Atmospheric Dispersion

Volcanic eruptions, forest fires, smoke and dust blown into the atmosphere all have one thing in common: they are made up of small particles or pollutants that travel through the atmosphere. While their large-scale transport is well understood, for example from satellite data, little is known about what happens in the real atmosphere at smaller scales (less than 50 km). In particular, little is known about what happens at the atmospheric boundary layer (ABL) and at the spectral gap of the atmosphere, which marks a change in the fluid's behavior. In addition, every situation will be different since there will always be different atmospheric conditions. Conditions at such small scales cannot be modeled in detail by numerical simulations, so we rely on experimental data to understand this phenomenon.

 

To study this, we attach small sensors to biodegradable balloons that measure their GPS position, velocity, relative humidity, temperature, and pressure. These balloons are released simultaneously and we track them for times varying from 10 minutes to 1.5 hours. 

 

When analyzed statistically, these measurements provide detailed information about local atmospheric conditions and how particles are separated under different atmospheric conditions (itself a proxy for mixing in the atmosphere), and will help us answer the question of how particles disperse in the atmosphere.  This has implications for climate modeling, a challenge that needs to be addressed in the context of climate change and early warning. These experiments will provide information on the smaller scales (<50 km) that can be used for parameterizations that will be helpful in the production of more reliable forecasts and models.

 

The first field experiments were conducted in the IMPACT field campaign held in May/June 2024 in Pallas, Finland. This project is part of SMARTIES, a joint collaboration between the Max Planck Institute for Dynamics and Self-Organization and the Fraunhofer Institute for Integrated Circuits.

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