Test Case 2: Bomex shallow cumulus

This test case is 3D and does not require the radiation code. This page provides the background information on test case 2 and examples of run of test case 2 on various machines.

Background information (from Jon Petch)

BOMEX was an observational campaign from the early 1970s looking at the heat and moisture transports associated with Trade Wind shallow cumuli. Trade Wind shallow cumuli are an important component of the global heat and moisture budget, as their mixing of heat and moisture in the vertical can help increase evaporation from the subtropical ocean surface. The Trade Winds then transport this moisture to the ITCZ where it fuels the tropical deep convection. Data from BOMEX has been used in several cloud modelling studies to help improve our understanding of shallow convection and, subsequently, representation of shallow convection in GCMs. Examples include Siebesma and Cuijpers (JAS, 1995) and Grant and Brown (QJ, 1999).

This case is based on the LEM resolution tests of Brown (1999). Three external forcings are used: a subsidence centred around 1500m, prescribed radiative cooling of 2K/day, decreasing up to the model top, and a humidity tendency representing the large-scale advective drying in the subcloud layer. The simulation is run in 3-D and for a total of six hours. Profiles averaged over the last four hours of the domain can be compared to the figures shown in Brown (1999).

Profiles averaged over last four hours of BOMEX case.

This case is a good example of the use of the LEM with non-precipitating moist processes.

Files required to run test case 2

The files needed to run this test case can be found in /home/lem/VER2.3/TEST_CASES/TEST2_2.3 and the table below indicates which files you'll need for which machines

	Turing (T3E - no longer available)	Department machines	Origins (i.e. wren, fermat or green)	Newton
run...f	runTEST2_2.3.f	runTEST2_2.3-m.f	runTEST2_2.3.f	runTEST2_2.3.f
end...f	endTEST2_2.3.f	endTEST2_2.3.f	endTEST2_2.3.f	endTEST2_2.3.f
nmlsetup...	nmlsetupTEST2_2.3	nmlsetupTEST2_2.3	nmlsetupTEST2_2.3	nmlsetupTEST2_2.3
nmlchain...	nmlchainTEST2_2.3	nmlchainTEST2_2.3	nmlchainTEST2_2.3	nmlchainTEST2_2.3
model...	modelTEST2_2.3	modelTEST2_2.3	modelTEST2_2.3-n	modelTEST2_2.3-n

Runs for Test Case 2

Computer	Run No	Version	PEs	IIP, JJP, KKP	Time Taken	Results
Newton	130	2.3	8	64, 64, 76	2.35 hrs	Profiles
Origins	30	2.3	8	64, 64, 76	7.25 hrs	Profiles
GRID	54	2.3	1	64, 64, 76	248 hrs (10.4 days)	Profiles
T3E at Met Office	N/A	2.2	8	64, 64, 76	unknown	Profiles
Turing	707	2.2	8	64, 64, 76	unknown	Profiles