Model UKMO (HadCM2): Elaborations


Model UKMO (HadCM2) is an entry in both the CMIP1 and CMIP2 intercomparisons, and is providing an optional extended set of output data in compliance with the CMIP2+ initiative.


Starting from Levitus (1982) climatological September values of oceanic potential temperature and salinity, the 510-year spinup was implemented mostly in a fully coupled mode, alternating between relaxation boundary conditions on SST and SSS . Reference SST and SSS climatologies for the relaxation phases were based on Levitus (1982) monthly-mean surface conditions (but with some adjustments made in SSS near Antarctica during Austral winter). Flux adjustments for heat and fresh water, which were calibrated from 5-day mean differences between the modeled and reference SST and SSS averaged over a 25-year run in the preceding relaxation phase, also were applied as prescribed, noninteractive terms. Cf. Johns et al. 1997 for further details.

Land Surface Processes

Sea Ice

Chief Differences from Closest AMIP Model

The atmospheric component of coupled model HadCM2 differs from features of the AMIP model UKMO HadAM1 (2.5x3.75 L19) 1993 in the following respects:


Bryan, K., (1969b) Climate and ocean circulation. III The ocean model. Mon. Wea. Rev., 97: 806-827.

Eagleson, P.S., 1978: Climate, soil and vegetation. Water Resources Res., 14, 705-776.

Gregory, D., and R.N.B. Smith, 1990: Canopy, surface, and soil hydrology. Unified Model Documentation Paper No. 25, United Kingdom Meteorological Office, Bracknell, Berkshire RG12 2SZ, UK.

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Johns. T.C., 1996: A description of the Second Hadley Centre Coupled Model (HadCM2). Climate Research Technical Note 71, Hadley Centre, United Kingdom Meteorological
Office, Bracknell Berkshire RG12 2SY, United Kingdom, 19 pp.

Johns, T.C., R.E. Carnell, J.F. Crossley, J.M. Gregory, J.F.B. Mitchell, C.A. Senior, S.F.B. Tett, and R.A. Wood, 1997: The second Hadley Centre coupled ocean-atmosphere GCM: Model description, spinup and validation. Climate Dyn., 13, 103-134.

Ledley, T.S.,  (1985) Sea ice: multiyear cycles and white ice. J. Geophy. Res., 90, 5676-5686.

Levitus, S., 1982: Climatological atlas of the world's oceans. NOAA Professional Paper 13, 173 pp.

Monteith, J.L., 1965: Evaporation and environment. Symp. Soc. Exptl. Biol., 19, 205-234.

Semtner, A.J., 1976: A model for the thermodynamic growth of sea ice in numerical investigations of climate.  J. Phys. Oceanogr., 6, 379-389.

Shuttleworth, W.J., 1988: Macrohydrology: The new challenge for process hydrology. J. Hydrol., 100, 31-56.

Smith, R.N.B., 1990b: Subsurface, surface, and boundary layer processes. Unified Model Documentation Paper No. 24, United Kingdom Meteorological Office, Bracknell, Berkshire RG12 2SZ, UK.

Warrilow, D.A., A.B. Sangster, and A. Slingo, 1986: Modelling of land surface processes and their influence on European climate. DCTN 38, Dynamical Climatology Branch, United Kingdom Meteorological Office, Bracknell, Berkshire RG12 2SZ, UK.


CMIP Documentation Directory


Last update 15 May, 2002.  This page is maintained by Tom Phillips (

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