Merge pull request #3056 from 23ccozad/thermo-profile-nans

Adjust user-provided parcel temperature profile for NaN values in EL and LFC

src/metpy/calc/thermo.py

@@ -667,12 +667,15 @@ def lfc(pressure, temperature, dewpoint, parcel_temperature_profile=None, dewpoi
        Renamed ``dewpt``,``dewpoint_start`` parameters to ``dewpoint``, ``dewpoint_start``
 
     """
-    pressure, temperature, dewpoint = _remove_nans(pressure, temperature, dewpoint)
     # Default to surface parcel if no profile or starting pressure level is given
     if parcel_temperature_profile is None:
-        new_stuff = parcel_profile_with_lcl(pressure, temperature, dewpoint)
-        pressure, temperature, dewpoint, parcel_temperature_profile = new_stuff
+        pressure, temperature, dewpoint = _remove_nans(pressure, temperature, dewpoint)
+        new_profile = parcel_profile_with_lcl(pressure, temperature, dewpoint)
+        pressure, temperature, dewpoint, parcel_temperature_profile = new_profile
         parcel_temperature_profile = parcel_temperature_profile.to(temperature.units)
+    else:
+        new_profile = _remove_nans(pressure, temperature, dewpoint, parcel_temperature_profile)
+        pressure, temperature, dewpoint, parcel_temperature_profile = new_profile
 
     if dewpoint_start is None:
         dewpoint_start = dewpoint[0]
@@ -878,12 +881,15 @@ def el(pressure, temperature, dewpoint, parcel_temperature_profile=None, which='
        Renamed ``dewpt`` parameter to ``dewpoint``
 
     """
-    pressure, temperature, dewpoint = _remove_nans(pressure, temperature, dewpoint)
     # Default to surface parcel if no profile or starting pressure level is given
     if parcel_temperature_profile is None:
-        new_stuff = parcel_profile_with_lcl(pressure, temperature, dewpoint)
-        pressure, temperature, dewpoint, parcel_temperature_profile = new_stuff
+        pressure, temperature, dewpoint = _remove_nans(pressure, temperature, dewpoint)
+        new_profile = parcel_profile_with_lcl(pressure, temperature, dewpoint)
+        pressure, temperature, dewpoint, parcel_temperature_profile = new_profile
         parcel_temperature_profile = parcel_temperature_profile.to(temperature.units)
+    else:
+        new_profile = _remove_nans(pressure, temperature, dewpoint, parcel_temperature_profile)
+        pressure, temperature, dewpoint, parcel_temperature_profile = new_profile
 
     # If the top of the sounding parcel is warmer than the environment, there is no EL
     if parcel_temperature_profile[-1] > temperature[-1]:

tests/calc/test_thermo.py

@@ -663,6 +663,27 @@ def test_lfc_equals_lcl():
     assert_almost_equal(lfc_temp, 15.8714 * units.celsius, 2)
 
 
+def test_lfc_profile_nan():
+    """Test LFC when the profile includes NaN values."""
+    levels = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar
+    temperatures = np.array([22.2, 14.6, np.nan, 9.4, 7., -38.]) * units.degC
+    dewpoints = np.array([19., -11.2, -10.8, -10.4, np.nan, -53.2]) * units.degC
+    lfc_pressure, lfc_temperature = lfc(levels, temperatures, dewpoints)
+    assert_almost_equal(lfc_pressure, 727.3365 * units.mbar, 3)
+    assert_almost_equal(lfc_temperature, 9.6977 * units.degC, 3)
+
+
+def test_lfc_profile_nan_with_parcel_profile():
+    """Test LFC when the profile includes NaN values, and parcel temp profile is specified."""
+    levels = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar
+    temperatures = np.array([22.2, 14.6, np.nan, 9.4, 7., -38.]) * units.degC
+    dewpoints = np.array([19., -11.2, -10.8, -10.4, np.nan, -53.2]) * units.degC
+    parcel_temps = parcel_profile(levels, temperatures[0], dewpoints[0]).to('degC')
+    lfc_pressure, lfc_temperature = lfc(levels, temperatures, dewpoints, parcel_temps)
+    assert_almost_equal(lfc_pressure, 727.3365 * units.mbar, 3)
+    assert_almost_equal(lfc_temperature, 9.6977 * units.degC, 3)
+
+
 def test_sensitive_sounding():
     """Test quantities for a sensitive sounding (#902)."""
     # This sounding has a very small positive area in the low level. It's only captured
@@ -987,6 +1008,27 @@ def test_el_below_lcl():
     assert_nan(el_t, t.units)
 
 
+def test_el_profile_nan():
+    """Test EL when the profile includes NaN values."""
+    levels = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar
+    temperatures = np.array([22.2, 14.6, np.nan, 9.4, 7., -38.]) * units.degC
+    dewpoints = np.array([19., -11.2, -10.8, -10.4, np.nan, -53.2]) * units.degC
+    el_pressure, el_temperature = el(levels, temperatures, dewpoints)
+    assert_almost_equal(el_pressure, 673.0104 * units.mbar, 3)
+    assert_almost_equal(el_temperature, 5.8853 * units.degC, 3)
+
+
+def test_el_profile_nan_with_parcel_profile():
+    """Test EL when the profile includes NaN values, and a parcel temp profile is specified."""
+    levels = np.array([959., 779.2, 751.3, 724.3, 700., 269.]) * units.mbar
+    temperatures = np.array([22.2, 14.6, np.nan, 9.4, 7., -38.]) * units.degC
+    dewpoints = np.array([19., -11.2, -10.8, -10.4, np.nan, -53.2]) * units.degC
+    parcel_temps = parcel_profile(levels, temperatures[0], dewpoints[0]).to('degC')
+    el_pressure, el_temperature = el(levels, temperatures, dewpoints, parcel_temps)
+    assert_almost_equal(el_pressure, 673.0104 * units.mbar, 3)
+    assert_almost_equal(el_temperature, 5.8853 * units.degC, 3)
+
+
 def test_wet_psychrometric_vapor_pressure():
     """Test calculation of vapor pressure from wet and dry bulb temperatures."""
     p = 1013.25 * units.mbar