def transport_divergence(ds,mask,varn='salt',kza=0,kzo=None,t=0):
_warn_virtual_salt_flux_units()
if varn == 'heat':
uvar,vvar = 'UET','VNT'
elif varn == 'salt':
uvar,vvar = 'UES','VNS'
dsvar = ds.variables
dxu = dsvar['DXU'][:] * 1e-2
dyu = dsvar['DYU'][:] * 1e-2
tarea = dsvar['TAREA'][:] * 1e-4
dz = dsvar['dz'][:] * 1e-2
if kzo is None: kzo = len(dz)
transport_divergence = 0.
for k in xrange(kza,kzo):
uflux = _fill0(dsvar[uvar][t,k])
uflux *= dyu
uflux *= dz[k]
uflux *= mask
vflux = _fill0(dsvar[vvar][t,k])
vflux *= dxu
vflux *= dz[k]
vflux *= mask
divergence = central_differences(uflux,dxu,axis=1) + central_differences(vflux,dyu,axis=0)
divergence *= mask
transport_divergence += np.sum(divergence*tarea)
if varn=='heat': warnings.warn('Units might be wrong for heat transport! Check!')
return transport_divergence
def transport_divergence(ds,mask,varn='salt',kza=0,kzo=None,t=0):
_warn_virtual_salt_flux_units()
if varn == 'heat':
uvar,vvar = 'UET','VNT'
elif varn == 'salt':
uvar,vvar = 'UES','VNS'
dsvar = ds.variables
dxu = dsvar['DXU'][:] * 1e-2
dyu = dsvar['DYU'][:] * 1e-2
tarea = dsvar['TAREA'][:] * 1e-4
dz = dsvar['dz'][:] * 1e-2
if kzo is None: kzo = len(dz)
transport_divergence = 0.
for k in range(kza,kzo):
uflux = _fill0(dsvar[uvar][t,k])
uflux *= dyu
uflux *= dz[k]
uflux *= mask
vflux = _fill0(dsvar[vvar][t,k])
vflux *= dxu
vflux *= dz[k]
vflux *= mask
divergence = central_differences(uflux,dxu,axis=1) + central_differences(vflux,dyu,axis=0)
divergence *= mask
transport_divergence += np.sum(divergence*tarea)
if varn=='heat': warnings.warn('Units might be wrong for heat transport! Check!')
return transport_divergence
def diffusion_component(ds,varn,regmask=1,kza=0,kzo=None,S0=34.8):
"""Temperature/Salt diffusion"""
dsvar = ds.variables
dxt = dsvar['DXT'][:]/100.
dyt = dsvar['DYT'][:]/100.
dz = dsvar['dz'][:]/100.
if kzo is None: kzo = len(dz)
diffusion = np.zeros(regmask.shape[0])
for k in xrange(kza,kzo):
layer = _fill0(dsvar['KAPPA_ISOP'][0,k]/1e4) # m2 s-1
if varn == 'heat':
scalar = _fill0(dsvar['TEMP'][0,k])
elif varn == 'salt':
scalar = _fill0(dsvar['SALT'][0,k])
elif varn == 'freshwater':
scalar = (S0 - _fill0(dsvar['SALT'][0,k])) / S0
gradient = central_differences(scalar,dyt,axis=0) # [scalar] m s-1
#gradient = np.zeros(scalar.shape)
#gradient[1:,:] = np.diff(scalar,axis=0)
#gradient[0] = gradient[1]
#gradient /= dyt
layer *= gradient
layer *= dz[k]
layer *= dxt
layer *= regmask
diffusion += np.sum(layer,axis=-1)
diffusion *= -1.
if varn == 'heat':
diffusion *= (1e3 * 4e3 * 1e-15) # PW
elif varn == 'salt':
diffusion *= 1e-6 # Sv PPT
return diffusion
def diffusion_component(ds, varn, regmask=1, kza=0, kzo=None, S0=34.8):
"""Temperature/Salt diffusion"""
dsvar = ds.variables
dxt = dsvar['DXT'][:] / 100.
dyt = dsvar['DYT'][:] / 100.
dz = dsvar['dz'][:] / 100.
if kzo is None: kzo = len(dz)
diffusion = np.zeros(regmask.shape[0])
for k in range(kza, kzo):
layer = _fill0(dsvar['KAPPA_ISOP'][0, k] / 1e4) # m2 s-1
if varn == 'heat':
scalar = _fill0(dsvar['TEMP'][0, k])
elif varn == 'salt':
scalar = _fill0(dsvar['SALT'][0, k])
elif varn == 'freshwater':
scalar = (S0 - _fill0(dsvar['SALT'][0, k])) / S0
gradient = central_differences(scalar, dyt, axis=0) # [scalar] m s-1
#gradient = np.zeros(scalar.shape)
#gradient[1:,:] = np.diff(scalar,axis=0)
#gradient[0] = gradient[1]
#gradient /= dyt
layer *= gradient
layer *= dz[k]
layer *= dxt
layer *= regmask
diffusion += np.sum(layer, axis=-1)
diffusion *= -1.
if varn == 'heat':
diffusion *= (1e3 * 4e3 * 1e-15) # PW
elif varn == 'salt':
diffusion *= 1e-6 # Sv PPT
return diffusion
def fluxbudget_diffusion(ds,mask,varn,kza=0,kzo=None,S0=34.8,t=0):
"""Compute flux of `varn` into region `mask` due to diffusion"""
_warn_virtual_salt_flux_units()
dsvar = ds.variables
dxt = dsvar['DXT'][:] * 1e-2
dyt = dsvar['DYT'][:] * 1e-2
dz = dsvar['dz'][:] * 1e-2
if kzo is None: kzo = len(dz)
fluxbudget = 0.
for k in xrange(kza,kzo):
# get scalar data
if varn == 'heat':
scalar = _fill0(dsvar['TEMP'][t,k])
elif varn == 'salt':
scalar = _fill0(dsvar['SALT'][t,k])
elif varn == 'freshwater':
scalar = (S0 - _fill0(dsvar['SALT'][t,k])) / S0
# get gradient
uflux = central_differences(scalar,dxt,axis=1) # [scalar] m-1
vflux = central_differences(scalar,dyt,axis=0) # [scalar] m-1
# multiply gradient by diffusion coefficient
kappa = _fill0(dsvar['KAPPA_ISOP'][t,k] * 1e-4) # m2 s-1
uflux *= kappa
vflux *= kappa
# multiply by horizontal grid spacing
uflux *= dyt
vflux *= dxt
# multiply by vertical grid spacing
uflux *= dz[k]
vflux *= dz[k]
# compute budget
fluxbudget += budget_over_region_2D(uflux,vflux,scalar=None,mask=mask)
# convert to right units
if varn == 'heat':
fluxbudget *= (1e3 * 4e3 * 1e-15) # PW
return fluxbudget
def fluxbudget_diffusion(ds,mask,varn,kza=0,kzo=None,S0=34.8,t=0):
"""Compute flux of `varn` into region `mask` due to diffusion"""
_warn_virtual_salt_flux_units()
dsvar = ds.variables
dxt = dsvar['DXT'][:] * 1e-2
dyt = dsvar['DYT'][:] * 1e-2
dz = dsvar['dz'][:] * 1e-2
if kzo is None: kzo = len(dz)
fluxbudget = 0.
for k in range(kza,kzo):
# get scalar data
if varn == 'heat':
scalar = _fill0(dsvar['TEMP'][t,k])
elif varn == 'salt':
scalar = _fill0(dsvar['SALT'][t,k])
elif varn == 'freshwater':
scalar = (S0 - _fill0(dsvar['SALT'][t,k])) / S0
# get gradient
uflux = central_differences(scalar,dxt,axis=1) # [scalar] m-1
vflux = central_differences(scalar,dyt,axis=0) # [scalar] m-1
# multiply gradient by diffusion coefficient
kappa = _fill0(dsvar['KAPPA_ISOP'][t,k] * 1e-4) # m2 s-1
uflux *= kappa
vflux *= kappa
# multiply by horizontal grid spacing
uflux *= dyt
vflux *= dxt
# multiply by vertical grid spacing
uflux *= dz[k]
vflux *= dz[k]
# compute budget
fluxbudget += budget_over_region_2D(uflux,vflux,scalar=None,mask=mask)
# convert to right units
if varn == 'heat':
fluxbudget *= (1e3 * 4e3 * 1e-15) # PW
return fluxbudget
def test_central_differences(self):
a = np.arange(100, dtype=float)
dx = np.ones(100)*2
result = stats.central_differences(a, dx)
expected = np.ones(100)*0.5
self.assertTrue(np.allclose(result, expected))