heat_index_nws

ncl/ncl_entries/meteorology.ipynb

@@ -17,6 +17,7 @@
     "\n",
     "- [dewtemp_trh](https://www.ncl.ucar.edu/Document/Functions/Built-in/dewtemp_trh.shtml)\n",
     "- [daylight_fao56](https://www.ncl.ucar.edu/Document/Functions/Crop/daylight_fao56.shtml)\n",
+    "- [heat_index_nws](https://www.ncl.ucar.edu/Document/Functions/Contributed/heat_index_nws.shtml)"
     "- [satvpr_temp_fao56](https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_temp_fao56.shtml)\n",
     "- [satvpr_tdew_fao56](https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_tdew_fao56.shtml)\n",
     "- [satvpr_slope_fao56](https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_slope_fao56.shtml)"
@@ -139,6 +140,15 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
+    "## heat_index_nws\n",
+    "\n",
+    "NCL's `heat_index_nws` computes the heat index as calculated by the National Weather Service{footcite}`nws_heat_index`\n",
+    "\n",
+    "Default coefficients when temperature if greater 80°F and relative humidity is greater than 40%\n",
+    "\n",
+    "Alternate coefficients when temperature is between 70°F and 115°F and relative humidity less than 80%\n",
+    "\n",
+    "The equation for the heat index to match the NOAA National Weather Service table is derived from regression analysis, so the default coefficients have a degree of error up to ±1.3°F{footcite}`rothfusz_heat_index`"
     "## satvpr_temp_fao56\n",
     "\n",
     "NCL's `satvpr_temp_fao56` calculates saturation vapor pressure using temperature as described in the Food and Agriculture Organization (FAO) Irrigation and Drainage Paper 56 [(Chapter 3, Equation 11)](https://www.fao.org/4/x0490e/x0490e07.htm) {footcite}`allan_fao_1998`.\n",
@@ -157,6 +167,28 @@
   },
   {
    "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "array([85.3104587])"
+      ]
+     },
+     "execution_count": 9,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# Input: Single Value\n",
+    "from geocat.comp import heat_index\n",
+    "\n",
+    "temp = 85  # Degrees Fahrenheit\n",
+    "rh = 45  # %\n",
+    "\n",
+    "heat_index(temp, rh)"
    "execution_count": null,
    "metadata": {},
    "outputs": [],
@@ -253,6 +285,28 @@
   },
   {
    "cell_type": "code",
+   "execution_count": 10,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "array([137.36135724, 135.8679973 ,  85.3104587 ])"
+      ]
+     },
+     "execution_count": 10,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# Input: List/Array\n",
+    "from geocat.comp import heat_index\n",
+    "\n",
+    "temps = [104, 100, 85]  # Degrees Fahrenheit\n",
+    "rhs = [55, 65, 45]  # %\n",
+    "\n",
+    "heat_index(temps, rhs)"
    "execution_count": null,
    "metadata": {},
    "outputs": [],
@@ -279,6 +333,7 @@
     "## Python Resources\n",
     "- [GeoCAT-comp `dewtemp` documentation](https://geocat-comp.readthedocs.io/en/latest/user_api/generated/geocat.comp.meteorology.dewtemp.html)\n",
     "- [Convert between different temperature scales in SciPy](https://docs.scipy.org/doc/scipy/reference/generated/scipy.constants.convert_temperature.html)\n",
+    "- [GeoCAT-comp `heat_index` documentation](https://geocat-comp.readthedocs.io/en/stable/user_api/generated/geocat.comp.meteorology.heat_index.html)\n",
     "- [GeoCAT-comp `max_daylight` Documentation](https://geocat-comp.readthedocs.io/en/latest/user_api/generated/geocat.comp.meteorology.max_daylight.html)\n",
     "- [GeoCAT-comp `saturation_vapor_pressure` Documentation](https://geocat-comp.readthedocs.io/en/latest/user_api/generated/geocat.comp.meteorology.saturation_vapor_pressure.html)\n",
     "- [GeoCAT-comp `actual_saturation_vapor_pressure` Documentation](https://geocat-comp.readthedocs.io/en/latest/user_api/generated/geocat.comp.meteorology.actual_saturation_vapor_pressure.html)\n",

ncl/ncl_index/ncl-index-table.csv

@@ -45,8 +45,9 @@ NCL Function,Description,Python Equivalent,Notes
 `round <https://www.ncl.ucar.edu/Document/Functions/Built-in/round.shtml>`__,"Rounds a float or double variable to the nearest whole number","``round()`` or ``numpy.round()``",`example notebook <../ncl_entries/general_applied_math.ipynb#decimalplaces-round>`__
 `daylight_fao56 <https://www.ncl.ucar.edu/Document/Functions/Crop/daylight_fao56.shtml>`__," Compute maximum number of daylight hours as described in FAO 56","``geocat.comp.meteorology.max_daylight()``",`example notebook <../ncl_entries/meteorology.ipynb#daylight-fao56>`__
 `dewtemp_trh <https://www.ncl.ucar.edu/Document/Functions/Built-in/dewtemp_trh.shtml>`__,"Calculates the dew point temperature given temperature and relative humidity","``geocat.comp.dewtemp()``",`example notebook <../ncl_entries/meteorology.ipynb#dewtemp-trh>`__
+`heat_index_nws <https://www.ncl.ucar.edu/Document/Functions/Contributed/heat_index_nws.shtml>`__,"Compute the 'heat index' as calculated by the National Weather Service","``geocat.comp.heat_index()``",`example notebook <../ncl_entries/meteorology.ipynb#heat-index-nws>`__
 `area_poly_sphere <https://www.ncl.ucar.edu/Document/Functions/Built-in/area_poly_sphere.shtml>`__,"Calculates the area enclosed by an arbitrary polygon on the sphere","``pyproj.Geod()`` and ``shapely.geometry.polygon.Polygon()``",`example notebook <../ncl_entries/great_circle.ipynb#area-poly-sphere>`__
 `css2c <https://www.ncl.ucar.edu/Document/Functions/Built-in/css2c.shtml>`__,"Converts spherical coordinates (lat/lon) to Cartesian coordinates on a unit sphere","``astropy.UnitSphericalRepresentation()``",`example notebook <../ncl_entries/great_circle.ipynb#css2c>`__
 `satvpr_temp_fao56 <https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_temp_fao56.shtml>`__,"Compute saturation vapor pressure using temperature as described in FAO 56","``geocat.comp.saturation_vapor_pressure()``",`example notebook <../ncl_entries/meteorology.ipynb#satvpr-temp-fao56>`__
 `satvpr_tdew_fao56 <https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_tdew_fao56.shtml>`__,"Compute actual saturation vapor pressure as described in FAO 56","``geocat.comp.actual_saturation_vapor_pressure()``",`example notebook <../ncl_entries/meteorology.ipynb#satvpr-tdew-fao56>`__
-`satvpr_slope_fao56 <https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_slope_fao56.shtml>`__," Compute the slope of the saturation vapor pressure curve as described in FAO 56","``geocat.comp.saturation_vapor_pressure_slope()``",`example notebook <../ncl_entries/meteorology.ipynb#satvpr-slope-fao56>`__
+`satvpr_slope_fao56 <https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_slope_fao56.shtml>`__," Compute the slope of the saturation vapor pressure curve as described in FAO 56","``geocat.comp.saturation_vapor_pressure_slope()``",`example notebook <../ncl_entries/meteorology.ipynb#satvpr-slope-fao56>`__

ncl/ncl_raw/meteorology.ncl

@@ -1,3 +1,18 @@
+; dewtemp_trh
+; Adapted from https://www.ncl.ucar.edu/Document/Functions/Built-in/dewtemp_trh.shtml
+
+; ncl -n dewtemp_trh.ncl >> dewtemp_trh_output.txt
+
+print("Temperature (K), Relative Humidity (%), Dew Temperature (C)")
+do tk=273,374
+	do rh=1,100
+		begin
+		dewtemp = dewtemp_trh(tk,rh)-273.15
+		print (tk +","+ rh +","+ dewtemp)
+		end
+	end do
+end do
+
 ; daylight_fao56
 ; Adapted from https://www.ncl.ucar.edu/Document/Functions/Crop/daylight_fao56.shtml
 
@@ -13,20 +28,17 @@ do doy=0,365
 	end do
 end do
 
-; dewtemp_trh
-; Adapted from https://www.ncl.ucar.edu/Document/Functions/Built-in/dewtemp_trh.shtml
+; heat_index_nws
+; https://www.ncl.ucar.edu/Document/Functions/Contributed/heat_index_nws.shtml
 
-; ncl -n dewtemp_trh.ncl >> dewtemp_trh_output.txt
+; ncl -n heat_index_nws.ncl >> heat_index_nws_output.txt
 
-print("Temperature (K), Relative Humidity (%), Dew Temperature (C)")
-do tk=273,374
+print("Temperature (F), Relative Humidity (%), Alternate Coefs (True/False), Heat Index (F)")
+do tf=0, 115
 	do rh=1,100
 		begin
-		dewtemp = dewtemp_trh(tk,rh)-273.15
-		print (tk +","+ rh +","+ dewtemp)
-		end
-	end do
-end do
+		heatindex = heat_index_nws(tf,rh,(/2,2/), False)
+		print (tf +","+ rh +"," + "0" + "," + heatindex)
 
 ; satvpr_temp_fao56
 ; Adapted from https://www.ncl.ucar.edu/Document/Functions/Crop/satvpr_temp_fao56.shtml

ncl/receipts/heat_index_nws.ncl

@@ -0,0 +1,18 @@
+print("Temperature (F), Relative Humidity (%), Alternate Coefs (True/False), Heat Index (F)")
+do tf=0, 115
+	do rh=1,100
+		begin
+		heatindex = heat_index_nws(tf,rh,(/2,2/), False)
+		print (tf +","+ rh +"," + "0" + "," + heatindex)
+		end
+	end do
+end do
+
+do tf=0,115
+	do rh=1,100
+		begin
+		heatindex = heat_index_nws(tf,rh,(/2,2/), True)
+		print (tf +","+ rh +"," + "1" + "," + heatindex)
+		end
+	end do
+end do