Impact of operational model nesting approaches and inherent errors for coastal simulations

Brown, Jennifer M, Norman, Danielle L, Amoudry, Laurent O ORCID: 0000-0002-6592-6790 and Souza, Alejandro J (2016) Impact of operational model nesting approaches and inherent errors for coastal simulations. OCEAN MODELLING, 107. pp. 48-63.

Access the full-text of this item by clicking on the Open Access link.

Official URL: http://dx.doi.org/10.1016/j.ocemod.2016.10.005

Abstract

A region of freshwater influence (ROFI) under hypertidal conditions is used to demonstrate inherent problems for nested operational modelling systems. Such problems can impact the accurate simulation of freshwater export within shelf seas, so must be considered in coastal ocean modelling studies. In Liverpool Bay (our UK study site), freshwater inflow from 3 large estuaries forms a coastal front that moves in response to tides and winds. The cyclic occurrence of stratification and remixing is important for the biogeochemical cycles, as nutrient and pollutant loaded freshwater is introduced into the coastal system. Validation methods, using coastal observations from fixed moorings and cruise transects, are used to assess the simulation of the ROFI, through improved spatial structure and temporal variability of the front, as guidance for best practise model setup. A structured modelling system using a 180 m grid nested within a 1.8 km grid demonstrates how compensation for error at the coarser resolution can have an adverse impact on the nested, high resolution application. Using 2008, a year of typical calm and stormy periods with variable river influence, the sensitivities of the ROFI dynamics to initial and boundary conditions are investigated. It is shown that accurate representation of the initial water column structure is important at the regional scale and that the boundary conditions are most important at the coastal scale. Although increased grid resolution captures the frontal structure, the accuracy in frontal position is determined by the offshore boundary conditions and therefore the accuracy of the coarser regional model.

Item Type:	Article
Uncontrolled Keywords:	ROFI, POLCOMS-GOTM, Liverpool Bay, Model nesting, Freshwater export, Initial and boundary conditions
Depositing User:	Symplectic Admin
Date Deposited:	16 Aug 2019 10:22
Last Modified:	19 Jan 2023 00:29
DOI:	10.1016/j.ocemod.2016.10.005
Open Access URL:	http://nora.nerc.ac.uk/id/eprint/514851/1/LBfront_...
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3051941