Search Results

You are looking at 51 - 60 of 9,053 items for :

  • Journal of the Atmospheric Sciences x
  • Refine by Access: All Content x
Clear All
Hye-Yeong Chun, In-Sun Song, and Takeshi Horinouchi

generated by cumulus clouds have high frequencies and they contribute significantly to the momentum forcing required for driving the quasi-biennial oscillation and semiannual oscillation ( Dunkerton 1997 ; Hamilton 1998 ). Compared with mountain-induced gravity waves, it is not straightforward to understand how convective sources generate gravity waves. In the literature, three generation mechanisms (thermal forcing, obstacle, and mechanical oscillator mechanisms) have been proposed ( Lane et al. 2001

Full access
Robert Gall, Richard Blakeslee, and Richard C. J. Somerville

1692 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUM-36Cyclone-Scale Forcing of U!tralong Waves ROBERT GALL AND RICHARD BLAKESLEEInstitute of Atmospheric Physics, The University of Arizona, Tucson, AZ 85721 RICHARD C. J. SOMERVILLENational Center for Atmospheric Research~, Boulder, CO 80307(Manuscript received 26 December 1978; in final form 4 May 1979)ABSTRACT A numerical experiment is

Full access
Werner Metz

1 SEPTEMBER 1987WERNER METZ2407Transient Eddy Forcing of Low-Frequency Atmospheric VariabilityWERNER METZMeteorological Institute, University of M-nchen, Federal Republic of Germany(Manuscript received 19 August 1986, in final form 16 February 1987)ABSTRACTThis paper is concerned with the forcing of the low-frequency variability (10 days up to 3 months) of thebarotropic planetary waves (wavenumbers 1 to 4) for wintertime conditions in the Northern Hemisphere. Inparticular, the forcing by the

Full access
J. F. Scinocca and P. H. Haynes

weak, a greater proportion of the planetary wave activity in the wintertime stratosphere is associated with travelling, rather than stationary, disturbances (e.g., Randel 1987 ; Manney et al. 1991 ; Yamazaki and Mechoso 1985 ; Mechoso et al. 1988 ). Another important tropospheric source of planetary wave forcing is likely to be associated with synoptic-scale weather systems. Only the largest scale disturbances can propagate upward into the stratosphere. While the weather systems themselves have

Full access
Max Popp, Hauke Schmidt, and Jochem Marotzke

1. Introduction In the 1960s, the idea was advanced that, under strong radiative forcing, a runaway water vapor feedback may occur, which may lead to the evaporation of all oceans on an Earthlike planet (e.g., Gold 1964 ; Komabyashi 1967 ; Ingersoll 1969 )—the runaway greenhouse. The idea was used to explain how Venus could have lost most of its water and could have ended up with the inhospitable atmosphere that it has today. Even though 50 years have passed, the role of clouds in the

Full access
Nicholas M. J. Hall

1. Introduction There are a multitude of different approaches to modeling climate perturbations. Often the approaches are complementary. A comprehensive general circulation model (GCM) might simulate the observed climate realistically using principles that are as physically based as possible. This engenders a certain amount of confidence in the GCM’s ability to simulate perturbations to the climate, whether they arise from anomalous external forcing or internal variability. However, GCMs are

Full access
Douglas A. Stewart

2710 JOURNAL OF THE ATMOSPHERIC SCIENCES VOL. 50, No. 16Persistent Anomaly Forcing in a Two-Level Global Circulation Model DOUGLAS A. STEWARTEnvironmental Dynamics Research, Inc., Miami, Florida(Manuscript received 29 January 1992, in final form 26 November 1992) ABSTRACT Perpetual January data from a simple global two-level model are used to diagnose the forcing of the

Full access
Gunnar Myhre, Frode Stordal, Tore F. Berglen, Jostein K. Sundet, and Ivar S. A. Isaksen

1. Introduction Several global studies of the direct effect of sulfate aerosols have been performed with large differences in the estimates of the radiative forcing ( Myhre et al. 1998 ; Haywood and Boucher 2000 ; Adams et al. 2001 ; Houghton et al. 2001 ). In addition to uncertainties in the global burden of sulfate, uncertainties in the forcing have several causes. First, there are uncertainties connected to the optical properties of sulfate aerosols. The optical properties adopted in the

Full access
Jun Zhai and William Boos

of monsoon dynamics. In the past 30 years, multiple theoretical advances made in understanding Earth’s Hadley circulation have been extended to solstice-like conditions representative of monsoons. Held and Hou (1980) developed an axisymmetric 1 theory for the strength and meridional extent of the annual-mean Hadley circulation, and Lindzen and Hou (1988) extended this theory to cross-equatorial flow driven by off-equatorial thermal forcings. Central to this axisymmetric theory is the idea

Full access
Sergio A. Sejas and Ming Cai

atmosphere, ocean, and land are changed. The perturbed variables of the climate system can amplify or suppress the surface warming response to the CO 2 forcing alone (i.e., without feedbacks). It is these climate feedbacks, triggered by the CO 2 forcing, that account for most of the global surface warming response ( Hansen et al. 1984 ; Wetherald and Manabe 1988 ; Zhang et al. 1994 ; Colman 2003 ; Soden and Held 2006 ; Taylor et al. 2013 ; Yoshimori et al. 2014 ). When the forcing and climate

Full access