Search Results

You are looking at 21 - 30 of 22,964 items for :

  • Middle atmosphere x
  • All content x
Clear All
B. K. Mukherjee, K. S. Rao, and Bh V. Ramana Murty

JOURNAL OF THE ATMOSPHERIC SCIENCES VOL. 4I, No. 4Vertical Motions within the Indian Tropical Middle AtmosphereB. K. IV[UKHERJEE, K. $. RAJA RAO AND BH. V. RAMANA ]V[URTYIndian Institute of Tropical Meteorology, Pune-411005, India(Manuscript received 2 May 1983, in final form 26 September 1983) Computations of vertical motions in the middle atmosphere over the Indian tropical region have been madebased on the thermodynamic

Full access
Erich Becker and Charles McLandress

incurred when using high spatial resolution (e.g., Hamilton et al. 1999 ; Becker 2009 ), the effects of small-scale GWs must be parameterized in general circulation models (GCMs) that are used for climate simulations. Consequently, for the foreseeable future there will be a continued need for GW parameterizations in comprehensive middle atmosphere GCMs ( Fomichev et al. 2002 ; Fritts and Alexander 2003 ; Schmidt et al. 2006 ; McLandress et al. 2006 ). Because of the many simplifying assumptions

Full access
Rolando R. Garcia

VOL. 44, NO. 24 JOURNAL OF THE ATMOSPHERIC SCIENCES 15 DECEMBER 1987On the Mean Meridional Circulation of the Middle Atmosphere ROLANDO R. GARCIA National Center for Atmospheric Research* Boulder, CO 80307(Manuscript received 13 November 1986, in final form 15 May 1987) ABSTRACT A zonally averaged, quasi-geostrophic residual Eulerian model is used to illustrate how the

Full access
H-L. Liu, F. Sassi, and R. R. Garcia

predictability (e.g., Kalnay 2003 ). In recent years, there has been increasing development of general circulation models (GCMs) and mechanistic models of the middle and upper atmosphere, and also models that extend from the earth’s surface to the middle or upper atmosphere. Examples of the former include the National Center for Atmospheric Research (NCAR) Thermosphere, Ionosphere, Mesosphere, and Electrodynamics General Circulation Model (TIME-GCM) (e.g., Roble 2000 ), the ROSE model ( Rose and Brasseur

Full access
Jason Goodman and John Marshall

) and McCartney et al. (1997) . Frankignoul (1985) concisely reviews middle-latitude atmosphere–ocean interactions. Many researchers suggest the atmosphere generates the climate variations on its own, and the ocean reacts passively to that stimulus. Some modeling studies (e.g., James and James 1989 ) show that a model atmosphere is capable, in the presence of fixed surface boundary conditions (fixed ocean), of exhibiting long-term persistent (climate) states, in clear contradiction to the usual

Full access
L. J. Sonmor and G. P. Klaassen

1. Introduction There is now nearly universal agreement that gravity waves generated in the troposphere provide a strong mesospheric drag force that controls the middle-atmosphere winds and maintains the observed radiative disequilibrium in the temperature distribution. However, there remains a great deal of uncertainty regarding both the nature of the source spectrum and the mechanisms responsible for the wave dissipation associated with the momentum flux divergence that causes the drag

Full access
Mark R. Schoeberl and Darrell F. Strobel

AemL1978 MARK R. SCHOEBERL AND DARRELL F. STROBEL 577The Zonally Averaged Circulation of the Middle Atmosphere MARK R. SCItOEBERL1Science Applications Inc., McLean, Va. 22101 DARRELL F. STROBELNaval Research Laboratory, Washington, D. C. 80375(Manuscript received 13 July 1977, in final form 5 December 1977)ABSTRACT The steady-state, zonally averaged circulation of the middle

Full access
Ruth S. Lieberman

1112 JOURNAL OF THE ATMOSPHERIC SCIENCES VOL. 48, NO.$Nonmigrating Diurnal Tides in the Equatorial Middle Atmosphere RUTH S. LIEBERMANDepartment of Atmospheric Sciences, University of Washington, Seattle, WashingtonManuscript received 26 June 1990, in final form 16 November 1990) Data from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) are used to extend the analysisof diurnal tides in the

Full access
Charles McLandress and Theodore G. Shepherd

1. Introduction Recent simulations using comprehensive middle atmosphere models predict an increase in the Brewer–Dobson circulation (BDC) in response to climate change, as diagnosed by changes in lower stratospheric tropical upwelling ( Butchart et al. 2000 ; Butchart and Scaife 2001 ; Sigmond et al. 2004 ; Butchart et al. 2006 ; Fomichev et al. 2007 ; Li et al. 2008 ; Garcia and Randel 2008 ). This increase is due to an increase in wave drag in the extratropical stratosphere, as

Full access
Jae H. Park and Julius London

sinks in the earth's middle atmosphere (30-100 kin) are investigated. The latitudinaland seasonal distributions of radiative heating rates for the region 30-100 km are computed consideringthe absorption of solar UV by O3 and Oa and the chemical heat release by O(~P) recombination. Absorptionof solar radiation by O3 is responsible for most of the radiative heating in the region 30-75 kin. Between75 and 90 km the heating rate is relatively small and is contributed to about equally by absorption by O

Full access