On eddy transport in the ocean. Part II: The advection tensor

2021 ◽  
pp. 101845
Author(s):  
Michael Haigh ◽  
Luolin Sun ◽  
James C. McWilliams ◽  
Pavel Berloff
Keyword(s):  
Eddy Transport

Parameterizing eddy transport of biogeochemical tracers

2021 ◽  
Author(s):  
Channing J. Prend ◽  
Glenn R. Flierl ◽  
Katherine M. Smith ◽  
Alexis K. Kaminski
Keyword(s):  
Eddy Transport ◽  
Biogeochemical Tracers

Eddy transport as a key component of the Antarctic overturning circulation

2014 ◽  
Vol 7 (12) ◽  
pp. 879-884 ◽  
Author(s):  
Andrew F. Thompson ◽  
Karen J. Heywood ◽  
Sunke Schmidtko ◽  
Andrew L. Stewart
Keyword(s):  
Overturning Circulation ◽  
Eddy Transport ◽  
The Antarctic

scholarly journals Unprecedented strength of Hadley circulation in 2015–2016 impacts on CO<sub>2</sub> interhemispheric difference

2018 ◽  
Author(s):  
Jorgen S. Frederiksen ◽  
Roger J. Francey
Keyword(s):  
Global Warming ◽  
Hadley Circulation ◽  
Co2 Concentration ◽  
Transport Processes ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Advective Transport ◽  
Interhemispheric Difference ◽  
Eddy Transport ◽  
The Difference

Abstract. The extreme El Niño of 2015 and 2016 coincided with record global warming and unprecedented strength of the Hadley circulation with significant impact on mean interhemispheric (IH) transport of CO2 and on the difference in CO2 concentration between Mauna Loa and Cape Grim (Cmlo-cgo). The relative roles of eddy transport and mean advective transport on IH CO2 annual differences from 1992 through to 2016 is explored. Eddy transport processes occur mainly in boreal winter-spring when Cmlo-cgo is large; an important component is due to Rossby wave generation by the Himalayas and propagation through the equatorial Pacific westerly duct generating and transmitting turbulent kinetic energy. Mean transport occurs mainly in boreal summer-autumn and varies with the strength of the Hadley circulation. The timing of annual changes in Cmlo-cgo is found to coincide well with dynamical indices that we introduce to characterize the transports. During the unrivalled 2009–2010 step in Cmlo-cgo indices of eddy and mean transport reinforce. In contrast for the 2015 to 2016 change in Cmlo-cgo the mean transport counteracts the eddy transport and the record strength of the Hadley circulation determines the annual IH CO2 difference. The interaction of increasing global warming and extreme El Niños may have important implications for altering the balance between eddy and mean IH CO2 transfer.

scholarly journals Quantifying tracer transport in the tropical lower stratosphere using WACCM

2013 ◽  
Vol 13 (5) ◽  
pp. 13245-13283 ◽  
Author(s):  
M. Abalos ◽  
W. J. Randel ◽  
D. E. Kinnison ◽  
E. Serrano
Keyword(s):  
Lower Stratosphere ◽  
Climate Model ◽  
Latitudinal Gradients ◽  
Explicit Calculation ◽  
Boreal Summer ◽  
Tracer Transport ◽  
Annual Cycles ◽  
Tropical Tropopause ◽  
Eddy Transport ◽  
Isentropic Coordinates

Abstract. The zonal mean transport of ozone and carbon monoxide (CO) near the tropical tropopause is investigated using the Whole-Atmosphere Community Climate Model version 4 (WACCM4). The variability in temperature, ozone and CO in the model shows good agreement with satellite and balloon observations. Modeled temperature and tracers exhibit large and closely coupled annual cycles in the tropical lower stratosphere, as in the observations. The thermodynamic and tracer budgets in the model are analyzed based on the Transformed Eulerian Mean (TEM) framework on log-pressure coordinates and also using the isentropic formulation. Results show that the coupled seasonal cycles are mainly forced by tropical upwelling over altitudes with large vertical tracer gradients, in agreement with previous observational studies. The model also allows explicit calculation of eddy transport terms, which make an important contribution to ozone tendencies in the tropical lower stratosphere. The character of the eddy fluxes changes with altitude. At higher levels (~2 km above the cold point tropopause), isentropic eddy transport occurs during winter and spring in each hemisphere in the sub-tropics, associated with transient Rossby waves acting on strong background latitudinal gradients. At lower altitudes, close to the tropical tropopause, there is a maximum in horizontal eddy transport during boreal summer associated with the Asian monsoon anticyclone. Sub-seasonal variability in ozone and CO, tied to fluctuations in temperature, is primarily driven by transient tropical upwelling. In isentropic coordinates, the overall tracer budgets are similar to the log-pressure results, highlighting cross-isentropic mean advection as the main term in the balance. However, in isentropic coordinates the tracer variability is largely reduced on both seasonal and sub-seasonal timescales, because the tracer and temperature fluctuations are highly correlated (as a response to upwelling).

scholarly journals Eddy transport of organic carbon and nutrients from the Chukchi Shelf: Impact on the upper halocline of the western Arctic Ocean

2007 ◽  
Vol 112 (C5) ◽  
Author(s):  
Jeremy T. Mathis ◽  
Robert S. Pickart ◽  
Dennis A. Hansell ◽  
David Kadko ◽  
Nicholas R. Bates
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Western Arctic Ocean ◽  
Eddy Transport ◽  
Western Arctic ◽  
Chukchi Shelf

scholarly journals Exact Averaging of Atmospheric State and Flow Variables

2012 ◽  
Vol 69 (5) ◽  
pp. 1750-1757 ◽  
Author(s):  
Andrew S. Kowalski
Keyword(s):  
Conservation Laws ◽  
Gas Phase ◽  
Air Temperature ◽  
Classical Mechanics ◽  
Mixing Ratio ◽  
Momentum Exchange ◽  
Weighting Factors ◽  
Eddy Transport ◽  
Atmospheric State ◽  
Flow Variables

Abstract A new set of averaging rules is put forward that exactly determines the means of air temperature, mixing ratio, and velocity by incorporating weighting factors in accordance with physical conservation laws. For the temperature and velocity, respectively, the means calculated according to these rules are shown to be in accordance with the gas law and the most fundamental definition from classical mechanics. By contrast, those reckoned according to traditional arithmetic averaging rules are found to be incorrect. For studies of eddy transport, and micrometeorology in particular, such imprecisely determined averages of state and flow variables bias the perturbation variables over the entire averaging domain and thereby skew estimates of mass, heat, and momentum exchange unless appropriate adjustments (such as density corrections) are applied. The exact calculation of gas-phase averages amends this problem and is equally applicable to planetary-, synoptic-, and mesoscale averaging, as well as to climatology.

scholarly journals Numerical Estimations of Horizontal Advection inside Canopies

2004 ◽  
Vol 43 (10) ◽  
pp. 1530-1538 ◽  
Author(s):  
Young-San Park ◽  
Kyaw Tha Paw U
Keyword(s):  
Eddy Diffusivity ◽  
Horizontal Distance ◽  
Universal Curve ◽  
Dimensionless Variable ◽  
Horizontal Advection ◽  
Wind Speeds ◽  
Eddy Diffusivities ◽  
Advection Diffusion Equation ◽  
Roughness Elements ◽  
Eddy Transport

Abstract Local advection of scalar quantities such as heat, moisture, or carbon dioxide occurs not only above inhomogeneous surfaces but also within roughness elements on these surfaces. A two-dimensional advection–diffusion equation is applied to examine the fractionation of scalar exchange into horizontal advection within a canopy and vertical turbulent eddy transport at the canopy top. Simulations were executed with combinations of various wind speeds, eddy diffusivities, canopy heights, and source strengths. The results show that the vertical turbulent fluxes at the canopy top increase along the fetch and approach a limit at some downstream distance. The horizontal advection in the canopy is maximum at the edge of canopy and decreases exponentially along the fetch. All cases have the same features, except the absolute quantities depend on the environmental conditions. When the horizontal axis is normalized by using the dimensionless variable xK/uh2, horizontal diffusion is negligible, and the upwind concentration profile is constant, the curves of horizontal advection and vertical flux collapse into single, unique lines, respectively (x is the horizontal distance from the canopy edge, K is the eddy diffusivity, u is the wind speed, and h is the canopy height). The ratios of horizontal advection to the vertical turbulent flux also collapse into one universal curve when plotted against the dimensionless variable xK/uh2, irrespective of source strength. The ratio R shows a power-law relation to the dimensionless distance [R = a(xK/uh2)−b, where a and b are constant].

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