def heat_content_freezing(temp,
salt,
grid,
eosType='MDJWF',
rhoConst=None,
Tref=None,
Sref=None,
tAlpha=None,
sBeta=None,
time_dependent=False):
dV = grid.dV
# Get 3D z (for freezing point)
z = z_to_xyz(grid.z, grid)
# Add time dimensions if needed
if time_dependent:
num_time = temp.shape[0]
dV = add_time_dim(dV, num_time)
z = add_time_dim(z, num_time)
# Calculate freezing temperature
Tf = tfreeze(salt, z)
# Calculate potential density
rho = potential_density(eosType,
salt,
temp,
rhoConst=rhoConst,
Tref=Tref,
Sref=Sref,
tAlpha=tAlpha,
sBeta=sBeta)
# Now calculate heat content relative to Tf, in J
return (temp - Tf) * rho * Cp_sw * dV
def vertical_average_column(data, hfac, grid, gtype='t', time_dependent=False):
if gtype == 'w':
dz = grid.dz_t
else:
dz = grid.dz
if time_dependent:
# Add time dimension to dz and hfac
dz = add_time_dim(dz, data.shape[0])
hfac = add_time_dim(hfac, data.shape[0])
return np.sum(data * dz * hfac, axis=-1) / np.sum(dz * hfac, axis=-1)
def prepare_dz_hfac(data, grid, gtype='t', time_dependent=False):
# Choose the correct integrand of depth
if gtype == 'w':
dz = grid.dz_t
else:
dz = grid.dz
# Make it 3D
dz = z_to_xyz(dz, grid)
# Get the correct hFac
hfac = grid.get_hfac(gtype=gtype)
if time_dependent:
# There's also a time dimension
dz = add_time_dim(dz, data.shape[0])
hfac = add_time_dim(hfac, data.shape[0])
return dz, hfac
def t_minus_tf(temp, salt, grid, time_dependent=False):
# Tile the z coordinates to be the same size as temp and salt
# First assume 3D arrays
z = z_to_xyz(grid.z, grid)
if time_dependent:
# 4D arrays
z = add_time_dim(z, temp.shape[0])
return in_situ_temp(temp, salt, z) - tfreeze(salt, z)
def transport_transect(u,
v,
grid,
point0,
point1,
shore='S',
time_dependent=False):
# Calculate normal velocity
u_norm = normal_vector(u,
v,
grid,
point0,
point1,
time_dependent=time_dependent)
# Extract the transect
u_norm_trans, left, right, below, above = get_transect(
u_norm, grid, point0, point1, time_dependent=time_dependent)
# Calculate integrands
dh = (right - left) * 1e3 # Convert from km to m
dz = above - below
if time_dependent:
# Make them 3D
num_time = u.shape[0]
dh = add_time_dim(dh, num_time)
dz = add_time_dim(dh, num_time)
# Integrate and convert to Sv
trans_S = np.sum(np.minimum(u_norm_trans, 0) * dh * dz * 1e-6,
axis=(-2, -1))
trans_N = np.sum(np.maximum(u_norm_trans, 0) * dh * dz * 1e-6,
axis=(-2, -1))
# Retrn onshore, then offshore transport
if shore == 'S':
return trans_S, trans_N
elif shore == 'N':
return trans_N, trans_S
else:
print 'Error (transport_transect): invalid shore ' + shore
sys.exit()
def prepare_integrand_mask(option,
data,
grid,
gtype='t',
time_dependent=False):
if option in ['dA', 'dV'] and gtype != 't':
print 'Error (prepare_integrand_mask): non-tracer grids not yet supported'
sys.exit()
elif option == 'dx' and gtype == 'u':
print 'Error (prepare_integrand_mask): u-grid not yet supported for dx'
sys.exit()
elif option == 'dy' and gtype == 'v':
print 'Error (prepare_integrand_mask): v-grid not yet supported for dy'
sys.exit()
# Get the mask as 1s and 0s
if isinstance(data, np.ma.MaskedArray):
mask = np.invert(data.mask).astype(float)
else:
# No mask, just use 1s everywhere
mask = np.ones(data.shape)
# Get the integrand
if option == 'dA':
integrand = grid.dA
elif option == 'dV':
integrand = grid.dV
elif option == 'dx':
integrand = grid.dx_s
elif option == 'dy':
integrand = grid.dy_w
else:
print 'Error (prepare_integrand_mask): invalid option ' + option
if (len(integrand.shape)
== 2) and ((time_dependent and len(data.shape) == 4) or
(not time_dependent and len(data.shape) == 3)):
# There's also a depth dimension; tile in z
integrand = xy_to_xyz(integrand, grid)
if time_dependent:
# Tile in time
integrand = add_time_dim(integrand, data.shape[0])
return integrand, mask
def prepare_coord(shape, grid, option, gtype='t', time_dependent=False):
if option == 'lon':
# Get 2D lon
coordinates = grid.get_lon_lat(gtype=gtype)[0]
elif option == 'lat':
# Get 2D lat
coordinates = grid.get_lon_lat(gtype=gtype)[1]
elif option == 'depth':
# Get 3D z
if gtype == 'w':
print 'Error (prepare_coord): w-grid not yet supported for depth derivatives'
sys.exit()
coordinates = z_to_xyz(grid.z, z)
if option in ['lon', 'lat'] and ((len(shape) == 3 and not time_dependent)
or (len(shape) == 4 and time_dependent)):
# Add depth dimension
coordinates = xy_to_xyz(coordinates, grid)
if time_dependent:
# Add time dimension
coordinates = add_time_dim(coordinates, shape[0])
return coordinates
