Research

Atmospheric transport and jet streams

A variety of gases and particulates are transported on large scales by the atmosphere, affecting atmospheric chemistry and air quality. I am particularly interested in:

• The effects of global warming on the behavior of the atmospheric jet streams. I am developing an improved jet tracking algorithm (called JetLag) in collaboration with Jezabel Curbelo to take a new look at this issue.
• The role of large wilfdire smoke plumes in the atmospheric composition and air quality from one continent to the next. I am working with Dr. Arlene Fiore and Dr. Sebastian Eastham to track plumes using satellite data and artificial intelligence.

Emergence of climate signals

The planet is warming, but certain detailed aspects of the consequences of this warming remain difficult to assess. The primary reasons for this are simple:

1) The climate system is full of random noise, and it is sometimes difficult to separate the signal from the noise;

2) Our observations of the climate system are far from perfect – they have gaps, biases, and their quality changes over time.

I am working to assess the degree of confidence we should place in long-term changes observed in our historical records, accounting for the effects of climate noise and observations being imperfect. This work led to a new method, currently in review at GRL.

Stratospheric ozone and circulation

The stratospheric ozone layer protects life on Earth from harmful ultraviolet (UV) radiation from the Sun, so it is no surprise that the ozone hole has garnered tremendous scientific concern. My contributions in this area primarily concern:

• Assisting the development of a new satellite mission at Caltech’s Jet Propulsion Laboratory to monitor the circulation of the stratosphere and its connection with its composition;
• Determining whether long-term changes in the stratospheric circulation are observable;
• Re-assessing the degree of confidence we should place in the recovery of the ozone hole as seen by satellites, with collaborators at Caltech’s Jet Propulsion Laboratory and at Princeton’s Geophysical Fluid Dynamics Laboratory.

Tropical cyclone risk in future climates

As the planet warms globally, regional changes also occur. In the context of tropical cyclones, this could mean that the regions where they form, intensify, and eventually make landfall could change over time. A project I am leading a collaboration with Purdue and NOAA to look at these changes and the uncertainty around them, to inform adaptation and mitigation planning.

Tropical cyclone structure and dynamics

Tropical cyclones have historically been studied from the surface up, mostly because of the extensive damage they produce at the surface. However, tropical cyclones also affect the upper atmosphere around them, with climate impacts that are still relatively uncertain. I provided a new detailed look at cold anomalies found above tropical cyclones, and ruled out the effect of clouds as the main driver of these cold anomalies. Remains to determine which other mechanisms may be responsible…