Add longwave_down to ERA5 variable map

Author: AdamRJensen

pvlib/iotools/era5.py

@@ -12,13 +12,15 @@
     'sp': 'pressure',
     'ssrd': 'ghi',
     'tp': 'precipitation',
+    'strd': 'longwave_down',
 
     # long names
     '2m_dewpoint_temperature': 'temp_dew',
     '2m_temperature': 'temp_air',
     'surface_pressure': 'pressure',
     'surface_solar_radiation_downwards': 'ghi',
     'total_precipitation': 'precipitation',
+    'surface_thermal_radiation_downwards': 'longwave_down',
 }