|
|
|
Sensitivity study of subgrid scale ocean mixing under sea ice using a two-column ocean grid in climate model CESM |
Meibing JIN1,*( ),Jennifer HUTCHINGS2,Yusuke KAWAGUCHI3 |
1. International Arctic Research Center, University of Alaska Fairbanks, AK 99775, USA 2. College of Earth, Ocean and Atmospheric Sciences, Oregon State University, OR 97331, USA 3. Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan |
|
|
|
|
Abstract Brine drainage from sea ice formation plays a critical role in ocean mixing and seasonal variations of halocline in polar oceans. The horizontal scale of brine drainage and its induced convection is much smaller than a climate model grid and a model tends to produce false ocean mixing when brine drainage is averaged over a grid cell. A two-column ocean grid (TCOG) scheme was implemented in the Community Earth System Model (CESM) using coupled sea ice-ocean model setting to explicitly solve the different vertical mixing in the two sub-columns of one model grid with and without brine rejection. The fraction of grid with brine rejection was tested to be equal to the lead fraction or a small constant number in a series of sensitivity model runs forced by the same atmospheric data from 1978 to 2009. The model results were compared to observations from 29 ice tethered profilers (ITP) in the Arctic Ocean Basin from 2004 to 2009. Compared with the control run using a regular ocean grid, the TCOG simulations showed consistent reduction of model errors in salinity and mixed layer depth (MLD). The model using a small constant fraction grid for brine rejection was found to produce the best model comparison with observations, indicating that the horizontal scale of the brine drainage is very small compared to the sea ice cover and even smaller than the lead fraction. Comparable to models using brine rejection parameterization schemes, TCOG achieved more improvements in salinity but similar in MLD.
|
| Keywords
climate model
sea ice
mixed-layer depth
ocean mixing
brine drainage
|
|
Corresponding Author(s):
Meibing JIN
|
|
Online First Date: 26 January 2015
Issue Date: 30 October 2015
|
|
| 1 |
Bitz C M, Holland M M, Weaver A J, Eby M (2001). Simulating the ice-thickness distribution in a coupled climate model. J Geophys Res, 106(C2): 2441–2463
https://doi.org/10.1029/1999JC000113
|
| 2 |
Danabasoglu G, Bates S, Briegleb B P, Jayne S R, Jochum M, Large W G, Peacock S, Yeager S G (2012). The CCSM4 ocean component. J Clim, 25(5): 1361–1389
https://doi.org/10.1175/JCLI-D-11-00091.1
|
| 3 |
Duffy P, Eby M, Weaver A (1999). Effects of sinking of salt rejected during formation of sea ice on results of an ocean-atmosphere-sea ice climate model. Geophysical Research Letter, 26(12), 1739–1742
|
| 4 |
Fetterer F, Knowles K, Meier K, Savoie M (2002). Updated 2009. Sea Ice Index [ice extent]. Boulder: National Snow and Ice Data Center.
|
| 5 |
Hunke E C, Lipscomb W H, Turner A K, Jeffery N, Elliott S (2013). CICE: The Los Alamos Sea Ice Model Documentation and Software User’s Manual Version 5.0 LA-CC-06–012, Los Alamos National Laboratory, USA
|
| 6 |
Jin M, Hutchings J, Kawaguchi Y, Kikuchi T (2012). Ocean mixing with lead-dependent subgrid scale brine rejection parameterization in climate model. J Ocean Univ China, 11(4): 473–480
https://doi.org/10.1007/s11802-012-2094-4
|
| 7 |
Kantha L H (1995). A numerical model of Arctic leads. J Geophys Res, 100(C3): 4653–4672
https://doi.org/10.1029/94JC02348
|
| 8 |
Lake R A, Lewis E L (1970). Salt rejection by sea ice during growth. J Geophys Res, 75(3): 583–597
https://doi.org/10.1029/JC075i003p00583
|
| 9 |
Large W, Danabasoglu G, Doney S, McWilliams J (1997). Sensitivity to surface forcing and boundary layer mixing in the NCAR CSM ocean model: annual-mean climatology. J Phys Oceanogr, 27(11): 2418–2447
https://doi.org/10.1175/1520-0485(1997)027<2418:STSFAB>2.0.CO;2
|
| 10 |
Large W G, McWilliams J C, Doney S C (1994). Oceanic vertical mixing: a review and a model with a vertical K-profile boundary layer parameterization. Rev Geophys, 32(4): 363–403
https://doi.org/10.1029/94RG01872
|
| 11 |
Large W G, Yeager S G (2009). The global climatology of an interannually varying air-sea flux data set. Clim Dyn, 33(2-3): 341–364
https://doi.org/10.1007/s00382-008-0441-3
|
| 12 |
Matsumura Y, Hasumi H (2008). Brine-driven eddies under sea ice leads and their impact on the Arctic Ocean mixed layer. Journal of Physical Oceanography, 38: 146–163
https://doi.org/10.1175/2007JPO3620.1
|
| 13 |
Morison J H (1993). The lead experiment. Eos Trans AGU, 74(35): 393–397
https://doi.org/10.1029/93EO00341
|
| 14 |
Nguyen A T, Menemenlis D, Kwok R (2009). Improved modeling of the Arctic halocline with a subgrid-scale brine rejection parameterization. J Geophys Res, 114(C11): C11014
https://doi.org/10.1029/2008JC005121
|
| 15 |
Steele M, Morley R, Ermold W (2001). PHC: a global ocean hydrography with a high quality Arctic Ocean. J Clim, 14(9): 2079–2087
https://doi.org/10.1175/1520-0442(2001)014<2079:PAGOHW>2.0.CO;2
|
| 16 |
Toole J M, Timmermans M L, Perovich D K, Krishfield R A, Proshutinsky A, Richter-Menge J A (2010). Influences of the ocean surface mixed layer and thermohaline stratification on Arctic Sea ice in the central Canada Basin. J Geophys Res, 115(C10): C10018
https://doi.org/10.1029/2009JC005660
|
| 17 |
Wakatsuchi M, Ono N (1983). Measurements of salinity and volume of brine excluded from growing sea ice. J Geophys Res, 88(C5): 2943–2951
https://doi.org/10.1029/JC088iC05p02943
|
| 18 |
Wettlaufer J S, Worster M C, Huppert H E (1997). The phase evolution of young ice. Geophys Res Lett, 24(10): 1251–1254
https://doi.org/10.1029/97GL00877
|
| 19 |
Zhang J, Steele M (2007). Effect of vertical mixing on the Atlantic Water layer circulation in the Arctic Ocean. J Geophys Res, 112(C4): C04S04
https://doi.org/10.1029/2006JC003732
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|