Esempio n. 1
0
def qflx_prec_2lhflx(QFLX, PRECC, PRECL, PRECSC, PRECSL):
    """computes LHFLX from QFLX and the precipitation variables PRECC, PRECL, PRECSC, PERCSL.
    Assumes that the input is in compatible units, such as kg/(m^2 s) for QFLX
    and m/s for PRECC, PRECL."""
    QFLX = convert_units(QFLX, 'kg/(m^2 s)')
    PRECC = convert_units(PRECC, 'm/s')
    PRECL = convert_units(PRECL, 'm/s')
    PRECSC = convert_units(PRECSC, 'm/s')
    PRECSL = convert_units(PRECSL, 'm/s')
    Lv = 2.501e6  # units J/kg
    Lf = 3.337e5  # units J/kg
    LHFLX = (Lv + Lf) * QFLX - Lf * 1.e3 * (PRECC + PRECL - PRECSC - PRECSL)
    LHFLX.units = "W/m^2"
    LHFLX.long_name = "Surf latent heat flux"
    return LHFLX
Esempio n. 2
0
def qflx_2lhflx(QFLX):
    """computes LHFLX from QFLX."""
    # Based on get_LHFLX in the NCL code for AMWG.  It may be that Susannah Burrow's qflx_lhflx_conversions.py
    # does the same thing in more generality, but I've not looked at it carefully.
    QFLX = convert_units(QFLX, 'kg/(m^2 s)')
    Lv = 2.501e6  # units J/kg
    LHFLX = Lv * QFLX
    LHFLX.units = "W/m^2"
    LHFLX.long_name = "Surf latent heat flux"
    return LHFLX
Esempio n. 3
0
def prect2precip( PRECT, seasonid ):
    """converts a precipitation rate PRECT (averaged over a season; typical units mm/day)
    to a cumulative precipitation PRECIP (summed over the season).  Thus PRECIP is PRECT multiplied
    by the length of the season.  PRECIP is returned.  We assume a 365-day (noleap) calendar."""
    lenseason = { 'ANN':365, 'JFMAMJJASOND':365, 'DJF':90, 'MAM':92, 'JJA':92, 'SON':91,
                  'JAN':31, 'FEB':28, 'MAR':31, 'APR':30, 'MAY':31,
                  'JUN':30, 'JUL':31, 'AUG':31, 'SEP':30, 'OCT':31, 'NOV':30, 'DEC':31 }
    if seasonid not in lenseason:
        raise DiagError( "While converting precipitation rate to cumulative, cannot identify season %s" % seasonid )
    
    PRECIP = lenseason[seasonid] * convert_units( PRECT, 'mm/day' )
    PRECIP.units = 'mm'
    return PRECIP
Esempio n. 4
0
        derived_var(
            vid='CLDLOW_TAU1.3-9.4_MISR', inputs=['CLMISR'], outputs=['CLDLOW_TAU1.3-9.4_MISR'],
            func=(lambda clmisr, h0=0,h1=3, t0=1.3,t1=9.4: reduce_height_thickness( clmisr, h0,h1, t0,t1) ) )
        #func=(lambda clmisr, h0=0,h1=6, t0=2,t1=4: reduce_height_thickness( clmisr, h0,h1, t0,t1) ) )
        ],
    #6-MISR
    'CLDLOW_TAU9.4_MISR':[
        derived_var(
            vid='CLDLOW_TAU9.4_MISR', inputs=['CLMISR'], outputs=['CLDLOW_TAU9.4_MISR'],
            func=(lambda clmisr, h0=0,h1=3, t0=9.4,t1=379: reduce_height_thickness(
                    clmisr, h0,h1, t0,t1) ) )
        ],
    #TGCLDLWP_OCEAN
    'TGCLDLWP_OCN':[derived_var(
            vid='TGCLDLWP', inputs=['TGCLDLWP_OCEAN'], outputs=['TGCLDLWP_OCN'],
            func=(lambda x: convert_units(x, 'g/m^2')) ), 
                derived_var(
            vid='TGCLDLWP_OCN', inputs=['TGCLDLWP', 'OCNFRAC'], outputs=['TGCLDLWP_OCN'],
            func=(lambda x, y, units='g/m^2': simple_vars.ocean_only(x,y, units)) )],
    #...end of clouds, Yuying Zhang

    # To compare LHFLX and QFLX, need to unify these to a common variable
    # e.g. LHFLX (latent heat flux in W/m^2) vs. QFLX (evaporation in mm/day).
    # The conversion functions are defined in qflx_lhflx_conversions.py.
    # [SMB: 25 Feb 2015]
    #'LHFLX':[derived_var(
    #        vid='LHFLX', inputs=['QFLX'], outputs=['LHFLX'],
    #        func=(lambda x: x) ) ],
    #'QFLX':[derived_var(
    #        vid='QFLX', inputs=['LHFLX'], outputs=['QFLX'],
    #        func=(lambda x: x) ) ],
Esempio n. 5
0
def ocean_only(var, OCNFRAC, units=None):
    if units != None:
        convert_units(var, units)
    return mask_by(var, OCNFRAC, lo=0.5, hi=None)