Dr Simon Alexander is an Atmospheric Scientist with an interest in Southern Ocean and Antarctic clouds, Polar ozone processes and Atmospheric gravity waves.
Southern Ocean and Antarctic clouds – Dr Alexander will soon be involved in the deployment of a suite of instruments to Macquarie Island and Davis to characterise clouds and surface radiation from hourly to seasonal timescales. Weather and climate models are challenged by uncertainties and biases in the simulation of Southern Ocean clouds due to poor physical understanding of cloud processes, phases and feedbacks. These uncertainties result in year-round warm sea surface temperature biases which are mainly due to too little modelled cloud.
Polar ozone processes – Dr Alexander was a Co-author of the World Meteorological Organisation Scientific Assessment of Ozone Depletion: 2014.
Atmospheric gravity waves – Dr Alexander aims to help determine the sources and characteristics of small-scale atmospheric gravity waves in the high southern latitudes to provide constraints for improving their representation in forecasting and climate models.
Characterisation of Southern Ocean and Antarctic clouds and associated model evaluation studies will lead to improved weather forecasting and climate projections and should decrease the current Southern Ocean sea surface temperature biases found in models.
Huang, Y., Franklin, C., Siems, S. T., Manton, M. J., Chubb, T., Lock, A., Alexander, S. P., Klekociuk, A. R. (2015), ‘Evaluation of Boundary Layer Cloud Forecasts over the Southern Ocean in a Limited-area Numerical Weather Prediction System with In-situ, Space-borne and Ground-based Observations’, Quarterly Journal of the Royal Meteorological Society, in press
Alexander, S. P., D. J. Murphy and A. R. Klekociuk (2013), High resolution VHF radar measurements of tropopause structure and variability at Davis, Antarctica (69°S, 78°E), Atmospheric Chemistry and Physics, 13, 3121–3132, doi:10.5194/acp-13-3121-2013
Alexander, S. P., A. R. Klekociuk, M. C. Pitts, A. J. McDonald, and A. Arevalo ‐ Torres (2011), ‘The effect of orographic gravity waves on Antarctic polar stratospheric cloud occurrence and composition’, Journal of Geophysical Research, 116, D06109, doi:10.1029/2010JD015184
Alexander, S. P., Tsuda T., Kawatani, Y., Takahashi, M. (2008), ‘Global distribution of atmospheric waves in the equatorial upper troposphere and lower stratosphere: COSMIC observations of wave mean flow interactions’, Journal of Geophysical Research, 113, D24115, doi:10.1029/2008JD010039
Alexander, S. P., Tsuda T., Kawatani, Y., (2008), ‘COSMIC GPS Observations of Northern Hemisphere Winter Stratospheric Gravity Waves and Comparisons with an Atmospheric General Circulation Model’, Geophysical Research Letters, 35, L10808, doi:10.1029/2008GL033174