Skill-assessments of statistical and Ensemble Kalman Filter data assimilative analyses using surface and deep observations in the Gulf of Mexico

Abstract

A new data assimilation algorithm (Quasi-EnKF) in ocean modeling, based on the Ensemble Kalman Filter scheme, is proposed in this paper. This algorithm assimilates not only surface measurements (sea surface height), but also deep (~2000 m) temperature observations from the Gulf of Mexico into regional ocean models. With the use of the Princeton Ocean Model (POM), integrated for approximately two years by assimilating both surface and deep observations, this new algorithm was compared to an existing assimilation algorithm (Mellor-Ezer Scheme) at different resolutions. The results show that, by comparing the observations, the new algorithm out-performs the existing one.

Keywords

data assimilation / deep observation / Gulf of Mexico

References

[1] Berntsen J, Oey L Y (2010). Estimation of the internal pressure gradient in σ-coordinate ocean models: Comparison of second-, fourth-, and sixth-order schemes. Ocean Dyn, 60(2): 317-330

[2] Chassignet E P, Hurlburt H E, Smedstad O M, Barron C N, Ko D S, Rhodes R C, Shriver J F., Wallcraft A J, Arnone R A (2005). Assessment of data assimilative ocean models in the Gulf of Mexico using ocean color. Geophysical Monograph-American Geophysical Union, 161: 87

[3] Cooper M, Haines K (1996). Altimetric assimilation with water property conservation. J Geophys Res, 101(C1): 1059-1077

[4] Craig P D, Banner M L (1994). Modeling wave-enhanced turbulence in the ocean surface layer. J Phys Oceanogr, 24(12): 2546-2559

[5] Donohue K, Hamilton P, Leaman K, Leben R, Prater M, Watts D R, Waddell E (2006). Exploratory Study of Deepwater Currents in the Gulf of Mexico, Vol. I and II. US Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS, 2006-073

[6] Evensen G (2003). The Ensemble Kalman Filter: theoretical formulation and practical implementation. Ocean Dyn, 53(4): 343-367

[7] Ezer T, Arango H, Hermann A (2003). Terrain-Following Ocean Models Users Workshop, Seattle, WA, <month>Aug</month>. <day>4-6</day>, AOS Program, Princeton University, 19

[8] Ezer T, Mellor G L (1994). Continuous assimilation of Geosat altimeter data into a three-dimensional primitive equation Gulf Stream model. J Phys Oceanogr, 24(4): 832-847

[9] Gaspari G, Cohn S E (1999). Construction of correlation function in two and three dimensions. Q J R Meteorol Soc, 125(554): 723-757

[10] Kalnay E (2003). Atmospheric Modeling, Data Assimilation and Predictability. New York: Cambridge University Press, 341

[11] Kantha L, Choi J K, Schaudt K J, Cooper C K (2005). A Regional Data-Assimilative Model for Operational Use in the Gulf of Mexico. Geophysical Monograph-American Geophysical Union, 161, 165

[12] Lin X H, Oey L Y, Wang D P (2007). Altimetry and drifter data assimilations of Loop Current and eddies. J Geophys Res, 112(C5): C05046

[13] MacKinnon J A, Gregg M C (2003). Shear and baroclinic energy flux on the summer New England Shelf. J Phys Oceanogr, 33(7): 1462-1475

[14] Mellor G L (2001). One-dimensional ocean surface layer modeling, a problem and a solution. J Phys Oceanogr, 31(3): 790-809

[15] Mellor G L (2004). User’s Guide for a Three-dimensional, Primitive Equation, Numerical Ocean Model. Program in Atmospheric and Oceanic Sciences, Princeton University, 42

[16] Mellor G L, Ezer T (1991). A Gulf Stream model and an altimetry assimilation scheme. J Geophys Res, 96(C5): 8779-8795

[17] Mellor G L, Yamada T (1982). Development of a turbulence closure model for geophysical fluid problems. Rev Geophys, 20(4): 851-875

[18] Oey L Y (1995). Eddy- and wind-forced shelf circulation. J Geophys Res, 100(C5): 8621-8637

[19] Oey L Y (1996 a). Flow around a coastal bend: a model of the Santa Barbara Channel eddy. J Geophys Res, 101(C7): 16,667-16,682

[20] Oey L Y (1996 b). Simulation of mesoscale variability in the Gulf of Mexico: sensitivity studies, comparison with observations, and trapped wave propagation. J Phys Oceanogr, 26(2): 145-175

[21] Oey L Y, Chen P (1992a). A model simulation of circulation in the Northeast Atlantic shelves and seas. J Geophys Res, 97(C12): 20,087-20,115

[22] Oey L Y, Chen P (1992b). A nested-grid ocean model: with application to the simulation of meanders and eddies in the Norwegian Coastal Current. J Geophys Res, 97(C12): 20,063-20,086

[23] Oey L Y, Lee H C, Schmitz W J (2003). Effects of winds and Caribbean eddies on the frequency of Loop Current eddy shedding: a numerical model study. Journal of Geophysical Research: Oceans (1978-2012), 108(C10)

[24] Oey L, Ezer T, Lee H (2005). Loop Current, rings and related circulation in the Gulf of Mexico: a review of numerical models and future challenges. Geophysical Monograph-American Geophysical Union, 161, 31

[25] Sturges W, Lugo-Fernandez A (2005). Circulation in the Gulf of Mexico: Observations and Models, Geophys. Monogr. Ser., Vol. 161. Washington, D C: AGU, 347

[26] Wang D P, Oey L Y, Ezer T, Hamilton P (2003). Near-surface currents in DeSoto Canyon (1997-99): comparison of current meters, satellite observation and model simulation. J Phys Oceanogr, 33(1): 313-326

[27] Yin X Q, Oey L Y (2007). Bred-ensemble ocean forecast of Loop Current and rings. Ocean Model, 17(4): 300-326

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