Search Results

You are looking at 1 - 10 of 98 items for :

  • Middle atmosphere x
  • Earth Interactions x
  • All content x
Clear All
D. Rind and X. Liao

1. Introduction Atmospheric aerosols, ozone, water vapor, and NO 2 all play important roles in global radiative and atmospheric chemical processes. Natural activities, for example, major volcanic eruptions, can inject gaseous sulfur dioxide, dust, and other chemicals into the upper atmosphere and therefore affect the radiative forcing of the climate system. Human activities also perturb the balance of atmospheric aerosols and trace gases. Since 1984, the Stratospheric Aerosol and Gas

Full access
Marcello Gugliotta, Jonathan G. Fairman Jr., David M. Schultz, and Stephen S. Flint

the atmosphere and ocean general circulation models as well as an interactive sea ice model. Topography, vegetation, and land surface type are fixed. Our control simulation was initialized by interpolating the Middle Jurassic paleogeographic reconstruction at 170 million years ago ( Colorado Plateau Geosystems 2014 ) to the model grid (cf. Figures 1b and 6a ). Because of the uncertainty in the paleobathymetry and for simplicity, the ocean depths were set to 110 m on continental shelves and 3100

Full access
Sébastien Gervois, Nathalie de Noblet-Ducoudré, Nicolas Viovy, Philippe Ciais, Nadine Brisson, Bernard Seguin, and Alain Perrier

Europe, de Noblet-Ducoudré (2005) simulated milder and wetter winters, and cooler summers, caused by both increased albedo and greater evapotranspiration rates when comparing present-day land cover with potential vegetation distribution (e.g., before the large deforestation of the Middle Ages). These modeling studies all agree that land-cover changes can have a significant impact on regional (and possibly global) climates, although their results differ quantitatively, and sometimes qualitatively

Full access
Jinyang Du and Qiang Liu

vertically polarized microwave radiation at 12 channels and six frequencies ranging from 6.9 to 89.0 GHz. Its observations at moderately low frequencies are very sensitive to land water in various forms, such as soil moisture, vegetation water content, and snow, and are little affected by atmosphere conditions. AMSR-E was launched in June 2002 and functioned well until October 2011. During this period, TGD experienced two impounding stages: the initial stage of impoundment with a water level increasing

Full access
Michael Garstang, David R. Fitzjarrald, Kurt Fristrup, and Conrad Brain

. ( Garstang et al. 1995 ) and Larom et al. ( Larom et al. 1997 ) used atmospheric observations of temperature and wind velocities in the lower atmosphere (<400 m) together with an acoustic model to calculate the maximum distances over which elephant calls could be heard by other elephants. They assumed a hearing threshold of 50 dB SPL ( Heffner and Heffner 1982 ), a value that is supported by the Langbauer et al. ( Langbauer et al. 1991 ) playback experiment assuming spherical spreading losses: 112 dB

Full access
A L. Hirsch, A. J. Pitman, J. Kala, R. Lorenz, and M. G. Donat

evapotranspiration ( Fischer et al. 2007 ; Lorenz et al. 2010 ; Jaeger and Seneviratne 2011 ; Zhang and Wu 2011 ; Mueller and Seneviratne 2012 ; Roundy et al. 2014 ). LUC modifies the biophysical characteristics of the land surface, the surface energy balance ( Boisier et al. 2012 ), and how the land connects to the boundary layer. In Australia, LUC is most commonly associated with a change from native forest to grasslands and crops and is known through observations to affect the atmosphere. Early studies

Full access
Brent M. Lofgren, Andrew D. Gronewold, Anthony Acciaioli, Jessica Cherry, Allison Steiner, and David Watkins

impacts from climatic projections also need to be considered. There are special considerations depending on the region. For instance, ice and snow processes are a special challenge at high and middle latitudes for varying portions of the year. Regions with a high amount of inland water or with ocean coasts have special interactions between land and water surfaces, mediated by the atmosphere. Again, energy budget–based methods of ET maintain consistency between the surface and atmosphere by making the

Full access
Lori T. Sentman, Elena Shevliakova, Ronald J. Stouffer, and Sergey Malyshev

1. Introduction The terrestrial biosphere is an important component of the global carbon cycle and actively exchanges carbon with the atmosphere on varying time scales. Conversion of natural lands for agriculture and wood harvesting has shaped the land surface for centuries. Hurtt et al. ( Hurtt et al. 2006 ) found that 42%–68% of the global land surface was altered by anthropogenic land-use activities between 1700 and 2000. Pongratz et al. ( Pongratz et al. 2009 ) showed that anthropogenic

Full access
Lei Meng and Yanjun Shen

1. Introduction Interactions between soil moisture (SM) and climate have received much attention because of their potential for improving long-term and large-scale climate prediction. SM is an important component in the climate system and its variation can affect water and energy exchange between the surface and the boundary layer of the atmosphere ( Seneviratne et al. 2010 ). Previous research has shown that SM anomalies can have substantial impacts on precipitation in the transitional region

Full access
Richard Seager, Nathan Lis, Jamie Feldman, Mingfang Ting, A. Park Williams, Jennifer Nakamura, Haibo Liu, and Naomi Henderson

arid–humid divide but concurred with Powell about its physical and human significance: As one contrasts the civilization of the Great Plains with that of the eastern timberland, one sees what may be called an institutional fault (comparable to a geological fault) running from middle Texas to Illinois or Dakota, roughly following the ninety-eighth meridian. At this fault the ways of life and of living changed. Practically every institution that was carried across it was either broken and remade

Full access