Ground subsidence effects on simulating dynamic high-latitude surface inundation under permafrost thaw using CLM5

• Published in: Geoscientific Model Development
• Main Authors: Ekici, Altug, Lee, Hanna, Lawrence, David M., Swenson, Sean C., Prigent, Catherine
• Other Authors: Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU]Sciences of the Universe [physics]; Canada; Ice; permafrost; Thermokarst
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03718067; https://hal-insu.archives-ouvertes.fr/insu-03718067/document; https://hal-insu.archives-ouvertes.fr/insu-03718067/file/gmd-12-5291-2019.pdf; https://doi.org/10.5194/gmd-12-5291-2019

International audience Simulating surface inundation is particularly challenging for the high-latitude permafrost regions. Ice-rich permafrost thaw can create expanding thermokarst lakes as well as shrinking large wetlands. Such processes can have major biogeochemical implications and feedbacks to the climate system by altering the pathways and rates of permafrost carbon release. However, the processes associated with it have not yet been properly represented in Earth system models. We show a new model parameterization that allows direct representation of surface water dynamics in CLM (Community Land Model), the land surface model of several Earth System Models. Specifically, we coupled permafrost-thaw-induced ground subsidence and surface microtopography distribution to represent surface water dynamics in the high latitudes. Our results show increased surface water fractions around western Siberian plains and northeastern territories of Canada. Additionally, localized drainage events correspond well to severe ground subsidence events. Our parameterization is one of the first steps towards a process-oriented representation of surface hydrology, which is crucial to assess the biogeochemical feedbacks between land and the atmosphere under changing climate.