PseudoNetCDF.derived package

Submodules

PseudoNetCDF.derived.met module

PseudoNetCDF.derived.met.add_derived_met(ifile, func, *args, **kwds)[source]
PseudoNetCDF.derived.met.esw_skewt_t(t)[source]
Parameters:

C (t - temperature in degrees)

Returns:

esw - Saturation vapor pressure in millibars

Adapted from NCL this function returns the saturation vapor pressure esw (millibars) over liquid water given the temperature t (celsius). the polynomial approximation below is due to herman wobus, a mathematician who worked at the navy weather research facility, norfolk, virginia, but who is now retired. the coefficients of the polynomial were chosen to fit the values in table 94 on pp. 351-353 of the smith- sonian meteorological tables by roland list (6th edition). the approximation is valid for -50 < t < 100c.

es0 = saturation vapor ressure over liquid water at 0c

PseudoNetCDF.derived.met.relhum_ttd(t, td, percent=False, add=True)[source]

t - temperature in K td - dewpoint temperature in K

; ; Calculate relative humidity given temperature (K) ; and dew point temperature (K) ; ; reference: John Dutton, Ceaseless Wind, 1976

PseudoNetCDF.derived.met.uv_wswd(ws, wd, isradians=False)[source]
Parameters:

  • array (wd - wind direction)

  • array

  • degrees (isradians - False if WD is in)

Returns:

U, V - u-component and v-component winds

https://www.eol.ucar.edu/projects/ceop/dm/documents/ refdata_report/eqns.html

PseudoNetCDF.derived.met.wmr_ptd(p, td, gkg=False)[source]
Inputs:

p = surface pressure in mb; Td = dew point in deg C;

Calculates

e = vapor pressure in mb;

Returns

q = specific humidity in kg/kg.

PseudoNetCDF.derived.met.wmr_skewt_pt(p, t)[source]

p - pressure in mb t - temperature in degrees C this function approximates the mixing ratio wmr (grams of water vapor per kilogram of dry air) given the pressure p (mb) and the temperature t (celsius). the formula used is given on p. 302 of the smithsonian meteorological tables by roland list (6th edition).

PseudoNetCDF.derived.met.wmrq_ptd(p, td, dry=False, kgkg=False)[source]

p - pressure in Pa td - temperature in degrees celcius dry - return results in mixing ratio or specific humidity in dry air kgkg - return results in kg/kg instead of g/kg

PseudoNetCDF.derived.met.wswd_uv(u, v, return_radians=False)[source]
Parameters:

  • winds (v - array of v-domponent)

  • winds

  • radians (return_radians - convert direction to)

Returns:

ws, wd - wind speed and direction (from direction)

https://www.eol.ucar.edu/projects/ceop/dm/documents/refdata_report/ eqns.html

Module contents