Imperial College London

DrPavelBerloff

Faculty of Natural SciencesDepartment of Mathematics

Reader in Applied Mathematics
 
 
 
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Contact

 

+44 (0)20 7594 9662p.berloff Website

 
 
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Location

 

745Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Haigh:2018:10.1017/jfm.2018.547,
author = {Haigh, MC and Berloff, PS},
doi = {10.1017/jfm.2018.547},
journal = {Journal of Fluid Mechanics},
pages = {199--225},
title = {Potential vorticity redistribution by localised transient forcing in the shallow-water model},
url = {http://dx.doi.org/10.1017/jfm.2018.547},
volume = {852},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - This study is motivated by the need to develop stochastic parameterisations for representing the effects of mesoscale oceanic eddies in non-eddy-resolving and eddy-permitting ocean circulation models. A necessary logical step on the way to such parameterisations is the understanding of flow responses to spatially stationary and localised, time-dependent ‘plunger’ forcings intended to represent transient eddy flux divergences. Specifically, this study develops an understanding of the plunger-induced convergence of potential vorticity (PV) fluxes using the linearised single-layer shallow-water model. Time-periodic solutions are obtained and the ‘footprint’, defined as the time-mean, quasi-linear PV flux convergence, quantifies the cumulative PV redistribution induced by the plunger. Using the footprint, the equivalent eddy flux (EEF) is defined such that it succinctly quantifies the extent of the PV redistribution, and its dependencies on the forcing latitude and the background flow are examined in detail. For a uniform background flow the EEF is positive for all forcing latitudes, corresponding to net-poleward PV flux convergence, as expected by current theory of -plane Rossby waves. The EEF also has a robust dependence on the direction and magnitude of a uniform background flow, which is a useful quality for the EEF to provide a basis for a parameterisation of eddy PV fluxes. We also examine the PV redistribution due to forcing on top of a Gaussian jet background flow and find that forcing proximity to the jet core is the primary factor in determining whether the jet is sharpened or broadened.
AU - Haigh,MC
AU - Berloff,PS
DO - 10.1017/jfm.2018.547
EP - 225
PY - 2018///
SN - 0022-1120
SP - 199
TI - Potential vorticity redistribution by localised transient forcing in the shallow-water model
T2 - Journal of Fluid Mechanics
UR - http://dx.doi.org/10.1017/jfm.2018.547
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000440670900003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR - http://hdl.handle.net/10044/1/62244
VL - 852
ER -