Comparison of the ocean surface vector winds from atmospheric reanalysis and scatterometer‐based wind products over the Nordic Seas and the northern North Atlantic and their application for ocean modeling

Abstract

Ocean surface vector wind fields from reanalysis data sets and scatterometer‐derived gridded products are analyzed over the Nordic Seas and the northern North Atlantic for the time period from 2000 to 2009. The data sets include the National Center for Environmental Prediction Reanalysis 2 (NCEPR2), Climate Forecast System Reanalysis (CFSR), Arctic System Reanalysis (ASR), Cross‐Calibrated Multiplatform (CCMP) wind product version 1.1 and recently released version 2.0, and QuikSCAT. The goal of the study is to assess discrepancies across the wind vector fields in the data sets and demonstrate possible implications of these differences for ocean modeling. Large‐scale and mesoscale characteristics of winds are compared at interannual, seasonal, and synoptic timescales. A cyclone tracking methodology is developed and applied to the wind fields to compare cyclone characteristics in the data sets. Additionally, the winds are evaluated against observations collected from meteorological buoys deployed in the Iceland and Irminger Seas. The agreement among the wind fields is better for longer time and larger spatial scales. The discrepancies are clearly apparent for synoptic timescales and mesoscales. CCMP, ASR, and CFSR show the closest overall agreement with each other. Substantial biases are found in the NCEPR2 winds. Numerical sensitivity experiments are conducted with a coupled ice‐ocean model forced by different wind fields. The experiments demonstrate differences in the net surface heat fluxes during storms. In the experiment forced by NCEPR2 winds, there are discrepancies in the large‐scale wind‐driven ocean dynamics compared to the other experiments.

RAS-NAAD: 40-yr High-Resolution North Atlantic Atmospheric Hindcast for Multipurpose Applications (New Dataset for the Regional Mesoscale Studies in the Atmosphere and the Ocean)

“…13a,b). These spectra characterize the atmospheric turbulence at different scales by the power law SKE(k) ; k 2g , where k is the wavenumber and g is changing from approximately 23 to approximately 25/3 between the ranges of space scales larger and smaller than 500 km (Waite and Snyder 2009;Condron and Renfrew 2013;Dukhovskoy et al 2017). Figure 13 demonstrates marked differences in the wavenumber spectra for HiRes and LoRes experiments.…”

“…3d) are consistent with those for ERA-Interim. Dukhovskoy et al (2017) noted differences between high-resolution satellite wind products and reanalyses attributing them to the subsynoptic and mesoscale processes. The impact of high-resolution and nonhydrostatic setting onto the wind field is especially evident for extreme winds (Figs.…”

“…This reflects stronger pressure gradients (and, thus, stronger winds) in synoptic and mesoscale transients in the HiRes experiment. Dukhovskoy et al (2017) ASR relative to global coarser-resolution reanalyses in the subpolar North Atlantic. Figure 13c shows the wavenumber kinetic energy spectra near the surface using data from NAAD HiRes and ASRv2 over the overlapping part of the two domains.…”

Meteorological buoy measurements in the Iceland Sea, 2007–2009

“…The buoy measurements are unique due to the sparsity of in situ observations over the ocean, especially in this region, and Dukhovskoy et al (2017) used it in an evaluation of ocean surface winds from reanalysis data sets and scatterometer-derived gridded products.…”

“…Although measurements from the data set have been used in both Harden et al (2015) and Dukhovskoy et al (2017) they have not been made publicly available earlier. However, now the data set has been quality-checked, suspect data removed and made publicly available from the PANGAEA Data Publisher.…”