Morey, S. L., Wienders, N., Dukhovskoy, D. S., & Bourassa, M. A. (2018). Impact of Stokes Drift on Measurements of Surface Currents from Drifters and HF Radar. In American Geophysical Union (Vol. Fall Meeting).
Abstract: Concurrent measurements by surface drifters of different configurations and HF radar reveal substantial differences in estimates of the near-surface seawater velocity. On average, speeds of small ultra-thin (5 cm) drifters are significantly greater than co-located drifters with a traditional shallow drogue design, while velocity measurements from the drogued drifters closely match HF radar velocity estimates. Analysis of directional wave spectra measurements from a nearby buoy reveals that Stokes drift accounts for much of the difference between the velocity measurements from the drogued drifters and the ultra-thin drifters, except during times of wave breaking. Under wave breaking conditions, the difference between the ultra-thin drifter velocity and the drogued drifter velocity is much less than the computed Stokes drift. The results suggest that surface currents measured by more common approaches or simulated in models may underrepresent the velocity at the very surface of the ocean that is important for determining momentum and enthalpy fluxes between the ocean and atmosphere and for estimating transport of material at the ocean surface. However, simply adding an estimate of Stokes drift may also not be an appropriate method for estimating the true surface velocity from models or measurements from drogued drifters or HF radar under all sea conditions.
Morey, S. L., Zavala-Hidalgo, J., & O'Brien, J. J. (2001). High-resolution ocean modeling of the Gulf of Mexico . Research Activities in Atmospheric and Ocean Modeling, Report No. 31 pp., World Meteorological Organization, Geneva, Switzerland.
Morey, S. L., Zavala-Hidalgo, J., & O'Brien, J. J. (2005). The seasonal variability of continental shelf circulation in the northern and western Gulf of Mexico from a high-resolution numerical model. In W. Sturges, & A. Lugo-Fernandez (Eds.), New Developments in the Circulation of the Gulf of Mexico . Geophys. Mongr. Ser., (161).
Morey, S. L., Baig, S., Bourassa, M. A., Dukhovskoy, D. S., & O'Brien, J. J. (2006). Remote forcing contribution to storm-induced sea level rise during Hurricane Dennis. Geophys. Res. Lett. , 33 (19).
Morey, S. L., Bourassa, M. A., Dukhovskoy, D. S., & O'Brien, J. J. (2006). Modeling studies of the upper ocean response to a tropical cyclone. Ocean Dynamics , 56 (5-6), 594–606.
Morey, S. L., Dukhovskoy, D. S., & Bourassa, M. A. (2009). Connectivity of the Apalachicola River flow variability and the physical and bio-optical oceanic properties of the northern West Florida Shelf. Continental Shelf Research , 29 (9), 1264–1275.
Morey, S. L., Schroeder, W. W., O'Brien, J. J., & Zavala-Hidalgo, J. (2003). The annual cycle of riverine influence in the eastern Gulf of Mexico basin. Geophys. Res. Lett. , 30 (16).
Morey, S. L., Shriver, J. F., & O'Brien, J. J. (1999). The effects of Halmahera on the Indonesian throughflow. J. Geophys. Res. , 104 (C10), 23281–23296.
Morey, S. L., Zavala-Hidalgo, J., & O'Brien, J. J. (2003). Impacts of vertical resolution on a numerical model of the Gulf of Mexico. In OCEANS 2003 MTS/IEEE: Celebrating the Past... Teaming toward the Future (pp. 435–438).
Moroni, D. F. (2008). Global and Regional Diagnostic Comparison of Air-Sea Flux Parameterizations during Episodic Events . Ph.D. thesis, Florida State University, Tallahassee, FL.
Abstract: Twenty turbulent flux parameterizations are compared globally and regionally with a focus on the differences associated with episodic events. The regional focus is primarily upon the Gulf Stream and Drake Passage, as these two regions contain vastly different physical characteristics related to storm and frontal passages, varieties of sea-states, and atmospheric stability conditions. These turbulent flux parameterizations are comprised of six stress-related parameterizations [i.e., Large and Pond (1981), Large et al. (1994), Smith (1988), HEXOS (Smith et al. 1992, 1996), Taylor and Yelland (2001), and Bourassa (2006)] which are paired with a choice of three atmospheric stability parameterizations ['Neutral' assumption, Businger-Dyer (Businger 1966, Dyer 1967, Businger et al. 1971, and Dyer 1974) relations, and Beljaars-Holtslag (1991) with Benoit (1977)]. Two remaining turbulent flux algorithms are COARE version 3 (Fairall et al. 2003) and Kara et al. (2005), where Kara et al. is a polynomial curve fit approximation to COARE; these have their own separate stability considerations. The following data sets were used as a common input for parameterization: Coordinated Ocean Reference Experiment version 1.0, Reynolds daily SST, and NOAA WaveWatch III. The overlapping time period for these data sets is an eight year period (1997 through 2004). Four turbulent flux diagnostics (latent heat flux, sensible heat flux, stress, curl of the stress) are computed using the above parameterizations and analyzed by way of probability distribution functions (PDFs) and RMS analyses. The differences in modeled flux consistency are shown to vary by region and season. Modeled flux consistency is determined both qualitatively (using PDF diagrams) and quantitatively (using RMS differences), where the best consistencies are found during near-neutral atmospheric stratification. Drake Passage shows the least sensitivity (in terms of the change in the tails of PDFs) to seasonal change. Specific flux diagnostics show varying degrees of consistency between stability parameterizations. For example, the Gulf Stream's latent heat flux estimates are the most inconsistent (compared to any other flux diagnostic) during episodic and non-neutral conditions. In all stability conditions, stress and the curl of stress are the most consistent modeled flux diagnostics. Sea-state is also a very important source of modeled flux inconsistencies during episodic events for both regions.
Keywords: Parameterizations, Parameterization, Algorithm, Probability Density, Probability Distribution, Pdf, Drake Passage, Kuroshio, Gulf Stream Ect, Cold Tongue, Indian Ocean, Pacific Ocean, Southern Oceans, Atlantic Ocean, Tropics, Sea-State
