Mountain ranges favour vigorous Atlantic meridional overturning
نویسندگان
چکیده
[1] We use a global Ocean-Atmosphere General Circulation Model (OAGCM) to show that the major mountain ranges of the world have a significant role in maintenance of the Atlantic Meridional Overturning Circulation (AMOC). A simulation with mountains has a maximum AMOC of 18 Sv (1 Sv = 10 m s ) compared with 0 Sv for a simulation without mountains. Atlantic heat transport at 25°N is 1.1 PW with mountains compared to 0.2 PW without. The difference in AMOC is due to major changes in surface heat and freshwater (FW) fluxes over the Atlantic. In the Pacific changed surface fluxes lead to a meridional overturning circulation of 10 Sv. Our results suggest that the effects of mountains on the largescale atmospheric circulation is to force the ocean towards a state with a vigorous AMOC and with no overturning in the Pacific. Citation: Sinha, B., A. T. Blaker, J. J.-M. Hirschi, S. Bonham, M. Brand, S. Josey, R. S. Smith, and J. Marotzke (2012), Mountain ranges favour vigorous Atlantic meridional overturning, Geophys. Res. Lett., 39, L02705, doi:10.1029/ 2011GL050485.
منابع مشابه
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene
An essential element of modern ocean circulation and climate is the Atlantic meridional overturning circulation (AMOC), which includes deep-water formation in the subarctic North Atlantic. However, a comparable overturning circulation is absent in the Pacific, the world's largest ocean, where relatively fresh surface waters inhibit North Pacific deep convection. We present complementary measure...
متن کاملSurface wind-stress threshold for glacial Atlantic overturning
[1] Using a coupled model of intermediate complexity the sensitivity of the last glacial maximum (LGM) Atlantic meridional overturning circulation (AMOC) to the strength of surface wind-stress is investigated. A threshold is found below which North Atlantic deep water formation (DWF) takes place south of Greenland and the AMOC is relatively weak. Above this threshold, DWF occurs north of the Gr...
متن کاملAtmospheric Control on the Thermohaline Circulation
In an attempt to elucidate the role of atmospheric and oceanic processes in setting a vigorous ocean overturning circulation in the North Atlantic but not in the North Pacific, a comparison of the observed atmospheric circulation and net surface freshwater fluxes over the North Atlantic and Pacific basins is conducted. It is proposed that the more erratic meridional displacements of the atmosph...
متن کاملAtlantic Dominance of the Meridional Overturning Circulation
North Atlantic (NA) deep-water formation and the resulting Atlantic meridional overturning cell is generally regarded as the primary feature of the global overturning circulation and is believed to be a result of the geometry of the continents. Here, instead, the overturning is viewed as a global energy–driven system and the robustness of NA dominance is investigated within this framework. Usin...
متن کاملObserved Basin-Scale Response of the North Atlantic Meridional Overturning Circulation to Wind Stress Forcing
The response of the North Atlantic meridional overturning circulation (MOC) to wind stress forcing is investigated from an observational standpoint, using four time series of overturning transports below and relative to 1000m, overlapping by 3.6 yr. These time series are derived from four mooring arrays located on the western boundary of the North Atlantic: the RAPIDWestern Atlantic Variability...
متن کامل