波致混合在大洋环流模式中的作用方式
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摘要
本文在非破碎波浪混合基础上,基于MASNUM(前身为LAGFD-WAM)海浪波数谱数值模式和POM(普林斯顿海洋模式)环流模式建立了准全球的MASNUM浪-流耦合模式。耦合的方法是首先利用MASNUM海浪波数谱数值模式来计算波浪的方向谱,再利用波致混合方案计算混合系数Bv,并将其引入到环流模式中,从而建立准全球的浪-流耦合数值模式。
通过将模拟温度与Levitus温度对比,以及对模拟流场的分析,验证了所建立的浪-流耦合模式具有较高的精度,满足做进一步数值实验的要求。设计了八个MASNUM浪-流耦合数值实验和两个MASNUM海浪数值实验,对所提出的三个问题进行研究。
首先分析了日平均的波致混合系数和月平均的波致混合系数在耦合模式中的作用(对比实验一和实验二),发现采用月平均的波致混合系数进行浪-流耦合会略微高估波致混合的作用。并利用西北太七月份温度变化作为个例,分析了月平均Bv在耦合模式中的作用强于日平均Bv的原因。
其次,运用所建立的两个不同的MASNUM海浪数值实验,分别计算了全部波长海浪所形成的波致混合系数以及去掉大于300m波长浪的波致混合系数,并分别用总的波致混合系数进行原浪-流耦合数值实验、去掉长波波致混合系数浪-流耦合数值实验和独立长波(波长大于300m)波致混合系数浪-流耦合数值实验,同时还建立一个不考虑波浪混合的数值实验。通过以上实验之间温度场结果对比,得出了长波波致混合系数Bv在浪-流耦合模式中主要对35-100m的海洋混合起主要作用。
最后探讨了波致混合分别在温盐方程和动量方程中的不同作用,发现：若仅考虑波致混合在温盐方程中的作用,会对赤道流系的模拟造成很大的误差,并会使赤道附近温度场误差较大；若仅考虑波致混合在动量方程中的作用会很大程度上低估波致混合的作用,即波致混合作用在绝大部分区域的作用不明显。
A wave-circulation coupled model was incorporated by the MASNUM wave model and the Princeton Ocean Model (POM) base on the non-broken wave induced mixing theory. While do coupling, the wave-number spectrum was calculated first, and then was the wave-induced mixing coefficient (Bv). After that, the Bv was introduced to the circulation model, and the wave-circulation coupled model was then constructed.
The wave-circulation coupled model was validated by the comparison of simulated ocean temperature to Levitus data and the objective analysis of simulated ocean current. Then, eight couple-model experiments and two wave-model experiments were designed regarding to three questions raised by our research interest.
The first two couple-model experiments were constructed to compare the results of inputting different time-scaled Bv:daily and monthly. And the results showed that the experiment inputted by monthly averaged Bv could somewhat overestimate the role of wave-induced mixing, and it was particularly evident in summer. Then, the simulated ocean temperature over the northwest Pacific in July was chosen to analyze the causes to result in the discrepancy.
Second, two wave-model experiments were designed to calculate the all-wavelength Bv, and the separated less than 300m-wavelength Bv(short-wave Bv) and longer than 300m-wavelength Bv(long-wave Bv). Then, the couple-model experiments were renewedly done using the above acquired Bv respectively, and the non-Bv experiment was also done at the same time. Shown by the simulated ocean temperature, the long-wave Bv could mainly influence the upper ocean mixing of 35m-100m.
Finally, the roles of wave induced mixing in the thermohaline equation and momentum equation were examined. The separately consideration of wave induced mixing in the thermohaline equations could cause large errors in the simulation of equatorial current system and the temperature field near the equator. On the other hand, the separately consideration of wave induced mixing in the momentum equations would significantly underestimate the role of wave induced mixing, i.e. the wave induced mixing could not play its role over the most regions.
通过将模拟温度与Levitus温度对比,以及对模拟流场的分析,验证了所建立的浪-流耦合模式具有较高的精度,满足做进一步数值实验的要求。设计了八个MASNUM浪-流耦合数值实验和两个MASNUM海浪数值实验,对所提出的三个问题进行研究。
首先分析了日平均的波致混合系数和月平均的波致混合系数在耦合模式中的作用(对比实验一和实验二),发现采用月平均的波致混合系数进行浪-流耦合会略微高估波致混合的作用。并利用西北太七月份温度变化作为个例,分析了月平均Bv在耦合模式中的作用强于日平均Bv的原因。
其次,运用所建立的两个不同的MASNUM海浪数值实验,分别计算了全部波长海浪所形成的波致混合系数以及去掉大于300m波长浪的波致混合系数,并分别用总的波致混合系数进行原浪-流耦合数值实验、去掉长波波致混合系数浪-流耦合数值实验和独立长波(波长大于300m)波致混合系数浪-流耦合数值实验,同时还建立一个不考虑波浪混合的数值实验。通过以上实验之间温度场结果对比,得出了长波波致混合系数Bv在浪-流耦合模式中主要对35-100m的海洋混合起主要作用。
最后探讨了波致混合分别在温盐方程和动量方程中的不同作用,发现：若仅考虑波致混合在温盐方程中的作用,会对赤道流系的模拟造成很大的误差,并会使赤道附近温度场误差较大；若仅考虑波致混合在动量方程中的作用会很大程度上低估波致混合的作用,即波致混合作用在绝大部分区域的作用不明显。
A wave-circulation coupled model was incorporated by the MASNUM wave model and the Princeton Ocean Model (POM) base on the non-broken wave induced mixing theory. While do coupling, the wave-number spectrum was calculated first, and then was the wave-induced mixing coefficient (Bv). After that, the Bv was introduced to the circulation model, and the wave-circulation coupled model was then constructed.
The wave-circulation coupled model was validated by the comparison of simulated ocean temperature to Levitus data and the objective analysis of simulated ocean current. Then, eight couple-model experiments and two wave-model experiments were designed regarding to three questions raised by our research interest.
The first two couple-model experiments were constructed to compare the results of inputting different time-scaled Bv:daily and monthly. And the results showed that the experiment inputted by monthly averaged Bv could somewhat overestimate the role of wave-induced mixing, and it was particularly evident in summer. Then, the simulated ocean temperature over the northwest Pacific in July was chosen to analyze the causes to result in the discrepancy.
Second, two wave-model experiments were designed to calculate the all-wavelength Bv, and the separated less than 300m-wavelength Bv(short-wave Bv) and longer than 300m-wavelength Bv(long-wave Bv). Then, the couple-model experiments were renewedly done using the above acquired Bv respectively, and the non-Bv experiment was also done at the same time. Shown by the simulated ocean temperature, the long-wave Bv could mainly influence the upper ocean mixing of 35m-100m.
Finally, the roles of wave induced mixing in the thermohaline equation and momentum equation were examined. The separately consideration of wave induced mixing in the thermohaline equations could cause large errors in the simulation of equatorial current system and the temperature field near the equator. On the other hand, the separately consideration of wave induced mixing in the momentum equations would significantly underestimate the role of wave induced mixing, i.e. the wave induced mixing could not play its role over the most regions.
引文
舒启.波致混合对大洋环流模式MOM4的改进.2009,硕士论文,国家海洋局第一海洋研究所.
乔方利,马建,夏长水,杨永增,袁业立.波浪和潮流混合对黄东海夏季温度垂直结构的影响研究.自然科学进展,2004,14(12)：1434-1441.
夏长水.基于POM的浪流耦合模式的建立及其在大洋和近海的应用,2005,博士论文,中国海洋大学.
杨永增,乔方利,赵伟,滕涌,袁业立.球坐标MASNUM海浪数值模式的建立及其应用,海洋学报,2005,27(2):1-7.
袁业立.黄海冷水团环流.海洋与湖沼,1979,10(3)：187-199.
袁业立.LAGFD-WAM海浪数值模式Ⅰ.基本物理模型.海洋学报,1992a,14(5)：1-7.
袁业立.LAGFD-WAM海浪数值模式Ⅱ.区域性特征线嵌入格式及其应用.海洋学报,1992b,14(6)：12-24.
袁业立.黄海冷水团环流结构及生成机制研究Ⅰ.0阶解及冷水团的环流结构,中国科学,1993,23(1)：93-103.
袁业立,乔方利,华锋.近海环流数值模式的建立Ⅰ.海波的搅拌和波流相互作用,水动力学研究与进展(A辑),1999,14(4B)：1-8.
于卫东,袁业立,潘增弟,等.关于第三代海浪数值模式控制方程的导出,海洋与湖沼,Vol,28,13-20,1997a.
于卫东,乔方利,袁业立,等.Betty(8710)台风过程风浪数值模拟,海洋学报,第19卷,第6期,27-37,1997b.
Canuto, V.M., Dubovikov, M.S.. A dynamical model for turbulence. I. General formalism. Physics of Fluids 8,1996,571-586.
Chen D, Rothstein L M, Busalacchi A J. A hybrid vertical mixing scheme and its application to tropical ocean models. Journal of Physical Oceanography,1994,24:2156-2179.
Craig, P.D., and M.L. Banner. Modeling wave-enhanced turbulence in the ocean surface layer. J. Phys.Oceanogr.,24,2546-2559,1994.
Ezer T. On the seasonal mixed layer simulated by a basin-scale ocean model and the Mellor-Yamada turbulence scheme. Geophys. Res,2000,105 (C7):16843-16855.
Griffies, Stephen, Matthew J Harrison, Ronald C Pacanowski, and Anthony Rosati:A Technical Guide to MOM4, GFDL Ocean Group Technical Report No.5, Princeton, NJ:: NOAA/Geophysical Fluid Dynamics Laboratory,2004,342 pp.
Harney, R. Surface thermal boundary condition for ocean circulation models. J.Phys.Oceanogr., 1,241-248,1971.
Komen, G.J., L.Cavaleri, M.Donelan,K.Hasselmann, S.Hasselmann, and P.A.E.M.Janssen.Dynamics and modeling of ocean waves.Cambridge Univ.Press,532 pp,1994.
Kraus E B, Turner J S. A one-dimensional model of the seasonal thermocline, II. The general theory and its consequences. Tellus,1967,19:98-105.
Ma, J. and F. Qiao, Simulation and analysis on seasonal variability of average salinity in the Yellow sea. Chin J. Oceanol. Limnol,2004a,22(3),306-313.
Ma, J., F. Qiao, C. Xia, and Y. Yang, Tidal effects on temperature front in the Yellow Sea. Chin. J. Oceanol. Limnol,2004b,22(3),314-321.
Martin, P.J. Simulation of the mixed layer at OWS November and Papa with several models. J.Geophys.Res.,90,581-597,1985.
Mellor, G. L. and T. Yamada. Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys. and Space Phys.,1982,20,851-875.
Mellor, G. L. User's guide for a three-dimensional, primitive equation, numerical ocean model [M]. Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ,1992,35 pp [Available from Princeton University, Princeton, NJ 08544].
Mellor, G. L., T. Ezer, and L. Y. Oey. On the pressure gradient conundrum of sigma-cordinate ocean models, J. atmos. Oceanic Technol.,1994,11,1120-1129.
Mellor G, The three-dimensional current and wave equations. J. Phys. Oceanogr.,2003,33, 1978-1989.
Price J F, Weller R A, Pinkel R. Diurnal cycling:observations and models of the upper ocean response to diurnal heating, cooling, and wind mixing. Journal of Geophysical Research, 1986,91:8411-8427.
Qiao, F., Y. Yuan, Y. Yang, Q. Zheng, C. Xia, and J. Ma. Wave-induced mixing in the upper ocean:Distribution and application to a global ocean circulation model. Geophys. Res. Lett., 2004,31, L11303, doi:10.1029/2004GL019824.
Song, Z., F. Qiao, Y. Yang, and Y. Yuan, An improvement of the too cold tongue in the tropical Pacific with the development of an ocean-wave-atmosphere coupled numerical model, Progress in Natural Science,2007,17(5),76-583.
Xia, C., F. Qiao, Y. Yang, J. Ma, and Y. Yuan, Three-dimensional structure of the summertime circulation in the Yellow Sea from a wave-tide-circulation coupled model, J. Geophys. Res., 2006,111,C11S03,doi:10.1029/2005JC003218.
乔方利,马建,夏长水,杨永增,袁业立.波浪和潮流混合对黄东海夏季温度垂直结构的影响研究.自然科学进展,2004,14(12)：1434-1441.
夏长水.基于POM的浪流耦合模式的建立及其在大洋和近海的应用,2005,博士论文,中国海洋大学.
杨永增,乔方利,赵伟,滕涌,袁业立.球坐标MASNUM海浪数值模式的建立及其应用,海洋学报,2005,27(2):1-7.
袁业立.黄海冷水团环流.海洋与湖沼,1979,10(3)：187-199.
袁业立.LAGFD-WAM海浪数值模式Ⅰ.基本物理模型.海洋学报,1992a,14(5)：1-7.
袁业立.LAGFD-WAM海浪数值模式Ⅱ.区域性特征线嵌入格式及其应用.海洋学报,1992b,14(6)：12-24.
袁业立.黄海冷水团环流结构及生成机制研究Ⅰ.0阶解及冷水团的环流结构,中国科学,1993,23(1)：93-103.
袁业立,乔方利,华锋.近海环流数值模式的建立Ⅰ.海波的搅拌和波流相互作用,水动力学研究与进展(A辑),1999,14(4B)：1-8.
于卫东,袁业立,潘增弟,等.关于第三代海浪数值模式控制方程的导出,海洋与湖沼,Vol,28,13-20,1997a.
于卫东,乔方利,袁业立,等.Betty(8710)台风过程风浪数值模拟,海洋学报,第19卷,第6期,27-37,1997b.
Canuto, V.M., Dubovikov, M.S.. A dynamical model for turbulence. I. General formalism. Physics of Fluids 8,1996,571-586.
Chen D, Rothstein L M, Busalacchi A J. A hybrid vertical mixing scheme and its application to tropical ocean models. Journal of Physical Oceanography,1994,24:2156-2179.
Craig, P.D., and M.L. Banner. Modeling wave-enhanced turbulence in the ocean surface layer. J. Phys.Oceanogr.,24,2546-2559,1994.
Ezer T. On the seasonal mixed layer simulated by a basin-scale ocean model and the Mellor-Yamada turbulence scheme. Geophys. Res,2000,105 (C7):16843-16855.
Griffies, Stephen, Matthew J Harrison, Ronald C Pacanowski, and Anthony Rosati:A Technical Guide to MOM4, GFDL Ocean Group Technical Report No.5, Princeton, NJ:: NOAA/Geophysical Fluid Dynamics Laboratory,2004,342 pp.
Harney, R. Surface thermal boundary condition for ocean circulation models. J.Phys.Oceanogr., 1,241-248,1971.
Komen, G.J., L.Cavaleri, M.Donelan,K.Hasselmann, S.Hasselmann, and P.A.E.M.Janssen.Dynamics and modeling of ocean waves.Cambridge Univ.Press,532 pp,1994.
Kraus E B, Turner J S. A one-dimensional model of the seasonal thermocline, II. The general theory and its consequences. Tellus,1967,19:98-105.
Ma, J. and F. Qiao, Simulation and analysis on seasonal variability of average salinity in the Yellow sea. Chin J. Oceanol. Limnol,2004a,22(3),306-313.
Ma, J., F. Qiao, C. Xia, and Y. Yang, Tidal effects on temperature front in the Yellow Sea. Chin. J. Oceanol. Limnol,2004b,22(3),314-321.
Martin, P.J. Simulation of the mixed layer at OWS November and Papa with several models. J.Geophys.Res.,90,581-597,1985.
Mellor, G. L. and T. Yamada. Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys. and Space Phys.,1982,20,851-875.
Mellor, G. L. User's guide for a three-dimensional, primitive equation, numerical ocean model [M]. Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ,1992,35 pp [Available from Princeton University, Princeton, NJ 08544].
Mellor, G. L., T. Ezer, and L. Y. Oey. On the pressure gradient conundrum of sigma-cordinate ocean models, J. atmos. Oceanic Technol.,1994,11,1120-1129.
Mellor G, The three-dimensional current and wave equations. J. Phys. Oceanogr.,2003,33, 1978-1989.
Price J F, Weller R A, Pinkel R. Diurnal cycling:observations and models of the upper ocean response to diurnal heating, cooling, and wind mixing. Journal of Geophysical Research, 1986,91:8411-8427.
Qiao, F., Y. Yuan, Y. Yang, Q. Zheng, C. Xia, and J. Ma. Wave-induced mixing in the upper ocean:Distribution and application to a global ocean circulation model. Geophys. Res. Lett., 2004,31, L11303, doi:10.1029/2004GL019824.
Song, Z., F. Qiao, Y. Yang, and Y. Yuan, An improvement of the too cold tongue in the tropical Pacific with the development of an ocean-wave-atmosphere coupled numerical model, Progress in Natural Science,2007,17(5),76-583.
Xia, C., F. Qiao, Y. Yang, J. Ma, and Y. Yuan, Three-dimensional structure of the summertime circulation in the Yellow Sea from a wave-tide-circulation coupled model, J. Geophys. Res., 2006,111,C11S03,doi:10.1029/2005JC003218.