Pancake sea ice floes in the marginal ice zone
Research
I am broadly interested in Earth's climate system, with a focus on the polar regions. My research aims to better understand the physics of coupled interactions between ice and climate. I typically work with climate models of varying levels of complexity, in combination with observations, aiming to improve climate projections. My specific interests include:
Marginal ice zone physics
The marginal ice zone is a dynamic region between dense interior sea ice and the open ocean. I previously developed a model for the sea ice floe size distribution that allowed interactions between sea ice and ocean surface waves to be represented in climate models for the first time. I am interested in further investigating the complex interactions between ocean surface waves and sea ice in this region, which may lead to enhanced melting and retreat of sea ice in a warming climate.
Related publications: Roach, Horvat et al. (2018), Roach, Bitz et al. (2019)
Historical and future sea ice change
The latest climate models suggest that the Arctic will become practically sea-ice-free before 2050. Future changes in Antarctic sea ice are much more uncertain, as models differ from satellite observations over the recent historical period where observations are available. I have led efforts evaluating Antarctic sea ice in climate models compared to observations. Recent work nudging winds towards values from reanalysis reveals successes and biases in the simulation of historical Arctic and Antarctic sea ice.
Related publications: Roach, Dean et al. (2018), Roach, Doerr et al. (2020), Blanchard-Wrigglesworth, Roach et al. (2021), Roach and Blanchard-Wrigglesworth (2022)
September Arctic sea ice in CMIP6 climate models
The Ross Ice Shelf, Antarctica, 2017
Ice sheet-climate coupling
Freshwater from the melt of ice sheets on Greenland and Antarctica is a key contributor to sea level rise and impacts global ocean circulation. I am working on validating and testing a coupled ice sheet configuration for the NASA GISS climate model.
Fundamental drivers of sea ice seasonality
The time taken for sea ice to retreat from its maximum area to its minimum area each year is significantly longer in the Arctic than the Antarctic. Our recent work using an idealized climate model shows that the explanation for the fast seasonal retreat of Antarctic sea may be simpler than previously thought.
Related publications: Roach et al. (2022)
Arctic vs Antarctic [source]
Drone operations on the PIPERS cruise
Integrating observations and models
I am interested in integrating observations with models to better understand and predict polar change. I have been fortunate to participate in fieldwork in the Arctic and Antarctic, both great learning experiences that led to new collaborations.
Related publications: Roach, Smith et al. (2018), Ackley et al. (2020)
