Colloquia for Fall 2026

Quantifying Reactive Nitrogen Emissions From Wildland-Urban Interface Fires: A Case Study of the 2025 Los Angeles Fires

September 24, 2026

Joshua Laughner

Hosted by Dien Wu

Wildland-urban interface (WUI) fires increasingly expose populations to air pollution; the January 2025 Eaton and Palisades fires killed 31 people and destroyed over 16,000 Los Angeles structures. NO2:CO enhancement ratios (ERs) are the standard satellite metric linking fire emissions to intensity. From the operational TROPOMI products used by default, ERs on 8 and 9 January were 4.5 ± 2.8…

Investigating the potential impact of spaceflight on Earth’s atmosphere

September 17, 2026

Chris Maloney

Hosted by Jim Hurrell and Jeff Pierce

Human activity in Low Earth Orbit (LEO) has grown at a nearly exponential rate over the past few years with numerous projections showing even more rapid growth in the coming decades. This proliferation of activity has highlighted the need for research into potential environmental impacts. Rocket launches and the re-entry and ablation of debris release both gases and particles throughout the…

Special Retirement Seminar and Celebration for Prof. Sonia Kreidenweis

September 10, 2026

Sonia Kreidenweis

Hosted by Department

Retirement Celebration

Continuity and Innovation: Advancing Earth Radiation Budget Science with the Libera Mission

September 03, 2026

Jake Gristey

Hosted by Christine Chiu

Over the last twenty years, Earth radiation budget (ERB) satellite measurements have uncovered significant Earth system change, including a doubling of Earth's energy imbalance and a persistent hemispheric albedo symmetry. In the future, ERB satellite measurements are likely to play an even more pivotal role in emerging application areas such as solar radiation management. This seminar will…

Catching Pac-Man: New Observational and Modeling Constraints on the Oxidizing Capacity of the Troposphere

August 27, 2026

Alex Turner

Hosted by Dien Wu

The hydroxyl radical (OH) is the primary oxidant in the troposphere. It governs the lifetime of methane, ozone depleting substances, and other pollutants. Despite this importance, OH remains one of the most poorly constrained quantities in atmospheric chemistry. Direct OH observations are sparse and imprecise, proxy species such as methyl chloroform are losing their utility to constrain OH,…