Estimation of momentum and heat fluxes in the constant flux layer from temperature measurements

1977 ◽  
Vol 12 (3) ◽  
pp. 299-305 ◽  
Author(s):  
R. M. Williams
Keyword(s):  
Heat Fluxes ◽  
Temperature Measurements ◽  
Constant Flux ◽  
Flux Layer ◽  
Momentum And Heat Fluxes

scholarly journals Swell Modulation on Wind Stress in the Constant Flux Layer

2020 ◽  
Vol 47 (20) ◽  
Author(s):  
Sheng Chen ◽  
Fangli Qiao ◽  
Jun A. Zhang ◽  
Hongyu Ma ◽  
Yuhuan Xue ◽  
...  
Keyword(s):  
Wind Stress ◽  
Constant Flux ◽  
Flux Layer

Climate Response of Linear and Quadratic Functionals Using the Fluctuation–Dissipation Theorem

2008 ◽  
Vol 65 (9) ◽  
pp. 2824-2841 ◽  
Author(s):  
Andrey Gritsun ◽  
Grant Branstator ◽  
Andrew Majda
Keyword(s):  
General Circulation ◽  
Atmospheric General Circulation Model ◽  
Circulation Model ◽  
Heat Fluxes ◽  
Heat Sources ◽  
State Variables ◽  
Fluctuation Dissipation ◽  
Fluctuation Dissipation Theorem ◽  
Low Pass ◽  
Momentum And Heat Fluxes

Abstract A generalization of the fluctuation–dissipation theorem (FDT) that allows generation of linear response operators that estimate the response of functionals of system state variables is tested for a system defined by an atmospheric general circulation model (AGCM). A sketch of the proof of this generalization is provided, followed by comparison of response estimates based on the theory and actual responses of the AGCM for various idealized anomalous equatorial heat sources. Tested response quantities include precipitation, variances of bandpass and low-pass streamfunction, and momentum and heat fluxes. The solutions from the FDT operators are very similar to the AGCM solutions in terms of structure while overestimating response amplitudes by about 20%. As an example of an application of such response operators, the FDT operator that estimates the response of bandpass upper-tropospheric streamfunction variance is used to find the most efficient means of disturbing the Atlantic storm tracks by tropical heating. The results of the study suggest that the generalized FDT is an attractive method for systematically studying response attributes of the climate system that are of interest to climate scientists and society.

scholarly journals The Modification of Bottom Boundary Layer Turbulence and Mixing by Internal Waves Shoaling on a Barrier Reef

2011 ◽  
Vol 41 (11) ◽  
pp. 2223-2241 ◽  
Author(s):  
Kristen A. Davis ◽  
Stephen G. Monismith
Keyword(s):  
Boundary Layer ◽  
Internal Waves ◽  
Fast Response ◽  
Heat Fluxes ◽  
Bottom Boundary Layer ◽  
Mixing Efficiency ◽  
Florida Shelf ◽  
Bottom Boundary ◽  
Boundary Layer Turbulence ◽  
Momentum And Heat Fluxes

Abstract Results are presented from an observational study of stratified, turbulent flow in the bottom boundary layer on the outer southeast Florida shelf. Measurements of momentum and heat fluxes were made using an array of acoustic Doppler velocimeters and fast-response temperature sensors in the bottom 3 m over a rough reef slope. Direct estimates of flux Richardson number Rf confirm previous laboratory, numerical, and observational work, which find mixing efficiency not to be a constant but rather to vary with Frt, Reb, and Rig. These results depart from previous observations in that the highest levels of mixing efficiency occur for Frt < 1, suggesting that efficient mixing can also happen in regions of buoyancy-controlled turbulence. Generally, the authors find that turbulence in the reef bottom boundary layer is highly variable in time and modified by near-bed flow, shear, and stratification driven by shoaling internal waves.

scholarly journals A theory for surface-layer scaling of thermally-driven slope flows

2021 ◽  
Author(s):  
Dino Zardi
Keyword(s):  
Boundary Layer ◽  
Surface Layer ◽  
Sensible Heat Flux ◽  
Viscous Sublayer ◽  
Transport Processes ◽  
Heat Fluxes ◽  
Night Time ◽  
Slope Winds ◽  
Thermally Driven ◽  
Momentum And Heat Fluxes

<p>Sloping terrains of any inclination favour the development, under the daily cycle of day time surface heating and night time cooling, of thermally-driven organised flows, displaying peculiar boundary layer structures, and eventually triggering the development of atmospheric convection.</p><p>The ubiquitous occurrence over the Earth of variously tilted surfaces - from gently sloping plains to steep cliffs, or valley and basin sidewalls – makes the understanding of such flows of utmost importance in view of the appropriate forecasting of the associated boundary layer transport processes. Also, they display a highly conceptual relevance, as they represent a prototypal situations for many other thermally driven-flows over complex terrain.   </p><p>An appropriate surface-layer scaling for slope wind is derived extending the classical analysis for flat horizontal terrain situations to the cover inclines. In the former, momentum and heat fluxes at the surface are two independent quantities, and vertical profiles of velocity and temperature can only be connected to them by means  of similiarity relationships, as fluxes are nearly invariant with height.</p><p>Instead, equations governing slope winds show that the mean wind and temperature profiles are closely connected to the flux structure normal to the slope, as this is not constant. Also, surface values of momentum flux and sensible heat flux are shown to be proportional to each other.</p><p>Based on the above relationships, suitable expressions are derived for the slope-normal profiles of velocity and temperature, both in the viscous sublayer and in the fully turbulent surface layer, as well as for the appropriate scaling factors in the two regions.</p>

scholarly journals Estimation of the atmospheric surface momentum and heat fluxes using a high resolution acoustic radar

1994 ◽  
Vol 04 (C5) ◽  
pp. C5-287-C5-290 ◽  
Author(s):  
C. G. HELMIS ◽  
J. A. KALOGIROS ◽  
K. H. PAPADOPOULOS ◽  
A. T. SOILEMES ◽  
D. N. ASIMAKOPOULOS
Keyword(s):  
High Resolution ◽  
Heat Fluxes ◽  
Momentum And Heat Fluxes

A note on estimating the height of the constant flux layer

1981 ◽  
Vol 20 (3) ◽  
pp. 397-398 ◽  
Author(s):  
Maurice Danard
Keyword(s):  
Constant Flux ◽  
Flux Layer

scholarly journals An Extremum Solution of the Monin–Obukhov Similarity Equations

2010 ◽  
Vol 67 (2) ◽  
pp. 485-499 ◽  
Author(s):  
Jingfeng Wang ◽  
Rafael L. Bras
Keyword(s):  
Surface Layer ◽  
Atmospheric Surface Layer ◽  
Turbulent Transport ◽  
Asymptotic Properties ◽  
Field Measurements ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Obukhov Length ◽  
Surface Heat Fluxes ◽  
Momentum And Heat Fluxes

Abstract An extremum hypothesis of turbulent transport in the atmospheric surface layer is postulated. The hypothesis has led to a unique solution of Monin–Obukhov similarity equations in terms of simple expressions linking shear stress (momentum flux) and heat flux to mean wind shear and temperature gradient. The extremum solution is consistent with the well-known asymptotic properties of the surface layer. Validation of the extremum solution has been made by comparison to field measurements of momentum and heat fluxes. Furthermore, a modeling test of predicting surface heat fluxes using the results of this work is presented. A critical reexamination of the interpretation of the Obukhov length is given.

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