def sigmatheta(s, t, p, pr=0):
r"""
:math:`\\sigma_{\\theta}` is a measure of the density of ocean water where the quantity :math:`\\sigma_{t}` is calculated using the potential temperature (:math:`\\theta`) rather than the in situ temperature and potential density of water mass relative to the specified reference pressure.
Parameters
----------
s(p) : array_like
salinity [psu (PSS-78)]
t(p) : array_like
temperature [:math:`^\\circ` C (ITS-90)]
p : array_like
pressure [db]. The shape can be "broadcasted"
pr : number
reference pressure [db], default = 0
Returns
-------
sgmte : array_like
density [kg m :sup:`3`]
See Also
--------
dens, sigma_t
Notes
-----
Density of Sea Water using UNESCO 1983 (EOS 80) polynomial.
Examples
--------
Data from Unesco Tech. Paper in Marine Sci. No. 44, p22
>>> import seawater.extras.sw_extras as swe
>>> import seawater.csiro as sw
>>> s = [0, 0, 0, 0, 35, 35, 35, 35]
>>> t = sw.T90conv([0, 0, 30, 30, 0, 0, 30, 30])
>>> p = [0, 10000, 0, 10000, 0, 10000, 0, 10000]
>>> swe.sigmatheta(s, t, p)
array([ -0.157406 , -0.20476006, -4.34886626, -3.63884068,
28.10633141, 28.15738545, 21.72863949, 22.59634627])
References
----------
.. [1] Fofonoff, P. and Millard, R.C. Jr UNESCO 1983. Algorithms for computation of fundamental properties of seawater. UNESCO Tech. Pap. in Mar. Sci., No. 44, 53 pp. Eqn.(31) p.39. http://www.scor-int.org/Publications.htm
.. [2] Millero, F.J., Chen, C.T., Bradshaw, A., and Schleicher, K. A new high pressure equation of state for seawater. Deap-Sea Research., 1980, Vol27A, pp255-264. doi:10.1016/0198-0149(80)90016-3
Modifications: Filipe Fernandes, 2010
10-01-26. Filipe Fernandes, first version.
"""
# Convert input to numpy arrays
s, t, p, pr = np.asarray(s), np.asarray(t), np.asarray(p), np.asarray(pr)
sgmte = sw.pden(s, t, p, pr) - 1000.0
return sgmte
def TS_diagram(ss,ts,ax,dlev=0.1):
from seawater import csiro as sw
from numpy import linspace,meshgrid,arange
from pylab import clabel
t= linspace(ts.min(), ts.max(), 30)
s= linspace(ss.min(), ss.max(), 30)
s2d,t2d = meshgrid(s,t)
#ax.scatter(ss,ts,c=colors, s=size, facecolor=facecolor, edgecolor = 'none', marker = marker)
h=ax.contour(s2d,t2d,sw.pden(s2d,t2d,s2d*0)-1000,levels=arange(20,30,dlev),colors='k')
clabel(h,inline=1,fontsize=9,fmt='%3.1f')
return
def TS_diagram(ss, ts, ax, dlev=0.1):
from seawater import csiro as sw
from numpy import linspace, meshgrid, arange
from pylab import clabel
t = linspace(ts.min(), ts.max(), 30)
s = linspace(ss.min(), ss.max(), 30)
s2d, t2d = meshgrid(s, t)
#ax.scatter(ss,ts,c=colors, s=size, facecolor=facecolor, edgecolor = 'none', marker = marker)
h = ax.contour(s2d,
t2d,
sw.pden(s2d, t2d, s2d * 0) - 1000,
levels=arange(20, 30, dlev),
colors='k')
clabel(h, inline=1, fontsize=9, fmt='%3.1f')
return
