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American Notes for General Circulation
Ocean Dynamics Reference library
Encyclopedia of Global Change
...exchanges heat with the atmosphere. This system of meridional overturning cells constitutes the thermohaline circulation for the global ocean. Net warm-to-cold-water conversion occurs in the northern North Atlantic, while cold-to-warm-water conversion occurs in the subtropical Indian and Pacific Oceans. Of note is the warm surface current that wends its way through each of the basins to terminate in the northern North Atlantic, where it supplies water for the formation of deep water. While the schematic shows principal pathways of the conveyor belt system, it...
Regional Patterns of Climate Change Reference library
The Oxford Companion to Global Change
...of greater (lesser) storminess. Also note that the land-ocean SLP contrast over Asia decreases in future climate conditions, which indicates a weakening of the South and East Asia monsoon circulations. Monsoon rain still increases, however, due to the greater water-holding capacity of the warmer future atmosphere. Regional Patterns of Climate Change. Figure 2. Same as Figure 1 but for precipitation change. Units are % of 1961–1990 precipitation. Regional Patterns of Climate Change. Figure 3. Same as Figure 1 but for sea level pressure (SLP). Units are...
Weather Forecasting Reference library
Encyclopedia of Global Change
...but they are run for decades rather than hours. These models are called general circulation models (GCMs), and are coupled to models of the oceans. To produce a climate forecast, the GCM is run for a number of past and future decades; the results for the predicted present climate are compared with our current knowledge of global climate. Once the GCM is tuned to model the present climate, it can be used to predict future climates—for example, providing estimates of global warming due to the increase in greenhouse gases. A weather forecast can easily be...
Climate Change Reference library
Encyclopedia of Global Change
...the Asian monsoonal circulation system; and accentuated continental-scale chemical weathering and denudation, which further reduced global atmospheric carbon dioxide levels. The formation of the Tibetan Plateau was accompanied by mountain building along the Pacific margin of South America, in western North America, and in the rift system of East Africa, which also contributed to the global cooling trend. The closure of the Isthmus of Panama around three million years ago caused significant reorganizations of North Atlantic ocean circulation, and the...
Drought Reference library
Encyclopedia of Global Change
...of the ITCZ and other circulation features. Drought: Sahel Drought in West Africa. Figure 6. Mean Rainfall for the Decade 1980–1989, Expressed as a Percentage Departure from the Long-Term Mean.Station data are averaged over 1° squares; positive values are shaded. More recent investigations have identified links between drought and sea surface temperatures and also between drought and characteristics of the atmospheric general circulation, such as the jet streams prevailing over West Africa and the intensity of other circulation features such as the Hadley...
Cultivation and Environmental Impact of Mushrooms Reference library
Shu Ting Chang and Solomon P. Wasser
The Oxford Encyclopedia of Agriculture and the Environment
...wool stopper. Four formulas in the preparation of the substrate for the cultivation of the mushroom are given here as reference: (a) Sawdust 82%, wheat bran 16%, gypsum 1.4%, potassium phosphate, dibasic 0.2%, and lime 0.4%; (b) Sawdust 54%, spent coffee grounds 30%, wheat bran 15%, and gypsum 1%; (c) Sawdust 63%, corncob powder 20%, wheat bran 15%, calcium superphosphate 1%, and gypsum 1%; (d) Sawdust 76%, wheat bran 18%, corn powder 2%, gypsum 2%, sugar 1.2%, calcium superphosphate 0.5%, and urea 0.3%. Commercial scale cultivation : In general, the operation...
Regional Assessment Reference library
Encyclopedia of Global Change
...or local scales. It brings a systems approach that analyzes the contributions of regions to global change and, in turn, traces regional impacts and potentials for adaptation to change and mitigation of adverse activities. In the context of climate change, regional assessment includes, on the one hand, local contributions to greenhouse gases and, on the other hand, downscaling from general circulation models to local climate change, tracing the consequences of that change, suggesting the resulting impacts on society, and specifying possible responses. Human...
El Niño–Southern Oscillation Reference library
Encyclopedia of Global Change
...for both private and public gain. The less developed nations of the world need help and guidance to use climate information effectively. Institutions have arisen, especially the International Research Institute for Climate Prediction, to do the physical and social science research needed to apply climate forecast information successfully in less developed parts of the world. See also Atmosphere Dynamics . Internet Resources A number of Web sites are now available for learning about El Niño and for watching the evolution of El Niño. A general site with...
Global Change Reference library
Encyclopedia of Global Change
...of, those of the Norse in Greenland, Newfoundland, and perhaps other localities in northeastern North America, were tiny in scale and failed to endure. But it was in that same general source of wanderers—northwestern and western Europe—a region that had long lagged behind the civilizations of Asia and the Mediterranean—that our great ongoing adventure in globalization was to take off. It was also there, as documented by Fernand Braudel ( 1981–1984 ), that, for whatever reasons, we find the earliest decisive stirrings of the capitalist system, arguably the most...
Amazonia, Deforestation Of Reference library
Encyclopedia of Global Change
...seventeen times larger than the Mississippi–Missouri system in North America. Some of the water vapor is transported by winds to Brazil's Central–South Region, where most of the country's agriculture is located. Brazil's annual harvest has a gross value of about U.S.$65 billion, and the dependence of even a small fraction of this on rainfall from Amazonian water vapor would translate into a substantial value for Brazil. Although movement of the water vapor is indicated by general circulation models (Eagleson, 1986; Salati and Vose, 1984), the amounts involved...
Sustainable Coffee Production Reference library
Sarada Krishnan
The Oxford Encyclopedia of Agriculture and the Environment
...& Export 143,306 88.17 93,275 88.21 Note : * Export statistics are for the period October 2015 to July 2016. Source : ICO ( 2016 ) . Sixty-five percent of the world’s coffee is consumed by just 17% of the world’s population ( Lewin et al., 2004 ). This provides tremendous opportunity for market expansion through promotion of coffee consumption in both producing and consuming countries. Table 3 provides statistics on imports by the top ten leading importing countries. The top ten countries account for about 81% of total imports, with the United...
Water Quality Reference library
Encyclopedia of Global Change
...its primary source is the weathering of parent rock. Natural levels of are generally well below 30 μgP/L and can be buffered by phosphorus circulation between soils and terrestrial vegetation. When the weathering rate is low, many elemental cycles (K, N, P, S, Si) may be controlled by the internal cycle within the forest stand from root uptake to fallen leaves decay. After logging, these cycles are broken, and a general release of elements is noted in surficial waters. Water Quality Issues in Natural Conditions Depending on local or regional conditions, the...
Amazonia and Deforestation Reference library
The Oxford Companion to Global Change
...is located. Brazil's annual harvest has a gross value of about U.S.$65 billion, and dependence of even a small fraction of this on rainfall from Amazonian water vapor is a substantial value for Brazil. This water is also critical to hydroelectric power generated in south-central Brazil. Although movement of the water vapor is indicated by global circulation models, the amounts involved are still poorly quantified ( Marengo et al., 2004 ). The role of Amazonian forest in the region's water cycle also implies increasing risk with increasing...
Reefs Reference library
The Oxford Companion to Global Change
...reefs (Hoegh-Guldberg, 1999 ), based on modeling changes in sea-surface temperatures using various general circulation models, is even more pessimistic, concluding that “bleaching events are projected to increase in frequency until they become yearly events by 2050 in most oceans” (p. 15). Noting that previous bleaching events (since 1979 ) have been triggered by unseasonably high temperatures associated with El Niño events, the author goes on to note that “in 20–40 years from now, bleaching is projected to be triggered by seasonal changes in water...
Fire Reference library
Encyclopedia of Global Change
...large areas of Indonesia experienced the worst drought for fifty years. This was a consequence of a change in the circulation patterns over the Pacific Ocean that occurs approximately once every four to six years. Normally, cold sea surface temperatures in the eastern Pacific encourage high-pressure air masses to form and winds to flow in a westerly direction toward areas of warm low pressure over Southeast Asia. The ascent of moist air masses in the western Pacific releases heavy convective rainfall. For reasons that are still not fully understood, this...
The Early Anthropogenic Hypothesis Reference library
William Ruddiman
The Oxford Encyclopedia of Agriculture and the Environment
...and John Kutzbach ran simulations using higher resolution general circulation models (GCM) that capture more of the high topography ( Kutzbach, Ruddiman, Vavrus, & Philippon, 2010 ; Kutzbach, Vavrus, Ruddiman, & Philippon-Berthier, 2011 ; Ruddiman, Vavrus, & Kutzbach, 2005 ; Vavrus, Philippon-Berthier, Kutzbach, & Ruddiman, 2011 ; Vavrus, Ruddiman, & Kutzbach, 2008 ). Because of the greater computational demands, these GCM simulations cover only a few decades, which is not enough time for ice sheets to form. But the models simulate months of snow...
Climate Change Impacts on Agriculture across Africa Reference library
Laura Pereira
The Oxford Encyclopedia of Agriculture and the Environment
...(IPCC) reports. The IPCC’s fourth assessment report ( IPCC, 2007 ) presented 23 general circulation models of climate (GCMs), but the underlying data used to generate information are so highly aggregated to be applicable at the global level that they are difficult to use in projecting regional climate ( Ziervogel et al., 2008 ). However, growing recognition of the need for climate information at finer scales has driven work aimed at downscaling global climate model information for local and regional decision makers; these are regional climate models (RCMs) (...
Soil Resources and the Delivery of Ecosystem Services and Value Reference library
David A. Robinson, Fiona Seaton, Katrina Sharps, Amy Thomas, Francis Parry Roberts, Martine van der Ploeg, Laurence Jones, Jannes Stolte, Maria Puig de la Bellacasa, Paula Harrison, and Bridget Emmett
The Oxford Encyclopedia of Agriculture and the Environment
...suites of ecosystem service models. This is similar to the approach used in running global circulation models for climate simulations, to capture some aspects of the variability in outputs between models and to start to address issues of uncertainty in model outputs. Joint Environmental and Socioeconomic Modeling at National to Global Scales. The ecosystem services approach recognizes that we live in a coupled socioeconomic-environmental system. Large-scale ecosystem service models take an integrated, systemic approach to understand better the linkages and...
Terracing: From Agriculture to Multiple Ecosystem Services Reference library
Paolo Socci, Alessandro Errico, Giulio Castelli, Daniele Penna, and Federico Preti
The Oxford Encyclopedia of Agriculture and the Environment
...suggesting that the distribution of failures on terraced systems may follow determined patterns that were hypothesized to be related to water circulation dynamics. Understanding the main hydrological processes that determine water flow pathways and runoff generation in Lamole and in other terraced landscapes is therefore of paramount importance for a better conceptualization of the functioning of these systems and for proper design and maintenance purposes ( Preti et al., 2018b ). Understanding the causes at the base of terrace failures positioning would help...
Human-Environmental Interrelationships and the Origins of Agriculture in Egypt and Sudan Reference library
Simon Holdaway and Rebecca Phillipps
The Oxford Encyclopedia of Agriculture and the Environment
...Planetary Science Letters , 371–372 , 163–176. Midant-Reynes, B. (2000). The prehistory of Egypt, from the first Egyptians to the first Pharaohs . Oxford: Blackwell. Nicholson, S. E. , & Flohn, H. (1980). African environmental and climatic changes and the general atmospheric circulation in Late Pleistocene and Holocene. Climatic Change , 2 , 313–348. Pennington, B. , Bunbury, J. & Hovius, N. (2016). Emergence of civilisation, changes in fluvio-deltaic style and nutrient redistribution forced by Holocene sea-level rise. Geoarchaeology , 31 , 194–210...
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