World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Assimilation of Sea-ice Concentration in a Global Climate Model – Physical and Statistical Aspects : Volume 9, Issue 1 (15/01/2013)

By Tietsche, S.

Click here to view

Book Id: WPLBN0004020639
Format Type: PDF Article :
File Size: Pages 18
Reproduction Date: 2015

Title: Assimilation of Sea-ice Concentration in a Global Climate Model – Physical and Statistical Aspects : Volume 9, Issue 1 (15/01/2013)  
Author: Tietsche, S.
Volume: Vol. 9, Issue 1
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2013
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Jungclaus, J. H., Notz, D., Marotzke, J., & Tietsche, S. (2013). Assimilation of Sea-ice Concentration in a Global Climate Model – Physical and Statistical Aspects : Volume 9, Issue 1 (15/01/2013). Retrieved from http://worldlibrary.net/


Description
Description: Max Planck Institute for Meteorology, Bundesstr. 53, 20146 Hamburg, Germany. We investigate the initialisation of Northern Hemisphere sea ice in the global climate model ECHAM5/MPI-OM by assimilating sea-ice concentration data. The analysis updates for concentration are given by Newtonian relaxation, and we discuss different ways of specifying the analysis updates for mean thickness. Because the conservation of mean ice thickness or actual ice thickness in the analysis updates leads to poor assimilation performance, we introduce a proportional dependence between concentration and mean thickness analysis updates. Assimilation with these proportional mean-thickness analysis updates leads to good assimilation performance for sea-ice concentration and thickness, both in identical-twin experiments and when assimilating sea-ice observations. The simulation of other Arctic surface fields in the coupled model is, however, not significantly improved by the assimilation. To understand the physical aspects of assimilation errors, we construct a simple prognostic model of the sea-ice thermodynamics, and analyse its response to the assimilation. We find that an adjustment of mean ice thickness in the analysis update is essential to arrive at plausible state estimates. To understand the statistical aspects of assimilation errors, we study the model background error covariance between ice concentration and ice thickness. We find that the spatial structure of covariances is best represented by the proportional mean-thickness analysis updates. Both physical and statistical evidence supports the experimental finding that assimilation with proportional mean-thickness updates outperforms the other two methods considered. The method described here is very simple to implement, and gives results that are sufficiently good to be used for initialising sea ice in a global climate model for seasonal to decadal predictions.

Summary
Assimilation of sea-ice concentration in a global climate model – physical and statistical aspects

Excerpt
Blanchard-Wrigglesworth, E., Armour, K. C., Bitz, C. M., and DeWeaver, E.: Persistence and inherent predictability of A}rctic sea ice in a {GCM ensemble and observations, J. Climate, 24, 231–250, doi:10.1175/2010JCLI3775.1, 2011{a}.; Blanchard-Wrigglesworth, E., Bitz, C. M., and Holland, M. M.: Influence of initial conditions and climate forcing on predicting A}rctic sea ice, Geophys. Res. Lett., 38, L18503, doi:10.1029/2011GL048807, 2011{b.; Bouttier, F. and Courtier, P.: Data assimilation concepts and methods – training course lecture notes, from http://www.ecmwf.int (last access: 11 January 2013), 1999.; Budikova, D.: Role of {A}rctic sea ice in global atmospheric circulation: A review, Global Planet. Change, 68, 149–163, doi:10.1016/j.gloplacha.2009.04.001, 2009.; Cavalieri, D., Parkinson, C., Gloersen, P., and Zwally, H. J.: Sea Ice Concentrations from N}imbus-7 {SMMR and DMSP {SSM/I} Passive Microwave Data, from http://nsidc.org/data/nsidc-0051.html (last access: 11 January 2013), 2008.; Dulière, V. and Fichefet, T.: On the assimilation of ice velocity and concentration data into large-scale sea ice models, Ocean Sci., 3, 321–335, doi:10.5194/os-3-321-2007, 2007.; Francis, J. A. and Vavrus, S. J.: Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophys. Res. Lett., 39, L06801, doi:10.1029/2012GL051000, 2012.; Hibler III, W. D.: A Dynamic Thermodynamic Sea Ice Model, J. Phys. Oceanogr., 9, 815–846, 1979.; Holland, M. M., Bailey, D. A., and Vavrus, S.: Inherent sea ice predictability in the rapidly changing {A}rctic environment of the {C}ommunity {C}limate {S}ystem {M}odel, version 3, Clim. Dynam., 36, 1239–1253, doi:10.1007/s00382-010-0792-4, 2011.; Honda, M., Inoue, J., and Yamane, S.: Influence of low {A}rctic sea ice minima on anomalously cold {E}urasian winters, Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079, 2009.; Hurrell, J., Meehl, G. A., Bader, D., Delworth, T. L., Kirtman, B., and Wielicki, B.: A Unified Modeling Approach to Climate System Prediction, Bull. Amer. Meteor. Soc., 90, 1819–1832, doi:10.1175/2009BAMS2752.1, 2009.; Jungclaus, J. H., Keenlyside, N., Botzet, M., Haak, H., Luo, J.-J., Latif, M., Marotzke, J., Mikolajewicz, U., and Roeckner, E.: Ocean Circulation and Tropical Variability in the Coupled Model ECHAM5}/{MPI-OM, J. Climate, 19, 3952–3972, 2006.; Kalnay, E.: Atmospheric Modeling, Data Assimilation and Predictability, Cambridge University Press, 2003.; Koenigk, T., Mikolajewicz, U., Haak, H., and Jungclaus, J.: Variability of {F}ram {S}trait sea ice export: causes, impacts and feedbacks in a coupled climate model, Clim. Dynam., 26, 17–34, doi:10.1007/s00382-005-0060-1, 2006.; Koldunov, N. V., Stammer, D., and Marotzke, J.: Present-Day A}rctic Sea Ice Variability in the Coupled {ECHAM5}/{MPI-OM Model, J. Climate, 23, 2520–2543, doi:10.1175/2009JCLI3065.1, 2010.; Kwok, R., Cunningham, G. F., Wensnahan, M., Rigor, I., Zwally, H. J., and Yi, D.: Thinning and volume loss of the {A}rctic {O}cean sea ice cover: 2003–2008, J. Geophys. Res., 114, C07005,

 

Click To View

Additional Books


  • Modelling Approach to the Assessment of ... (by )
  • The Link Between the Barents Sea and Ens... (by )
  • The Radmed Monitoring Program: Towards a... (by )
  • Weighing the Ocean with Bottom-pressure ... (by )
  • Towards Closure of Regional Heat Budgets... (by )
  • Tidal Variability of the Motion in the S... (by )
  • The Civitavecchia Coastal Environment Mo... (by )
  • Atlantic Meridional Ocean Heat Transport... (by )
  • Long-term Spatial Variations in the Balt... (by )
  • Evaluation of Release-05 Grace Time-vari... (by )
  • Mechanisms Controlling Primary and New P... (by )
  • Annual Cycles of Chlorophyll-A, Non-alga... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.