Current Lab Members

My previous work focused on the role of photochemistry in the cycling of marine dissolved organic matter (DOM). The basic approach for each photochemical reaction begins with determination of its photochemical efficiency spectrum, defined as apparent quantum yield (AQY; molar ratio of photoproduct to photons absorbed by colored dissolved organic matter (CDOM)). AQY spectra are then used in ocean color-based models to estimate photochemical production rates on regional and global scales from remote sensing or in situ optics. While this approach has undeniably allowed expanded spatial and temporal evaluation of photochemical reactions from coastal zones to the global ocean, significant challenges remain. The accuracy of these photoproduction estimates from optical data is constrained by limited availability of AQY spectral data and the ability to match observed variations in surface ocean optical properties with appropriate AQY spectra. Until molecular level information becomes available that identify the specific absorbing compounds and interactions responsible for CDOM absorption as well as specific photoproducts, we remain limited by using the absorption coefficient for all chromophores in solution to determine the rate of photon absorption (the AQY denominator) for all photoproducts. Here, I will be working on the NSF sargassum project investigating the molecular complexity and reactivity of DOM released from this brown algae, and to see how these are related to general CDOM photochemistry. I hope to gain a better molecular level understanding of CDOM (and DOM in general) and perhaps move the field away from defining AQY spectra by “photons absorbed by CDOM.”

I study the composition of septic system wastewater and landfill leachate. I mainly work on a collaborative project between Dr Michael Gonsior, Dr. Andrew Heyes, and Dr. Lora Harris to develop new organic tracers for septic system effluent and assess the performance of already used wastewater tracers like emerging contaminants, nutrients, chloride, and isotopic signatures. We are also trying to quantify the amount of septic system effluent in waterways and compare the performance of older septic systems to newer nitrogen removing systems in Maryland. I am interested in human impacts on water quality and hope that my work will better inform wastewater management and treatment.

I am a Ph.D. student co-advised by Dr. Margaret Palmer through the MEES (Marine Estuarine Environmental Sciences) graduate program at the University of Maryland. I want to better understand the relationships between hydrologic connectivity and ecosystem functions in the Choptank River watershed with a particular focus on the characterization, role, movement, and transformation of dissolved organic matter using fluorometric, mass spectrometric, and perhaps stable isotope analytical techniques. My research is currently focused on freshwater systems and Delmarva bays in the mid-Atlantic coastal plain in forested landscapes with strong agricultural influences.

I am masters student working with Dr. Michael Gonsior on his latest research with Dr. Feng Chen on the fate of lysis products of picocyanobacteria contributes to marine humic-like chromophoric dissolved organic matter. My research works with detailed optical properties analysis with detailed DOM characterization using non-targeted mass spectrometric approaches to enhances our understanding of marine CDOM.