UKCA Chemistry and Aerosol UMvn13.0 Tutorial 2

UKCA Chemistry and Aerosol Tutorials at UMvn13.0

Difficulty	EASY
Time to Complete	Under 1 hour
Video instructions

Remember to run mosrs-cache-password in your Rose suite and UM branch terminals.

Changing UKCA Box Model Options

This tutorial describes how to change the time settings, meteorological conditions, tracer initialisations, chemistry, and aerosol options in the UKCA Box Model.

Changing the Box Model Time Settings

The time settings for the box model can be found in the ukca $\rightarrow$ namelist $\rightarrow$ Time Settings panel and the ukca $\rightarrow$ namelist $\rightarrow$ Science Settings $\rightarrow$ Chemistry panel. The key variables are:

Panel	Variable	Description	Example
Time Settings	model_basis_time	The nominal start time of the model, defined as YEAR, MONTH, DAY, HOUR, MINUTE, SECOND	1989,09,01,00,00,00 (i.e. midnight on 1st September 1989)
Time Settings	run_target_end	The run length of model, defined as YEARS, MONTHS, DAYS, HOURS, MINUTES, SECONDS	0,0,1,0,0,0 (i.e. 1 day)
Time Settings	steps_per_periodim	The number of "dynamical" timesteps per "period" (a model day, containing the number of seconds given in the secs_per_periodim variable above)	24 (i.e. 1 hour)
Chemistry	chem_timestep	The number of seconds in a chemical timestep. This must be a multiple of the value of steps_per_periodim	3600 (i.e. 1 hour)

Task 2.1: Change the Start Time

TASK 2.1: Change the start time of the model to begin at midday rather than midnight.

Solution
Change the value of model_basis_time to be 1989,09,01,12,00,00

Checklist

☐ List suites using rosie go

☐ Copy suites using the right-click menu

☐ Run suites using the play button

☐ Plot output using gnuplot

Tutorial 2

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Written by Luke Abraham 2022