A new convective adjustment scheme, Pts. I and II
A new convective adjustment scheme is proposed, based on the simultaneous relaxation of temperature and moisture fields towards observed quasi-equilibrium thermodynamic structures, with a relaxation time of order two hours. Separate schemes are used for deep and shallow (non-precipitating) convection.
The schemes are tested using single-column data sets from tropical field experiments (GATE, BOMEX, ATEX) and an arctic air-mass transformation. Preliminary global forecasts show significant improvements in the global surface fluxes and mean tropical temperature tendency over the operational Kuo convection scheme.
This is the ECMWF Technical Report that outlined the Betts-Miller scheme, dated October 1984. It was later published in the QJRMS as Betts (1986) and Betts and Miller (1986)
Betts, A. K. and M. J. Miller, 1984: A new convective adjustment scheme, Pts. I and II. ECMWF Tech. Rep. No. 43. http://www.ecmwf.int/publications/library/ecpublications/_pdf/tr/tr43.pdf ECMWF, Reading, RG2 9AX, England, 68 pp.