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Weile Wang, Bruce T. Anderson, Dara Entekhabi, Dong Huang, Yin Su, Robert K. Kaufmann, and Ranga B. Myneni

1. Introduction Terrestrial vegetation covers more than 70% of the Earth’s land surface and can be looked at as one of many dynamic interfaces between the land and the atmosphere. On the one hand, vegetation is strongly controlled by climate, and thus variations in surface temperature, precipitation, and solar radiation will cause subsequent variations in vegetation (e.g., Budyko 1974 ; Walter 1985 ; Woodward 1987 ). On the other hand, because vegetation plays an active role in regulating

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Allison L. Steiner, Dori Mermelstein, Susan J. Cheng, Tracy E. Twine, and Andrew Oliphant

1. Introduction The surface energy budget describes the exchange of energy, mass and momentum between the land surface and the atmosphere and is strongly impacted by incoming solar radiation. Radiation absorbed at the surface ( R n ) is stored in surface elements (often approximated by the ground heat flux G ) or transported into the atmosphere via sensible ( H ) or latent ( λE ) heat fluxes. This relationship can be written as The Bowen ratio ( B ), or the ratio of H to λE , quantifies the

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Mônica Carneiro Alves Senna, Marcos Heil Costa, Lucía Iracema Chipponelli Pinto, Hewlley Maria Acioli Imbuzeiro, Luciana Mara Freitas Diniz, and Gabrielle Ferreira Pires

( Cox et al. 2000 ; Friedlingstein et al. 2001 ; Friedlingstein et al. 2006 ) and climate change ( Betts et al. 1997 ; Brovkin et al. 1999 ; Foley et al. 2000 ; Liu et al. 2006 ; Notaro et al. 2007 ). The initial climate projections with a coupled ocean–vegetation–atmosphere general circulation model that consider carbon exchanges among the oceans, land, and atmosphere showed that the overall effect of carbon–climate interaction is a positive feedback, mostly because of the negative impacts of

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Ruixin Yang, Allison Fairley, and Wonsun Park

cold groups, there are many short flat segments in the counts of the named storms. This figure clearly demonstrates the commonly accepted relationship between ENSO and TC activity in the Atlantic, cold episodes being favorable to TCs and warm episodes depressing TCs as the cold average is always higher than the warm average. However, this relationship is only significant for certain periods such as the most recent period starting in the 1980s. In the middle part of the whole study time range, from

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Tomas F. Domingues, Joseph A. Berry, Luiz A. Martinelli, Jean P. H. B. Ometto, and James R. Ehleringer

; Williams et al. 1998 ; Asner et al. 2000 ; Botta and Foley 2002 ; Chou et al. 2002 ; Zhan et al. 2003 ; Santos and Costa 2004 ). While some studies identified rain forest Amazonian ecosystems as sinks for atmospheric carbon ( Grace et al. 1995 ; Malhi et al. 1998 ; Phillips et al. 1998 ; Andreae et al. 2002 ; Araújo et al. 2002 ; Carswell et al. 2002 ), other studies indicate an equilibrium situation or even that these ecosystems are a source of CO 2 to the atmosphere ( Chou et al. 2002

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Wilfrid Schroeder, Jeffrey T. Morisette, Ivan Csiszar, Louis Giglio, Douglas Morton, and Christopher O. Justice

:// ). During these months, a large high pressure system tends to cover the region, inhibiting precipitation and reducing relative humidity due to the subsidence of dry air from the upper levels of the atmosphere ( Figueroa and Nobre 1990 ; Nobre et al. 1998 ). These circulation patterns result in the retention of smoke emitted by burning over a large horizontal expanse, reducing visibility to the point of closing airports and causing respiratory problems among local populations ( Reinhardt et al. 2001

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Thomas F. Lee, Francis J. Turk, Jeffrey Hawkins, and Kim Richardson

images from 37 GHz. 2. Passive microwave imaging The SSM/I instrument is a passive microwave radiometer that collects radiation naturally emitted by the surface of the Earth and the intervening atmosphere ( Table 1 ). In the Tropics, large gaps appear between successive 1400-km swaths of the SSM/I. However, in recent years there have been at least two, and sometimes three, DMSP polar-orbiting spacecraft with SSM/I instruments in orbit at any given time, increasing the frequency of coverage and

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Daniel M. Brown, Gerhard W. Reuter, and Thomas K. Flesch

year in the biggest box (defined in Figure 2 ). (b) Blue lines are the ratio (percentage) of the lightning density in the innermost area to that in the middle ring. Shown in (b) is the ratio of the lightning density in the innermost area to that in the outer ring. The areas and rings are defined in Figure 2 . 4. Discussion and conclusions Based on the analysis described above, we conclude that the oil sands development has raised local overnight temperatures in all seasons (statistically

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Mustapha El Maayar, Navin Ramankutty, and Christopher J. Kucharik

atmospheric chemistry, through its exchanges of energy, momentum, water vapor, and various trace gases such as CO 2 and CH 4 with the atmosphere ( Schlesinger 1991 ; Pielke et al. 1998 ). For that reason, considerable efforts have been made over the last three decades to develop terrestrial ecosystem models that describe the multiple interactions that occur at the land surface, and between the surface and the atmosphere at varying spatiotemporal scales ( Foley 1995 ; Hurtt et al. 1998 ). For instance

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Sandra I. Saad, Humberto R. da Rocha, Maria A. F. Silva Dias, and Rafael Rosolem

, over hundreds of square kilometers, and do not commonly agree on the impacts of deforestation. The question of how rainfall may change over local and mesoscale (<10 2 and 10 2 –10 5 km 2 ; D’Almeida et al. 2007 ) deforestation areas is widely open. Soil water storage, clouds, and aerosols play a substantial role in land–atmosphere coupling in the Amazon, where processes of precipitation show strong seasonal variability and cloud growth and formation influenced by fires ( Betts and Silva Dias

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