(611e) Identification of Pollutant (fume, dust, chemical vapours) Transport Barriers (wildfire in British Columbia, August 2010)

Identification of barriers to the transport of pollutants (fume, dust, or toxic chemicals) by investigation of the wind flow field by the method of Lagrangian Coherent Structures (LCS) in the territory of West and Central Canada is the most accurate and reliable way to determine the relevant dynamical distribution of the pollutant transported from the source to other regions of interest (case study: Wildfire in British Columbia, August 2010).

In particular, we develop a computing tool for environmental monitoring, which 1.) integrates and utilizes free real-time wind weather data available from Canadian Daily Climate Data (CDCD)[1]; 2.) computes the flow map of the wind in the provinces and territories (BC,AB,SW,MN,YU,NW) and identifies barriers and patterns of possible pollutant transfer; 3.) provides an analysis on flow patterns and pollution associated with the fume with respect to historically available data. In particular we consider the case of large scale British Columbia wildfire in August 2010.

We utilize the Lagrangian framework of description of fluid flow systems which is one of important tools to answer the question where do particles placed in the wind advective flow go? In particular, the Lagrangian framework of fluid flow description provides quantitative tools for answering such a question. The wind advective flow in general is the main type of the transport present in nature and the fundamental characteristic of these flows is their time varying nature. In other words, the non-stationary feature of the flow time evolution requires to come up with the quantitative characterization of the flow characteristics which is posed as a question of ``how much two particles drift from each other as they are advected by the flow’’. The answer to that question is a quantifiable pattern of the Lagrangian coherent Structures (LCS) [2] contours representing the material lines or surfaces which fold, elongate and differentiate the flow with the regions of different dynamical behavior. In other words, the LCS are material lines in the flow of the greatest particle path separation which provide the information of the underlying skeleton of the turbulence and give an insight into the transport of particles within fluid flows from one region to another [3].

Finally, we report on the findings regarding the wind and fume patters present in the Western Canadian territories for the period of the British Columbia wildfire in August 2010.

[1] National Climate Data and Information Archive, Canada, http://www.climate.weatheroffice.gc.ca/

[2] Haller, G.; Yuan, G. Lagrangian coherent structures and mixing in two-dimensional turbu- lence. Physica D: Nonlinear Phenomena 2000, 147, 352–370.

[3] Haller, G. Lagrangian coherent structures from approximate velocity data. Physics of Fluids 2002, 14, 1851–1861.