Robert Sica, Professor, and Department Chair

Robert Sica

Contact Information

Office: PAB 256
Tel: (519) 661-2111 x83521
E-mail: pachair@uwo.ca

Research Blog
Purple Crow Lidar

Research Areas

Space and Atmospheric Science


Research Interests

My research mainly concerns measurements of atmospheric temperature and composition. My current research efforts are in establishing the Canadian Micro-Pulse Lidar Network, MPLCAN.  Forest fire smoke and pollutant tracking are of great importance for the health and safety of Canadians. For example, in summer 2017, British Columbia experienced its worst forest fire season on record. Firefighting and evacuation efforts would be improved by an ability to track the smoke from the fires in real time. In Europe, during the April 2010 eruption of the Eyjafjallajökull volcano in Iceland, the ash clouds covered much of Northern Europe and closed airports in 20 countries, affecting over 10 million travellers. Also important to Canada are the effects of a warming climate. One important effect is changes in the amount of ozone in the stratosphere, which is important for shielding the surface from harmful ultraviolet radiation. To improve understanding of the transport of particulates, as well as studying the impact of these particulates on interpreting ozone trends and their role in the formation of fog and clouds, we have established 4 nodes in the new Canadian Micro-Pulse Lidar Network (MPLCAN). The MPLs are being deployed to London, ON, Sherbrooke, Halifax, and in the High Arctic (Eureka, NU). A fifth MPL already established in Toronto has joined the network. These instruments are part of the global [NASA Micro-pulse Lidar Network](https://mplnet.gsfc.nasa.gov/data.cgi?site=London-CDN). The micro-pulse lidars (MPLs) will allow the structure of the atmosphere to be profiled in both height and time, for both the amount and type of particulates present, in addition to allowing liquid water to be discriminated from ice in developing clouds, precipitation, and fog.  We also measure layers of smoke particles in the upper troposphere and stratosphere (> 10 km altitude) associated with distant forest fires, injected into the stratosphere via a process called pyroconvection. The smoke particles can travel great distances, and affect both ozone concentration and temperature. With the number and severity of forest fires increasing, forest fires play a more complex role in global warming than anticipated, and we are trying to understand these effects.

bobs-bio-page.png

Micro-pulse lidar measurements of California wildfire smoke transported over the Sherbrooke, Quebec  MPLCAN site in September 2020. A lidar transmits a laser beam, which is partially backscattered into the lidar’s telescope and measured.  By measuring the polarization state of the lidar return we can separate smoke (cyan and orange) from cirrus ice clouds (red).

We actively collaborate nationally and internationally on projects involving atmospheric dynamics (in particular gravity waves), composition (including water vapour and ozone), and aerosols. We work with lidar systems in the high Canadian Arctic at the [Polar Environment Atmospheric Research Laboratory](https://www.candac.ca/candacweb/index.php). We also have close ties with the [Swiss Meteorological service](https://www.meteoswiss.admin.ch/home/measurement-and-forecasting-systems/atmosphere/lidar-and-ceilometers.html)  and work with them developing innovative new ways to analyze lidar measurements. Some of my students visit these locations for research and to make measurements. Maybe [you want to join them!](https://physics.uwo.ca/graduate/future_students/research/potential_research_topics/Probing_the_Atmosphere.html)

Publications

  1. Gamage, S. M. et al. (2020), A 1D Var Retrieval of Relative Humidity Using the ERA5 Dataset for the Assimilation of Raman Lidar Measurements, Journal of Atmospheric and Oceanic Technology, 37(11), 2051-2064, doi:10.1175/jtech-d-19-0170.1.
  2. Hicks-Jalali, S. et al. (2020), A Raman lidar tropospheric water vapour climatology and height-resolved trend analysis over Payerne, Switzerland, Atmospheric Chemistry and Physics, 20(16), 9619-9640, doi:10.5194/acp-20-9619-2020.
  3. Farhani, G. et al. (2019), Improved ozone DIAL retrievals in the upper troposphere and lower stratosphere using an optimal estimation method, Applied Optics, 58(6), 1374, doi:10.1364/ao.58.001374.
  4. McCullough, E. M. et al. (2017), Depolarization calibration and measurements using the CANDAC Rayleigh–Mie–Raman lidar at Eureka, Canada, Atmospheric Measurement Techniques, 10(11), 4253-4277, doi:10.5194/amt-10-4253-2017.
  5. Sica, R. J., and Haefele, A. (2015), Retrieval of temperature from a multiple-channel Rayleigh-scatter lidar using an optimal estimation method, Applied Optics, 54(8), 1872-1889, doi:10.1364/AO.54.001872.
    [Complete Publications Listing]

Teaching

I have developed courses at The University of Western Ontario in both atmospheric sciences (e.g. Physics 2070 for non-scientists and Physics 2700 for physics students) and the science of the sporting environment (Physics 2065). The sports course, intended for non-science students, is unique as it focusses on the effect of the land, air and water on an athlete’s performance using examples from activities including cycling, skating, athletics and swimming. 

Awards

  • 2003    The University of Western Ontario's Florence Bucke Science Prize
  • 1995    Editor's Citation for Excellence in Refereeing for Geophysical Research Letters (American Geophysical Union)

Professional Activities

  • Associate Editor, _Atmospheric Measurement Techniques_
  • Member, Network for Detection of Atmospheric  and Climate Change (NDACC) Lidar Working Group
  • Principle Investigator, Canadian Micro-Pulse Lidar Network (MPLCAN)
  • Visiting Scientist, MeteoSwiss, Payerne, Switzerland