Search Results

You are looking at 111 - 120 of 3,529 items for :

  • Journal of the Atmospheric Sciences x
  • Refine by Access: All Content x
Clear All
Robert M. Haberle, Howard C. Houben, Rolf Hertenstein, and Tomas Herdtle

Martian soil. The data used for comparison were obtained by the Viking I and 2 landers for early northern summer. Ateach site, these data include a single profile of wind and temperature between 1.5 and 4 km and their diurnalvariations at 1.6 m above the surface. Model-predicted temperatures are in good agreement with the data, thoughthey show a greater variation at 1.6 m than is evident in the data. Model-predicted winds compare less favorablyin that they can match the surface data or the profiles

Full access
M. T. Chahine, H. H. Aumann, and F. W. Taylor

verified in thispaper. The verification is based on radiance data measured in the 4.3 and 15 ~m COg bands using a multidetector sounder mounted on an aircraft. The results presented here show that, from the aircraft heightof 7.6 km and in the presence of multiple cloud formations, it is possible to recover simultaneously: 1) The clear-column atmospheric temperature profile with an rlns error of 1 K with respect to radiosondes. 2) The land and sea surface temperature at all sun zenith angles. The

Full access
Étienne Vignon, Ghislain Picard, Claudio Durán-Alarcón, Simon P. Alexander, Hubert Gallée, and Alexis Berne

2015 ; Alexander et al. 2017 ), over the trans-Antarctic mountains ( Baumgaertner and McDonald 2007 ; Zhao et al. 2017 ) or over nunataks in Dronning Maud Land ( Valkonen et al. 2010 ). Using global climate simulations, Watanabe et al. (2006) show that fierce katabatic winds are also responsible for the excitation of large scale—with horizontal wavelengths of several hundred kilometers—orographic gravity waves when they reach the abrupt coastal slopes of the ice sheet. Inspecting the vertical

Free access
Kay Sušelj, João Teixeira, and Georgios Matheou

updrafts in the SCM. In the current scheme, the updraft PDF of θ L and q t is utilized to define the condensation within the updraft. This is an encouraging result since it shows that a simple updraft scheme is physically sound. In future versions of the model, it could be used, for example, for the parameterization of radiation. b. ARM case The ARM case corresponds to nonstationary convection over land forced by a diurnal variation of surface sensible and latent heat fluxes. The SCM model can

Full access
Christian L. Keppenne and Andrew P. Ingersoll

, California Institute of Technology, Pasadena, California(Manuscript received 25 August 1993, in final form 7 November 1994)ABSTRACT A shallow water model with realistic topography and idealized zonal wind forcing is used to investigateorographically forced modes in the Martian atmosphere. Locally, the model produces barotropic modes withperiods within the broad range of periods observed at the sites of Viking Lander I and//(VL1 and VL2) duringthe fall and spring seasons. Its variability at those sites

Full access
David James Brayshaw, Brian Hoskins, and Michael Blackburn

to be plotted in similar units. As in Brayshaw et al. (2008) , we use the 250-hPa level for E H and the 850-hPa level for E p , and λ corresponds to damping time scales ( λ −1 ) of 0.7 and 0.35 days over ocean and land, respectively. Here the pressure depths Δ p 1 and Δ p 2 are taken as 450 and 150 hPa, respectively. The former is twice that used in Brayshaw et al. (2008) because this has been found to be a better representation of the upper tropospheric structure. A weak smoothing is

Full access
William Physick

used to investigate the circulations induced by differential heating in the vicinity of a land-locked semi-infinite body of water. The semi-empiricalboundary-layer formulation of Clarke is used with an expanding ~ grid of 15 vertical levels. Surface temperature is computed by means of a heat-flux balance equation and a radiation condition is used at the lateralboundaries. For purposes of comparison, one run was also made with reflective boundary conditions and itwas found that the two solutions

Full access
Vladimir M. Gryanik, Christof Lüpkes, Andrey Grachev, and Dmitry Sidorenko

of turbulent mixing, so that it does not help to solve the well known problems of nocturnal boundary layer decoupling over land ( Louis 1979 ) and of a too weak life cycle of atmospheric cyclones in polar regions ( Jung et al. 2016 ; Vihma et al. 2014 ). On the contrary, the use of the G2007a functions would make the solution of these problems even more difficult. Indeed, the functions of G2007a provide almost the lowest surface fluxes in the above mentioned stability range from all

Open access
Mian Chin, Paul Ginoux, Stefan Kinne, Omar Torres, Brent N. Holben, Bryan N. Duncan, Randall V. Martin, Jennifer A. Logan, Akiko Higurashi, and Teruyuki Nakajima

at a few surface sites. In our study, we have used a factor of 8–10 higher spatially resolved model and assimilated meteorological data. We have incorporated the most recent and much improved aerosol sources, especially dust and biomass burning emissions. Our results are compared with the very recent satellite retrieval of aerosol optical thickness from the Total Ozone Mapping Spectrometer (TOMS; Torres et al. 2002 ) over both land and ocean, and with two different AVHRR retrieval products

Full access
Jonathan Poterjoy and Fuqing Zhang

levels, most of which are concentrated in the lowest 8 km, with the model top at 10 hPa. The physical parameterization schemes used for this study include the Grell–Devenyi cumulus scheme ( Grell and Devenyi 2002 ) for the two course domains, WRF single-moment six-class microphysics with graupel ( Hong et al. 2004 ), a thermal diffusion scheme for the land surface, the Monin–Obukhov scheme for the surface layer, and the Yonsei State University (YSU) scheme ( Noh et al. 2003 ) to parameterize

Full access