模式仍屬於這段數十年資訊的一部分,2007年的颶風活動因此預料會異於往常。

依照經驗法則,接下來幾個月將為反聖嬰現象是否出現的關鍵時期。氣候預報中心認為反聖嬰現象應會在3個月內形成,屆時大西洋上風暴活動的頻率,極可能超出原先的預測數量;但即使反聖嬰現象未如期出現,2007年颶風季的活動頻率仍可能屬於異常。

Up to Five Major Atlantic Hurricanes Forecast for 2007
WASHINGTON, DC, May 23, 2007 (ENS)

Sea surface temperatures in the Pacific Ocean are cooling while Atlantic temperatures are warming. Hurricane experts at the Climate Prediction Center operated by NOAA, said Tuesday there is a 75 percent chance that the Atlantic hurricane season will be above normal this year.

"For the 2007 Atlantic hurricane season, NOAA scientists predict 13 to 17 named storms, with seven to 10 becoming hurricanes, of which three to five could become major hurricanes of Category 3 strength or higher," said NOAA Administrator Conrad Lautenbacher. An average Atlantic hurricane season brings 11 named storms, with six becoming hurricanes, including two major hurricanes.

Climate patterns responsible for the expected 2007 hurricane activity continue to be the ongoing multi-decadal signal - the set of ocean and atmospheric conditions that spawn increased Atlantic hurricane activity, as well as warmer than normal sea surface temperatures in the Atlantic Ocean, and the El Niño/La Niña cycle in the Pacific.

Historically, the next couple of months are a critical time period for the possible emergence of La Niña. The Climate Prediction Center is indicating that La Niña could form in the next one to three months. If La Niña develops, storm activity will likely be in the upper end of the predicted range, but even if La Niña does not develop, the conditions associated with the ongoing active hurricane era still favor an above-normal season.

全文及圖片詳見 ENS報導