DOI: 10.1002/2015MS000610
Scopus记录号: 2-s2.0-84966392145
论文题名: On the cumulus diurnal cycle over the tropical warm pool
作者: Ruppert J ; H ; , Johnson R ; H
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2016
卷: 8, 期: 2 起始页码: 669
结束页码: 690
语种: 英语
英文关键词: Atmospheric temperature
; Boundary layers
; Clouds
; Heat convection
; Lakes
; Subsidence
; Surface measurement
; Surface waters
; Wetting
; Cloud resolving model
; Control simulation
; Cumulus
; Diurnal
; Radiative heating
; Sea surface temperature (SST)
; Subsidence drying
; Vertical motions
; Oceanography
; boundary layer
; cloud microphysics
; cloud radiative forcing
; convective cloud
; cumulus
; diurnal variation
; nonlinearity
; sea surface temperature
; shortwave radiation
; warm pool
英文摘要: An idealized cloud-resolving model experiment is executed to study the prominent cumulus diurnal cycle in suppressed regimes over the tropical warm pool. These regimes are characterized by daytime cumulus invigoration and cloud-layer moistening connected with enhanced diurnal cycles in shortwave radiative heating (SW) and sea surface temperature (SST). The relative roles of diurnally varying SW and SST in this cumulus diurnal cycle are assessed, wherein radiation is modeled and SST is prescribed. Large-scale subsidence is parameterized using the spectral weak temperature gradient (WTG) scheme, such that large-scale vertical motion (wwtg), and hence subsidence drying, is modulated by diurnal changes in diabatic heating. A control simulation exhibits daytime cumulus invigoration that closely matches observations, including midday cloud-layer moistening. This cumulus invigoration is composed of two distinct modes: (1) a midday nonprecipitating (“forced”) mode of predominately shallow clouds, driven by the peak in SST and surface fluxes as the mixed layer deepens and dries; and (2) a precipitating late-afternoon (“active”) mode characterized by deeper clouds in connection with a more moist cloud layer. This cloud-layer moistening is driven by the daytime relaxation of wwtg subsidence, which is prompted by the midday peak in SW. The transition from the surface flux-driven forced mode to the active precipitating mode is accompanied by a transition from relatively small-scale boundary layer circulation cells to larger cells that are highly modulated by cold pools, consistent with observations. When the diurnal cycle is removed, clouds are persistently shallower with virtually no rainfall, emphasizing the inherent nonlinearity of the cumulus diurnal cycle. © 2016. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75916
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States; Now at Max Planck Institute for Meteorology, Hamburg, Germany
Recommended Citation:
Ruppert J,H,, Johnson R,et al. On the cumulus diurnal cycle over the tropical warm pool[J]. Journal of Advances in Modeling Earth Systems,2016-01-01,8(2)