11-Year cyclicity of the near-surface heat flux at the Vostok station

2013 ◽  
Vol 53 (7) ◽  
pp. 887-890 ◽  
Author(s):  
D. M. Volobuev
Keyword(s):  
Heat Flux ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Near Surface ◽  
Vostok Station

scholarly journals Topographic and Mixed Layer Submesoscale Currents in the Near-Surface Southwestern Tropical Pacific

2017 ◽  
Vol 47 (6) ◽  
pp. 1221-1242 ◽  
Author(s):  
Kaushik Srinivasan ◽  
James C. McWilliams ◽  
Lionel Renault ◽  
Hristina G. Hristova ◽  
Jeroen Molemaker ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Layer ◽  
Kinetic Energy ◽  
Wind Stress ◽  
Mixed Layer ◽  
Surface Heat Flux ◽  
Seasonal Cycle ◽  
Surface Heat ◽  
Near Surface ◽  
Coral Sea

AbstractThe distribution and strength of submesoscale (SM) surface layer fronts and filaments generated through mixed layer baroclinic energy conversion and submesoscale coherent vortices (SCVs) generated by topographic drag are analyzed in numerical simulations of the near-surface southwestern Pacific, north of 16°S. In the Coral Sea a strong seasonal cycle in the surface heat flux leads to a winter SM “soup” consisting of baroclinic mixed layer eddies (MLEs), fronts, and filaments similar to those seen in other regions farther away from the equator. However, a strong wind stress seasonal cycle, largely in sync with the surface heat flux cycle, is also a source of SM processes. SM restratification fluxes show distinctive signatures corresponding to both surface cooling and wind stress. The winter peak in SM activity in the Coral Sea is not in phase with the summer dominance of the mesoscale eddy kinetic energy in the region, implying that local surface layer forcing effects are more important for SM generation than the nonlocal eddy deformation field. In the topographically complex Solomon and Bismarck Seas, a combination of equatorial proximity and boundary drag generates SCVs with large-vorticity Rossby numbers (Ro ~ 10). River outflows in the Bismarck and Solomon Seas make a contribution to SM generation, although they are considerably weaker than the topographic effects. Mean to eddy kinetic energy conversions implicate barotropic instability in SM topographic wakes, with the strongest values seen north of the Vitiaz Strait along the coast of Papua New Guinea.

scholarly journals Process-Oriented Diagnosis of Tropical Cyclones in High-Resolution GCMs

2018 ◽  
Vol 31 (5) ◽  
pp. 1685-1702 ◽  
Author(s):  
Daehyun Kim ◽  
Yumin Moon ◽  
Suzana J. Camargo ◽  
Allison A. Wing ◽  
Adam H. Sobel ◽  
...  
Keyword(s):  
Heat Flux ◽  
High Resolution ◽  
Tropical Cyclones ◽  
Surface Heat Flux ◽  
Surface Wind ◽  
Atmospheric Model ◽  
Surface Heat ◽  
The Other ◽  
Near Surface ◽  
Surface Latent Heat Flux

This study proposes a set of process-oriented diagnostics with the aim of understanding how model physics and numerics control the representation of tropical cyclones (TCs), especially their intensity distribution, in GCMs. Three simulations are made using two 50-km GCMs developed at NOAA’s Geophysical Fluid Dynamics Laboratory. The two models are forced with the observed sea surface temperature [Atmospheric Model version 2.5 (AM2.5) and High Resolution Atmospheric Model (HiRAM)], and in the third simulation, the AM2.5 model is coupled to an ocean GCM [Forecast-Oriented Low Ocean Resolution (FLOR)]. The frequency distributions of maximum near-surface wind near TC centers show that HiRAM tends to develop stronger TCs than the other models do. Large-scale environmental parameters, such as potential intensity, do not explain the differences between HiRAM and the other models. It is found that HiRAM produces a greater amount of precipitation near the TC center, suggesting that associated greater diabatic heating enables TCs to become stronger in HiRAM. HiRAM also shows a greater contrast in relative humidity and surface latent heat flux between the inner and outer regions of TCs. Various fields are composited on precipitation percentiles to reveal the essential character of the interaction among convection, moisture, and surface heat flux. Results show that the moisture sensitivity of convection is higher in HiRAM than in the other model simulations. HiRAM also exhibits a stronger feedback from surface latent heat flux to convection via near-surface wind speed in heavy rain-rate regimes. The results emphasize that the moisture–convection coupling and the surface heat flux feedback are critical processes that affect the intensity of TCs in GCMs.

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.

Heat Transfer Characteristics of Downward Facing Hot Horizontal Surfaces Using Mist Jet Impingement

2017 ◽  
Author(s):  
Ashutosh Kumar Yadav ◽  
Parantak Sharma ◽  
Avadhesh Kumar Sharma ◽  
Mayank Modak ◽  
Vishal Nirgude ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Heat Flux ◽  
Cooling System ◽  
Water Pressure ◽  
Jet Impingement ◽  
Surface Heat ◽  
Heat Transfer Characteristics ◽  
Impingement Cooling ◽  
Transfer Characteristics

Impinging jet cooling technique has been widely used extensively in various industrial processes, namely, cooling and drying of films and papers, processing of metals and glasses, cooling of gas turbine blades and most recently cooling of various components of electronic devices. Due to high heat removal rate the jet impingement cooling of the hot surfaces is being used in nuclear industries. During the loss of coolant accidents (LOCA) in nuclear power plant, an emergency core cooling system (ECCS) cool the cluster of clad tubes using consisting of fuel rods. Controlled cooling, as an important procedure of thermal-mechanical control processing technology, is helpful to improve the microstructure and mechanical properties of steel. In industries for heat transfer efficiency and homogeneous cooling performance which usually requires a jet impingement with improved heat transfer capacity and controllability. It provides better cooling in comparison to air. Rapid quenching by water jet, sometimes, may lead to formation of cracks and poor ductility to the quenched surface. Spray and mist jet impingement offers an alternative method to uncontrolled rapid cooling, particularly in steel and electronics industries. Mist jet impingement cooling of downward facing hot surface has not been extensively studied in the literature. The present experimental study analyzes the heat transfer characteristics a 0.15mm thick hot horizontal stainless steel (SS-304) foil using Internal mixing full cone (spray angle 20 deg) mist nozzle from the bottom side. Experiments have been performed for the varied range of water pressure (0.7–4.0 bar) and air pressure (0.4–5.8 bar). The effect of water and air inlet pressures, on the surface heat flux has been examined in this study. The maximum surface heat flux is achieved at stagnation point and is not affected by the change in nozzle to plate distance, Air and Water flow rates.

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