ギリシャ文字のρ (ロー)で表すことが多い
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter06/chapter06_05.htm
概略値ですむ場合も多いので、掲載しておく。
ρ0 =1025.0 ! kg/m3
Fortranのコード
real,parameter :: rho0=1025.0 ! kg/m3
2011年現在用いられている状態方程式
式の説明
http://www.littlewaves.info/marine/wq_density.htm
プログラム
Fortran 77: eqst2.f (ダウンロード)
Fortran 90: eqst2.f90 (ダウンロード)
論文
UNESCO, "Background papers and supporting data on the International Equation of State of Seawater 1980," UNESCO Technical papers in marine science No. 38, 1981.
pdfファイルへのリンク: http://fermi.jhuapl.edu/denscalc/unesco1981.pdf
Fofonoff and Millard, "Algorithms for computation of fundamental properties of seawater," UNESCO Technical papers in marine science No. 44, 1983.
pdfファイルへのリンク: http://fermi.jhuapl.edu/denscalc/fofonoff_millard_1983.pdf
新しい海水の状態方程式と新しい塩分の定義について
http://uminokenkyu.no.coocan.jp/19-2/19-2-3.pdf
最近公表されたもの
Journal of Atmospheric and Oceanic Technology
Volume 23, Issue 12 (December 2006)
Article: pp. 1709–1728 | Abstract | PDF (1.35M)
Algorithms for Density, Potential Temperature, Conservative Temperature, and the Freezing Temperature of Seawater
Journal of Atmospheric and Oceanic Technology
Article: pp. 730–741 | Full Text | PDF (282K)
Accurate and Computationally Efficient Algorithms for Potential Temperature and Density of Seawater
Trevor J. McDougall and David R. Jackett
Daniel G. Wright
Rainer Feistel
計算プログラム (FortranとMatlab)
Equations Of State (for the World's Oceans)
http://www.marine.csiro.au/~jackett/eos/
主に理論的な解析に使う．
saline expansivity
coefficient of thermal expansion
linear equation of state
http://edl.engr.ucdavis.edu/Publications/Dissertations/Warner/chapter1.pdf
rho = rho0*(1 + alpha* (s - s0) - beta*(T - T0)) (1.5)
where u(x,y,z,t), v(x,y,z,t), and w(x,y,z,t) are the velocities in the x, y, and z orthogonal
directions, t is time, ρ(x,y,z,t) is density, ρ0 is a reference density, P(x,y,z,t) is pressure, g
is the acceleration of gravity, and u’, v’, and w’ are the turbulent fluctuations, s(x,y,z,t) is
salinity, T(x,y,z,t) is temperature, s0 is a reference salinity (35), T0 is a reference
temperature (10o C), α is the coefficient of saline expansivity
(7.6 x 10-4), and β is the coefficient of thermal expansion
(1.7 x 10-4 K-1) (Cushman-Roisin, 1994).
Cushman-Roisin, B. (1994). Introduction to Geophysical Fluid Dynamics. Prentice Hall,
Englewood Cliffs, New Jersey.
α = 7.7 x 10-4 psu-1 (p. 711, McCready, JPO, 1999)
宇野木(1993), p330
大気圧，20℃, S=32の近辺
α = 7.6 x 10-4 psu-1
β = 2.6 x 10-4 deg-1
2010年1月から塩分の定義が変わる！