The daily average shortwave radiation is not conserved if UTC time is used. This can be seen by running 3 test cases:
a benchmark at 10 minute timestep
a 3 hour timestep with local timestamps
a 3 hour timestep with UTC timestamps
Then, for a basin on each the east and west coast I did the following:
Time shifted the UTC timestamp back to local time
Aggregated each of the test cases to mean daily shortwave values
Compared these for a year
The resulting figure is for a west coast US location (UTC -7):
As can be seen the UTC shortwave values do not always line up. The cause for this is during the shortwave radiation disaggregation we use the daily shortwave as calculated via MTCLIM to scale the shifted timeseries. Of course, since the timeseries is shifted, the daily shortwave doesn't always fall on 24 hour boundaries anymore. This leads to these errors. A fix is to reweight the daily shortwave so that the correct amount of shortwave is partitioned throughout the day even when UTC offsets are used.
arbennett
commented
4 years ago
The daily average shortwave radiation is not conserved if UTC time is used. This can be seen by running 3 test cases:
Then, for a basin on each the east and west coast I did the following:
The resulting figure is for a west coast US location (UTC -7):
As can be seen the UTC shortwave values do not always line up. The cause for this is during the shortwave radiation disaggregation we use the daily shortwave as calculated via MTCLIM to scale the shifted timeseries. Of course, since the timeseries is shifted, the daily shortwave doesn't always fall on 24 hour boundaries anymore. This leads to these errors. A fix is to reweight the daily shortwave so that the correct amount of shortwave is partitioned throughout the day even when UTC offsets are used.