loading page

Modelling the impacts of future enhanced winter warming events on subarctic ecosystems using LPJ-GUESS
  • +1
  • Didac Pascual,
  • Margareta Johansson,
  • Jing Tang,
  • Alexandra Pongracz
Didac Pascual
Lund University

Corresponding Author:[email protected]

Author Profile
Margareta Johansson
Lund University
Author Profile
Jing Tang
Lund University
Author Profile
Alexandra Pongracz
Lund University
Author Profile

Abstract

Winter warming events (WWEs) are short-lasting events of unusually warm weather, occasionally combined with rainfall, which can cause severe ecosystem impacts by altering ground temperatures and water fluxes. These impacts are generally overlooked in large-scale ecosystem models. The frequency and intensity of WWEs will likely increase further in the future. We used an ecosystem model, LPJ-GUESS, to investigate the responses of four subarctic ecosystems to different levels of predicted WWEs, and identify model gaps hindering accurate estimates of these responses. In response to WWEs, the model simulated substantial ground cooling (up to 2 °C in winter) in contrast to the observed warming, leading to changes in biogeochemical fluxes often comparable in magnitude to those from altered winter climatologies. The mismatch between the modelled and the observed ground temperature changes may be due to the 1) lacking surface energy balance, 2) daily timestep, and 3) simplistic water retention scheme in LPJ-GUESS.