Dr Edmund Ryan

Senior Research Associate

Research Overview

Ed's broad research interest is how applied mathematics and statistics can be used together to solve critical environmental problems. His current work at the Lancaster Environment Centre is to understand better, and quantify the uncertainties of, the key parameters and processes in current numerical models of atmospheric chemistry and transport. This will lead to a better grasp of the uncertainty in important model outputs such as tropospheric ozone levels and methane lifetime, and will help to explain differences in these outputs between different models. To achieve these goals, he is using cutting edge methods of: (i) statistical emulation, (ii) sensitivity analysis, (iii) structural uncertainty estimation and, (iv) parameter estimation, such as Generalised Linear Uncertainty Estimation and calibration-emulation techniques.

Ed's previous post-doc at Arizona State University in the US used field data, models, and hierarchical Bayesian statistics to improve our understanding of how and why multi-annual rates of photosynethesis and soil respiration will change under a future climate of elevated CO2 and warming. He also built a novel model of soil CO2 production and transport at multiple depths and times to test commonly adopted steady-state assumptions, under different environmental and meteorological conditions.

Fast sensitivity analysis methods for computationally expensive models with multidimensional output
Ryan, E., Wild, O., O'Connor, F., Voulgarakis, A., Lee, L. 13/11/2017 In: Geoscientific Model Development.
Journal article

Modelling soil CO2 production and transport with dynamic source and diffusion terms: Testing the steady-state assumption using DETECT v1.0
Ryan, E., Ogle, K., Kropp, H., Samuels-Crow, K., Carrillo, Y., Pendall, E. 10/10/2017 In: Geoscientific Model Development.
Journal article

Challenging terrestrial biosphere models with data from the long-term multifactor Prairie Heating and CO2 Enrichment experiment
De Kauwe, M., Medlyn, B., Walker, A., Zaehle, S., Asao, S., Guenet, B., Harper, A., Hickler, T., Jain, A., Luo, Y., Lu, C., Luus, K., Parton, W., Shu, S., Wang, Y., Werner, C., Xia, J., Pendall, E., Morgan, J., Ryan, E., Carrillo, Y., Dijkstra, F., Norby, R. 09/2017 In: Global Change Biology. 23, 9, p. 3623-3645. 23 p.
Journal article

Gross primary production responses to warming, elevated CO2, and irrigation: quantifying the drivers of ecosystem physiology in a semiarid grassland
Ryan, E., Ogle, K., Peltier, D., Walker, A., De Kauwe, M., Medlyn, B., Williams, D., Parton, W., Asao, S., Guenet, B., Harper, A., Lu, X., Luus, K., Shu, S., Werner, C., Xia, J., Zaehle, S., Pendall, E. 08/2017 In: Global Change Biology. 23, 8, p. 3092-3106. 15 p.
Journal article

Quantifying and reducing uncertainties in estimated soil CO2 fluxes with hierarchical data-model integration
Ogle, K., Ryan, E., Dijkstra, F., Pendall, E. 3/12/2016 In: Journal of Geophysical Research: Biogeosciences. 121, 12, p. 2935-2948. 14 p.
Journal article

Antecedent moisture and temperature conditions modulate the response of ecosystem respiration to elevated CO2 and warming
Ryan, E., Ogle, K., Zelikova, T., LeCain, D., Williams, D., Morgan, J., Pendall, E. 07/2015 In: Global Change Biology. 21, 7, p. 2588-2602. 15 p.
Journal article

The use of CO2 flux time series for parameter and carbon stock estimation in carbon cycle research
Hill, T., Ryan, E., Williams, M. 01/2012 In: Global Change Biology. 18, 1, p. 179-193. 15 p.
Journal article