Search Results

You are looking at 61 - 70 of 78 items for :

  • Boundary currents x
  • Meteorological Monographs x
  • Refine by Access: All Content x
Clear All
Sue Ellen Haupt, Robert M. Rauber, Bruce Carmichael, Jason C. Knievel, and James L. Cogan

growth of raindrops, which then fall to the surface as precipitation in a time frame shorter than the lifetime of the cloud. Hygroscopic dynamic-mode seeding hypothesis: Seeding a cumulus congestus/cumulonimbus with hygroscopic nuclei initiates rainfall through the collision–coalescence process. Once rain develops, evaporation below cloud base triggers the formation of cool-air outflows. Lifting along the outflow boundaries forms new convective cells, increasing areal coverage of convection and

Full access
S. A. Ackerman, S. Platnick, P. K. Bhartia, B. Duncan, T. L’Ecuyer, A. Heidinger, G. Skofronick-Jackson, N. Loeb, T. Schmit, and N. Smith

over the last six decades of atmospheric satellite observations, along with selected examples to demonstrate the importance of space-based assets to our current understanding of the atmosphere. While progress truly has been an international achievement, in accord with a monograph observing the centennial of the American Meteorological Society, as well as limited space, our emphasis is on the U.S. satellite effort. The notion of viewing the Earth from high above was conceived well before the birth

Full access
Guoxiong Wu and Yimin Liu

-II reanalysis for the period 1979–98. It is evident that deviating air currents flow from the winter hemisphere into the summer hemisphere, diverging out of continents and converging toward oceans in midlatitude areas in the winter hemisphere, but converging toward the continents and diverging out of oceans in the summer hemisphere. A remarkable circulation reversal appears over the Asian–Australian (A–A) monsoon area. In January the surface air diverges out of the TP region toward South Africa and

Full access
J. Verlinde, B. D. Zak, M. D. Shupe, M. D. Ivey, and K. Stamnes

experienced difficulty representing the boundary layer temperature inversion height and strength, overestimated the cloud fraction by 20% or more, and underestimated the liquid water path by over 50% in the cold season. In similar studies, but looking at different models, de Boer et al. (2012) found similar problems with the critical lower-troposphere processes and phenomena in the Community Climate System Model, version 4, and Walsh et al. (2009) found biases in radiative fluxes and cloud radiative

Full access
Daniel J. Cziczo, Luis Ladino, Yvonne Boose, Zamin A. Kanji, Piotr Kupiszewski, Sara Lance, Stephan Mertes, and Heike Wex

in hydrometeors are called ice residuals (IRs). To date, attempts to compare ice number density to residuals have proven difficult because of shattering of ice crystals on cloud probes ( Korolev and Isaac 2005 ; Cziczo and Froyd 2014 ). For these reasons, IRs and INPs cannot currently be assumed to be identical. Table 8-1. List of acronyms. Nevertheless, atmospheric IRs have been studied to understand which particles initiated the formation of ice crystals. One technique is to examine particles

Full access
Beat Schmid, Robert G. Ellingson, and Greg M. McFarquhar

) again suggested that cloudy skies absorb more shortwave radiation than predicted by current models. Unfortunately, these studies were not able to define a region in the solar spectrum where the anomalous absorption was taking place. In the end, uncertainties concerning the instrumentation, the small number of overcast samples, and the meteorological conditions led to a variety of challenges to the conclusions (see Smith et al. 1997 ; Li et al. 1999 ; O’Hirok et al. 2000 ). Therefore, questions

Full access
V. Ramaswamy, W. Collins, J. Haywood, J. Lean, N. Mahowald, G. Myhre, V. Naik, K. P. Shine, B. Soden, G. Stenchikov, and T. Storelvmo

describing the agents driving Earth’s climate change since preindustrial times (1750) and the formulation of the “radiative forcing” (RF) (see section 2 ) of climate change. The central purpose of this paper is to trace the progression in the RF concept leading to our current knowledge and estimates of the major agents known to perturb climate. Below, we give a perspective into the key milestones marking advances in the knowledge of RF. Subsequent sections of the paper focus on the evolution of the

Full access
Guang J. Zhang and Xiaoliang Song

precipitation efficiency in convection. They found that clouds with high precipitation efficiency produced cold and dry climate and clouds with low precipitation efficiency produced moist and warm climate. They argue that convective parameterization schemes currently in use in GCMs bypass the microphysical processes by making arbitrary assumptions on convective precipitation and moistening, and thus are inadequate for climate change studies. Early convection parameterization schemes treat cloud microphysics

Full access
E. J. Mlawer and D. D. Turner

, radiative transfer model calculations at wavenumbers as small as 220 cm −1 (45 μ m) could be evaluated with the RHUBC-II dataset. Five interferometers were deployed during RHUBC-II, along with one of the 183-GHz radiometers from RHUBC-I. This experiment provided the first complete spectral measurement of the entire downwelling terrestrial infrared spectrum from the ground ( Turner et al. 2012b ) and demonstrated that to first order the current water vapor continuum model, which includes the big change

Full access
Mark P. Baldwin, Thomas Birner, Guy Brasseur, John Burrows, Neal Butchart, Rolando Garcia, Marvin Geller, Lesley Gray, Kevin Hamilton, Nili Harnik, Michaela I. Hegglin, Ulrike Langematz, Alan Robock, Kaoru Sato, and Adam A. Scaife

be better understood and represented in the climate models employed to predict how our atmosphere is likely to evolve in the future. However, we are currently in a period where many relatively long-lived satellite missions have ended or are well over their guaranteed lifetime in space. It is unclear whether there will be an adequate set of satellite observations to meet the future needs of the scientific community. The lack of an adequate continuous set of measurements providing vertical profiles

Full access