scholarly journals Thermally Forced Transients in the Thermohaline Circulation

2015 ◽  
Vol 45 (11) ◽  
pp. 2820-2835 ◽  
Author(s):  
Michael A. Spall
Keyword(s):  
Heat Flux ◽  
Surface Heat Flux ◽  
Thermohaline Circulation ◽  
Numerical Models ◽  
Ocean Basin ◽  
Surface Heat ◽  
Meridional Overturning Circulation ◽  
Time Dependent ◽  
Boundary Current ◽  
Model Calculations

AbstractThe response of a convective ocean basin to variations in atmospheric temperature is explored using numerical models and theory. The results indicate that the general behavior depends strongly on the frequency at which the atmosphere changes relative to the local response time to air–sea heat flux. For high-frequency forcing, the convective region in the basin interior is essentially one-dimensional and responds to the integrated local surface heat flux anomalies. For low-frequency forcing, eddy fluxes from the boundary current into the basin interior become important and act to suppress variability forced by the atmosphere. A theory is developed to quantify this time-dependent response and its influence on various oceanic quantities. The amplitude and phase of the temperature and salinity of the convective water mass, the meridional overturning circulation, the meridional heat flux, and the air–sea heat flux predicted by the theory compare well with that diagnosed from a series of numerical model calculations in both strongly eddying and weakly eddying regimes. Linearized analytic solutions provide direct estimates of each of these quantities and demonstrate their dependence on the nondimensional numbers that characterize the domain and atmospheric forcing. These results highlight the importance of mesoscale eddies in modulating the mean and time-dependent ocean response to atmospheric variability and provide a dynamical framework with which to connect ocean observations with changes in the atmosphere and surface heat flux.

scholarly journals On the Circulation of Atlantic Water in the Arctic Ocean

2013 ◽  
Vol 43 (11) ◽  
pp. 2352-2371 ◽  
Author(s):  
Michael A. Spall
Keyword(s):  
Heat Flux ◽  
Numerical Model ◽  
Arctic Ocean ◽  
Surface Heat Flux ◽  
Atlantic Water ◽  
Surface Heat ◽  
The Arctic ◽  
Analytic Model ◽  
Boundary Current ◽  
The Arctic Ocean

Abstract An idealized eddy-resolving numerical model and an analytic three-layer model are used to develop ideas about what controls the circulation of Atlantic Water in the Arctic Ocean. The numerical model is forced with a surface heat flux, uniform winds, and a source of low-salinity water near the surface around the perimeter of an Arctic basin. Despite this idealized configuration, the model is able to reproduce many general aspects of the Arctic Ocean circulation and hydrography, including exchange through Fram Strait, circulation of Atlantic Water, a halocline, ice cover and transport, surface heat flux, and a Beaufort Gyre. The analytic model depends on a nondimensional number, and provides theoretical estimates of the halocline depth, stratification, freshwater content, and baroclinic shear in the boundary current. An empirical relationship between freshwater content and sea surface height allows for a prediction of the transport of Atlantic Water in the cyclonic boundary current. Parameters typical of the Arctic Ocean produce a cyclonic boundary current of Atlantic Water of O(1 − 2 Sv; where 1 Sv ≡ 106 m3 s−1) and a halocline depth of O(200 m), in reasonable agreement with observations. The theory compares well with a series of numerical model calculations in which mixing and environmental parameters are varied, thus lending credibility to the dynamics of the analytic model. In these models, lateral eddy fluxes from the boundary and vertical diffusion in the interior are important drivers of the halocline and the circulation of Atlantic Water in the Arctic Ocean.

Local and Remote Responses of Atmospheric and Oceanic Heat Transports to Climate Forcing: Compensation versus Collaboration

2018 ◽  
Vol 31 (16) ◽  
pp. 6445-6460 ◽  
Author(s):  
Zhengyu Liu ◽  
Chengfei He ◽  
Feiyu Lu
Keyword(s):  
Heat Flux ◽  
Surface Heat Flux ◽  
Climate Changes ◽  
Energy Transport ◽  
Thermohaline Circulation ◽  
Theoretical Study ◽  
Coupled System ◽  
Surface Heat ◽  
Climate Forcing ◽  
Balance Model

We present a theoretical study on local and remote responses of atmosphere and ocean meridional heat transports (AHT and OHT, respectively) to climate forcing in a coupled energy balance model. We show that, in general, a surface heat flux forces opposite AHT and OHT responses in the so-called compensation response, while a net heat flux into the coupled system forces AHT and OHT responses of the same direction in the so-called collaboration response. Furthermore, unless the oceanic thermohaline circulation is significantly changed, a remote climate response far away from the forcing region tends to be dominated by the collaboration response, because of the effective propagation of a coupled ocean–atmosphere energy transport mode of collaboration structure. The relevance of our theory to previous CGCM experiments is also discussed. Our theoretical result provides a guideline for understanding of the response of heat transports and the associated climate changes.

Heat wave phenomena in solids subjected to time dependent surface heat flux

2007 ◽  
Vol 44 (4) ◽  
pp. 381-392 ◽  
Author(s):  
G. Heidarinejad ◽  
R. Shirmohammadi ◽  
M. Maerefat
Keyword(s):  
Heat Flux ◽  
Heat Wave ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Time Dependent ◽  
Wave Phenomena

Analysis of significant measures for thermal conductivity

2020 ◽  
pp. 35-42
Author(s):  
Yuri P. Zarichnyak ◽  
Vyacheslav P. Khodunkov
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Heat Flux Density ◽  
Measurement Method ◽  
Conductivity Measurement ◽  
Surface Heat ◽  
Measuring Instrument ◽  
New Class ◽  
Achievable Accuracy

The analysis of a new class of measuring instrument for heat quantities based on the use of multi-valued measures of heat conductivity of solids. For example, measuring thermal conductivity of solids shown the fallacy of the proposed approach and the illegality of the use of the principle of ambiguity to intensive thermal quantities. As a proof of the error of the approach, the relations for the thermal conductivities of the component elements of a heat pump that implements a multi-valued measure of thermal conductivity are given, and the limiting cases are considered. In two ways, it is established that the thermal conductivity of the specified measure does not depend on the value of the supplied heat flow. It is shown that the declared accuracy of the thermal conductivity measurement method does not correspond to the actual achievable accuracy values and the standard for the unit of surface heat flux density GET 172-2016. The estimation of the currently achievable accuracy of measuring the thermal conductivity of solids is given. The directions of further research and possible solutions to the problem are given.

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