Thermohaline circulation

Generalized model of therm aMne circulation GlobarConveyor Belt  

Our point is absent the predominance of the abrupt climate change novum and the political and ecological pressures to embrace geoengineering nostrums in a crisis-filled, highly mobilized political climate, the best and most immediate option 

But if we ask how much Kim Stanley Robinson s Science in the Capital trilogy helps to advance those pressing societal priorities grounded in a multi-pronged policy of de-carbonization, the answer seems to be very little. Indeed, one of the key insights his main protagonist Frank Vanderwal offers early in the second book is this  

1 mean even the Gulf Stretun is only a proximate cause. The ultimate causes have to do with the whole situation. Carbon, consumption, population, technology, all that. We U have to take all that on if we re going to actually do something. (Fifty 19-20) 

As it turns out, almost none of these things are directly tackled. And the novum of abrupt climate change and contextual imperatives of geoengineering have much to do with why the whole situation is conflated and attacked by instmments of planetary engineering (Table 126.1). 

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Broecker, W. S. (1997). Thermohaline circulation, the Achilles heel of our climate system Will man-made CO2 upset the current balance Science 278, 1582-1588. 

Haug, G. H. and Tiedemann, R. (1998). Effect of the formation of the Isthmus of Panama on Atlantic Ocean thermohaline circulation. Nature, 393, 673-676. 

Zauker, F. and Broecker, W. S. (1992). Influence of interocean fresh water transports on ocean thermohaline circulation. /. Geophys. Res. 97, 2765-2773. 

Adkins JF, Boyle EA, Keigwin LD, Cortijo E (1997) Variability of the North Atlantic thermohaline circulation during the last interglacial period. Nature 390 154-156 Anderson RF (1982) Concentration, vertical flux and remineralization of particulate uranium in seawater. Geochim Cosmochim Acta 46 1293-1299... 

Marcantonio F, Turekian KK, Higgins S, Anderson RF, Stute M, Schlosser P (1999) The accretion rate of extraterrestrial He based on oceanic °Th flux and the relation to Os isotope variation over the past 200,000 years in an Indian Ocean core. Earth Planet Sci Lett 170 157-168 Marchal O, Francois R, Stocker TF, Joos F (2000) Ocean thermohaline circulation and sedimentary 23ipa/230Th ratio. Paleoceanography 15(6) 625-641... 

Yu E-F, Francois R, Bacon M (1996) Similar rates of modem and last-glacial ocean thermohaline circulation inferred from radiochemical data. Nature 379 689-694 Zheng Y, Anderson RF, van Geen A, Fleisher MQ (2002) Preservation of particulate non-lithogenic uranium in marine sediments. Geochim Cosmochim Acta 66(17) 3085-3092. 

Schmittner A, Stoecker TF (1999) The stability of the thermohaline circulation in global warming experiments. J Climate 12 1117-1133... 

Thermohaline circulation Deep-water circulaUon caused by density differences created in the surface waters of polar regions. Cooling increases the density of the surface waters, which sink and then advect horizontally throughout the deep ocean. The water is returned to the sea surface by eddy diffusion. 

Driscoll, N. W., and G. H. Haug, A Short Circuit in Thermohaline Circulation A Cause for Northern Hemisphere Glaciation Science, 282, 436-438 (1998). 

The concentration of RDOM is simply equal to the measured concentration of DOM in deep waters (>1000 m), where its apparent radiocarbon age of 4000-6000 years is substantially greater than the timescale of thermohaline circulation in the earth s oceans (Druffel et al., 1992). Bioassay experiments have been used to verify the refractory nature of DOM in the deep sea (Barber, 1968). 

The climatic system involves numerous factors that intensify climatic changes with minimum forcings. The withering or death of plants, for example, may cause a decrease in evapotranspiration and hence lead to precipitation attenuation, which may further increase drought conditions. In cold-climate regions snow cover formation is accompanied by a strong increase in albedo, which favors further cooling (the so-called albedo effect ). Substantial climatic feedbacks are associated with the dynamics of thermohaline circulation. 

The thermohaline circulation dominated by the Arctic Ocean and Nordic Seas is responsible for a considerable part of the Earth s poleward heat transport and may also serve as a sink for CO2. Alterations of this circulation, as have been observed during climatic changes of the past, can affect global climate and in particular the climate of Europe and North America. ... 

Calculations of anthropogenic (greenhouse) climate change show that thermohaline circulation (THC) in NH oceans may weaken in the future. However, even the models that show this weakening still demonstrate that greenhouse warming in Europe will persist. So far, no one knows whether irreversible collapse of THC is a possibility or which threshold conditions correspond to such a collapse. No existing model predicts total cessation of THC for the next 60 years. 

OguzT, Malanotte-Rizzoli P (1997) Wind and thermohaline circulation of the Black Sea driven by yearly mean and monthly climatological forcing. In Science for stability. NATO TU-Black Sea project Symposium on scientific results. Crimea, Ukraine, p 156... 

The density of the water controls the deepwater circulation. If the density of a water body increases, it has a tendency to sink. Subsequently, it will spread out over a horizon of uniform circulatory system is also known as thermohaline circulation. As shown in Figure 5 of the ocean conveyor belt, the densest oceanic waters are formed in Polar Regions due to the relatively low temperatures and the salinity increase that results from ice formation. Antarctic Bottom Water (ABW) is generated in the Weddell Sea and flows northward into the South Atlantic. North Atlantic Deep Water (NADW)... 

Figure 5 A schematic diagram of the thermohaline circulation of the world ocean, also know as the great ocean conveyor belt, highlighting polar regions of deepwater formation, deepwater circulation eastward from the poles and the returning westward surface water flow (Adapted from IPCC, 2001. )...

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