Ocean–atmosphere dynamics during Hurricane Ida and Nor’Ida: An application of the coupled ocean–atmosphere–wave–sediment transport (COAWST) modeling system

Abstract

a b s t r a c tThe coupled ocean-atmosphere-wave-sediment transport (COAWST) modeling system was used to investigate atmosphere-ocean-wave interactions in November 2009 during Hurricane Ida and its subsequent evolution to Nor'Ida, which was one of the most costly storm systems of the past two decades. One interesting aspect of this event is that it included two unique atmospheric extreme conditions, a hurricane and a nor'easter storm, which developed in regions with different oceanographic characteristics. Our modeled results were compared with several data sources, including GOES satellite infrared data, JASON-1 and JASON-2 altimeter data, CODAR measurements, and wave and tidal information from the National Data Buoy Center (NDBC) and the National Tidal Database. By performing a series of numerical runs, we were able to isolate the effect of the interaction terms between the atmosphere (modeled with Weather Research and Forecasting, the WRF model), the ocean (modeled with Regional Ocean Modeling System (ROMS)), and the wave propagation and generation model (modeled with Simulating Waves Nearshore (SWAN)). Special attention was given to the role of the ocean surface roughness. Three different ocean roughness closure models were analyzed: DGHQ (which is based on wave age), TY2001 (which is based on wave steepness), and OOST (which considers both the effects of wave age and steepness). Including the ocean roughness in the atmospheric module improved the wind intensity estimation and therefore also the wind waves, surface currents, and storm surge amplitude. For example, during the passage of Hurricane Ida through the Gulf of Mexico, the wind speeds were reduced due to wave-induced ocean roughness, resulting in better agreement with the measured winds. During Nor'Ida, including the wave-induced surface roughness changed the form and dimension of the main low pressure cell, affecting the intensity and direction of the winds. The combined wave age-and wave steepness-based parameterization (OOST) provided the best results for wind and wave growth prediction. However, the best agreement between the measured (CODAR) and computed surface currents and storm surge values was obtained with the wave steepness-based roughness parameterization (TY2001), although the differences obtained with respect to DGHQ were not significant. The influence of sea surface temperature (SST) fields on the atmospheric boundary layer dynamics was examined; in particular, we evaluated how the SST affects wind wave generation, surface currents and storm surges. The integrated hydrograph and integrated wave height, parameters that are highly correlated with the storm damage potential, were found to be highly sensitive to the ocean surface roughness parameterization.Published by Elsevier Ltd.

Ocean–atmosphere–wave characterisation of a wind jet (Ebro shelf, NW Mediterranean Sea)

“…This behaviour is consistent with other coupling atmosphere-ocean investigations under a high level of meteorological energy (e.g. Olabarrieta et al, 2012). In parallel, the wave field is modified by the feedback between wave and wind stress.…”

“…The ocean-atmosphericwave online coupling was implemented in the finer domain (mesh O4 for the wave and circulation model, and mesh M4 for the meteorological model) where the scale of the coupling process due to cross-shelf winds may be more evident in the results. In this case, air-sea coupled effects are included considering the Taylor and Yelland formulation (Taylor and Yelland, 2001), for the ocean surface roughness modification due to the wave effect, and vortex force for the wave effects on currents (Olabarrieta et al, 2012). Table 1.…”

“…Warner et al (2010) developed a fully coupled numerical system (COAWST: Coupled Ocean-Atmosphere-WaveSediment Transport) to investigate the impact of storms on coastal systems. Using COAWST, Olabarrieta et al (2012) and Renault et al (2012) proved numerically that the waveinduced ocean surface roughness is a key parameter in the air-sea momentum transfer. Under severe storm conditions (hurricanes and cyclones), this parameter influences the spatial and temporal evolution of the meteo-oceanographic variables.…”

Observed near-surface currents under four super typhoons

“…The general relationships between the observed current velocity and the storm's translation speed and between the maximum current velocities and the Saffir-Simpson hurricane scale are also provided. Our results are congruent with recent studies (Olabarrieta et al, 2012;Warner et al, 2010;Yablonsky and Ginis, 2009;Zambon et al, submitted for publication) and provide useful tool for model validation. …”

“…In addition to current acceleration, existing modeling studies showed that TCs enhance drastically the upper ocean mixing and in turn affect the fluxes of heat and moisture across the air-ocean interface and change the dynamic height and sea surface temperature with the bias towards the right-side (Chang and Anthes, 1978;Chu et al, 2000;Jacob and Shay, 2003;Olabarrieta et al, 2012;Price, 1981;Price et al, 1994;Warner et al, 2010;Yablonsky and Ginis, 2009;Zambon et al, submitted for publication); and that TCs' passage affects upper ocean responses to the Kuroshio currents in the northwestern Pacific (Kuo et al, 2011;Tsai et al, 2008;Wu et al, 2008).…”