Naumov L.M., Gordeeva S.M.

Based on ECMWF ORAS4 and ORAS5 reanalysis data volumetric flow rate and also heat and salt fluxes and their balances have been calculated on the lateral boundaries of the Lofoten Basin area in the Norwegian Sea. These results have been compared with results based on CMEMS reanalysis GLORYS12V1 data. We revealed, that the most physically justified in the volumetric flow rate is the ORAS5 reanalysis with a 6.0 % discrepancy. Heat balance estimation based on the GLORYS12V1 reanalysis data is more realistic because it shows an increased heat influx that participates in the ocean-atmosphere heat exchange. We conclude that the influx from the southern boundary dominates while the outflux through the eastern boundary is prevalent in the study area, which is mainly determined by the region’s waters dynamics. All of three reanalysis shows an excess of water and salt inflow over outflow for the Lofoten Basin. That indicates the balances for individual basins are not closed and approaches to using these data are limited.
All reanalysis data demonstrate the irregular fluctuations in the temporal variability of the fluxes through the boundaries with the different variance rate. Using the ORAS5 reanalysis data from 1993–2016, we estimate significant linear trends of the studied fluxes through all boundaries, except the northern one. It can be a real proof of increasing transport through the Lofoten Basin. The linear trends of the balance calculated using the ORAS5 data of the same period show the accumulation of water in the region as well as the cooling and accumulation of salt. The linear trends of the balance calculated using the GLORYS12V1 reanalysis demonstrate positive values indicating the warming of the basin.

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