def pv(dgl):
"""pv(dgl) requires u,v and b to be loaded already"""
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
fld_exists = mit.check_field(dgl,'pvz')
if not fld_exists:
dgl = mit.add_field(dgl,'pvz')
zlen = len(dgl[0]['z'])
dgl[0]['pvz'] = np.array(0.5*(dgl[0]['z'][0:zlen-1] + dgl[0]['z'][1:zlen]))
pv_exists = mit.check_field(dgl,'pv')
if not pv_exists:
dgl = mit.add_field(dgl,'pv')
for ti in np.arange(0,tlen):
"""Loop in time to reduce memory requirement"""
if len(dgl[0]['x']) > 1:
p1 = pv1_calc(dgl[0]['v'][:,:,:,ti],
dgl[0]['b'][:,:,:,ti],dgl[0]['x'],dgl[0]['z'])
else:
p1 = np.zeros(np.shape(dgl[0]['pv'][:,:,:,0]))
if len(dgl[0]['y']) > 1:
p2 = pv2_calc(dgl[0]['u'][:,:,:,ti],
dgl[0]['b'][:,:,:,ti],dgl[0]['y'],dgl[0]['z'])
else:
p2 = np.zeros(np.shape(ylen,xlen,zlen-1))
if len(dgl[0]['z']) > 1:
p3 = pv3_calc(dgl[0]['f'],dgl[0]['u'][:,:,:,ti],
dgl[0]['v'][:,:,:,ti],dgl[0]['b'][:,:,:,ti],dgl[0]['x'],dgl[0]['y'],dgl[0]['z'])
else:
p3 = np.zeros(np.shape(ylen,xlen,zlen-1))
dgl[0]['pv'][:,:,:,ti] = p1 + p2 + p3
return dgl
def pv2(dgl):
"""Calculate pv2 and add it to dgl"""
fld_exists = mit.check_field(dgl,'pvz')
if not fld_exists:
dgl = mit.add_field(dgl,'pvz')
zlen = len(dgl[0]['z'])
dgl[0]['pvz'] = 0.5*(dgl[0]['z'][0:zlen-1] + dgl[0]['z'][1:zlen])
pv2_exists = mit.check_field(dgl,'pv2')
w_exists = mit.check_field(dgl,'w')
if not pv2_exists:
dgl = mit.add_field(dgl,'pv2')
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
for ti in np.arange(0,tlen):
"""Loop in time to reduce memory requirement"""
if ylen > 1:
if not w_exists:
p2 = pv2_calc(dgl[0]['u'][:,:,:,ti],
dgl[0]['b'][:,:,:,ti],dgl[0]['y'],dgl[0]['z'])
else:
p2 = pv2_calc(dgl[0]['u'][:,:,:,ti],
dgl[0]['b'][:,:,:,ti],dgl[0]['y'],dgl[0]['z'],dgl[0]['w'][:,:,:,ti])
else:
p2 = np.zeros(np.shape(dgl[0]['pv2'][:,:,:,0]))
dgl[0]['pv2'][:,:,:,ti] = p2
return dgl
def buoy_dgl(dgl,
eos,
alpha=None,
sbeta=None,
g=None,
lat=None,
Tref=None,
Sref=None):
"""Calculate the buoyancy field for a structured array dgl"""
import mit
b_exists = mit.check_field(dgl, 'b')
if not b_exists:
dgl = mit.add_field(dgl, 'b')
S_exists = mit.check_field(dgl, 's')
T_exists = mit.check_field(dgl, 't')
if eos == 'lin':
alpha, sbeta, g, Tref, Sref = lin_eos_params(alpha, sbeta, g, lat,
Tref, Sref)
for rw in np.arange(0, len(dgl[0]['y'])):
if T_exists and not S_exists:
"""Thermal contribution only"""
dgl[0]['b'][rw, :, :, :] = g * alpha * (
dgl[0]['t'][rw, :, :, :] - Tref)
if S_exists and not T_exists:
"""Haline contribution only"""
dgl[0]['b'][rw, :, :, :] = -g * sbeta * (
dgl[0]['s'][rw, :, :, :] - Sref)
if T_exists and S_exists:
dgl[0]['b'][rw, :, :, :] = g * alpha * (
dgl[0]['t'][rw, :, :, :] - Tref)
-g * sbeta * (dgl[0]['s'][rw, :, :, :] - Sref)
elif eos == 'jmd':
g = 9.81
import jmd95
import seawater
import mit
if not T_exists:
T = np.zeros(np.shape(dgl[0]['s']))
if not S_exists:
S = np.zeros(np.shape(dgl[0]['t']))
rhoConst = 1000
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
#Pressure needed in decibars
press = seawater.pres(-dgl[0]['z'], lat=45)
buoy_fac = g / rhoConst
#Loop this routine along t and y to avoid running out of memory
for ti in np.arange(0, tlen):
for rw in np.arange(0, ylen):
dgl[0]['b'][rw, :, :, ti] = -buoy_fac * (jmd95.densjmd95(
np.squeeze(dgl[0]['s'][rw, :, :, ti]),
np.squeeze(dgl[0]['t'][rw, :, :, ti]), press) - 1030)
return dgl
def n2(dgl):
"""Calculate n2 for stand-alone calculations rather than as part of PV.
N2 is at w-points. This function adds n2 (and pvz if needed) to the dgl output array"""
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
fld_exists = mit.check_field(dgl,'pvz')
if not fld_exists:
dgl = mit.add_field(dgl,'pvz')
zlen = len(dgl[0]['z'])
dgl[0]['pvz'] = 0.5*(dgl[0]['z'][0:zlen-1] + dgl[0]['z'][1:zlen])
fld_exists = mit.check_field(dgl,'n2')
if not fld_exists:
dgl = mit.add_field(dgl,'n2')
for ti in np.arange(0,tlen):
dgl[0]['n2'][:,:,:,ti]= n2_calc(dgl[0]['b'][:,:,:,ti],dgl[0]['z'])
return dgl
def rv(dgl, normf = False):
"""Calculate the vertical component of relative vorticity for
stand-alone calculations rather than as part of PV.
RV is at the lower-left of the first cell at the same depth as u and v points
This function adds rv to the dgl output array"""
#Check if rv is already a field of dgl
fld_exists = mit.check_field(dgl,'rv')
#Add rv as a field if it isn't already
if not fld_exists:
dgl = mit.add_field(dgl,'rv')
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
if xlen>1:
dx = 1e3*(dgl[0]['x'][1] - dgl[0]['x'][0])
else:
dx = []
if ylen>1:
dy = 1e3*(dgl[0]['y'][1] - dgl[0]['y'][0])
else:
dy = []
for ti in np.arange(0,tlen):
dgl[0]['rv'][:,:,:,ti] = rv_calc(dgl[0]['u'][:,:,:,ti],
dgl[0]['v'][:,:,:,ti],dx,dy)
if normf is True:
dgl[0]['rv'] = dgl[0]['rv']/dgl[0]['f']
return dgl
def rib(dgl):
"""Caclulate the balanced Richardson number and add to dgl"""
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
fld_exists = mit.check_field(dgl,'pvz')
if not fld_exists:
dgl = mit.add_field(dgl,'pvz')
zlen = len(dgl[0]['z'])
dgl[0]['pvz'] = 0.5*(dgl[0]['z'][0:zlen-1] + dgl[0]['z'][1:zlen])
fld_exists = mit.check_field(dgl,'rib')
if not fld_exists:
dgl = mit.add_field(dgl,'rib')
print dgl.dtype
print tlen
for ti in np.arange(tlen):
dgl[0]['rib'][:,:,:,ti] = rib_calc(dgl[0]['b'][:,:,:,ti],
dgl[0]['f'],dgl[0]['x'],dgl[0]['y'],dgl[0]['z'])
return dgl
def vbyz(dgl):
"""Calculate the effect on stratification of differential meridional
buoyancy fluxes"""
#First ensure that the correct vertical field is present
fld_exists = mit.check_field(dgl,'pvz')
if not fld_exists:
dgl = mit.add_field(dgl,'pvz')
zlen = len(dgl[0]['z'])
dgl[0]['pvz'] = 0.5*(dgl[0]['z'][0:zlen-1] + dgl[0]['z'][1:zlen])
import eosmit #This routine checks if buoyancy is already loaded before running
eos = 'jmd'
dgl = eosmit.buoy_dgl(dgl,eos=eos)
fld_exists = mit.check_field(dgl,'vbxz')
if not fld_exists:
dgl = mit.add_field(dgl,'vbyz')
dgl[0]['vbyz'] = dgl[0]['v']*mit.ddy(dgl[0]['b'],dgl[0]['y'])
return dgl
def buoy_dgl(dgl,eos,alpha = None,sbeta = None, g = None, lat = None,
Tref = None, Sref = None):
"""Calculate the buoyancy field for a structured array dgl"""
import mit
b_exists = mit.check_field(dgl,'b')
if not b_exists:
dgl = mit.add_field(dgl,'b')
S_exists = mit.check_field(dgl,'s')
T_exists = mit.check_field(dgl,'t')
if eos == 'lin':
alpha, sbeta, g, Tref, Sref = lin_eos_params(alpha,sbeta,g,lat,Tref,Sref)
for rw in np.arange(0,len(dgl[0]['y'])):
if T_exists and not S_exists:
"""Thermal contribution only"""
dgl[0]['b'][rw,:,:,:] = g*alpha*(dgl[0]['t'][rw,:,:,:] - Tref)
if S_exists and not T_exists:
"""Haline contribution only"""
dgl[0]['b'][rw,:,:,:] = -g*sbeta*(dgl[0]['s'][rw,:,:,:] - Sref)
if T_exists and S_exists:
dgl[0]['b'][rw,:,:,:] = g*alpha*(dgl[0]['t'][rw,:,:,:] - Tref)
-g*sbeta*(dgl[0]['s'][rw,:,:,:] - Sref)
elif eos == 'jmd':
g = 9.81
import jmd95
import seawater
import mit
if not T_exists:
T = np.zeros(np.shape(dgl[0]['s']))
if not S_exists:
S = np.zeros(np.shape(dgl[0]['t']))
rhoConst = 1000
ylen, xlen, zlen, tlen = mit.dgl_dims(dgl)
#Pressure needed in decibars
press = seawater.pres(-dgl[0]['z'],lat = 45)
buoy_fac = g/rhoConst
#Loop this routine along t and y to avoid running out of memory
for ti in np.arange(0,tlen):
for rw in np.arange(0,ylen):
dgl[0]['b'][rw,:,:,ti] =-buoy_fac*(jmd95.densjmd95(
np.squeeze(dgl[0]['s'][rw,:,:,ti]),
np.squeeze(dgl[0]['t'][rw,:,:,ti]),press) - 1030)
return dgl