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@@ 246-289 (lines=44) @@
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return np.nan * pressure.units, np.nan * temperature.units |
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else: |
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return x[0], y[0] |
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@exporter.export |
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@check_units('[pressure]', '[temperature]', '[temperature]') |
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def el(pressure, temperature, dewpt): |
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r"""Calculate the equilibrium level. |
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This works by finding the last intersection of the ideal parcel path and |
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the measured environmental temperature. If there is one or fewer intersections, there is |
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no equilibrium level. |
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Parameters |
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---------- |
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pressure : `pint.Quantity` |
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The atmospheric pressure |
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temperature : `pint.Quantity` |
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The temperature at the levels given by `pressure` |
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dewpt : `pint.Quantity` |
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The dew point at the levels given by `pressure` |
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Returns |
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------- |
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`pint.Quantity, pint.Quantity` |
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The EL pressure and temperature |
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See Also |
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-------- |
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parcel_profile |
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""" |
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ideal_profile = parcel_profile(pressure, temperature[0], dewpt[0]).to('degC') |
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x, y = find_intersections(pressure[1:], ideal_profile[1:], temperature[1:]) |
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# If there is only one intersection, there are two possibilities: |
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# the dataset does not contain the EL, or the LFC = LCL. |
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if len(x) <= 1: |
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if (ideal_profile[-1] < temperature[-1]) and (len(x) == 1): |
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# Profile top colder than environment with one |
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# intersection, EL exists and LFC = LCL |
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return x[-1], y[-1] |
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else: |
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# The EL does not exist, either due to incomplete data |
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# or no intersection occurring. |
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return np.nan * pressure.units, np.nan * temperature.units |
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else: |
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return x[-1], y[-1] |
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@@ 200-243 (lines=44) @@
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xtol=eps, maxiter=max_iters) |
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lcl_p = units.Quantity(fp, pressure.units) |
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return lcl_p, dewpoint(vapor_pressure(lcl_p, w)) |
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@exporter.export |
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@check_units('[pressure]', '[temperature]', '[temperature]') |
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def lfc(pressure, temperature, dewpt): |
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r"""Calculate the level of free convection (LFC). |
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This works by finding the first intersection of the ideal parcel path and |
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the measured parcel temperature. |
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Parameters |
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---------- |
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pressure : `pint.Quantity` |
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The atmospheric pressure |
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temperature : `pint.Quantity` |
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The temperature at the levels given by `pressure` |
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dewpt : `pint.Quantity` |
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The dew point at the levels given by `pressure` |
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Returns |
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------- |
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`pint.Quantity` |
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The LFC pressure and temperature |
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See Also |
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-------- |
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parcel_profile |
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""" |
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ideal_profile = parcel_profile(pressure, temperature[0], dewpt[0]).to('degC') |
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# The parcel profile and data have the same first data point, so we ignore |
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# that point to get the real first intersection for the LFC calculation. |
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x, y = find_intersections(pressure[1:], ideal_profile[1:], temperature[1:], |
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direction='increasing') |
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# Two possible cases here: LFC = LCL, or LFC doesn't exist |
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if len(x) == 0: |
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if np.any(ideal_profile > temperature): |
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# LFC = LCL |
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x, y = lcl(pressure[0], temperature[0], dewpt[0]) |
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return x, y |
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# LFC doesn't exist |
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else: |
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return np.nan * pressure.units, np.nan * temperature.units |
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else: |
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return x[0], y[0] |
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Unidata /
MetPy
