JULES-Peat modifies the peatland scheme in the Joint UK Land Environment Simulator (JULES), the land surface component of the UK Earth System Model. In particular, JULES-Peat changes the vegetation litter composition and the dependence of peat decay on soil moisture.

The modifications are informed by field measurements and comparing the simulated peat accumulation and loss over 20,000 years with peat core records, including the “Ghost Interval” period when reduced precipitation starting ~5,000 years before present resulted in significant peat loss. JULES-Peat is driven with a reconstruction of precipitation from peat core proxy data and other meteorological data from a global palaeoclimate model.

The original JULES peatland scheme was unable to accumulate the observed quantities of peat or simulate the losses of peat suggested by palaeo records. This updated version of JULES simulates peat increases until 3,000 BP, when reduced precipitation results in substantial loss until 1,000 BP.

The JULES-Peat code is available on the Met Office Science Repository Service (requires registration for an account): https://code.metoffice.gov.uk/trac/jules/browser/main/branches/dev/eleanorburke/vn6.2_accumulate_soil