Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Caroline B. Alden

Research Interests

Much of my work has focused on using trace gas measurements in the atmosphere to understand atmosphere-biosphere fluxes at regional to global scales. More recently, I have begun to use the same techniques to develop tools for identifying greenhouse gas emissions at local scales. 

Prior to joining CIRES, I worked on connecting climate extremes in the Amazon Basin to variations in net biosphere exchange of CO2 with the atmosphere as a postdoctoral fellow with Prof. Noah Diffenbaugh at Stanford University. For my PhD, I worked with Prof. Jim White and Dr. John B. Miller (NOAA/ERSL) to develop an inversion framework for delta13C of atmospheric CO2, and explore its potential as a tracer for regional drought stress in North America. I have also published work on global CO2 sink strength and on atmospheric 13CO2 as a potential indicator of global terrestrial carbon exchange, water stress, and the partitioning of C3/C4 plant productivity.

Current Research

I am currently working with Greg Rieker in the Mechanical Engineering department at CU, Colm Sweeney at the NOAA/ESRL Carbon Cycle Group, and the NIST Engineering Laboratory, to develop tools for the detection, quantification, and attribution of leaks of methane and other hydrocarbons during natural gas production, distribution and storage. Our team has deployed the first fielded dual frequency comb spectrometer at a series of field sites in Colorado to test and implement this new observing system. In the fall of 2017, we will be deploying our system for extended periods of continuous monitoring of active natural gas facilities in a region of high oil and gas production in the Denver-Julesburg Basin here in Colorado, and at an underground natural gas storage facility in Northern California. Using inverse modeling of trace gases observed by open path frequency comb lasers, we hope to continue demonstrating this technique as a viable and cost-effective option for mitigation of emissions from this sector. Stay tuned for the exciting new science we expect to emerge from these upcoming deployments.

I am also currently working with colleagues at the Carbon Cycle Group at NOAA/ESRL in the Global Monitoring Division to better understand what can be learned about fluxes of CO2 in the Amazon Basin in response to climate variability. Using vertical profiles of trace gas measurements collected by light aircraft over the Amazon, we hope to learn about tropical climate impacts and feedbacks as well as the utility and limits of aircraft profiles for understanding biosphere carbon exchange.