Research

Research interests

  • Climate variability and change
  • Large-scale atmospheric dynamics
  • Data assimilation
  • Inverse modeling of greenhouse gas fluxes
  • Carbon cycle dynamics

My research aims to improve our understanding of the Earth's climate system by combining information from observations, theory, and numerical models using innovative methods based on data assimilation, Bayesian inference, statistics, and machine learning. I'm particularly interested in processes that affect the weather and climate we experience on daily to multidecadal time scales.

At the moment my research focuses on two topics:

  • Data assimilation and inverse methods to estimate regional-scale CO2 sources and sinks
  • Arctic amplification and linkages to mid-latitude weather and climate

Current projects

CO2 Human Emissions

CO2 Human Emissions (CHE) is an EU Horizon 2020 project aimed at exploring the development of an operational capacity to monitor anthropogenic CO2 emissions. This initiative brings together a consortium of 22 European partners and is coordinated by ECMWF.

My role in CHE is to evaluate how enhanced space-borne and in situ observations can improve top-down quantification of fossil fuel CO2 emissions. I use the Carbon Cycle Fossil Fuel Data Assimilation System (CCFFDAS), a comprehensive modeling chain consisting of process-based terrestrial biosphere and fossil fuel emission models and inverse procedures, to perform Quantitative Network Design to evaluate different sampling strategies. I am currently quantifying how observations of atmospheric radiocarbon can help to disentangle natural and anthropogenic sources and sinks of CO2.

Read more about CHE

CO2 Human Emissions project
An artist's depiction of a satellite observing anthropogenic and natural CO2 emissions. Image credit: CHE project.

Past projects

Atmospheric Carbon and Transport - America

The NASA-funded Atmospheric Carbon and Transport - America (ACT-America) project aims at improving our understanding of atmospheric transport uncertainties and regional-scale sources and sinks of CO2 and methane through targeted airborne campaigns. Five intensive airborne field campaigns were conducted, spanning two weeks each and covering three regions in the eastern United States, to study the transport of atmospheric carbon.

As part of the ACT-America project I modeled the mesoscale transport of CO2 using the WRF-Chem model and developed the foundation of a coupled atmosphere–carbon data assimilation system based on the PSU WRF ensemble Kalman Filter system. Furthermore, I used the airborne observations collected during the first two field campigns to evaluate two global CO2 analysis products.

Read more about ACT-America

ACT-America project
ACT-America logo showing the key elements of the project. Image credit: NASA.

Arctic amplification and linkages to mid-latitude weather and climate

The Arctic region is warming more than twice as fast as the rest of the world, a phenomenon known as Arctic amplification, with dramatic changes in the Arctic climate system including a rapid decline of Arctic sea ice. The Arctic warming has coincided with many unusually cold winters over the mid-latitude continents. Some studies have suggested that the amplified Arctic warming can cause systematic shifts in mid-latitude weathern patterns, which would make extreme cold winter days more likely as the Arctic warms. However, other studies argue that the recent cold winters over the continents are just a manifestation of internal variability and not forced by Arctic warming.

I'm interested in both the mechanisms behind Arctic amplification and how it influences mid-latitude weather and climate variability. I study these processes using a combination of observations, reanalysis datasets, numerical model experiments, and statistical and machine learning techniques.

FIXME
Cold air outbreak over the Northern Hemisphere continents on January 29, 2019. Image credits: NASA.