As a doctoral student in the Ecosystem Biogeochemistry Group, my central research goal is understanding how environmental change will impact carbon cycling in freshwater ecosystems at multiple spatial and temporal scales. The concentrations and fluxes of carbon in freshwaters relate to climate feedbacks, nutrient availability and global elemental budgets. My primary tools include sensor-based field measurements in combination with satellite and airborne observations.
My research, which broadly lies at the intersection of global biogeochemical cycling and the remote sensing of inland waters, has been supported through the eScience Institute, a NASA Earth and Space Science Fellowship (NESSF), an Integral Environmental Big Data Award, Achievement Rewards for College Scientists and the Natural Capital Project.
Arctic-Boreal Lake Carbon Dynamics
I am developing spatially explicit models for northern lake carbon dynamics using a multi-sensor approach as part of the NASA Arctic and Boreal Vulnerability Experiment, including hyperspectral imagery analysis from NASA’S airborne AVIRIS-NG sensor. The primary goal of my research for this project is to address the variability in and drivers of lake color and chemistry in a warming north.
Freshwater Initiative, 2018 Field Notes: Ground-Truthing “Greenness” in Arctic-Boreal Lakes
Mapping Chemistry in Major Rivers with Landsat-8 and Sentinel-2: How Important Is Atmospheric Correction?
My early dissertation research combined field and satellite observations to map spatial synchrony in turbidity and chlorophyll-a gradients within large rivers systems using Landsat-8 and Sentinel-2 satellite imagery. A major focus of this work, conducted in collaboration with the USGS and NASA, was constraining uncertainties generated during atmospheric correction of satellite imagery over inland waters. This research included field data generated by high-resolution, underway water chemistry mapping and showed atmospheric correction can result in a 4 - 59% bias in estimations of chlorophyll-a and turbidity, which is much less than previously expected.
Kuhn C, de Matos Valerio A, Ward N, Loken L, Sawakuchi HO, Kampel M, Richey J, Stadler P, Crawford J, Striegl R, Vermote E. Performance of Landsat-8 and Sentinel-2 surface reflectance products for river remote sensing retrievals of chlorophyll-a and turbidity. Remote sensing of environment. 2019 Apr 1;224:104-18.
Greenhouse Gas Emissions from Mountain Streams
Before UW, I received my master's degree in environmental science from the Yale School of Forestry & Environmental Studies and my B.A from Loyola University Chicago. My master's thesis research (advised by Dr. Peter Raymond, Yale University) investigated anthropogenic impacts to aquatic carbon cycling along wilderness to agricultural gradients with support from the Ucross High Plains Stewardship Initiative. My work, conducted in Wyoming's Bighorn range, addressed the shortage of direct measurements of greenhouse gas emissions from mountainous systems and suggests hydrology may play an important role in controlling seasonal development of biogeochemical hotspots.
Kuhn, C., Bettigole, C., Glick, H.B., Seegmiller, L., Oliver, C.D. and Raymond, P., 2017. Patterns in stream greenhouse gas dynamics from mountains to plains in northcentral Wyoming. Journal of Geophysical Research: Biogeosciences, 122(9), pp.2173-2190.
SERVICE and TEACHING
As a former public school teacher and Oakland Teaching Fellow, I am committed to expanding pathways to STEM careers and building community in the sciences for underrepresented groups. At the university level, I have helped developed several cutting-edge new courses ranging from an upper-level graduate seminar synthesis about the effects of management on ecosystem carbon storage to a freshman-level undergraduate data science course focused on statistics, data science and programming modeled after Berkeley’s Data 8. I am a founding instructor of Geohackweek at the University of Washington, which is a new type of scientific workshop designed to foster open data practices, inclusive collaboration and the rapid dissemination of emerging data practices through the lateral transfer of knowledge between participants. I frequently give seminars about freshwater ecosystems, the remote sensing of water, and data science techniques including Google Earth Engine for groups ranging from small to large.
I serve as a reviewer for JGR:Biogeosciences, Remote Sensing of the Environment, Limnology & Oceanography Letters, Water Resources Research and Global Change Biology.
Kuhn, C., Ward, N., Loken, L., Sawakuchi, H., Crawford, J., Stadler, P., Richey, J., Striegl, R., Butman, D. (2019). Performance of Landsat-8 and Sentinel-2 surface reflectance products for river remote sensing retrievals of chlorophyll-a and turbidity. Remote Sensing of Environment, 224, 104-118.
Bogard, M., Kuhn, C., Johnston, S.E., Striegl, R., Holtgrieve, G., Dornblaser, M., Spencer, R., Wickland, K., and Butman, D. (2019) “Negligible terrestrial carbon cycling in many lakes of the arid circumpolar landscape.” Nature Geosciences, 12.3: 180.
Kuhn, C., Bettigole, C., Glick, H. B., Seegmiller, L., Oliver, C. D., & Raymond, P. (2017). Patterns in stream greenhouse gas dynamics from mountains to plains in northcentral Wyoming. Journal of Geophysical Research: Biogeosciences, 122(9), 2173-2190.
Crawford, J. T., Butman, D. E., Loken, L. C., Stadler, P., Kuhn, C., & Striegl, R. G. (2017). Spatial variability of CO2 concentrations and biogeochemistry in the Lower Columbia River. Inland Waters, 7(4), 417-427.
Glick, H. B., Routh, D., Bettigole, C., Seegmiller, L., Kuhn, C., & Oliver, C. D. (2016). Modeling the effects of horizontal positional error on classification accuracy statistics. Photogrammetric Engineering & Remote Sensing, 82(10), 789-802.