- 相關(guān)推薦
Mapping of an Approximate Neutral Density Surface with Ungridded Data
A neutral density surface is a logical study frame for water-mass mixing since water parcels spread along such a surface without doing work against buoyancy restoring force. Mesoscale eddies are believed to stir and subsequently mix predominantly along such surfaces. Because of the nonlinear nature of the equation of state of seawater, the process of accurately mapping a neutral density surface necessarily involves lateral computation from one conductivity, temperature and depth (CTD) cast to the next in a logical sequence. By contrast, the depth of a potential density surface on any CTD cast is found solely from the data on this cast. The lateral calculation procedure causes a significant inconvenience. In a previous paper by present author published in this journal (You,2006), the mapping of neutral density surfaces with regularly gridded data such as Levitus data has been introduced. In this note, I present a new method to find the depth of a neutral density surface from a cast without having to specify an integration path in space.An appropriate reference point is required that is on the neutral density surface and thereafter the neutral density surface can be determined by using the CTD casts in any order. This method is only approximate and the likely errors can be estimated by plotting a scatter diagram of all the pressures and potential temperatures on the neutral density surfaces. The method assumes that the variations of potential temperature and pressure (with respect to the values at the reference point) on the neutral density surface are proportional.It is important to select the most appropriate reference point in order to approximately satisfy this assumption, and in practice this is found by inspecting the θ-p plot of data on the surface. This may require that the algorithm be used twice. When the straight lines on the θ-p plot, drawn from the reference point to other points on the neutral density surface, enclose an area that is external to the cluster of θ-p points of the neutral density surface, errors will occur, and these errors can be quantified from this diagram. Examples showing the use of the method are presented for each of the world's main oceans.
作 者： YOU Yuzhu 作者單位： University of Sydney Institute of Marine Science, Building H11, University of Sydney, NSW 2006, Australia 刊 名： 中國海洋大學(xué)學(xué)報(bào)（英文版） ISTIC 英文刊名： JOURNAL OF OCEAN UNIVERSITY OF CHINA 年，卷(期)： 2008 7(1) 分類號(hào)： P7 關(guān)鍵詞： neutral density surface McDougall Surface mapping of a neutral density surface nonlinear equation of state of sea water ungridded data water-mass mixing world oceans【Mapping of an Approximate Neutral De】相關(guān)文章：
Electrochemical Study on the Interaction Betwwen Neutral Red and DNA04-28
方興未艾de綠色消費(fèi)04-26
給老婆DE辭職報(bào)告04-27
法國葡萄酒de等級(jí)04-29
Mapping of QTLs for Leaf Malondialdehyde Content Associated with Stress Tolerance in Rice04-26
可降解塑料de發(fā)展04-28
神秘遙遠(yuǎn)de八幫寺04-29
Genetic Analysis and Mapping of TWH Gene in Rice Twisted Hull Mutant04-26