Water properties and circulation in Arctic Ocean models

Abstract

[1] As a part of the Arctic Ocean Model Intercomparison Project, results from 10 Arctic ocean/ice models are intercompared over the period 1970 through 1999. Models' monthly mean outputs are laterally integrated over two subdomains (Amerasian and Eurasian basins), then examined as functions of depth and time. Differences in such fields as averaged temperature and salinity arise from models' differences in parameterizations and numerical methods and from different domain sizes, with anomalies that develop at lower latitudes carried into the Arctic. A systematic deficiency is seen as AOMIP models tend to produce thermally stratified upper layers rather than the ''cold halocline'', suggesting missing physics perhaps related to vertical mixing or to shelf-basin exchanges. Flow fields pose a challenge for intercomparison. We introduce topostrophy, the vertical component of VÂr r r rD where V is monthly mean velocity and r r r rD is the gradient of total depth, characterizing the tendency to follow topographic slopes. Positive topostrophy expresses a tendency for cyclonic ''rim currents''. Systematic differences of models' circulations are found to depend strongly upon assumed roles of unresolved eddies.

On the Benefit of Current and Future ALPS Data for Improving Arctic Coupled Ocean-Sea Ice State Estimation

“…In the absence of direct observations, mixing fields are often inferred from indirect observations and theories (e.g., Kunze et al, 2006;Whalen et al, 2012;Cole et al, 2015). At high latitudes, lack of knowledge in the three-dimensional distribution of these mixing fields is one of the primary reasons the Arctic Ocean's mean horizontal and vertical hydrographic structure is not well reproduced in numerical models (Holloway et al, 2007;Nguyen et al, 2011;Ilicak et al, 2016).…”

Arctic Ocean Warming Contributes to Reduced Polar Ice Cap

“…Observational fine structure and microstructure data suitable for inferring diapycnal eddy diffusivity are scarce in the Arctic, precluding the reliable parameterization of mixing rates for the highlatitude subsurface waters. However, 1D mixing models as a part of more general 3D ocean models have been successfully used to simulate the Arctic Ocean (e.g., Holloway et al 2007). Frequently in these cases, the turbulence closure models were tuned to improve model representation of observed general features of the Arctic Ocean.…”

Ice–ocean coupled computations for sea-ice prediction to support ice navigation in Arctic sea routes

“…Later, since 2001, the international Arctic Ocean Model Intercomparison Project (AOMIP) has focused on improving Arctic regional models and has investigated many aspects of the Arctic Ocean structure and sea-ice changes (Holloway et al 2007). In general, most results obtained from the AOMIP numerical model accurately reproduce largescale sea-ice dynamics using coarser resolution models.…”