臺大實驗林轄區雲遮蔽時空變化

Spatio-temporal Distribution of Cloud Cover on Experimental Forest, NTU

賴彥任(Yen-Jen Lai)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 31卷2期 (2017/06) Pp. 67-76

https://doi.org/10.6542/EFNTU.2017.31(2).1

摘要

臺灣中海拔是臺灣生物多樣性最為豐富的區域，其中700m至2,600m的森林常為雲霧繚繞，蘊育出許多適生於此環境之動植物相，學者稱此區域為霧林帶。本研究利用MODIS雲遮蔽產品探討臺大實驗林轄區雲霧之年際、季節、日夜分佈特性。分析結果顯示，轄區內雲遮蔽率無明顯年際消長趨勢，然年間有0.35〜0.60變動，此變動與海洋聖嬰指數具有統計上顯著的關係。季節與日夜分析顯示4〜6月於午後至凌晨的雲遮蔽率最高。營林區則以溪頭地區雲遮蔽率最高，該地區的長期趨勢於1〜3月似有減少，4〜6月及10〜12月似有增加。

關鍵字

中級解析度成像分光輻射度計 ； 雲遮蔽率 ； 海洋聖嬰指數

並列摘要

Mid-elevation area, approximately from 700 m to 2,600 m a.s.l., is usually covered by cloud and fog, and it possesses a rich diversity of flora and fauna in Taiwan. Forest ecosystem of this area are often referred as ＂Cloud Forests＂. This study used cloud cover products, which were inversed from the long-term monitoring images of Moderate Resolution Imaging Spectroradiometer (MODIS), to assess interannual, seasonal and diurnal patterns of cloud cover over the NTU Experimental Forests. The results indicated that there was no significant change in trend of long-term mean annual cloud cover. However, annual variability was between 0.35 to 0.6 and was significantly correlated with Oceanic Niño Index. Seasonal and diurnal analyses showed that the highest cloud cover ratio occurred from noon to midnight during April to June, and the highest cloud cover ratio occurred at the Xitou tract. Further analysis showed that long-term seasonal trends decreased from January to March, but increased from April to June and October to December.

並列關鍵字

MODIS ； Cloud Cover Ratio ； Oceanic Niño Index