Atmospheric chemistry & physics

The air we breathe consists mostly of molecular nitrogen and oxygen, yet the atmosphere contains a multitude of other, less abundant chemical species, including reactive gases, aerosol particles, liquid water and ice clouds. Atmospheric chemistry and physics is the broad field within atmospheric science concerned with the quantitative understanding of the atmospheric chemical composition, physicochemical properties of gaseous and airborne particulate matter, clouds and precipitation, and their interactions with solar and terrestrial radiation. This encompasses the chemical and physical processes governing temporal and spatial variability in air composition, reactions on surfaces and within aerosol and cloud particles, and their links to air quality, weather phenomena and climate.

The areas and the associated faculty members are:

Aerosols and Trace Gases

Faculty members: Ariya, Preston, Zuend

Aerosols and trace gases are among the most variable constituents of Earth’s atmosphere. Aerosols are tiny, nano- to micrometer-sized, liquid, solid, or semi-solid particles suspended in the air, some composed of multiple phases. Trace gases, such as volatile organic compounds, ammonia and ozone are of great interest in atmospheric chemistry and constitute major ingredients of air pollution.

Both trace gases and particles originate from a variety of sources, including the incomplete combustion of fossil fuels, emerging contaminants from volatile consumer products, photochemical reactions in the air, as well as natural emissions. Our research groups explore and quantify, among others, the important roles of aerosols and trace gases in air quality, multiphase chemistry, the formation of clouds, and aerosol–cloud–radiation interactions, of relevance for regional and global climate.


Clouds and Precipitation

Faculty members: AriyaFabry, YauZuend

Clouds have a dynamic of their own, with complex microphysics, which ultimately leads to the formation of precipitation. Clouds have radiative effects that depend on their nature (solid, liquid, mixed-phase), hence their importance for climate research. Processes leading to precipitation vary greatly.

Even some fundamental questions, such as why does it rain, are not properly answered. This is why we seek to characterize, explain, and predict cloud and precipitation processes for weather and climate forecasting applications using theory, field measurements, laboratory experiments and numerical simulations.

Radiation and Remote Sensing

Faculty members: FabryHuang

Radiation is a form of energy that fuels weather, climate and photochemistry and, thus, is a core topic in atmospheric and oceanic sciences. We study how radiation transfers through the atmosphere and interacts with atmospheric constituents, including greenhouse gases, aerosols and clouds. Applying the knowledge of radiative transfer, we also develop methods that remotely sense the atmosphere and ocean using satellite, airborne and ground-based radiometric measurements, and radar.

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