大氣重力波位能之時空分布及控因;Analysis of the Distribution and Controlling Factors in the Atmospheric Gravity Wave Potential Energy

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Title:	大氣重力波位能之時空分布及控因;Analysis of the Distribution and Controlling Factors in the Atmospheric Gravity Wave Potential Energy
Authors:	楊時賢;YANG,Shih-Sian
Contributors:	太空科學研究所
Keywords:	大氣重力波;綜觀尺度;atmospheric gravity waves;synoptic scale
Date:	2015-11-26
Issue Date:	2016-01-05 17:27:35 (UTC+8)
Publisher:	國立中央大學
Abstract:	在過去數十年間，大氣重力波的全球形態和季節特性已被廣泛的研究，並被歸納主要為地形和對流系統、以及高緯度地區極夜噴流和平流層瞬間暖化的影響。然而這些控因並不能完全解釋重力波的時空分布。為了補充前人研究之不足，本論文進行了一系列的分析，調查大氣背景參數和綜觀尺度系統對重力波位能值（Ep）的影響。利用TIMED/SABER所觀測的大氣溫度剖面資料，經濾波後求出2002年至2013年間、共12年全球的Ep值分布，再以ERA-Interim再分析資料提供的大氣背景及綜觀尺度參數進行調查，瞭解這些參數與Ep值的關聯性。赤道大氣克耳文波對Ep值有相當大的貢獻，並促成了Ep值與背景風場的關聯性。臭氧濃度在20 至 27公里高度達到絕對最大值，使Ep值在24公里高度附近具有局部的最大值。在溫帶氣旋及間熱帶輻合區附近，Ep值具有較高的數值；而在副熱帶高壓的勢力範圍內，Ep值具有較低的數值。此外，亦改以對流可用位能（CAPE）聯結對流系統與Ep值之間的關聯性，為本論文的論點進行佐證。本論文針對大氣背景參數及對流活動和Ep值之關聯性做了更詳盡的解釋，並且首度嘗試引入綜觀尺度參數分析重力波活動，進一步證實綜觀尺度系統與Ep值之關聯性。;In the past years, global morphology and climatology of atmospheric gravity waves have been widely studied and the effects of topography, convection systems, polar night jet, and sudden stratospheric warming events have been evaluated, but the complete gravity wave distribution could not be explained by these effects. To find the missing controlling factors, a series of analyses is performed in the present study to investigate relationships between atmospheric parameters, synoptic scale factors, and potential energy (Ep) associated with gravity waves. Global distribution of Ep during a 12-year period from 2002 to 2013 is derived using temperature profiles retrieved from observations of Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Atmospheric parameters and synoptic scale factors obtained from the ECMWF Interim reanalysis (ERA-Interim) data are employed to investigate the correlation between synoptic systems and Ep. Kelvin waves contribute most of Ep over the equatorial region. The local maximum of Ep around 24 km altitude is related to the maximum concentration of stratospheric ozone. It is found that Ep values are high around extratropical cyclones over mid-latitudes (30° – 60°) and around the Intertropical Convergence Zone (ITCZ) over low-latitudes (10° – 30°). Ep values are low around subtropical highs over both mid- and low-latitudes. Furthermore, the convective available potential energy (CAPE) is employed as a proxy, to link the convective systems to Ep distribution. The relationship between synoptic systems and Ep is also established by analyzing the correlation between CAPE and Ep. In the present study, the missing controlling factors are complemented, and this is also the first time that a synoptic scale analysis of Ep distribution is performed, and the influence of synoptic scale factors on Ep confirmed.
Appears in Collections:	[Graduate Institute of Space Science] Department of Earth Sciences

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