def density(temp,
sal,
depth=None,
lat=None,
potential=False,
getdepth=False,
getlat=False,
format_axes=False):
"""Compute density from temperature, salinity and depth (and latitude)
:Params:
- **temp**: Insitu or potential temperature.
- **sal**: Salinity.
- **depth**, optional: Depth at temperature and salinty points.
Assumed to be 0 if not found.
- **lat**, optional: Latitude. Error when not found.
- **potential**, optional: True to get the potential density (at atmospheric
pressure).
:Algo:
>>> pressure = seawater.csiro.pres(depth, lat)
>>> density = seawater.csiro.dens(sal, temp, depth)
"""
# Compute
if not potential and depth is not False: # In-situ
# Get depth and latitude
lat = grow_lat(temp, lat, mode='raise', getvar=False)
if lat is None: raise VACUMMError('No latitude found for density')
depth = grow_depth(temp, depth, mode='raise', getvar=False)
if N.abs(depth.max()) < N.abs(depth.min()): # positive
depth = -depth
if (depth.asma() < 0).any():
depth = depth - depth.min() # top=0
# Get density
pres = sw_pres(depth, lat)
dens = sw_dens(sal, temp, pres)
del pres
else: # Potential
dens = sw_dens0(sal, temp)
getdepth = getlat = False
# Format
dens.setAxisList(temp.getAxisList())
set_grid(dens, get_grid(temp))
format_var(dens, 'dens', format_axes=format_axes)
# Out
if not getdepth and not getlat: return dens
dens = dens,
if getdepth: dens += depth,
if getlat: dens += lat,
return dens
def density(temp, sal, depth=None, lat=None, potential=False,
getdepth=False, getlat=False, format_axes=False):
"""Compute density from temperature, salinity and depth (and latitude)
:Params:
- **temp**: Insitu or potential temperature.
- **sal**: Salinity.
- **depth**, optional: Depth at temperature and salinty points.
Assumed to be 0 if not found.
- **lat**, optional: Latitude. Error when not found.
- **potential**, optional: True to get the potential density (at atmospheric
pressure).
:Algo:
>>> pressure = seawater.csiro.pres(depth, lat)
>>> density = seawater.csiro.dens(sal, temp, depth)
"""
# Compute
if not potential and depth is not False: # In-situ
# Get depth and latitude
lat = grow_lat(temp, lat, mode='raise', getvar=False)
if lat is None: raise VACUMMError('No latitude found for density')
depth = grow_depth(temp, depth, mode='raise', getvar=False)
if N.abs(depth.max())<N.abs(depth.min()): # positive
depth = -depth
if (depth.asma()<0).any():
depth = depth-depth.min() # top=0
# Get density
pres = sw_pres(depth, lat)
dens = sw_dens(sal, temp, pres) ; del pres
else: # Potential
dens = sw_dens0(sal, temp)
getdepth = getlat = False
# Format
dens.setAxisList(temp.getAxisList())
set_grid(dens, get_grid(temp))
format_var(dens, 'dens', format_axes=format_axes)
# Out
if not getdepth and not getlat: return dens
dens = dens,
if getdepth: dens += depth,
if getlat: dens += lat,
return dens
def mixed_layer_depth(data, depth=None, lat=None, zaxis=None,
mode=None, deltatemp=.2, deltadens=.01, kzmax=0.0005,
potential=True, format_axes=False):
"""Get mixed layer depth from temperature and salinity
:Params:
- **temp**: Insitu or potential temperature.
- **sal**: Salinity.
- **depth**, optional: Depth at temperature and salinty points.
- **lat**, optional: Latitude.
- **mode**, optional: ``"deltatemp"``, ``"deltadens"``, ``"kz"``
or ``"twolayers"``
:Raise: :class:`~vacumm.VACUMMError` if can't get depth (and latitude for density).
"""
# TODO: positive up
# Inspection
if isinstance(data, tuple): # data = temp,sal
temp, sal=data
# Get density
if mode!='deltatemp':
res = density(temp, sal, depth=depth, lat=lat,
format_axes=False, potential=potential, getdepth=True)
if isinstance(res, tuple):
dens, depth = res
else:
dens = res
dens = dens.asma()
if mode is None:
mode = 'deltadens'
else:
temp = data[0]
# Check mode
if mode == 'kz':
warn("Switching MLD computation mode to 'deltadens'")
mode = "deltadens"
elif match_var(data, 'temp', mode='nslu'):
if mode is not None and mode!='deltatemp':
warn("Switching MLD computation mode to 'deltatemp'")
mode = 'deltatemp'
temp = data
elif match_var(data, 'dens', mode='nslu'):
if mode in ['kz', 'deltatemp']:
warn("Switching MLD computation mode to 'deltadens'")
mode = None
if mode is None:
mode = "deltadens"
dens = data
elif match_var(data, 'kz', mode='nslu'):
if mode is None:
mode = "kz"
if mode != "kz":
warn("Switching MLD computation mode to 'kz'")
kz = data
else:
if mode in ['deltadens', 'twolayers']:
dens = data
elif mode == "deltatemp":
temp = data
elif mode == "kz":
kz = data
elif mode is not None:
raise VACUMMError("Invalid MLD computation mode : '%s'"%mode)
else:
raise VACUMMError("Can't guess MLD computation mode")
temp = delta
# Find Z dim
data0 = data[0] if isinstance(data, tuple) else data
depth = grow_depth(data0, depth, mode='raise', getvar=False)
zaxis = get_zdim(data0, axis=zaxis)
if zaxis is None:
raise VACUMMError("Can't guess zaxis")
slices = get_axis_slices(data0, zaxis)
# Init MLD
axes = data0.getAxisList()
del axes[zaxis]
mld = MV2.array(data0.asma()[slices['first']], copy=1, axes=axes, copyaxes=False)
set_grid(mld, get_grid(data0))
format_var(mld, 'mld', format_axes=format_axes)
mld[:] = MV2.masked
# Two-layers
if mode=='twolayers':
densbot = dens[slices['first']]
denstop = dens[slices['last']]
del dens
H = 1.5*depth[slices['first']] - 0.5*depth[slices['firstp1']]
H = -1.5*depth[slices['last']] + 0.5*depth[slices['lastm1']]
mld[:] = -H*(densbot-denstop)/(densbot-denstop)
del H
elif mode=='deltadens':
denscrit = dens[slices['last']]+deltadens
mld[:] = -_val2z_(dens, depth, denscrit, zaxis, -1)
del dens
elif mode=='deltatemp':
tempcrit = temp[slices['last']]-deltatemp
mld[:] = -_val2z_(temp, depth, tempcrit, zaxis, 1)
elif mode=='kz':
mld[:] = -_valmin2z_(kz, depth, kzmax, zaxis, 1)
else:
raise VACUMMError("Invalid mode for computing MLD (%s)."%mode +
"Please choose one of: deltadens, twolayers")
# Mask zeros
mld[:] = MV2.masked_values(mld, 0., copy=0)
return mld
def mixed_layer_depth(data,
depth=None,
lat=None,
zaxis=None,
mode=None,
deltatemp=.2,
deltadens=.03,
kzmax=0.0005,
potential=True,
format_axes=False):
"""Get mixed layer depth from temperature and salinity
:Params:
- **temp**: Insitu or potential temperature.
- **sal**: Salinity.
- **depth**, optional: Depth at temperature and salinty points.
- **lat**, optional: Latitude.
- **mode**, optional: ``"deltatemp"``, ``"deltadens"``, ``"kz"``
or ``"twolayers"``
:Raise: :class:`~vacumm.VACUMMError` if can't get depth (and latitude for density).
"""
# TODO: positive up
# Inspection
if isinstance(data, tuple): # data = temp,sal
temp, sal = data
# Get density
if mode != 'deltatemp':
res = density(temp,
sal,
depth=depth,
lat=lat,
format_axes=False,
potential=potential,
getdepth=True)
if isinstance(res, tuple):
dens, depth = res
else:
dens = res
dens = dens.asma()
if mode is None:
mode = 'deltadens'
else:
temp = data[0]
# Check mode
if mode == 'kz':
warn("Switching MLD computation mode to 'deltadens'")
mode = "deltadens"
elif match_var(data, 'temp', mode='nslu'):
if mode is not None and mode != 'deltatemp':
warn("Switching MLD computation mode to 'deltatemp'")
mode = 'deltatemp'
temp = data
elif match_var(data, 'dens', mode='nslu'):
if mode in ['kz', 'deltatemp']:
warn("Switching MLD computation mode to 'deltadens'")
mode = None
if mode is None:
mode = "deltadens"
dens = data
elif match_var(data, 'kz', mode='nslu'):
if mode is None:
mode = "kz"
if mode != "kz":
warn("Switching MLD computation mode to 'kz'")
kz = data
else:
if mode in ['deltadens', 'twolayers']:
dens = data
elif mode == "deltatemp":
temp = data
elif mode == "kz":
kz = data
elif mode is not None:
raise VACUMMError("Invalid MLD computation mode : '%s'" % mode)
else:
raise VACUMMError("Can't guess MLD computation mode")
temp = delta
# Find Z dim
data0 = data[0] if isinstance(data, tuple) else data
depth = grow_depth(data0, depth, mode='raise', getvar=False)
zaxis = get_zdim(data0, axis=zaxis)
if zaxis is None:
raise VACUMMError("Can't guess zaxis")
slices = get_axis_slices(data0, zaxis)
# Init MLD
axes = data0.getAxisList()
del axes[zaxis]
mld = MV2.array(data0.asma()[slices['first']],
copy=1,
axes=axes,
copyaxes=False)
set_grid(mld, get_grid(data0))
format_var(mld, 'mld', format_axes=format_axes)
mld[:] = MV2.masked
# Two-layers
if mode == 'twolayers':
densbot = dens[slices['first']]
denstop = dens[slices['last']]
del dens
H = 1.5 * depth[slices['first']] - 0.5 * depth[slices['firstp1']]
H = -1.5 * depth[slices['last']] + 0.5 * depth[slices['lastm1']]
mld[:] = -H * (densbot - denstop) / (densbot - denstop)
del H
elif mode == 'deltadens':
denscrit = dens[slices['last']] + deltadens
mld[:] = -_val2z_(dens, depth, denscrit, zaxis, -1)
del dens
elif mode == 'deltatemp':
tempcrit = temp[slices['last']] - deltatemp
mld[:] = -_val2z_(temp, depth, tempcrit, zaxis, 1)
elif mode == 'kz':
mld[:] = -_valmin2z_(kz, depth, kzmax, zaxis, 1)
else:
raise VACUMMError("Invalid mode for computing MLD (%s)." % mode +
"Please choose one of: deltadens, twolayers")
# Mask zeros
mld[:] = MV2.masked_values(mld, 0., copy=0)
return mld
