LI-COR-Environmental / eddypro-engine

EddyPro Engine
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Potential radiation calculation does not take into account time zone #8

Open erkkar opened 1 year ago

erkkar commented 1 year ago

It seems that the potential radiation calculation in EddyPro does not take into consideration that the time stamps in the raw data might be in UTC but always assumes local (standard) time.

In the FLUXNET output one can see the column SW_IN_POT with calculated potential radiation. With our raw data using UTC timestamps, I was expecting to see the maximum around 10am beacuse our site has UTC+2 time offset (Finland). Instead, the maximum appears at 12 o’clock, which indicates that EddyPro assumes times to be in local time. See image below with results from a few days in July.

image

In the metadata file there is a setting possibly related to this:

[Timing]
acquisition_frequency=10.000
file_duration=30
pc_time_settings=local

The setting pc_time_settings is by default ’local‘ and there is no way it can be changed through the GUI. Changing this manually in the .metadata file did not have any effect on the results.

The relevant source files seem to be src/src_common/potential_radiation.f90 and src/src_common/date_subs.f90.

@geryatejina