Application of a new statistically rigorous comparison tool of observed and modelled flow directions of the last British-Irish ice sheet over time

Past ice flow direction can be inferred through mapping of subglacial lineations (e.g. drumlins and mega-scale glacial lineations). A numerical ice sheet model can also be used to reconstruct possible ice flow directions according to ice physics. These two methods are rarely integrated to see if the model can explain the observational data. Previous model-data comparison workflows made a large step forward. However, they lack statistical rigour and certain capabilities, such as comparing an ensemble of model simulations. To overcome these challenges, we created the Likelihood of Accordant Lineations Analysis (LALA) tool.  LALA is a tool to compare numerical model ice sheet simulations to observational data of past flow direction. LALA was created to take a step forward in improving model-data comparisons; making comparisons statistically rigorous and adding the ability to directly grade multiple simulations against each other, a feature that was missing from previous tools. For this poster, we show an example of the tool in action and use LALA to compare model simulations of the British-Irish ice sheet and observations of flow direction from subglacial lineations taken from the BRITICE-CHRONO project. We present the best and the worst fitting simulations according to LALA. We also dissect the score produced to give an indication of the flow directions which are most (and least) regularly matched by the numerical modelling. These results highlight opportunities for model development and the potential to reevaluate observations.