Laboratory for Atmospheric and Space Physics (LASP)

Volatile organic compounds (VOCs) emitted into Earth’s atmosphere from ecosystems, wildfires, and human activity drive secondary pollutant formation, affect global biogeochemical cycling, and alter the atmosphere’s oxidizing capacity. Quantifying these effects lies at the heart of our ability to model air pollution and predict environmental change. In this seminar I will discuss my group’s work combining space-based data, in-situ observations, and modeling to better understand the emissions and chemistry of atmospheric VOCs.

The discovery of the Antarctic ozone hole in the 1980s marked a major environmental concern and prompted global regulation of man-made ozone-depleting substances (ODSs) under the Montreal Protocol. Although Antarctic ozone has shown signs of recovery since the 2000s, quantifying the extent to which this recovery is driven by reductions in ODSs, rather than other forcings or natural variability, remains a key challenge.

Cloud microphysics—the processes governing droplets, ice, and aerosols at microscopic scales—remains a leading source of uncertainty in weather and climate predictions. These processes shape cloud structure, precipitation, and radiative feedbacks, yet they are neither resolvable in large-scale models nor directly constrained by most observing systems. Bridging the scale gap between observations, microphysical processes, and predictive models is a central challenge in atmospheric science.

Our planetary neighbors hold important clues about the universal limits planetary evolution and atmospheric escape place on habitability. In my work, I take a whole-atmosphere approach to understanding how these objects have evolved, combining ab initio computational modeling, spacecraft mission data analysis, and instrument and mission development to propel the field forward.

Satellite measurements of Earth’s radiation budget (ERB) have uncovered profound mysteries within the Earth system, including a doubling of Earth’s energy imbalance over the last two decades and a sustained hemispheric albedo symmetry. In this seminar, I will demonstrate that a targeted exploration of the spatial, diurnal, and spectral dimensions of ERB is essential to advance the field from the current state of broadband monitoring toward a robust, process-oriented understanding.

In this seminar, I present recent results on the structure, variability and energetics of the far upper atmosphere found by the method of solar occultation, where atmospheric properties are inferred using sunlight as it passes through an atmosphere. The extreme ultraviolet (EUV) band is strongly absorbed in the thermosphere, enabling EUV occultations to provide a unique window into a sparsely observed region of the atmosphere.

The dynamics of Earth’s radiation belts remain one of the central challenges in space weather research. Despite decades of satellite observations, predicting when and how the belts will intensify or decay remains difficult. This seminar will discuss recent work combining multi-mission datasets from 36 multi-agency satellites to produce the highest-resolution phase space density (PSD) observations of the outer belt to date, and how these have been used to identify dominant acceleration and loss mechanisms.

Wildfires are becoming increasingly frequent and intense in a warming climate, reversing decades of air quality improvements, as seen in the 2025 Los Angeles Fires and many other record-breaking events worldwide. Crucially, what burns locally doesn’t stay local—wildfire smoke often rises, travels, and affects the atmosphere and climate far beyond its source. I will share new insights into the far-reaching impacts of wildfire smoke based on aircraft measurements, satellite observations, and modeling.

Understanding the chemical composition of exoplanet atmospheres is key to identifying habitable worlds and potential biosignatures. Current instruments face challenges in detecting weak atmospheric signals from small-sized exoplanets due to telluric and stellar contamination, spectral overlap, and limited resolution.

We have entered a new era of studying the physics of planetary atmospheres. Powered by new facilities like the James Webb Space Telescope and upcoming 30-meter class telescopes, we can observe exoplanet atmospheres in exquisite detail for the first time. With these measurements, we can test our understanding of the physics and chemistry of atmospheres in exotic environments: heating planets up to thousands of degrees or placing them around stars with very different properties.