The climate system is complex, and models are critical tools for advancing our understanding of this system, allowing us to project outcomes and impacts. Developing ice sheet models allows us to consider the future by building different dynamic representations of how the ice sheet might behave given certain conditions or inputs. Models are built on inputs/data, and the data collected from the many separate parts of the Snow on Ice project will contribute to updates to both large scale and regional models.
The project uses a pair of models in order to examine a high resolution look at southwest Greenland through a ‘catchment’ model of the Kangerlussuaq area, and then build to the large scale structure of the full ice sheet. We start by focusing on the southwestern section of the Greenland Ice Sheet, the area of our fieldwork, and where we see the most notable change. This region appears both today, and historically, to be the most susceptible to climate warming. Applying the data collected from our field campaigns, we will use the VarGlaS model (Variational Glacial Simulator) to build new reconstructions for the southwestern Greenland Ice Sheet.. The image to the left shows the VarGlaS model output for the retreat of the Iunguata Sermia (left) and Russell (right) glaciers from southwestern Greenland. This region is one of three focus regions in the study and the high resolution modeling experiments allows a direct comparison of the model outputs to the geological ice sheet reconstruction.
Expanding outward from southwestern Greenland we update the Ice Sheet System Model (ISSM), a Greenland Ice Sheet full scale model. ISSM was designed to model the evolution of both of the polar ice caps. In Snow on Ice we will use it to model the Greenland Ice Sheet for the past 8000 years, the climate interval of most interest to this project (see model videos). Data collected through the project research is being used to provide inputs for a complete ice sheet reconstruction of this period, expanding both across the ice sheet and through time. ISSM produces results for ice velocity, ice sheet surface height, ice mass flux along the coastline and ice margin position for areas that are currently unknown. In addition ice sheet sensitivities to the impact of changes in temperature and precipitation on the ice sheet shape, volume and mass flux into the ocean will be computed for this same time period.
New and exciting resources are being developed with ISSM including interactivity that allows the user to explore how models can be used to visualize data. We are feeding our data into these visualizations to better show the links between sea ice, precipitation and changes in the ice sheet.
Some early iterations of the regional and wider Greenland model can be seen on the video page.