Please use this identifier to cite or link to this item:
The Study of Downhill Wind Effects on the Temperature Variations of Coastal Water in Nanwan Bay
|Authors: ||Lin, Yi-Li|
|Contributors: ||NTOU:Department of Marine Environmental Informatics|
downhill wind;temperature drop;upwelling
|Issue Date: ||2020-01-20T06:20:39Z
|Abstract: ||落山風是南灣海域秋冬到初春間盛行的現象，風吹持續且強勁，對冷水湧升有一定影響，本研究即針對此風場效應，經由希爾伯特黃轉換 (HHT)，以EMD分解訊號，找出較接近風吹的週期(2~10天)之IMF分量，進行與溫降現象間的相關性探討。 研究結果顯示，落山風盛行期間，海水確有離岸流向，風場效應影響之週期較長，在2~3天週期IMF分量，對南灣海水溫度突降平均有8.20%的貢獻；在3~10天週期IMF分量，對南灣海水溫度突降平均有1.81%的貢獻，整體調和合併約有10%的貢獻幅度。|
The downhill wind is a special phenomenon when the northeasterly wind prevails in winter, blowing from local maintain peak to hill and then over the sea surface during late autumn to early spring in NanWan Bay. The continuous and strong winds could have a certain impact on the seawaters, leading to the cold water upwelled. This study is aimed at this wind field effect and through the Hilbert-Huang Transform (HHT) to decompose the signal by EMD to find the IMF components that are selected by the wind cycle (2~10 days). The results integrated from the selected IMF components will be used to discuss the correlation between the seawater temperature drop and local winds. The results of the study show that, during the prevailing downhill winds, seawater flows offshore, and period of the wind effect is longer than that of tides. As a result, with the period of 2 to 3 days, the IMF component contributes an average value of 8.20% to the seawater temperature drop in NanWan Bay; the longer period of IMF component with 3 to 10 day cycles contributes an average value of 1.81% to the seawater temperature drop, and the two harmonic consolidation to the downhill wind effects has a notably contribution with a magnitude of about 10%.
|Appears in Collections:||[海洋環境資訊系] 博碩士論文|
All items in NTOUR are protected by copyright, with all rights reserved.