Interesting comment that WeeWX uses current temperature only. Perhaps Tom can confirm. Does WeeWX use current temp or the 12 hour average?
MSLP calculations are country specific. In North America 12 hr temperature averages are used. Why? Dr. David Burch author of "The Barometer Handbook" has the best explanatiion: ..*.This 12-hr time average is not an obvious choice. It is also not the result of a mathematical theory, but we can expect that some average is called for. We know the virtual temperature of this virtual air column affects the pressure, and it is reasonable to assume that the the pressure at the base of this column cannot respond instantly to a change in temperature at the top, so we are led to averaging over some time period to reach equilibrium. In other words, the air temperature at the moment is not what we should use to project this pressure down to the sea level, but rather some average of what it has been in the recent past.* For instance, In the UK current temperature is used instead of the average and humidity is excluded as well from the equation. In Germany, it appears that current temperature is used. Hope this helps... On Saturday, June 24, 2023 at 6:59:44 AM UTC-4 Karen K wrote: > The wiki page Barometer, pressure, and altimeter > <https://github.com/weewx/weewx/wiki/Barometer,-pressure,-and-altimeter> > says, > that calculating the barometer value "requires the temperature 12 hours ago > in order to correct for diurnal tide effects." > > In contrary in the weewx.wxxtypes.PressureCooker.barometer() function the > actual temperature is used only. There is no database access. > > Could someone explain, what the reference to temperature 12 hours ago in > the wiki means? > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/5362114b-a040-4ad2-9b79-c8667234992bn%40googlegroups.com.
