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Assessment of the Ecco2 Reanalysis on the Representation of Antarctic Bottom Water Properties : Volume 11, Issue 2 (28/03/2014)

By Azaneu, M.

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Book Id: WPLBN0004020770
Format Type: PDF Article :
File Size: Pages 69
Reproduction Date: 2015

Title: Assessment of the Ecco2 Reanalysis on the Representation of Antarctic Bottom Water Properties : Volume 11, Issue 2 (28/03/2014)  
Author: Azaneu, M.
Volume: Vol. 11, Issue 2
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2014
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Kerr, R., Mata, M. M., & Azaneu, M. (2014). Assessment of the Ecco2 Reanalysis on the Representation of Antarctic Bottom Water Properties : Volume 11, Issue 2 (28/03/2014). Retrieved from http://hawaiilibrary.net/


Description
Description: Laboratório de Estudos dos Oceanos e Clima, Instituto de Oceanografia, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, 96203-900, Brazil. We analyzed the ability of the Estimating the Circulation and Climate of the Ocean – Phase II (ECCO2) reanalysis to represent the hydrographic properties and variability of the Antarctic Bottom Water (AABW) in the Southern Ocean. We used a twenty-year observational database to perform comparisons of hydrographic properties and reanalysis data for the same time period (1992–2011). In addition, we evaluated four case studies based on current meter data and the AABW volume transport estimates previously reported in the literature. The main Southern Ocean oceanographic features, as well as the characteristic shape of the regional potential temperature–salinity (Θ–S) diagrams, are adequately represented by the reanalysis. However, the opening of an oceanic polynya in the Weddell Sea Sector, which has been clearly visible since 2005, contributed to an unrealistic representation of the hydrographic properties of the Southern Ocean primarily after 2004. In this sense, our analyses focused on the period that was identified as more reliable (1992–2004). In general, the reanalysis data showed surface waters that were warmer, saltier, and denser than observations, which may have resulted from the absence of Ice Shelf Water and from the overestimation of sea ice concentrations that limit oceanic heat loss during austral winters. Intermediate waters were generally colder, fresher, and denser than observations, whereas deep waters were warmer and less dense. These differences in deep water properties were partially a result of the inability to reproduce the densest AABW variety by reanalysis for most of the analyzed period and also because of the model's relatively coarse vertical resolution. Despite differences in absolute values, the upper AABW limit (Γn ≥ 28.27 kg m−3) and AABW occupied area were well represented in the WOCE repeat sections SR2 and SR4 for the studied periods. In section WOCE SR3, however, the estimates from the differences were not as well correlated, and the AABW layer thickness was underrepresented. The case studies showed a good representation of the AABW volume export and current velocity variability in the most important region of dense water export (i.e., the Weddell Sea). The exception is the AABW volume transport near the Kerguelen Plateau, in which the rugged local bathymetry and the relatively coarse model resolution hampered a fair representation of the transport variability by the reanalysis. Despite the consistency in terms of variability, absolute volume transport, and velocity, estimates were underrepresented in all cases. Moreover, the reanalysis was capable of reproducing the general variability pattern and trends of the AABW hydrographic properties reported by previous studies. Therefore, the ECCO2 data from the 1992–2004 period was considered adequate for investigating the circulation of the AABW and variability of the hydrographic properties, whereas data from the latter period (2005–2011) must be given careful attention.

Summary
Assessment of the ECCO2 reanalysis on the representation of Antarctic Bottom Water properties

Excerpt
Lee, T., Awaji, T., Balmaseda, M., Ferry, N., Fujii, Y., Fukumori, I., Giese, B., Heimbach, P., Köhl, A., Masina, S., Remy, E., Rosati, A., Schodlok, M., Stammer, D., and Weaver, A.: Consistency and fidelity of Indonesian-throughflow total volume transport estimated by 14 ocean data assimilation products, Dynam. Atmos. Oceans, 50, 201–223, doi:10.1016/j.dynatmoce.2009.12.004, 2010.; Lumpkin, R. and Speer, K.: Global ocean meridional overturning, J. Phys. Oceanogr., 37, 2550–2562, 2007.; Marshall, J., Adcroft, A., Hill, C., Perelman, L., and Heisey, C.: A finite-volume, incompressible Navier–Stokes model for studies of the ocean on parallel computers, J. Geophys. Res., 102, 5753–5766, 1997.; Maximenko, N. and Niiler, P.: Hybrid decade-mean global sea level with mesoscale resolution, in: Recent Advances in Marine Science and Technology, edited by: Saxena, N., PACON International, Honolulu, 55–59, 2005.; Mazloff, M. R., Heimbach, P., and Wunsch, C.: An eddy-permitting Southern Ocean state estimate, J. Phys. Oceanogr., 40, 880–899, 2010.; McKee, D. C., Yuan, X., Gordon, A. L., Huber, B. A., and Dong, Z.: Climate impact on interannual variability of Weddell Sea Bottom Water, J. Geophys. Res., 116, 1–17, 2011.; Meccia, V., Wainer, I., Tonelli, M., and Curchitser, E.: Coupling a thermodynamically active ice shelf to a regional simulation of the Weddell Sea, Geosci. Model Dev., 6, 1209–1219, doi:10.5194/gmd-6-1209-2013, 2013.; Menemenlis, D., Fukumori, I., and Lee, T.: Using Green's functions to calibrate an ocean general circulation model, Mon. Weather Rev., 133, 1224–1240, 2005.; Muench, R. D. and Gordon, A. L.: Circulation and transport of water along the western Weddell Sea margin, J. Geophys. Res., 100, 18503–18515, 1995.; Menemenlis, D., Campin, J. M., Heimbach, P., Hill, C., Lee, T., Schodlok, M., and Zhang, H.: ECCO2: high resolution global ocean and sea ice data synthesis, Mercator Ocean Quarterly Newsletter, 31, 13–21, 2008.; Meredith, M. P., Locarnini, R. A., Van Scoy, K. A., Watson, A. J., Heywood, K. J., and King, B. A.: On the sources of Weddell Gyre Antarctic Bottom Water, J. Geophys. Res., 105, 1093–1104, 2000.; Muench, R. D. and Hellmer, H. H.: The international DOVETAIL program, Deep Sea Res.-Pt. II, 49, 4711–4714, 2002.; Naveira Garabato, A. C., McDonagh, E. L., Stevens, D. P., Heywood, K. J., and Sanders, R. J.: On the export of Antarctic Bottom Water from the Weddell Sea, Deep-Sea Res., 49, 4715–4742, 2002.; Nguyen, A. T., Menemenlis, D., and Kwok, R.: Improved modeling of the Arctic halocline with a subgrid-scale brine rejection parameterization, J. Geophys. Res., 114, C11014, doi:10.1029/2008JC005121, 2009.; Nicholls, K. W., Østerhus, S., Makinson, K., Gammelsrød, T., and Fahrbach, E.: Ice–ocean processes over the continental shelf of the southern Weddell Sea, Antarctica: a review, Rev. Geophys., 47, 1–23, doi:10.1029/2007RG000250, 2009.; Nowlin, W. D., Whitworth III, T., and Pillsbury, R. D.: Structure and transport of the Antarctic Circumpolar Current at Drake Passage from short-term measurements, J. Phys. Oceanogr., 7, 788–802, 1977.; Onogi, K., Tsutsui, J., Koide, H., Sakamoto, M., Kobayashi, S., Hatsushika, H., Matsumoto, T., Yamazaki, N., Kamahori, H., Takahashi, K., Kadokura, S., Wada, K., Kato, K., Oyama, R., Ose, T., Mannoji, N., and Taira, R.: The JRA-25 reanalysis, J. Meteorol. Soc. Jpn., 85, 1–3, 2007.; Orsi, A. H., Nowlin, W. D., and Whitworth, T.: On the circulation and stratification of the Weddell Gyre, Deep-Sea Res. Pt. I, 40, 169–303, 1993.; Orsi, A. H., Whitworth III, T., Nowlin Jr., W. D., Whitworth, T., and Nowlin, W. D.: On the meridional extent and fronts of the Antarctic Circumpolar Current, Deep-Sea Res. Pt. I, 42, 641–673, 1

 

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