DOI: 10.1175/JCLI-D-17-0023.1
Scopus记录号: 2-s2.0-85028512159
论文题名: Stratospheric response to the 11-yr solar cycle: Breaking planetary waves, internal reflection, and resonance
作者: Lu H. ; Gray L.J. ; White I.P. ; Bracegirdle T.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 18 起始页码: 7169
结束页码: 7190
语种: 英语
Scopus关键词: Climate change
; Dynamics
; Fighter aircraft
; Solar energy
; Vortex flow
; Wave propagation
; Waveguides
; Climate variability
; Planetary Waves
; Seasonal cycle
; Solar cycle
; Stratospheric circulations
; Upper atmosphere
英文摘要: Breaking planetary waves (BPWs) affect stratospheric dynamics by reshaping the waveguides, causing internal wave reflection, and preconditioning sudden stratospheric warmings. This study examines observed changes in BPWs during the northern winter resulting from enhanced solar forcing and the consequent effect on the seasonal development of the polar vortex. During the period 1979-2014, solar-induced changes in BPWs were first observed in the uppermost stratosphere. High solar forcing was marked by sharpening of the potential vorticity (PV) gradient at 30°-45°N, enhanced wave absorption at high latitudes, and a reduced PV gradient between these regions. These anomalies instigated an equatorward shift of the upper-stratospheric waveguide and enhanced downward wave reflection at high latitudes. The equatorward refraction of reflected waves from the polar upper stratosphere then led to enhanced wave absorption at 35°-45°N and 7-20 hPa, indicative of a widening of the midstratospheric surf zone. The stratospheric waveguide was thus constricted at about 45°-60°N and 5-10 hPa in early boreal winter; reduced upward wave propagation through this region resulted in a stronger upper-stratospheric westerly jet. From January, the regions with enhanced BPWs acted as ''barriers'' for subsequent upward and equatorward wave propagation. As the waves were trapped within the stratosphere, anomalies of zonal wavenumbers 2 and 3 were reflected poleward from the stratospheric surf zone. Resonant excitation of some of these reflected waves resulted in rapid growth of wave disturbances and a more disturbed polar vortex in late winter. These results provide a process-oriented explanation for the observed solar cycle signal. They also highlight the importance of nonlinearity in the processes that drive the stratospheric response to external forcing. © 2017 American Meteorological Society. 资助项目: NERC, Natural Environment Research Council
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48726
Appears in Collections: 气候减缓与适应 气候变化与战略
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作者单位: British Antarctic Survey, Cambridge, United Kingdom; Clarendon Laboratory, Department of Physics, Oxford University, Oxford, United Kingdom; National Centre for Atmospheric Science, Natural Environment Research Council, Leeds, United Kingdom; Institute of Earth Sciences, Hebrew University of Jerusalem, Israel
Recommended Citation:
Lu H.,Gray L.J.,White I.P.,et al. Stratospheric response to the 11-yr solar cycle: Breaking planetary waves, internal reflection, and resonance[J]. Journal of Climate,2017-01-01,30(18)