Abstract
Abstract. The continental tropics play a leading role in the terrestrial energy, water, and carbon cycles. Land–atmosphere interactions are integral in the regulation of these fluxes across multiple spatial and temporal scales over tropical continents. We review here some of the important characteristics of tropical continental climates and how land–atmosphere interactions regulate them. Along with a wide range of climates, the tropics manifest a diverse array of land–atmosphere interactions. Broadly speaking, in tropical rainforest climates, light and energy are typically more limiting than precipitation and water supply for photosynthesis and evapotranspiration (ET), whereas in savanna and semi-arid climates, water is the critical regulator of surface fluxes and land–atmosphere interactions. We discuss the impact of the land surface, how it affects shallow and deep clouds, and how these clouds in turn can feed back to the surface by modulating surface radiation and precipitation. Some results from recent research suggest that shallow clouds may be especially critical to land–atmosphere interactions. On the other hand, the impact of land-surface conditions on deep convection appears to occur over larger, nonlocal scales and may be a more relevant land–atmosphere feedback mechanism in transitional dry-to-wet regions and climate regimes.
Highlights
The tropics play a substantial role in regulating the global hydrologic and carbon cycles
Tropical rainforests are one of the main terrestrial carbon sinks (Nakicenovic and Swart, 2000; Friedlingstein et al, 2006), but their projected responses to a warming climate remain unclear because of uncertainties associated with the representation of abiotic and biotic processes in models as well as confounding factors such as deforestation and changes in land use and land cover (Wang et al, 2009; Davidson et al, 2012; Fu et al, 2013; Saatchi et al, 2013; Hilker et al, 2014; Boisier et al, 2015; Doughty et al, 2015; Gatti et al, 2015; Knox et al, 2015; Saleska et al, 2016)
Some regions of the tropics have been further identified as hotspots in which land–atmosphere interactions modify the climate (Dirmeyer, 2011; Koster et al, 2011; Green et al, 2017) locally, i.e., at horizontal scales on the order of a few boundary layer heights, regionally, at scales up to a few hundred kilometers, or at larger scales, over several thousand kilometers, through coupling between the surface and the overlying atmosphere (Lintner and Neelin, 2009)
Summary
The tropics play a substantial role in regulating the global hydrologic and carbon cycles. Two decades after the inception of LBA, the relationship between tropical deforestation and precipitation remains uncertain despite progress with respect to key processes such as vegetation access to deep water in the dry season (Oliveira et al, 2005) and modulation of energy availability for photosynthesis via cloud cover (Betts and Silva Dias, 2010) Another field campaign, the African Monsoon Multidisciplinary Analysis (AMMA) campaign, focused on the West African monsoon system, especially the Sahel transition zone (Redelsperger et al, 2006; Boone et al, 2009b). Techniques exist to represent the effect of large-scale dynamics on the convective scales, which, when combined with cloud-resolving simulations, yield powerful tools for understanding land– atmosphere interactions in the tropics, as we elaborate further below
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
