DOI: 10.1002/jgrd.50632
论文题名: The lower thermosphere during the northern hemisphere winter of 2009: A modeling study using high-altitude data assimilation products in WACCM-X
作者: Sassi F. ; Liu H.-L. ; Ma J. ; Garcia R.R.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 16 起始页码: 8954
结束页码: 8968
语种: 英语
Scopus关键词: Gravitational effects
; NASA
; Global atmospheric prediction system
; Molecular diffusion
; Northern Hemispheres
; Research and application
; Retrospective analysis
; Stratospheric warmings
; Vertical structures
; Whole atmosphere community climate models
; Tides
; altitude
; climate modeling
; data assimilation
; diffusion
; Kelvin wave
; Northern Hemisphere
; numerical model
; prediction
; stratosphere
; thermosphere
英文摘要: We present numerical simulations using the Whole Atmosphere Community Climate Model, extended version, constrained below 90 km by a combination of NASA's Modern Era Retrospective Analysis for Research and Applications and the U.S. Navy's Operational Global Atmospheric Prediction System - Advanced Level Physics High Altitude assimilation products. The period examined is January and February 2009, when a large stratospheric warming occurred on 24 January 2009, with anomalous circulation persisting for several weeks after the event. In this study, we focus on the dynamical response of the lower thermosphere up to 200 km. We find evidence of migrating and nonmigrating tides, Rossby and Rossby-gravity modes, and Kelvin waves, whose amplitudes appear to be modulated at the times leading and following the stratospheric warming. While the Rossby, Rossby-gravity, and Kelvin modes are rapidly dissipated in the lower thermosphere (above 110 km), the tides maintain substantial amplitude throughout the thermosphere, but their vertical structure becomes external above about 120-150 km. Most waves identified in the simulations decrease in amplitude in the thermosphere, indicating remote forcing from below and strong dissipation by molecular diffusion at high altitudes; however, the amplitude of the migrating DW1 tide increases in the thermosphere suggesting in situ forcing. We show that the amplitude of the tides (such as the DW1) changes as the background wind alters the vorticity in the tropics, which broadens or narrows the tropical waveguide. Our results also suggest that fast Rossby normal modes (periods ≤ 10 days) are excited by instability of the zonal-mean wind distribution following the stratospheric warming. © 2013. Her Majesty the Queen in Right of Canada. American Geophysical Union. 资助项目: X09AJ83G
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63414
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Space Science Division, Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC, 20375, United States; High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, United States; Computational Physics Inc., Springfield, VA, United States; Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
Sassi F.,Liu H.-L.,Ma J.,et al. The lower thermosphere during the northern hemisphere winter of 2009: A modeling study using high-altitude data assimilation products in WACCM-X[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(16)