airpres is the sea-level pressure correct?

[NicWayand]

airpres is the sea-level pressure correct?

[andywood]

l would use local pressure, which can be pretty different from SLP. But it's possible I've been doing this incorrectly if there's a hardwired/automatic elevational adjustment in the code that I have overlooked. That might be a decent user option if it's not there, btw.

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[wknoben]

I believe Andy is correct. The docs specify airpres should be at measurement height, which is defined as:

the height (above bare ground) where the meteorological variables are specified

• https://summa.readthedocs.io/en/latest/input_output/SUMMA_input/#meteorological-forcing-files
• https://summa.readthedocs.io/en/latest/input_output/SUMMA_input/#forcing_file_measurement_height

There is a conversion function that converts sea level pressure into pressure at a specified elevation, but as far as I can tell that's not used (anymore?) in the rest of the code.

summa/build/source/engine/conv_funcs.f90

Lines 104 to 114 in 3ca07b7

	FUNCTION MSLP2AIRP(MSLP, ELEV)
	IMPLICIT NONE
	real(rkind), INTENT(IN) :: MSLP ! base pressure (Pa)
	real(rkind), INTENT(IN) :: ELEV ! elevation difference from base (m)
	real(rkind) :: MSLP2AIRP ! Air pressure (Pa)
	MSLP2AIRP = MSLP * ( (293.-0.0065*ELEV) / 293. )**5.256
	END FUNCTION MSLP2AIRP

[NicWayand]

Thanks Andy and Wouter!