Research
I am interested in the role that rivers play in carbon cycle, coastal processes and how they are influenced by hydrological processes and anthropogenic change.
The overall goal of my research is: 1) to gain a greater insight into processes driving terrestrial biogeochemical cycles and sediment fluxes; 2) to assess how river fluxes impact lake and marine biogeochemical cycles; and 3) to determine how anthropogenic, climate change and land-use drivers enhance or dampen these natural cycles.
I have a wide variety of research interests including the following mostly in the humid tropics: terrestrial and climate influence at the land-ocean interface; earth surface processes (landslide dynamics); critical zone science; river biogeochemistry (carbon and nitrogen); impacts of extreme events (drought and rainfall); river particulate organic carbon (POC) export; river suspended sediment export; river nutrients and water quality; catchment hydrology; impact of land-use and land cover (LULC) on soil, rivers, and erosion; mangrove dieback; and marine hypoxia.
I use a variety of methods in my research in part because I carry out a lot of research in the tropics where you need to collect most of the data yourself.
In the field: tropical field measurements; river and marine water sampling; water filtration for suspended & dissolved load; coupled river, rainfall and marine sampling and monitoring; and soil and vegetation sampling; ISCO river water samplers to measure flooding events; cross-section river discharge measurements; river height continuous measurements using loggers.
In the lab: carbon and nitrogen analysis of sediment using an Isotope Ratio Mass Spectrometre (IRMS) and elemental analyser (C, N); water filtration; sediment, soil, and vegetation preparation for analytical analyses.
In the computer lab: LoadEstimator for river constituents loads (LoadEst); stage height or concentration discharge rating curves; mapping of landslides or land cover using satellite imagery (Landsat, Quickbird/Worldview, air photos); end-member mixing models; variety of techniques in ArcGIS (classification of land cover, interpolation of rainfall patterns and catchment distribution, and map making); rain event separation; catchment carbon mapping.
Assessing Freshwater and Nutrient Contributions into a Tropical Bay which Suffers from Annual Hypoxia
Freshwater inputs into a Caribbean Bay
I am evaluating freshwater inputs (rainfall and river discharge) and nutrient fluxes into Almirante Bay (Caribbean coast in Panama) as they are likely important drivers of annual hypoxia in the bay. This project is in collaboration with Smithsonian Tropical Research Institute (STRI) scientist Rachel Collin. This is an NSF-funded project to model marine hypoxia in a tropical bay, collaborating with oceanographers from the University of California Irvine and UC San Diego (Geno Pawlak, Kristen Davis, Sarah Giddings, Sam Kastner, and Annie Aldeson).