Search Results

You are looking at 101 - 110 of 14,279 items for :

  • Atmosphere-land interactions x
  • All content x
Clear All
Nuria Vargas and Víctor Magaña

rural and urban regions. The MCMA is located in the lower part of the valley of Mexico, surrounded by mountains ( Fig. 1 ). The temperature decreases with height, resulting in a natural large thermal gradient between the lower and higher parts. But the MCMA UHI has formed mainly in relation to land-use changes, from natural vegetation to urban infrastructure. Therefore, the UHI may be defined as a canopy-layer UHI ( Oke et al. 2017 ), where deforestation and urbanization enhance the local warming

Free access
Mimi Stith, Alessandra Giannini, John del Corral, Susana Adamo, and Alex de Sherbinin

). Independent of evidence from remote sensing, climate research had already demonstrated that large-scale drying could be explained by factors external to the region, namely, changes in the surface temperature of the global oceans ( Folland et al. 1986 ), with no need to invoke regional-scale land degradation and its interaction with atmospheric dynamics as originally envisaged. More recent research has confirmed the dominant role of global sea surface temperature patterns in driving the twentieth

Full access
Patrick D. Broxton, Xubin Zeng, William Scheftic, and Peter A. Troch

1. Introduction Vegetation cover influences the land–atmosphere exchanges of water, energy, and carbon (e.g., Dickinson et al. 1986 ; Sellers et al. 1996 ; Bonan 1996 ; Dai et al. 2003 ). Green vegetation fraction (GVF; Deardorff 1978 ) is widely used in global models along with many other applications such as studies of land-cover (LC) change. Along with leaf area index (LAI; Myneni et al. 2002 ), GVF is used to describe the abundance of vegetation in most global models. Some models

Full access
Trevor Lewis and Walter Skinner

variations in land cover, such as vegetation and surface water ( Roy et al., 1972 ; Blackwell et al., 1980 ; Cermak et al., 1992 ; Lewis and Wang, 1992 ; Lewis and Wang, 1998 ). These effects must be modeled and accounted for. The underground temperature anomalies from surface cover changes, both temporal and spatial, have been shown to be both consistently and accurately predicted by simple models. GST histories inverted from borehole temperatures are site specific. To reach conclusions on climatic

Full access
Jason A. Otkin, Martha C. Anderson, Christopher Hain, Iliana E. Mladenova, Jeffrey B. Basara, and Mark Svoboda

becomes strong after significant damage has already occurred to the vegetation ( Moran 2003 ). A faster response signal of incipient drought stress may be conveyed through remotely sensed maps of land surface temperature (LST), retrieved using satellite-based thermal infrared (TIR) observations ( Anderson et al. 2013 ). As the amount of root zone moisture decreases, less energy is used to evaporate and transpire water, thereby causing canopy temperatures to elevate in comparison with unstressed

Restricted access
Jiangfeng Wei, Paul A. Dirmeyer, and Zhichang Guo

intraseasonal variability of precipitation has a strong influence on the soil moisture variability ( Wei et al. 2008 ), but little study has been performed on the connection between this variability and land–atmosphere coupling. By comparison, the connection between intraseasonal variability and air–sea interaction has been studied much better (e.g., Pegion and Kirtman 2008a , b ). In this paper, GLACE-type experiments with the COLA AGCM coupled to three land models are performed. We examine the large

Full access
Daniel R. Cheresnick and Jeffrey B. Basara
Full access
Gokhan Kirkil, Jeff Mirocha, Elie Bou-Zeid, Fotini Katopodes Chow, and Branko Kosović

1. Introduction The atmospheric boundary layer (ABL) is the lowest layer of the earth’s atmosphere through which exchanges of momentum, energy, and other chemical species with the surface are transported vertically, via turbulent motions, on a time scale that is rapid in comparison with exchanges within the free atmosphere above (e.g., Stull 1988 ). As such, the ABL plays a critical role in both the evolution of flow near the surface, and in the evolution of larger-scale weather phenomena as

Full access
Timothy DelSole, Mei Zhao, and Paul Dirmeyer

circulation that is more complicated than the regional land–atmosphere interaction discussed earlier. Finally, the maximum height tends to be larger downwind from coastal boundaries and insignificant over the oceans, reflecting the moderating effect of maritime air on land–atmosphere feedback. We performed several other statistical analyses of the deep tropics but were not able to formulate a satisfactory picture of why this region stands out relative to midlatitudes. We stress, however, that the mere

Full access
Joseph A. Santanello Jr., Mark A. Friedl, and Michael B. Ek

and feedbacks caused by land–atmosphere interactions has been under scrutiny. For example, results from the Project for Intercomparison of Land-surface Parameterization Schemes (PILPS; Henderson-Sellers et al. 1996 ) experiments have shown that simulated fluxes can be quite sensitive to atmospheric feedbacks ( Liu et al. 2003 , 2004 , 2005 ). As a result, it is clear that the land surface and planetary boundary layer cannot be realistically simulated independently of one another, and that land

Full access