def test_dwpt():
input_p = 900
correct_t = 11.52599445805832
returned_t = interp.dwpt(prof, input_p)
npt.assert_almost_equal(returned_t, correct_t)
input_p = [900, 800, 600, 400]
correct_t = np.asarray([11.52599445805832, 6.07174951,
-13.34348479, -35.7])
returned_t = interp.dwpt(prof, input_p)
npt.assert_almost_equal(returned_t, correct_t)
def test_dwpt():
input_p = 900
correct_t = 11.52599445805832
returned_t = interp.dwpt(prof, input_p)
npt.assert_almost_equal(returned_t, correct_t)
input_p = [900, 800, 600, 400]
correct_t = np.asarray([11.52599445805832, 6.07174951,
-13.34348479, -35.7])
returned_t = interp.dwpt(prof, input_p)
npt.assert_almost_equal(returned_t, correct_t)
def precip_water(lower, upper, prof):
'''
Calculates the precipitable water from a profile object within the
specified layer. The default layer (lower=-1 & upper=-1) is defined to
be surface to 400 hPa.
Inputs
------
lower (float) Lower pressure level
upper (float) Upper pressure level
prof (profile object) Profile Object
Returns
-------
pwat (float) Precipitable Water (in)
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = 400.
# Find lower and upper ind bounds for looping
i = 0
while prof.gSndg[i][prof.pind] > lower:
i += 1
lptr = i
while prof.gSndg[i][prof.pind] > upper:
i += 1
uptr = i
# Start with interpolated bottom level
d1 = interp.dwpt(lower, prof)
p1 = lower
w1 = thermo.mixratio(p1, d1)
# Loop through every level that has a dew point
pwat = 0
for i in range(lptr, uptr + 1):
if QC(prof.gSndg[i][prof.tdind]):
p2 = prof.gSndg[i][prof.pind]
w2 = thermo.mixratio(p2, prof.gSndg[i][prof.tdind])
pwat += ((w1 + w2) / 2.) * (p1 - p2)
p1 = p2
w1 = w2
# Finish with interpolated top level
d2 = interp.dwpt(upper, prof)
p2 = upper
w2 = thermo.mixratio(p2, d2)
pwat += ((w1 + w2) / 2.) * (p1 - p2)
return pwat * 0.00040173
def precip_water(lower, upper, prof):
'''
Calculates the precipitable water from a profile object within the
specified layer. The default layer (lower=-1 & upper=-1) is defined to
be surface to 400 hPa.
Inputs
------
lower (float) Lower pressure level
upper (float) Upper pressure level
prof (profile object) Profile Object
Returns
-------
pwat (float) Precipitable Water (in)
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = 400.
# Find lower and upper ind bounds for looping
i = 0
while prof.gSndg[i][prof.pind] > lower: i+=1
lptr = i
while prof.gSndg[i][prof.pind] > upper: i+=1
uptr = i
# Start with interpolated bottom level
d1 = interp.dwpt(lower, prof)
p1 = lower
w1 = thermo.mixratio(p1, d1)
# Loop through every level that has a dew point
pwat = 0
for i in range(lptr, uptr+1):
if QC(prof.gSndg[i][prof.tdind]):
p2 = prof.gSndg[i][prof.pind]
w2 = thermo.mixratio(p2, prof.gSndg[i][prof.tdind])
pwat += ((w1 + w2) / 2.) * (p1 - p2)
p1 = p2
w1 = w2
# Finish with interpolated top level
d2 = interp.dwpt(upper, prof)
p2 = upper
w2 = thermo.mixratio(p2, d2)
pwat += ((w1 + w2) / 2.) * (p1 - p2)
return pwat * 0.00040173
def haines_high(prof):
'''
Haines Index High Elevation calculation
Calculates the Haines Index(Lower Atmosphere Severity Index)
using the higher elevation parmeters, used above 3000ft or 914 m.
Pressure levels 700 mb and 500 mb
Dewpoint depression at 700 mb
Lapse Rate Term
---------------
1 : < 18C
2 : 18C to 21C
3 : > 21C
Dewpoint Depression Term
------------------------
1 : < 15C
2 : 15C to 20C
3 : > 20C
Adapted from S-591 course
Added by Nickolai Reimer (NWS Billings, MT)
Parameters
----------
prof : profile object
Profile object
Returns
-------
param : number
the Haines Index high
'''
tp1 = interp.temp(prof, 700)
tp2 = interp.temp(prof, 500)
tdp1 = interp.dwpt(prof, 700)
if utils.QC(tp1) and utils.QC(tp2) and utils.QC(tdp1):
lapse_rate = tp1 - tp2
dewpoint_depression = tp1 - tdp1
if lapse_rate < 18:
a = 1
elif 18 <= lapse_rate and lapse_rate <= 21:
a = 2
else:
a = 3
if dewpoint_depression < 15:
b = 1
elif 15 <= dewpoint_depression and dewpoint_depression <= 20:
b = 2
else:
b = 3
return a + b
else:
return constants.MISSING
def insertLevels(prof, zeroHt, zeroPres, level):
prof.dwpc = np.insert(prof.dwpc,level,
[interp.dwpt(prof,zeroPres)])
prof.vtmp = np.insert(prof.vtmp,level,
[interp.vtmp(prof,zeroPres)])
prof.thetae = np.insert(prof.thetae,level,
[interp.thetae(prof,zeroPres)])
#prof.wetbulb = np.insert(prof.wetbulb,level,
# [interp.generic_interp_pres(np.log10(zeroPres), prof.logp[::-1], prof.wetbulb[::-1])])
try:
dir,mag = interp.vec(prof,zeroPres)
prof.wdir = np.insert(prof.wdir,level,[dir])
prof.wspd = np.insert(prof.wspd,level,[mag])
prof.u, prof.v = utils.vec2comp(prof.wdir, prof.wspd)
except:
prof.wdir = np.insert(prof.wdir,level,[0])
prof.wspd = np.insert(prof.wspd,level,[0])
prof.u, prof.v = utils.vec2comp(prof.wdir, prof.wspd)
prof.hght = np.insert(prof.hght,level,[zeroHt])
prof.pres = np.insert(prof.pres,level,[zeroPres])
prof.logp = np.log10(prof.pres.copy())
return prof
def lift_parcels(prof):
"""Lift all the parcels within a given height interval and return the CAPEs, CINHs, and LFCs"""
## the height bottom, top, and interval
zvals = np.arange(0, 5000, 100)
pvals = interp.pres(prof, interp.to_msl(prof, zvals))
tvals = interp.temp(prof, pvals)
dvals = interp.dwpt(prof, pvals)
hvals = interp.hght(prof, pvals)
hvals = interp.to_agl(prof, hvals)
## empty lists for storing the result
cape_arr = []
cinh_arr = []
lfc_arr = []
## lift each parcel in the vertical profile
for p, t, td, h in zip(pvals, tvals, dvals, hvals):
## use SHARPpy to compute the parcel indices
pcl = params.parcelx(prof, pres=p, tmpc=t, dwpc=td)
## store the parcel indices
cape_arr.append(pcl.bplus)
cinh_arr.append(pcl.bminus)
lfc_arr.append(pcl.lfchght - h)
## return the data
return np.ma.masked_invalid(cape_arr), np.ma.masked_invalid(
cinh_arr), np.ma.masked_invalid(lfc_arr)
def __mu(self, prof, **kwargs):
''' Create the most unstable parcel within defined level '''
self.desc = 'Most Unstable Parcel in Lowest %.2f hPa' % self.presval
diff = prof.gSndg[prof.sfc][prof.pind] - self.presval
self.pres = unstable_level(prof, -1, diff)
self.temp = interp.temp(self.pres, prof)
self.dwpt = interp.dwpt(self.pres, prof)
return
def __mu(self, prof, **kwargs):
''' Create the most unstable parcel within defined level '''
self.desc = 'Most Unstable Parcel in Lowest %.2f hPa' % self.presval
diff = prof.gSndg[prof.sfc][prof.pind] - self.presval
self.pres = unstable_level(prof, -1, diff)
self.temp = interp.temp(self.pres, prof)
self.dwpt = interp.dwpt(self.pres, prof)
return
def __user(self, prof, **kwargs):
''' Create a user-defined parcel '''
self.desc = '%.2f hPa Parcel' % self.presval
self.pres = self.presval
if 'temp' in kwargs: self.temp = kwargs.get('temp')
else: self.temp = interp.temp(self.pres, prof)
if 'dwpt' in kwargs: self.dwpt = kwargs.get('dwpt')
else: self.dwpt = interp.dwpt(self.pres, prof)
return
def __user(self, prof, **kwargs):
''' Create a user-defined parcel '''
self.desc = '%.2f hPa Parcel' % self.presval
self.pres = self.presval
if 'temp' in kwargs: self.temp = kwargs.get('temp')
else: self.temp = interp.temp(self.pres, prof)
if 'dwpt' in kwargs: self.dwpt = kwargs.get('dwpt')
else: self.dwpt = interp.dwpt(self.pres, prof)
return
def k_index(prof):
'''
Calculates the K-Index from a profile object
Inputs
------
prof (profile object) Profile Object
Returns
-------
kind (float) K-Index
'''
t8 = interp.temp(850., prof)
t7 = interp.temp(700., prof)
t5 = interp.temp(500., prof)
td7 = interp.dwpt(700., prof)
td8 = interp.dwpt(850., prof)
if not QC(t8) or not QC(t7) or not QC(t5) or not QC(td8) or not QC(td7):
return RMISSD
else:
return t8 - t5 + td8 - (t7 - td7)
def k_index(prof):
'''
Calculates the K-Index from a profile object
Inputs
------
prof (profile object) Profile Object
Returns
-------
kind (float) K-Index
'''
t8 = interp.temp(850., prof)
t7 = interp.temp(700., prof)
t5 = interp.temp(500., prof)
td7 = interp.dwpt(700., prof)
td8 = interp.dwpt(850., prof)
if not QC(t8) or not QC(t7) or not QC(t5) or not QC(td8) or not QC(td7):
return RMISSD
else:
return t8 - t5 + td8 - (t7 - td7)
def c_totals(prof):
'''
Calculates the Cross Totals Index from data in profile object.
Inputs
------
prof (profile object) Profile Object
Returns
-------
c_totals (float) Cross Totals
'''
t5 = interp.temp(500., prof)
td8 = interp.dwpt(850., prof)
return td8 - t5
def c_totals(prof):
'''
Calculates the Cross Totals Index from data in profile object.
Inputs
------
prof (profile object) Profile Object
Returns
-------
c_totals (float) Cross Totals
'''
t5 = interp.temp(500., prof)
td8 = interp.dwpt(850., prof)
return td8 - t5
def haines_ma(prof):
'''
Haines Index, Middle Altitude
The Haines Index (or Lower Atmospheric Severity Index) was developed in order to help forecast fire "blow up"
potential. It is a function of lower atmospheric stability and moisture content. Three versions were
developed, to be used depending on the altitude of the surface. Values of 2 or 3 indicate very low "blow up"
potential; a value of 4 indicates low potential; a value of 5 indicates moderate potential; and a value of
6 indicates high potential.
The middle altitude version was developed primarily for use when the surface level pressure is between 950
and 850 mb.
Parameters
----------
prof - Profile object
Returns
-------
haines_ma : number
Haines Index, Middle Altitude (number)
'''
tmp850 = interp.temp(prof, 850)
tmp700 = interp.temp(prof, 700)
dpt850 = interp.dwpt(prof, 850)
lr87 = tmp850 - tmp700
tdd850 = tmp850 - dpt850
if lr87 <= 5:
stab_tm = 1
elif 5 < lr87 and lr87 < 11:
stab_tm = 2
else:
stab_tm = 3
if tdd850 <= 5:
mois_tm = 1
elif 5 < tdd850 and tdd850 < 13:
mois_tm = 2
else:
mois_tm = 3
haines_ma = stab_tm + mois_tm
return haines_ma
def haines_ha(prof):
'''
Haines Index, High Altitude
The Haines Index (or Lower Atmospheric Severity Index) was developed in order to help forecast fire "blow up"
potential. It is a function of lower atmospheric stability and moisture content. Three versions were
developed, to be used depending on the altitude of the surface. Values of 2 or 3 indicate very low "blow up"
potential; a value of 4 indicates low potential; a value of 5 indicates moderate potential; and a value of
6 indicates high potential.
The low altitude version was developed primarily for use when the surface level pressure is between 850 and
700 mb.
Parameters
----------
prof - Profile object
Returns
-------
haines_ha : number
Haines Index, High Altitude (number)
'''
tmp700 = interp.temp(prof, 700)
tmp500 = interp.temp(prof, 500)
dpt700 = interp.dwpt(prof, 700)
lr75 = tmp700 - tmp500
tdd700 = tmp700 - dpt700
if lr75 <= 17:
stab_tm = 1
elif 17 < lr75 and lr75 < 22:
stab_tm = 2
else:
stab_tm = 3
if tdd700 <= 14:
mois_tm = 1
elif 14 < tdd700 and tdd700 < 21:
mois_tm = 2
else:
mois_tm = 3
haines_ha = stab_tm + mois_tm
return haines_ha
def interp(self, dp=-25):
"""
Interpolate the profile object to a specific pressure level spacing.
"""
if self.isEnsemble():
raise ValueError("Cannot interpolate the ensemble profiles.")
prof = self._profs[self._highlight][self._prof_idx]
# Save original, if one hasn't already been saved
if self._prof_idx not in self._orig_profs:
self._orig_profs[self._prof_idx] = prof
cls = type(prof)
# Copy the tmpc, dwpc, etc. profiles to be inteprolated
keys = ['tmpc', 'dwpc', 'hght', 'wspd', 'wdir', 'omeg']
prof_vars = {
'pres': np.arange(prof.pres[prof.sfc], prof.pres[prof.top], dp)
}
prof_vars['tmpc'] = interp.temp(prof, prof_vars['pres'])
prof_vars['dwpc'] = interp.dwpt(prof, prof_vars['pres'])
prof_vars['hght'] = interp.hght(prof, prof_vars['pres'])
if prof.omeg.all() is not np.ma.masked:
prof_vars['omeg'] = interp.omeg(prof, prof_vars['pres'])
else:
prof_vars['omeg'] = np.ma.masked_array(prof_vars['pres'],
mask=np.ones(len(
prof_vars['pres']),
dtype=int))
u, v = interp.components(prof, prof_vars['pres'])
prof_vars['u'] = u
prof_vars['v'] = v
interp_prof = cls.copy(prof, **prof_vars)
self._profs[self._highlight][self._prof_idx] = interp_prof
# Save the original like in modify()
if self._prof_idx not in self._interp_profs:
self._interp_profs[self._prof_idx] = interp_prof
# Update bookkeeping
self._interp[self._prof_idx] = True
def interp(self, dp=-25):
"""
Interpolate the profile object to a specific pressure level spacing.
"""
if self.isEnsemble():
raise ValueError("Cannot interpolate the ensemble profiles.")
prof = self._profs[self._highlight][self._prof_idx]
# Save original, if one hasn't already been saved
if self._prof_idx not in self._orig_profs:
self._orig_profs[self._prof_idx] = prof
cls = type(prof)
# Copy the tmpc, dwpc, etc. profiles to be inteprolated
keys = ['tmpc', 'dwpc', 'hght', 'wspd', 'wdir', 'omeg']
prof_vars = {'pres': np.arange(prof.pres[prof.sfc], prof.pres[prof.top], dp)}
prof_vars['tmpc'] = interp.temp(prof, prof_vars['pres'])
prof_vars['dwpc'] = interp.dwpt(prof, prof_vars['pres'])
prof_vars['hght'] = interp.hght(prof, prof_vars['pres'])
if prof.omeg.all() is not np.ma.masked:
prof_vars['omeg'] = interp.omeg(prof, prof_vars['pres'])
else:
prof_vars['omeg'] = np.ma.masked_array(prof_vars['pres'], mask=np.ones(len(prof_vars['pres']), dtype=int))
u, v = interp.components(prof, prof_vars['pres'])
prof_vars['u'] = u
prof_vars['v'] = v
interp_prof = cls.copy(prof, **prof_vars)
self._profs[self._highlight][self._prof_idx] = interp_prof
# Save the original like in modify()
if self._prof_idx not in self._interp_profs:
self._interp_profs[self._prof_idx] = interp_prof
# Update bookkeeping
self._interp[self._prof_idx] = True
def unstable_level(prof, lower, upper):
'''
Finds the most unstable level between the lower and upper levels.
Inputs
------
prof (profile object) Profile Object
lower (float) Bottom level (hPa) [-1=SFC]
upper (float) Top level (hPa) [-1=SFC-100hPa]
Returns
-------
Pressure Level of most unstable level (float [hPa])
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = prof.gSndg[prof.sfc][prof.pind] - 400.
# Make sure this is a valid layer
while not QC(interp.dwpt(upper, prof)):
upper += 50.
if not QC(interp.temp(lower, prof)): lower = prof.gSndg[prof.sfc][0]
# Find lowest observations in the layer
i = 0
while prof.gSndg[i][prof.pind] > lower:
i += 1
while not QC(prof.gSndg[i][prof.tind]):
i += 1
lptr = i
if prof.gSndg[i][prof.pind] == lower: lptr += 1
# Find highest observations in the layer
i = prof.gNumLevels - 1
while prof.gSndg[i][prof.pind] < upper:
i -= 1
uptr = i
if prof.gSndg[i][prof.pind] == upper: uptr -= 1
# Start with interpolated bottom layer
p1 = lower
t1 = interp.temp(p1, prof)
td1 = interp.dwpt(p1, prof)
p2, t2 = thermo.drylift(p1, t1, td1)
tmax = thermo.wetlift(p2, t2, 1000.)
pmax = p1
# Calculate every level that reports a dew point
for i in range(lptr, uptr + 1):
if QC(prof.gSndg[i][prof.tdind]):
p1 = prof.gSndg[i][prof.pind]
t1 = prof.gSndg[i][prof.tind]
td1 = prof.gSndg[i][prof.tdind]
p2, t2 = thermo.drylift(p1, t1, td1)
t1 = thermo.wetlift(p2, t2, 1000.)
if t1 > tmax:
tmax = t1
pmax = p1
# Finish with interpolated top layer
p1 = upper
t1 = interp.temp(p1, prof)
td1 = interp.dwpt(p1, prof)
p2, t2 = thermo.drylift(p1, t1, td1)
t1 = thermo.wetlift(p2, t2, 1000.)
if t1 > tmax:
pmax = prof.gSndg[i][prof.pind]
return pmax
def haines_mid(prof):
'''
Haines Index Mid Elevation calculation
Calculates the Haines Index(Lower Atmosphere Severity Index)
using the middle elevation parmeters, used
between 1000 ft or 305 m and 3000 ft or 914 m.
Pressure levels 850 mb and 700 mb
Dewpoint depression at 850 mb
Lapse Rate Term
---------------
1 : < 6C
2 : 6C to 10C
3 : > 10C
Dewpoint Depression Term
------------------------
1 : < 6C
2 : 6C to 12C
3 : > 12C
Adapted from S-591 course
Added by Nickolai Reimer (NWS Billings, MT)
Parameters
----------
prof : profile object
Profile object
Returns
-------
param : number
the Haines Index mid
'''
tp1 = interp.temp(prof, 850)
tp2 = interp.temp(prof, 700)
tdp1 = interp.dwpt(prof, 850)
if utils.QC(tp1) and utils.QC(tp2) and utils.QC(tdp1):
lapse_rate = tp1 - tp2
dewpoint_depression = tp1 - tdp1
if lapse_rate < 6:
a = 1
elif 6 <= lapse_rate and lapse_rate <= 10:
a = 2
else:
a = 3
if dewpoint_depression < 6:
b = 1
elif 6 <= dewpoint_depression and dewpoint_depression <= 12:
b = 2
else:
b = 3
return a + b
else:
return constants.MISSING
def mean_mixratio(prof, lower=-1, upper=-1):
'''
Calculates the mean mixing ratio from a profile object within the
specified layer.
Inputs
------
prof (profile object) Profile Object
lower (float) Bottom level (hPa) [-1=SFC]
upper (float) Top level (hPa) [-1=SFC-100hPa]
Returns
-------
Mean Mixing Ratio (float)
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = prof.gSndg[prof.sfc][prof.pind] - 100.
if not QC(interp.temp(upper, prof)): mmw = RMISSD
if not QC(interp.temp(lower, prof)): prof.gSndg[prof.sfc][prof.pind]
# Find lowest observations in the layer
i = 0
while prof.gSndg[i][prof.pind] > lower:
i += 1
while not QC(prof.gSndg[i][prof.tdind]):
i += 1
lptr = i
if prof.gSndg[i][prof.pind] == lower: lptr += 1
# Find highest observations in the layer
i = prof.gNumLevels - 1
while prof.gSndg[i][prof.pind] < upper:
i -= 1
uptr = i
if prof.gSndg[i][prof.pind] == upper: uptr -= 1
totd = 0
totp = 0
# Start with interpolated bottom layer
p1 = lower
dp1 = interp.dwpt(p1, prof)
num = 1
# Calculate every level that reports a dew point
for i in range(lptr, uptr + 1):
if QC(prof.gSndg[i][prof.tdind]):
dp2 = prof.gSndg[i][prof.tdind]
p2 = prof.gSndg[i][prof.pind]
dpbar = (dp1 + dp2) / 2.
pbar = (p1 + p2) / 2.
totd += dpbar
totp += pbar
dp1 = dp2
p1 = p2
num += 1
# Finish with top layer
dp2 = interp.dwpt(upper, prof)
p2 = upper
dbar = (dp1 + dp2) / 2.
pbar = (p1 + p2) / 2.
totd += dbar
totp += pbar
return thermo.mixratio(totp / num, totd / num)
def parcelx(lower, upper, pres, temp, dwpt, prof, **kwargs):
'''
Lifts the specified parcel, calculated various levels and parameters from
the profile object. B+/B- are calculated based on the specified layer.
!! All calculations use the virtual temperature correction unless noted. !!
Inputs
------
lower (float) Lower-bound lifting level (hPa)
upper (float) Upper-bound lifting level
pres (float) Pressure of parcel to lift (hPa)
temp (float) Temperature of parcel to lift (C)
dwpt (float) Dew Point of parcel to lift (C)
prof (profile object) Profile Object
Returns
-------
pcl (parcel object) Parcel Object
'''
pcl = Parcel(-1, -1, pres, temp, dwpt)
if 'lplvals' in kwargs: pcl.lplvals = kwargs.get('lplvals')
else:
lplvals = DefineParcel(prof, 5, pres=pres, temp=temp, dwpt=dwpt)
pcl.lplvals = lplvals
if prof.gNumLevels < 1: return pcl
lyre = -1
cap_strength = RMISSD
cap_strengthpres = RMISSD
li_max = RMISSD
li_maxpres = RMISSD
totp = 0.
totn = 0.
tote = 0.
cinh_old = 0.
# See if default layer is specified
if lower == -1:
lower = prof.gSndg[prof.sfc][prof.pind]
pcl.blayer = lower
if upper == -1:
upper = prof.gSndg[prof.gNumLevels-1][prof.pind]
pcl.tlayer = upper
# Make sure that this is a valid layer
if lower > pres:
lower = pres
pcl.blayer = lower
if not QC(interp.vtmp(lower, prof)) or \
not QC(interp.vtmp(upper, prof)):
return RMISSD
# Begin with the Mixing Layer
te1 = interp.vtmp(pres, prof)
pe1 = lower
h1 = interp.hght(pe1, prof)
tp1 = thermo.virtemp(pres, temp, dwpt)
# te1 = tp1
# Lift parcel and return LCL pres (hPa) and LCL temp (c)
pe2, tp2 = thermo.drylift(pres, temp, dwpt)
blupper = pe2 # Define top of layer as LCL pres
h2 = interp.hght(pe2, prof)
te2 = interp.vtmp(pe2, prof)
pcl.lclpres = pe2
pcl.lclhght = interp.agl(h2, prof)
# Calculate lifted parcel theta for use in iterative CINH loop below
# RECALL: lifted parcel theta is CONSTANT from LPL to LCL
theta_parcel = thermo.theta(pe2, tp2, 1000.)
# Environmental theta and mixing ratio at LPL
bltheta = thermo.theta(pres, interp.temp(pres, prof), 1000.)
blmr = thermo.mixratio(pres, dwpt)
# ACCUMULATED CINH IN MIXING LAYER BELOW THE LCL
# This will be done in 10mb increments, and will use the virtual
# temperature correction where possible
pinc = -10
a = int(lower)
b = int(blupper)
for pp in range(a, b, int(pinc)):
pp1 = pp
pp2 = pp + pinc
if pp2 < blupper: pp2 = blupper
dz = interp.hght(pp2, prof) - interp.hght(pp1, prof)
# Calculate difference between Tv_parcel and Tv_environment at top
# and bottom of 10mb layers. Make use of constant lifted parcel
# theta and mixing ratio from LPL to LCL
tv_env_bot = thermo.virtemp(pp1, thermo.theta(pp1,
interp.temp(pp1, prof), 1000.), interp.dwpt(pp1, prof))
tdef1 = (thermo.virtemp(pp1, theta_parcel,
thermo.temp_at_mixrat(blmr, pp1)) - tv_env_bot) / \
(thermo.ctok(tv_env_bot))
tv_env_top = thermo.virtemp(pp2, thermo.theta(pp2,
interp.temp(pp2, prof), 1000.), interp.dwpt(pp2, prof))
tdef2 = (thermo.virtemp(pp2, theta_parcel,
thermo.temp_at_mixrat(blmr, pp2)) - tv_env_top) / \
(thermo.ctok(tv_env_bot))
lyre = G * (tdef1 + tdef2) / 2. * dz
if lyre < 0: totn += lyre
# Move the bottom layer to the top of the boundary layer
if lower > pe2:
lower = pe2
pcl.blayer = lower
# Calculate height of various temperature levels
p0c = temp_lvl(0., prof)
pm10c = temp_lvl(-10., prof)
pm20c = temp_lvl(-20., prof)
pm30c = temp_lvl(-30., prof)
hgt0c = interp.hght(p0c, prof)
hgtm10c = interp.hght(pm10c, prof)
hgtm20c = interp.hght(pm20c, prof)
hgtm30c = interp.hght(pm30c, prof)
pcl.p0c = p0c
pcl.pm10c = pm10c
pcl.pm20c = pm20c
pcl.pm30c = pm30c
pcl.hght0c = hgt0c
pcl.hghtm10c = hgtm10c
pcl.hghtm20c = hgtm20c
pcl.hghtm30c = hgtm30c
# Find lowest observation in layer
i = 0
while prof.gSndg[i][prof.pind] > lower:
if i == prof.gNumLevels-1: break
i += 1
while not QC(prof.gSndg[i][prof.tdind]):
if i == prof.gNumLevels-1: break
i += 1
lptr = i
if prof.gSndg[i][prof.pind] == lower:
if i != prof.gNumLevels-1: lptr += 1
# Find highest observation in layer
i = prof.gNumLevels-1
while prof.gSndg[i][prof.pind] < upper:
if i < lptr: break
i -= 1
uptr = i
if prof.gSndg[i][prof.pind] == upper:
if i > lptr: uptr -= 1
# START WITH INTERPOLATED BOTTOM LAYER
# Begin moist ascent from lifted parcel LCL (pe2, tp2)
pe1 = lower
h1 = interp.hght(pe1, prof)
te1 = interp.vtmp(pe1, prof)
tp1 = thermo.wetlift(pe2, tp2, pe1)
lyre = 0
lyrlast = 0
for i in range(lptr, prof.gNumLevels):
if not QC(prof.gSndg[i][prof.tind]): continue
pe2 = prof.gSndg[i][prof.pind]
h2 = prof.gSndg[i][prof.zind]
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe1, tp1, pe2)
tdef1 = (thermo.virtemp(pe1, tp1, tp1) - te1) / thermo.ctok(te1)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / thermo.ctok(te2)
lyrlast = lyre
lyre = G * (tdef1 + tdef2) / 2. * (h2 - h1)
# Add layer energy to total positive if lyre > 0
if lyre > 0: totp += lyre
# Add layer energy to total negative if lyre < 0, only up to EL
else:
if pe2 > 500.: totn += lyre
# Check for Max LI
mli = thermo.virtemp(pe2, tp2, tp2) - te2
if mli > li_max:
li_max = mli
li_maxpres = pe2
# Check for Max Cap Strength
mcap = te2 - mli
if mcap > cap_strength:
cap_strength = mcap
cap_strengthpres = pe2
tote += lyre
pelast = pe1
pe1 = pe2
h1 = h2
te1 = te2
tp1 = tp2
# Is this the top of the specified layer
if i >= uptr and not QC(pcl.bplus):
pe3 = pe1
h3 = h1
te3 = te1
tp3 = tp1
lyrf = lyre
if lyrf > 0:
pcl.bplus = totp - lyrf
pcl.bminus = totn
else:
pcl.bplus = totp
if pe2 > 500.: pcl.bminus = totn + lyrf
else: pcl.bminus = totn
pe2 = upper
h2 = interp.hght(pe2, prof)
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.bplus += lyrf
else:
if pe2 > 500.: pcl.bminus += lyrf
if pcl.bplus == 0: pcl.bminus = 0.
# Is this the freezing level
if te2 < 0. and not QC(pcl.bfzl):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.bfzl = totp - lyrf
else: pcl.bfzl = totp
if not QC(p0c) or p0c > pe3:
pcl.bfzl = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgt0c - h3)
if lyrf > 0: pcl.bfzl += lyrf
# Is this the -10C level
if te2 < -10. and not QC(pcl.wm10c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm10c = totp - lyrf
else: pcl.wm10c = totp
if not QC(pm10c) or pm10c > pcl.lclpres:
pcl.wm10c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm10c - h3)
if lyrf > 0: pcl.wm10c += lyrf
# Is this the -20C level
if te2 < -20. and not QC(pcl.wm20c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm20c = totp - lyrf
else: pcl.wm20c = totp
if not QC(pm20c) or pm20c > pcl.lclpres:
pcl.wm20c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm20c - h3)
if lyrf > 0: pcl.wm20c += lyrf
# Is this the -30C level
if te2 < -30. and not QC(pcl.wm30c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm30c = totp - lyrf
else: pcl.wm30c = totp
if not QC(pm30c) or pm30c > pcl.lclpres:
pcl.wm30c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm30c - h3)
if lyrf > 0: pcl.wm30c += lyrf
# Is this the 3km level
if pcl.lclhght < 3000.:
h = interp.agl(interp.hght(pe2, prof), prof)
if h >= 3000. and not QC(pcl.b3km):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0: pcl.b3km = totp - lyrf
else: pcl.b3km = totp
h2 = interp.msl(3000., prof)
pe2 = interp.pres(h2, prof)
if QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.b3km += lyrf
else: pcl.b3km = 0.
# Is this the 6km level
if pcl.lclhght < 6000.:
h = interp.agl(interp.hght(pe2, prof), prof)
if h >= 6000. and not QC(pcl.b6km):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0: pcl.b6km = totp - lyrf
else: pcl.b6km = totp
h2 = interp.msl(6000., prof)
pe2 = interp.pres(h2, prof)
if QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.b6km += lyrf
else: pcl.b6km = 0.
# LFC Possibility
if lyre >= 0. and lyrlast <= 0.:
tp3 = tp1
te3 = te1
pe2 = pe1
pe3 = pelast
while interp.vtmp(pe3, prof) > thermo.virtemp(pe3,
thermo.wetlift(pe2, tp3, pe3), thermo.wetlift(pe2, tp3, pe3)):
pe3 -= 5
pcl.lfcpres = pe3
pcl.lfchght = interp.agl(interp.hght(pe3, prof), prof)
cinh_old = totn
tote = 0.
pcl.elpres = RMISSD
li_max = RMISSD
if cap_strength < 0.: cap_strength = 0.
pcl.cap = cap_strength
pcl.cappres = cap_strengthpres
# Hack to force LFC to be at least at the LCL
if pcl.lfcpres > pcl.lclpres:
pcl.lfcpres = pcl.lclpres
pcl.lfchght = pcl.lclhght
# EL Possibility
if lyre <= 0. and lyrlast >= 0.:
tp3 = tp1
te3 = te1
pe2 = pe1
pe3 = pelast
while interp.vtmp(pe3, prof) < thermo.virtemp(pe3,
thermo.wetlift(pe2, tp3, pe3), thermo.wetlift(pe2, tp3, pe3)):
pe3 -= 5
pcl.elpres = pe3
pcl.elhght = interp.agl(interp.hght(pe3, prof), prof)
pcl.mplpres = RMISSD
pcl.limax = -li_max
pcl.limaxpress = li_maxpres
# MPL Possibility
if tote < 0. and not QC(pcl.mplpres) and QC(pcl.elpres):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
totx = tote - lyre
pe2 = pelast
while totx > 0:
pe2 -= 1
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
h2 = interp.hght(pe2, prof)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
totx += lyrf
tp3 = tp2
te3 = te2
pe3 = pe2
pcl.mplpres = pe2
pcl.mplhght = interp.agl(interp.hght(pe2, prof), prof)
# 500 hPa Lifted Index
if prof.gSndg[i][prof.pind] <= 500. and pcl.li5 == RMISSD:
a = interp.vtmp(500., prof)
b = thermo.wetlift(pe1, tp1, 500.)
pcl.li5 = a - thermo.virtemp(500, b, b)
# 300 hPa Lifted Index
if prof.gSndg[i][prof.pind] <= 300. and pcl.li3 == RMISSD:
a = interp.vtmp(300., prof)
b = thermo.wetlift(pe1, tp1, 300.)
pcl.li3 = a - thermo.virtemp(300, b, b)
# Calculate BRN if available
pcl = bulk_rich(pcl, prof)
pcl.bminus = cinh_old
if pcl.bplus == 0: pcl.bminus = 0.
return pcl
def parcelx(lower, upper, pres, temp, dwpt, prof, **kwargs):
'''
Lifts the specified parcel, calculated various levels and parameters from
the profile object. B+/B- are calculated based on the specified layer.
!! All calculations use the virtual temperature correction unless noted. !!
Inputs
------
lower (float) Lower-bound lifting level (hPa)
upper (float) Upper-bound lifting level
pres (float) Pressure of parcel to lift (hPa)
temp (float) Temperature of parcel to lift (C)
dwpt (float) Dew Point of parcel to lift (C)
prof (profile object) Profile Object
Returns
-------
pcl (parcel object) Parcel Object
'''
pcl = Parcel(-1, -1, pres, temp, dwpt)
if 'lplvals' in kwargs: pcl.lplvals = kwargs.get('lplvals')
else:
lplvals = DefineParcel(prof, 5, pres=pres, temp=temp, dwpt=dwpt)
pcl.lplvals = lplvals
if prof.gNumLevels < 1: return pcl
lyre = -1
cap_strength = RMISSD
cap_strengthpres = RMISSD
li_max = RMISSD
li_maxpres = RMISSD
totp = 0.
totn = 0.
tote = 0.
cinh_old = 0.
# See if default layer is specified
if lower == -1:
lower = prof.gSndg[prof.sfc][prof.pind]
pcl.blayer = lower
if upper == -1:
upper = prof.gSndg[prof.gNumLevels - 1][prof.pind]
pcl.tlayer = upper
# Make sure that this is a valid layer
if lower > pres:
lower = pres
pcl.blayer = lower
if not QC(interp.vtmp(lower, prof)) or \
not QC(interp.vtmp(upper, prof)):
return RMISSD
# Begin with the Mixing Layer
te1 = interp.vtmp(pres, prof)
pe1 = lower
h1 = interp.hght(pe1, prof)
tp1 = thermo.virtemp(pres, temp, dwpt)
# te1 = tp1
# Lift parcel and return LCL pres (hPa) and LCL temp (c)
pe2, tp2 = thermo.drylift(pres, temp, dwpt)
blupper = pe2 # Define top of layer as LCL pres
h2 = interp.hght(pe2, prof)
te2 = interp.vtmp(pe2, prof)
pcl.lclpres = pe2
pcl.lclhght = interp.agl(h2, prof)
# Calculate lifted parcel theta for use in iterative CINH loop below
# RECALL: lifted parcel theta is CONSTANT from LPL to LCL
theta_parcel = thermo.theta(pe2, tp2, 1000.)
# Environmental theta and mixing ratio at LPL
bltheta = thermo.theta(pres, interp.temp(pres, prof), 1000.)
blmr = thermo.mixratio(pres, dwpt)
# ACCUMULATED CINH IN MIXING LAYER BELOW THE LCL
# This will be done in 10mb increments, and will use the virtual
# temperature correction where possible
pinc = -10
a = int(lower)
b = int(blupper)
for pp in range(a, b, int(pinc)):
pp1 = pp
pp2 = pp + pinc
if pp2 < blupper: pp2 = blupper
dz = interp.hght(pp2, prof) - interp.hght(pp1, prof)
# Calculate difference between Tv_parcel and Tv_environment at top
# and bottom of 10mb layers. Make use of constant lifted parcel
# theta and mixing ratio from LPL to LCL
tv_env_bot = thermo.virtemp(
pp1, thermo.theta(pp1, interp.temp(pp1, prof), 1000.),
interp.dwpt(pp1, prof))
tdef1 = (thermo.virtemp(pp1, theta_parcel,
thermo.temp_at_mixrat(blmr, pp1)) - tv_env_bot) / \
(thermo.ctok(tv_env_bot))
tv_env_top = thermo.virtemp(
pp2, thermo.theta(pp2, interp.temp(pp2, prof), 1000.),
interp.dwpt(pp2, prof))
tdef2 = (thermo.virtemp(pp2, theta_parcel,
thermo.temp_at_mixrat(blmr, pp2)) - tv_env_top) / \
(thermo.ctok(tv_env_bot))
lyre = G * (tdef1 + tdef2) / 2. * dz
if lyre < 0: totn += lyre
# Move the bottom layer to the top of the boundary layer
if lower > pe2:
lower = pe2
pcl.blayer = lower
# Calculate height of various temperature levels
p0c = temp_lvl(0., prof)
pm10c = temp_lvl(-10., prof)
pm20c = temp_lvl(-20., prof)
pm30c = temp_lvl(-30., prof)
hgt0c = interp.hght(p0c, prof)
hgtm10c = interp.hght(pm10c, prof)
hgtm20c = interp.hght(pm20c, prof)
hgtm30c = interp.hght(pm30c, prof)
pcl.p0c = p0c
pcl.pm10c = pm10c
pcl.pm20c = pm20c
pcl.pm30c = pm30c
pcl.hght0c = hgt0c
pcl.hghtm10c = hgtm10c
pcl.hghtm20c = hgtm20c
pcl.hghtm30c = hgtm30c
# Find lowest observation in layer
i = 0
while prof.gSndg[i][prof.pind] > lower:
if i == prof.gNumLevels - 1: break
i += 1
while not QC(prof.gSndg[i][prof.tdind]):
if i == prof.gNumLevels - 1: break
i += 1
lptr = i
if prof.gSndg[i][prof.pind] == lower:
if i != prof.gNumLevels - 1: lptr += 1
# Find highest observation in layer
i = prof.gNumLevels - 1
while prof.gSndg[i][prof.pind] < upper:
if i < lptr: break
i -= 1
uptr = i
if prof.gSndg[i][prof.pind] == upper:
if i > lptr: uptr -= 1
# START WITH INTERPOLATED BOTTOM LAYER
# Begin moist ascent from lifted parcel LCL (pe2, tp2)
pe1 = lower
h1 = interp.hght(pe1, prof)
te1 = interp.vtmp(pe1, prof)
tp1 = thermo.wetlift(pe2, tp2, pe1)
lyre = 0
lyrlast = 0
for i in range(lptr, prof.gNumLevels):
if not QC(prof.gSndg[i][prof.tind]): continue
pe2 = prof.gSndg[i][prof.pind]
h2 = prof.gSndg[i][prof.zind]
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe1, tp1, pe2)
tdef1 = (thermo.virtemp(pe1, tp1, tp1) - te1) / thermo.ctok(te1)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / thermo.ctok(te2)
lyrlast = lyre
lyre = G * (tdef1 + tdef2) / 2. * (h2 - h1)
# Add layer energy to total positive if lyre > 0
if lyre > 0:
totp += lyre
# Add layer energy to total negative if lyre < 0, only up to EL
else:
if pe2 > 500.: totn += lyre
# Check for Max LI
mli = thermo.virtemp(pe2, tp2, tp2) - te2
if mli > li_max:
li_max = mli
li_maxpres = pe2
# Check for Max Cap Strength
mcap = te2 - mli
if mcap > cap_strength:
cap_strength = mcap
cap_strengthpres = pe2
tote += lyre
pelast = pe1
pe1 = pe2
h1 = h2
te1 = te2
tp1 = tp2
# Is this the top of the specified layer
if i >= uptr and not QC(pcl.bplus):
pe3 = pe1
h3 = h1
te3 = te1
tp3 = tp1
lyrf = lyre
if lyrf > 0:
pcl.bplus = totp - lyrf
pcl.bminus = totn
else:
pcl.bplus = totp
if pe2 > 500.: pcl.bminus = totn + lyrf
else: pcl.bminus = totn
pe2 = upper
h2 = interp.hght(pe2, prof)
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.bplus += lyrf
else:
if pe2 > 500.: pcl.bminus += lyrf
if pcl.bplus == 0: pcl.bminus = 0.
# Is this the freezing level
if te2 < 0. and not QC(pcl.bfzl):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.bfzl = totp - lyrf
else: pcl.bfzl = totp
if not QC(p0c) or p0c > pe3:
pcl.bfzl = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgt0c - h3)
if lyrf > 0: pcl.bfzl += lyrf
# Is this the -10C level
if te2 < -10. and not QC(pcl.wm10c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm10c = totp - lyrf
else: pcl.wm10c = totp
if not QC(pm10c) or pm10c > pcl.lclpres:
pcl.wm10c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm10c - h3)
if lyrf > 0: pcl.wm10c += lyrf
# Is this the -20C level
if te2 < -20. and not QC(pcl.wm20c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm20c = totp - lyrf
else: pcl.wm20c = totp
if not QC(pm20c) or pm20c > pcl.lclpres:
pcl.wm20c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm20c - h3)
if lyrf > 0: pcl.wm20c += lyrf
# Is this the -30C level
if te2 < -30. and not QC(pcl.wm30c):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0.: pcl.wm30c = totp - lyrf
else: pcl.wm30c = totp
if not QC(pm30c) or pm30c > pcl.lclpres:
pcl.wm30c = 0
elif QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (hgtm30c - h3)
if lyrf > 0: pcl.wm30c += lyrf
# Is this the 3km level
if pcl.lclhght < 3000.:
h = interp.agl(interp.hght(pe2, prof), prof)
if h >= 3000. and not QC(pcl.b3km):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0: pcl.b3km = totp - lyrf
else: pcl.b3km = totp
h2 = interp.msl(3000., prof)
pe2 = interp.pres(h2, prof)
if QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.b3km += lyrf
else: pcl.b3km = 0.
# Is this the 6km level
if pcl.lclhght < 6000.:
h = interp.agl(interp.hght(pe2, prof), prof)
if h >= 6000. and not QC(pcl.b6km):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
lyrf = lyre
if lyrf > 0: pcl.b6km = totp - lyrf
else: pcl.b6km = totp
h2 = interp.msl(6000., prof)
pe2 = interp.pres(h2, prof)
if QC(pe2):
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
if lyrf > 0: pcl.b6km += lyrf
else: pcl.b6km = 0.
# LFC Possibility
if lyre >= 0. and lyrlast <= 0.:
tp3 = tp1
te3 = te1
pe2 = pe1
pe3 = pelast
while interp.vtmp(pe3, prof) > thermo.virtemp(
pe3, thermo.wetlift(pe2, tp3, pe3),
thermo.wetlift(pe2, tp3, pe3)):
pe3 -= 5
pcl.lfcpres = pe3
pcl.lfchght = interp.agl(interp.hght(pe3, prof), prof)
cinh_old = totn
tote = 0.
pcl.elpres = RMISSD
li_max = RMISSD
if cap_strength < 0.: cap_strength = 0.
pcl.cap = cap_strength
pcl.cappres = cap_strengthpres
# Hack to force LFC to be at least at the LCL
if pcl.lfcpres > pcl.lclpres:
pcl.lfcpres = pcl.lclpres
pcl.lfchght = pcl.lclhght
# EL Possibility
if lyre <= 0. and lyrlast >= 0.:
tp3 = tp1
te3 = te1
pe2 = pe1
pe3 = pelast
while interp.vtmp(pe3, prof) < thermo.virtemp(
pe3, thermo.wetlift(pe2, tp3, pe3),
thermo.wetlift(pe2, tp3, pe3)):
pe3 -= 5
pcl.elpres = pe3
pcl.elhght = interp.agl(interp.hght(pe3, prof), prof)
pcl.mplpres = RMISSD
pcl.limax = -li_max
pcl.limaxpress = li_maxpres
# MPL Possibility
if tote < 0. and not QC(pcl.mplpres) and QC(pcl.elpres):
pe3 = pelast
h3 = interp.hght(pe3, prof)
te3 = interp.vtmp(pe3, prof)
tp3 = thermo.wetlift(pe1, tp1, pe3)
totx = tote - lyre
pe2 = pelast
while totx > 0:
pe2 -= 1
te2 = interp.vtmp(pe2, prof)
tp2 = thermo.wetlift(pe3, tp3, pe2)
h2 = interp.hght(pe2, prof)
tdef3 = (thermo.virtemp(pe3, tp3, tp3) - te3) / \
thermo.ctok(te3)
tdef2 = (thermo.virtemp(pe2, tp2, tp2) - te2) / \
thermo.ctok(te2)
lyrf = G * (tdef3 + tdef2) / 2. * (h2 - h3)
totx += lyrf
tp3 = tp2
te3 = te2
pe3 = pe2
pcl.mplpres = pe2
pcl.mplhght = interp.agl(interp.hght(pe2, prof), prof)
# 500 hPa Lifted Index
if prof.gSndg[i][prof.pind] <= 500. and pcl.li5 == RMISSD:
a = interp.vtmp(500., prof)
b = thermo.wetlift(pe1, tp1, 500.)
pcl.li5 = a - thermo.virtemp(500, b, b)
# 300 hPa Lifted Index
if prof.gSndg[i][prof.pind] <= 300. and pcl.li3 == RMISSD:
a = interp.vtmp(300., prof)
b = thermo.wetlift(pe1, tp1, 300.)
pcl.li3 = a - thermo.virtemp(300, b, b)
# Calculate BRN if available
pcl = bulk_rich(pcl, prof)
pcl.bminus = cinh_old
if pcl.bplus == 0: pcl.bminus = 0.
return pcl
def init_phase(prof):
'''
Inital Precipitation Phase
Adapted from SHARP code donated by Rich Thompson (SPC)
This function determines the initial phase of any precipitation source in the profile.
It does this either by finding a source of precipitation by searching for the highest 50 mb
layer that has a relative humidity greater than 80 percent at the top and the bottom
of the layer. This layer may be found either in the lowest 5 km of the profile, and if
an OMEG profile is specified in the profile object, it will search for the layers with
upward motion.
The precipitation type is determined by using a.) the interpolated temperature in the middle
of the precipitation source layer and b.) set temperature thresholds to determine the
precipitation type. The type may be "Rain", "Freezing Rain", "ZR/S Mix", or "Snow".
Parameters
----------
prof : Profile object (omega profile optional)
Returns
-------
plevel : the pressure level of the precipitation source (mb)
phase : the phase type of the precipitation (int)
phase == 0 for "Rain"
phase == 1 for "Freezing Rain" or "ZR/S Mix"
phase == 3 for "Snow"
tmp : the temperature at the level that is the precipitation source
st : a string naming the precipitation type
'''
# Needs to be tested
plevel = 0
phase = -1
# First, determine whether Upward VVELS are available. If they are,
# use them to determine level where precipitation will develop.
avail = np.ma.where(prof.omeg < .1)[0]
hght_agl = interp.to_agl(prof, prof.hght)
if len(avail) < 5:
# No VVELS...must look for saturated level
# Find the highest near-saturated 50mb layer below 5km agl
below_5km_idx = np.ma.where((hght_agl < 5000.) &\
(hght_agl >= 0))[0]
else:
# Use the VV to find the source of precip.
below_5km_idx = np.ma.where((hght_agl < 5000.) &\
(hght_agl >= 0) &\
(prof.omeg <= 0))[0]
# Compute the RH at the top and bottom of 50 mb layers
rh = thermo.relh(prof.pres, prof.tmpc, prof.dwpc)[below_5km_idx]
sats = np.ma.where(rh > 80)[0]
new_pres = prof.pres[below_5km_idx][sats] + 50.
new_temp = interp.temp(prof, new_pres)
new_dwpt = interp.dwpt(prof, new_pres)
rh_plus50 = thermo.relh(new_pres, new_temp, new_dwpt)
# Find layers where the RH is >80% at the top and bottom
layers_idx = np.ma.where(rh_plus50 > 80)[0]
if len(layers_idx) == 0:
# Found no precipitation source layers
st = "N/A"
return prof.missing, phase, prof.missing, st
# Find the highest layer up via the largest index
top_most_layer = np.ma.max(layers_idx)
plevel = new_pres[top_most_layer] - 25.
# Determine the initial precip type based on the temp in the layer
tmp = interp.temp(prof, plevel)
if tmp > 0:
phase = 0
st = "Rain"
elif tmp <= 0 and tmp > -5:
phase = 1
st = "Freezing Rain"
elif tmp <=-5 and tmp > -9:
phase = 1
st = "ZR/S Mix"
elif tmp <= -9:
phase = 3
st = "Snow"
else:
st = "N/A"
return plevel, phase, tmp, st
def mean_mixratio(prof, lower=-1, upper=-1):
'''
Calculates the mean mixing ratio from a profile object within the
specified layer.
Inputs
------
prof (profile object) Profile Object
lower (float) Bottom level (hPa) [-1=SFC]
upper (float) Top level (hPa) [-1=SFC-100hPa]
Returns
-------
Mean Mixing Ratio (float)
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = prof.gSndg[prof.sfc][prof.pind] - 100.
if not QC(interp.temp(upper, prof)): mmw = RMISSD
if not QC(interp.temp(lower, prof)): prof.gSndg[prof.sfc][prof.pind]
# Find lowest observations in the layer
i = 0
while prof.gSndg[i][prof.pind] > lower: i+=1
while not QC(prof.gSndg[i][prof.tdind]): i+=1
lptr = i
if prof.gSndg[i][prof.pind] == lower: lptr+=1
# Find highest observations in the layer
i = prof.gNumLevels - 1
while prof.gSndg[i][prof.pind] < upper: i-=1
uptr = i
if prof.gSndg[i][prof.pind] == upper: uptr-=1
totd = 0
totp = 0
# Start with interpolated bottom layer
p1 = lower
dp1 = interp.dwpt(p1, prof)
num = 1
# Calculate every level that reports a dew point
for i in range(lptr, uptr+1):
if QC(prof.gSndg[i][prof.tdind]):
dp2 = prof.gSndg[i][prof.tdind]
p2 = prof.gSndg[i][prof.pind]
dpbar = (dp1 + dp2) / 2.
pbar = (p1 + p2) / 2.
totd += dpbar
totp += pbar
dp1 = dp2
p1 = p2
num += 1
# Finish with top layer
dp2 = interp.dwpt(upper, prof)
p2 = upper
dbar = (dp1 + dp2) / 2.
pbar = (p1 + p2) / 2.
totd += dbar
totp += pbar
return thermo.mixratio(totp/num, totd/num)
def unstable_level(prof, lower, upper):
'''
Finds the most unstable level between the lower and upper levels.
Inputs
------
prof (profile object) Profile Object
lower (float) Bottom level (hPa) [-1=SFC]
upper (float) Top level (hPa) [-1=SFC-100hPa]
Returns
-------
Pressure Level of most unstable level (float [hPa])
'''
if lower == -1: lower = prof.gSndg[prof.sfc][prof.pind]
if upper == -1: upper = prof.gSndg[prof.sfc][prof.pind] - 400.
# Make sure this is a valid layer
while not QC(interp.dwpt(upper, prof)): upper += 50.
if not QC(interp.temp(lower, prof)): lower = prof.gSndg[prof.sfc][0]
# Find lowest observations in the layer
i = 0
while prof.gSndg[i][prof.pind] > lower: i+=1
while not QC(prof.gSndg[i][prof.tind]): i+=1
lptr = i
if prof.gSndg[i][prof.pind] == lower: lptr+=1
# Find highest observations in the layer
i = prof.gNumLevels - 1
while prof.gSndg[i][prof.pind] < upper: i-=1
uptr = i
if prof.gSndg[i][prof.pind] == upper: uptr-=1
# Start with interpolated bottom layer
p1 = lower
t1 = interp.temp(p1, prof)
td1 = interp.dwpt(p1, prof)
p2, t2 = thermo.drylift(p1, t1, td1)
tmax = thermo.wetlift(p2, t2, 1000.)
pmax = p1
# Calculate every level that reports a dew point
for i in range(lptr, uptr+1):
if QC(prof.gSndg[i][prof.tdind]):
p1 = prof.gSndg[i][prof.pind]
t1 = prof.gSndg[i][prof.tind]
td1 = prof.gSndg[i][prof.tdind]
p2, t2 = thermo.drylift(p1, t1, td1)
t1 = thermo.wetlift(p2, t2, 1000.)
if t1 > tmax:
tmax = t1
pmax = p1
# Finish with interpolated top layer
p1 = upper
t1 = interp.temp(p1, prof)
td1 = interp.dwpt(p1, prof)
p2, t2 = thermo.drylift(p1, t1, td1)
t1 = thermo.wetlift(p2, t2, 1000.)
if t1 > tmax:
pmax = prof.gSndg[i][prof.pind]
return pmax
def posneg_wetbulb(prof, start=-1):
'''
Positive/Negative Wetbulb profile
Adapted from SHARP code donated by Rich Thompson (SPC)
Description:
This routine calculates the positive (above 0 C) and negative (below 0 C)
areas of the wet bulb profile starting from a specified pressure (start).
If the specified pressure is not given, this routine calls init_phase()
to obtain the pressure level the precipitation expected to fall begins at.
This is an routine considers the wet-bulb profile instead of the temperature profile
in case the profile beneath the profile beneath the falling precipitation becomes saturated.
Parameters
----------
prof : Profile object
start : the pressure level the precpitation originates from (found by calling init_phase())
Returns
-------
pos : the positive area (> 0 C) of the wet-bulb profile in J/kg
neg : the negative area (< 0 C) of the wet-bulb profile in J/kg
top : the top of the precipitation layer pressure in mb
bot : the bottom of the precipitation layer pressure in mb
'''
# Needs to be tested
# If there is no sounding, don't compute anything
if utils.QC(interp.temp(prof, 500)) == False and utils.QC(interp.temp(prof, 850)) == False:
return np.ma.masked, np.ma.masked, np.ma.masked, np.ma.masked
# Find lowest obs in layer
lower = prof.pres[prof.get_sfc()]
lptr = prof.get_sfc()
# Find the highest obs in the layer
if start == -1:
lvl, phase, st = init_phase(prof)
if lvl > 0:
upper = lvl
else:
upper = 500.
else:
upper = start
# Find the level where the pressure is just greater than the upper pressure
idxs = np.where(prof.pres > upper)[0]
if len(idxs) == 0:
uptr = 0
else:
uptr = idxs[-1]
# Start with the upper layer
pe1 = upper;
h1 = interp.hght(prof, pe1);
te1 = thermo.wetbulb(pe1, interp.temp(prof, pe1), interp.dwpt(prof, pe1))
tp1 = 0
warmlayer = coldlayer = lyre = totp = totn = tote = ptop = pbot = lyrlast = 0
for i in np.arange(uptr, lptr-1, -1):
pe2 = prof.pres[i]
h2 = prof.hght[i]
te2 = thermo.wetbulb(pe2, interp.temp(prof, pe2), interp.dwpt(prof, pe2))
tp2 = 0
tdef1 = (0 - te1) / thermo.ctok(te1);
tdef2 = (0 - te2) / thermo.ctok(te2);
lyrlast = lyre;
lyre = 9.8 * (tdef1 + tdef2) / 2.0 * (h2 - h1);
# Has a warm layer been found yet?
if te2 > 0:
if warmlayer == 0:
warmlayer = 1
ptop = pe2
# Has a cold layer been found yet?
if te2 < 0:
if warmlayer == 1 and coldlayer == 0:
coldlayer = 1
pbot = pe2
if warmlayer > 0:
if lyre > 0:
totp += lyre
else:
totn += lyre
tote += lyre
pelast = pe1
pe1 = pe2
h1 = h2
te1 = te2
tp1 = tp2
if warmlayer == 1 and coldlayer == 1:
pos = totp
neg = totn
top = ptop
bot = pbot
else:
neg = 0
pos = 0
bot = 0
top = 0
return pos, neg, top, bot
def posneg_wetbulb(prof, start=-1):
'''
Positive/Negative Wetbulb profile
Adapted from SHARP code donated by Rich Thompson (SPC)
Description:
This routine calculates the positive (above 0 C) and negative (below 0 C)
areas of the wet bulb profile starting from a specified pressure (start).
If the specified pressure is not given, this routine calls init_phase()
to obtain the pressure level the precipitation expected to fall begins at.
This is an routine considers the wet-bulb profile instead of the temperature profile
in case the profile beneath the profile beneath the falling precipitation becomes saturated.
Parameters
----------
prof : Profile object
start : the pressure level the precpitation originates from (found by calling init_phase())
Returns
-------
pos : the positive area (> 0 C) of the wet-bulb profile in J/kg
neg : the negative area (< 0 C) of the wet-bulb profile in J/kg
top : the top of the precipitation layer pressure in mb
bot : the bottom of the precipitation layer pressure in mb
'''
# Needs to be tested
# If there is no sounding, don't compute anything
if utils.QC(interp.temp(prof, 500)) == False and utils.QC(
interp.temp(prof, 850)) == False:
return np.masked, np.masked, np.masked, np.masked
# Find lowest obs in layer
lower = prof.pres[prof.get_sfc()]
lptr = prof.get_sfc()
# Find the highest obs in the layer
if start == -1:
lvl, phase, st = init_phase(prof)
if lvl > 0:
upper = lvl
else:
upper = 500.
else:
upper = start
# Find the level where the pressure is just greater than the upper pressure
idxs = np.where(prof.pres > upper)[0]
if len(idxs) == 0:
uptr = 0
else:
uptr = idxs[-1]
# Start with the upper layer
pe1 = upper
h1 = interp.hght(prof, pe1)
te1 = thermo.wetbulb(pe1, interp.temp(prof, pe1), interp.dwpt(prof, pe1))
tp1 = 0
warmlayer = coldlayer = lyre = totp = totn = tote = ptop = pbot = lyrlast = 0
for i in np.arange(uptr, lptr - 1, -1):
pe2 = prof.pres[i]
h2 = prof.hght[i]
te2 = thermo.wetbulb(pe2, interp.temp(prof, pe2),
interp.dwpt(prof, pe2))
tp2 = 0
tdef1 = (0 - te1) / thermo.ctok(te1)
tdef2 = (0 - te2) / thermo.ctok(te2)
lyrlast = lyre
lyre = 9.8 * (tdef1 + tdef2) / 2.0 * (h2 - h1)
# Has a warm layer been found yet?
if te2 > 0:
if warmlayer == 0:
warmlayer = 1
ptop = pe2
# Has a cold layer been found yet?
if te2 < 0:
if warmlayer == 1 and coldlayer == 0:
coldlayer = 1
pbot = pe2
if warmlayer > 0:
if lyre > 0:
totp += lyre
else:
totn += lyre
tote += lyre
pelast = pe1
pe1 = pe2
h1 = h2
te1 = te2
tp1 = tp2
if warmlayer == 1 and coldlayer == 1:
pos = totp
neg = totn
top = ptop
bot = pbot
else:
neg = 0
pos = 0
bot = 0
top = 0
return pos, neg, top, bot
def init_phase(prof):
'''
Inital Precipitation Phase
Adapted from SHARP code donated by Rich Thompson (SPC)
This function determines the initial phase of any precipitation source in the profile.
It does this either by finding a source of precipitation by searching for the highest 50 mb
layer that has a relative humidity greater than 80 percent at the top and the bottom
of the layer. This layer may be found either in the lowest 5 km of the profile, and if
an OMEG profile is specified in the profile object, it will search for the layers with
upward motion.
The precipitation type is determined by using a.) the interpolated temperature in the middle
of the precipitation source layer and b.) set temperature thresholds to determine the
precipitation type. The type may be "Rain", "Freezing Rain", "ZR/S Mix", or "Snow".
Parameters
----------
prof : Profile object (omega profile optional)
Returns
-------
plevel : the pressure level of the precipitation source (mb)
phase : the phase type of the precipitation (int)
phase == 0 for "Rain"
phase == 1 for "Freezing Rain" or "ZR/S Mix"
phase == 3 for "Snow"
tmp : the temperature at the level that is the precipitation source
st : a string naming the precipitation type
'''
# Needs to be tested
plevel = 0
phase = -1
# First, determine whether Upward VVELS are available. If they are,
# use them to determine level where precipitation will develop.
avail = np.ma.where(prof.omeg < .1)[0]
hght_agl = interp.to_agl(prof, prof.hght)
if len(avail) < 5:
# No VVELS...must look for saturated level
# Find the highest near-saturated 50mb layer below 5km agl
below_5km_idx = np.ma.where((hght_agl < 5000.) &\
(hght_agl >= 0))[0]
else:
# Use the VV to find the source of precip.
below_5km_idx = np.ma.where((hght_agl < 5000.) &\
(hght_agl >= 0) &\
(prof.omeg <= 0))[0]
# Compute the RH at the top and bottom of 50 mb layers
rh = thermo.relh(prof.pres, prof.tmpc, prof.dwpc)[below_5km_idx]
sats = np.ma.where(rh > 80)[0]
new_pres = prof.pres[below_5km_idx][sats] + 50.
new_temp = interp.temp(prof, new_pres)
new_dwpt = interp.dwpt(prof, new_pres)
rh_plus50 = thermo.relh(new_pres, new_temp, new_dwpt)
# Find layers where the RH is >80% at the top and bottom
layers_idx = np.ma.where(rh_plus50 > 80)[0]
if len(layers_idx) == 0:
# Found no precipitation source layers
st = "N/A"
return prof.missing, phase, prof.missing, st
# Find the highest layer up via the largest index
top_most_layer = np.ma.max(layers_idx)
plevel = new_pres[top_most_layer] - 25.
# Determine the initial precip type based on the temp in the layer
tmp = interp.temp(prof, plevel)
if tmp > 0:
phase = 0
st = "Rain"
elif tmp <= 0 and tmp > -5:
phase = 1
st = "Freezing Rain"
elif tmp <= -5 and tmp > -9:
phase = 1
st = "ZR/S Mix"
elif tmp <= -9:
phase = 3
st = "Snow"
else:
st = "N/A"
return plevel, phase, tmp, st
def haines_low(prof):
'''
Haines Index Low Elevation calculation
Calculates the Haines Index(Lower Atmosphere Severity Index)
using the lower elevation parmeters, used below 1000ft or 305 m.
Pressure levels 950 mb and 850 mb
Dewpoint depression at 850 mb
Lapse Rate Term
---------------
1 : < 4C
2 : 4C to 7C
3 : > 7C
Dewpoint Depression Term
------------------------
1 : < 6C
2 : 6C to 9C
3 : > 9C
Adapted from S-591 course
Added by Nickolai Reimer (NWS Billings, MT)
Parameters
----------
prof : profile object
Profile object
Returns
-------
param : number
the Haines Index low
'''
tp1 = interp.temp(prof, 950)
tp2 = interp.temp(prof, 850)
tdp2 = interp.dwpt(prof, 850)
if utils.QC(tp1) and utils.QC(tp2) and utils.QC(tdp2):
lapse_rate = tp1 - tp2
dewpoint_depression = tp2 - tdp2
if lapse_rate < 4:
a = 1
elif 4 <= lapse_rate and lapse_rate <= 7:
a = 2
else:
a = 3
if dewpoint_depression < 6:
b = 1
elif 6 <= dewpoint_depression and dewpoint_depression <= 9:
b = 2
else:
b = 3
return a + b
else:
return constants.MISSING
