海洋学报（中文版）
海洋學報（中文版）
해양학보（중문판）
ACTA OCEANOLOGICA SINICA
2013年
4期
19-28
,共10页
M2分潮%垂直分辨率%底摩擦%EFDC%长江口
M2分潮%垂直分辨率%底摩抆%EFDC%長江口
M2분조%수직분변솔%저마찰%EFDC%장강구
M2 tide%vertical resolution%bottom stress%EFDC%Changjiang Estuary
基于EFDC（Environmental Fluid Dynamics Code）模式建立了长江口及其邻近海域的三维水动力学模型，研究模型的垂直分辨率对该海域M2分潮模拟的影响。结果表明：垂直分辨率的变化对M2分潮传播方向的模拟结果影响较小，但其可通过底摩擦和湍流耗散两个计算过程来影响潮能通量的模拟结果，最终对长江口和杭州湾内的M2分潮振幅产生显著的影响。最底层厚度较大时，上层自由水体的高流速特征在最底层过于明显，进而导致计算的底摩擦应力偏高，此时提高底层的垂直分辨率会降低底摩擦对能量的耗散。另一方面，垂直湍流混合作用会随垂直分辨率的增加而增强，所以垂直分辨率增加到一定程度后，上层自由水体的高流速会经由增强的湍流混合而更多的传入底层，使计算的底摩擦应力随垂直分辨率的提高而有重新增加的趋势，进而又增强底摩擦对潮能的耗散。
基于EFDC（Environmental Fluid Dynamics Code）模式建立瞭長江口及其鄰近海域的三維水動力學模型，研究模型的垂直分辨率對該海域M2分潮模擬的影響。結果錶明：垂直分辨率的變化對M2分潮傳播方嚮的模擬結果影響較小，但其可通過底摩抆和湍流耗散兩箇計算過程來影響潮能通量的模擬結果，最終對長江口和杭州灣內的M2分潮振幅產生顯著的影響。最底層厚度較大時，上層自由水體的高流速特徵在最底層過于明顯，進而導緻計算的底摩抆應力偏高，此時提高底層的垂直分辨率會降低底摩抆對能量的耗散。另一方麵，垂直湍流混閤作用會隨垂直分辨率的增加而增彊，所以垂直分辨率增加到一定程度後，上層自由水體的高流速會經由增彊的湍流混閤而更多的傳入底層，使計算的底摩抆應力隨垂直分辨率的提高而有重新增加的趨勢，進而又增彊底摩抆對潮能的耗散。
기우EFDC（Environmental Fluid Dynamics Code）모식건립료장강구급기린근해역적삼유수동역학모형，연구모형적수직분변솔대해해역M2분조모의적영향。결과표명：수직분변솔적변화대M2분조전파방향적모의결과영향교소，단기가통과저마찰화단류모산량개계산과정래영향조능통량적모의결과，최종대장강구화항주만내적M2분조진폭산생현저적영향。최저층후도교대시，상층자유수체적고류속특정재최저층과우명현，진이도치계산적저마찰응력편고，차시제고저층적수직분변솔회강저저마찰대능량적모산。령일방면，수직단류혼합작용회수수직분변솔적증가이증강，소이수직분변솔증가도일정정도후，상층자유수체적고류속회경유증강적단류혼합이경다적전입저층，사계산적저마찰응력수수직분변솔적제고이유중신증가적추세，진이우증강저마찰대조능적모산。
A three-dimensional hydrodynamic model for Changjiang Estuary and the adjacent sea was developed within the framework of Environmental Fluid Dynamics Code (EFDC) .The effect of vertical resolution on the simulation of M2 tide was analyzed .The direction of M2 tide propagation was simulated correctly .The M2 tide propagated from southeast to northwest in open sea ,then it propagated inland along coastline in Changjiang River and Hangzhou Bay .The bottom stress and turbulence varying with vertical resolution determined the energy prop-agated into Changjiang River and Hangzhou Bay .This made the amplitude of M 2 tide decrease with increasing ver-tical resolution in Changjiang River .But in Hangzhou Bay ,the amplitude of M 2 tide increased with increasing ver-tical resolution at first ,then decreased with increasing vertical resolution .The computation of bottom stress was based on the mixing length theory and the boundary layer was assumed to be a constant fluxes layer .The bottom layer should be thin enough so that the higher velocity of the upper water ,which resulted in higher bottom stress , was of little importance in bottom layer .The intensity of vertical turbulence increased with increasing vertical reso-lution .This transmitted more high velocity of upper water into bottom layer and resulted in higher bottom stress again .Finally ,the more consumption of energy caused by higher bottom stress made the amplitude of M 2 tide be-come smaller .
