The Total Meridional Heat Flux and Its Oceanic and Atmospheric Partition

2005 ◽  
Vol 18 (21) ◽  
pp. 4374-4380 ◽  
Author(s):  
Carl Wunsch
Keyword(s):  
Northern Hemisphere ◽  
Energy Transport ◽  
Atmospheric Model ◽  
Heat Fluxes ◽  
Radiation Budget ◽  
Meridional Heat Transport ◽  
Atmospheric Flux ◽  
Oceanic Surface ◽  
Earth Radiation Budget ◽  
Estimated Error

Abstract Atmospheric meridional heat transport is inferred as a residual from the Earth Radiation Budget Experiment (ERBE) data and in situ oceanic estimates. Reversing the conventional approach of computing the ocean as an atmospheric model residual is done to permit calculation of a preliminary uncertainty estimate for the atmospheric flux. The structure of the ERBE errors is itself an important uncertainty. Total energy transport is almost indistinguishable from a hemispherically antisymmetric analytic function, despite the great asymmetry of the oceanic heat fluxes. ERBE data appear sufficiently noisy so that a considerable range of atmospheric transports remains possible: the maximum atmospheric value lies between 3 and 5 PW in the Northern Hemisphere, at one standard deviation, although the values are sensitive to the noise assumptions made here. The Northern Hemisphere ocean and atmosphere carry comparable poleward heat fluxes to about 28°N where the oceanic flux drops rapidly, but does not actually vanish until the oceanic surface area goes to zero. Within the estimated error bars, there is a remarkable antisymmetry about the equator of the combined ocean and atmospheric transports, despite the marked oceanic transport asymmetry.

scholarly journals A model for the longwave radiation budget of the northern hemisphere: Comparison with Earth Radiation Budget Experiment data

1999 ◽  
Vol 104 (D8) ◽  
pp. 9489-9500 ◽  
Author(s):  
N. Hatzianastassiou ◽  
B. Croke ◽  
N. Kortsalioudakis ◽  
I. Vardavas ◽  
K. Koutoulaki
Keyword(s):  
Northern Hemisphere ◽  
Longwave Radiation ◽  
Radiation Budget ◽  
Experiment Data ◽  
Earth Radiation Budget ◽  
Earth Radiation

The Tropical Precipitation Response to Andes Topography and Ocean Heat Fluxes in an Aquaplanet Model

2014 ◽  
Vol 28 (1) ◽  
pp. 381-398 ◽  
Author(s):  
Elizabeth A. Maroon ◽  
Dargan M. W. Frierson ◽  
David S. Battisti
Keyword(s):  
Energy Transport ◽  
Atmospheric Model ◽  
Heat Fluxes ◽  
Geophysical Fluid Dynamics Laboratory ◽  
Ocean Energy ◽  
Tropical Rainfall ◽  
Tropical Precipitation ◽  
The North ◽  
The Andes ◽  
Precipitation Response

Abstract This aquaplanet modeling study using the Geophysical Fluid Dynamics Laboratory Atmospheric Model, version 2.1 (GFDL AM2.1), examines how ocean energy transport and topography influence the location of tropical precipitation. Adding realistic Andes topography regionally displaces tropical rainfall from the equator into the Northern Hemisphere, even when the wind–evaporation feedback is disabled. The relative importance of the Andes compared to the asymmetric hemispheric heating of the atmosphere by ocean transport is examined by including idealized and realistic zonally averaged surface heat fluxes (also known as q fluxes) in the slab ocean. A hemispherically asymmetric q flux displaces the tropical rainfall toward the hemisphere receiving the greatest heating by the ocean. The zonal-mean displacement of rainfall is greater in simulations with a realistic q flux than with a realistic Andes topography. Simulations that add both a q flux and topography displace rainfall farther to the north in the region 120° to the west of the Andes than in simulations that only have a q flux. Cloud and clear-sky radiative feedbacks in the tropics and subtropics of this model both act to amplify the energy flux and the precipitation response to a given hemispheric asymmetry in oceanic forcing.

scholarly journals Climate response to imposed solar radiation reductions in high latitudes

2012 ◽  
Vol 3 (2) ◽  
pp. 715-757 ◽  
Author(s):  
M. C. MacCracken ◽  
H.-J. Shin ◽  
K. Caldeira ◽  
G. A. Ban-Weiss
Keyword(s):  
Solar Radiation ◽  
Sea Ice ◽  
High Latitude ◽  
Energy Transport ◽  
Atmospheric Model ◽  
Radiation Budget ◽  
Polar Regions ◽  
High Latitudes ◽  
Surface Cooling ◽  
Inter Tropical Convergence Zone

Abstract. Increasing concentrations of greenhouse gases are the primary contributor to the 0.8 °C increase in the global average temperature since the late 19th century, shortening cold seasons and lengthening warm seasons. The warming is amplified in polar regions, causing retreat of sea ice, snow cover, permafrost, mountain glaciers, and ice sheets, while also modifying mid-latitude weather, amplifying global sea level rise, and initiating high-latitude carbon feedbacks. Model simulations in which we reduced solar insolation over high latitudes not only cooled those regions, but also drew energy from lower latitudes, exerting a cooling influence over much of the hemisphere in which the reduction was imposed. Our simulations, which used the National Center for Atmospheric Research's CAM3.1 atmospheric model coupled to a slab ocean, indicated that, on a normalized basis, high-latitude reductions in absorbed solar radiation have a significantly larger cooling influence than equivalent solar reductions spread evenly over the Earth. This amplified influence occurred because high-latitude surface cooling preferentially increased sea ice fraction and, therefore, surface albedo, leading to a larger deficit in the radiation budget at the top of the atmosphere than from an equivalent global reduction in solar radiation. Reductions in incoming solar radiation in one polar region (either north or south) resulted in increased poleward energy transport during that hemisphere's cold season and shifted the Inter-Tropical Convergence Zone (ITCZ) away from that pole, whereas equivalent reductions in both polar regions tended to leave the ITCZ approximately in place. Together, these results suggest that, until emissions reductions are sufficient to limit the warming influence of greenhouse gas concentrations, polar reductions in solar radiation, if they can be efficiently and effectively implemented, might, because of fewer undesirable side effects than for global solar radiation reductions, be a preferred approach to limiting both high-latitude and global warming.

Ground and in-flight calibrations of the Earth Radiation Budget Experiment nonscanning radiometers

1990 ◽  
Author(s):  
Jack Paden ◽  
Dhirendra K. Pandey ◽  
Robert S. Wilson ◽  
Susan Thomas ◽  
Michael A. Gibson ◽  
...  
Keyword(s):  
Radiation Budget ◽  
The Earth ◽  
Earth Radiation Budget ◽  
Earth Radiation

scholarly journals Oceanic Overturning and Heat Transport: The Role of Background Diffusivity

2019 ◽  
Vol 32 (3) ◽  
pp. 701-716 ◽  
Author(s):  
Magnus Hieronymus ◽  
Jonas Nycander ◽  
Johan Nilsson ◽  
Kristofer Döös ◽  
Robert Hallberg
Keyword(s):  
Heat Transport ◽  
Large Scale ◽  
Energy Transport ◽  
Climate Model ◽  
Potential Temperature ◽  
Meridional Heat Transport ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Meridional Overturning

The role of oceanic background diapycnal diffusion for the equilibrium climate state is investigated in the global coupled climate model CM2G. Special emphasis is put on the oceanic meridional overturning and heat transport. Six runs with the model, differing only by their value of the background diffusivity, are run to steady state and the statistically steady integrations are compared. The diffusivity changes have large-scale impacts on many aspects of the climate system. Two examples are the volume-mean potential temperature, which increases by 3.6°C between the least and most diffusive runs, and the Antarctic sea ice extent, which decreases rapidly as the diffusivity increases. The overturning scaling with diffusivity is found to agree rather well with classical theoretical results for the upper but not for the lower cell. An alternative empirical scaling with the mixing energy is found to give good results for both cells. The oceanic meridional heat transport increases strongly with the diffusivity, an increase that can only partly be explained by increases in the meridional overturning. The increasing poleward oceanic heat transport is accompanied by a decrease in its atmospheric counterpart, which keeps the increase in the planetary energy transport small compared to that in the ocean.

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