River plumes.
My postdoc research at UBC is focused on understanding the near-surface dynamics of the Fraser River plume in the Strait of Georgia. In particular, I am interested in combining HF radar velocity measurements with ship-of-opportunity observations and satellite imagery to learn how wind, tides, and river discharge govern the behaviour of the plume. The research is part of the Marine Environmental Observation Prediction and Response Network (MEOPAR). In fact this is highly related to my PhD work, which was to use ship-of-opportunity data to study mixing in the Fraser River plume, and to study how the plume impacts phytoplankton biomass. Radiowave oceanography. The use of high-frequency radar systems to measure surface currents has existed for 40 years, but it has proliferated in the last decade. Numerous studies have shown that the radial velocity measurements are imperfect at the level of perhaps 3 - 10 cm/s. Direction-finding systems (e.g. CODAR's SeaSonde) rely on a non-linear algorithm to map the currents, and there is reason to suspect that it assigns some Doppler bins to the wrong bearing. Recently, we have been conducting drifter-based validation studies in the Strait of Georgia to assess the accuracy of a 25 MHz CODAR system in the Strait of Georgia which is operated by Ocean Networks Canada. Circulation in fjord-like systems. The Strait of Georgia and Prince William Sound are two examples of "fjord-like" basins with limited connections to the ocean at large. They resemble fjords in that they are deeper than the adjacent shelf, and also in that they receive precipitation in excess of evaporation. However, both systems are relatively wide compared to the internal deformation radius, which allows for a more complex circulation. While at the Prince William Sound Science Center in Cordova, Alaska, I had the pleasure of deploying and recovering moorings in the passageways connecting Prince William Sound to the northern Gulf of Alaska. Transport estimates made from ADCP records revealed that the nature of the water exchange between Prince William Sound and the shelf differs from other systems (e.g. the Strait of Georgia or Chesapeake Bay) because it has two large passages, rather than one. Application of complex network theory to geophysics. I also have an interest in the application of complex network theory to the earth sciences. Complex network analysis has been applied to a wide range of problems, from finance to social networks to ecology, but it has been (in my opinion) under-utilized in the earth sciences. With Sean Fleming of Environment Canada, I applied complex network theory to a system of streamflow gauges in the Coast Mountains to explore whether this technique could aid in the design of sampling networks. We found that network theory can be easily applied a system of hydrometric gauges, and then showed that a number of tools from the technique can extract useful information from the network. However, many questions remain... |