Supervised by:

Christophe Kinnard (Regular Member (Co-researcher))

Research project description

Snow cover heterogeneity and its impact on the Climate and Carbon cycle of Arctic regions (SnowC2)

Introduction

The Canadian Land Surface Scheme including Biogeochemical Cycles (CLASSIC), has limitations, notably the use of a single-layer snow scheme, without an explicit parameterization for the snow cover fraction (SCF) and blowing snow sublimation losses. This affects simulations of snow conditions and runoff in the Arctic and climate projections. Our project aims to enhance understanding and representation of snow heterogeneity in the Arctic for more robust simulations of snow cover conditions, surface energy fluxes, and carbon fluxes under current and future climates. To that purpose, we will develop new parameterizations, consider a multi-layer snow scheme, and blowing snow processes in CLASSIC adapted for Arctic snowpack. Collaboration with French institutes, the European Spatial Agency Snow CCI project, and Environment and Climate Change Canada (ECCC) is part of the effort.

Objectives

The main objective of the project is to improve our understanding of the impact of the spatial heterogeneity of the snow cover on the simulated response of the snow cover and carbon fluxes to climate change in Arctic regions. This main objective will be pursued through three specific objectives: 1. Develop, implement, and assess new snow cover fraction (SCF) parameterizations in the CLASSIC land surface component of the Earth System Model CanESM, using Snow CCI datasets and in-situ stations for calibration/validation, in order to improve the representation of snow cover heterogeneity. 2. Implement a two-layer snow scheme and blowing snow sublimation processes to improve the snowpack evolution in the Arctic region. 3. Assess the influence of these new developments on the Snow CCI variables for different land types, and on the simulated surface energy fluxes and carbon cycle in the Arctic.

Study Sites

An ongoing snow cover monitoring program led by UQTR/CEN will be used along a subarctic-Arctic gradient that encompasses different bioclimatic zones of northeastern Canada (i) Kangiqsualujjuaq (KAN: 58.7° N, -65.9° W; Low Arctic shrub tundra); (ii) Salluit (SAL: 62.1° N, -75.6° W; Mid-Arctic dwarf shrub tundra) (iii) Bylot Island (BYL: 73.2° N, -79.9° W; High-Arctic tundra). The gradient leverages existing infrastructures and ongoing research at the sites: fully equipped automatic weather stations at all sites, research initiated by Prof. C. Kinnard (UQTR) since 2018 at BYL and starting collaborations at SAL and KAN, and the presence of research stations maintained by the Centre for Northern Studies (CEN) at all sites. The in-situ observations at the monitoring sites will serve as a reference and validation points for the Snow CCI data that will be widely used for the development, tuning, and evaluation of the SCF parameterizations and snow schemes described above.

Material and methods

The objective is to enhance the CLASSIC land surface model for better representation of Arctic snow cover. This involves implementing new parameterizations, simulating historical and future snow cover conditions, and addressing limitations in CLASSIC. Specifically, a new snow cover parameterization and a multi-layer snow scheme, including blowing snow sublimation losses, will be added. These enhancements will be tested using satellite-derived data and Snow CCI datasets. Validation will occur at study sites and pan-Arctic scale. The updated model will be evaluated by examining changes in simulated energy and carbon fluxes. CLASSIC will next be forced by ensemble climate projections from CMIP6. Online simulations within CanESM are planned within collaboration with ECCC. This work aims to provide a more accurate representation of snow cover heterogeneity in CLASSIC and improve simulations of snow cover evolution under present and future climate over the whole Arctic region.

Expected results

The project outputs will be: 1. An improved snow scheme in the CLASSIC LSM (including a new SCF parameterization, a multi-layer snowpack representation, and inclusion of blowing snow sublimation losses). 2. A robust assessment of the impact of these new developments on the simulated snow cover, surface energy and carbon fluxes. 3. An improved offline snow cover simulations over the whole Arctic region at a 12.5 km resolution under present and future climates. 4. Optional: online (coupled) simulations within CanESM through future collaboration with Environment and Climate Change Canada.

Research Site Coordinates