Aerosols, ranging from dust, soot, sea salt to organic materials, some of which travel thousands of miles, form the skeletons of clouds. Around these nuclei, water and ice in the atmosphere condense and grow leading to precipitation. Scientists are trying to understand how they form as clouds play a critical role by both cooling the atmosphere and affect regional precipitation processes.
ICE-L was the first aircraft-based deployment of the aircraft aerosol time-of-flight mass spectrometer (A-ATOFMS) nicknamed "Shirley," which was recently developed at UCSD with funding from NSF. The ICE-L team mounted the mass spectrometer and an ice chamber run by Colorado State University researcher Paul DeMott onto a C-130 aircraft operated by NCAR and made a series of flights through a type of cloud known as a wave cloud. The researchers performed in-situ measurements of cloud ice crystal residues and found that half were mineral dust and about a third contained nitrogen, phosphorus and carbon the signature elements of biological matter.
The second-by-second analysis speed allowed the researchers to make distinctions between residues of water droplets and ice nuclei in real-time. Ice nuclei are rarer than droplet nuclei and are more likely to create precipitation.
The A-ATOFMS also allowed the unambiguous measurement of biological particles in the cloud ice, which scientists previously concluded serve as ice nuclei based on simulations in laboratory experiments and precipitation measurements. Based on modeling and the chemical composition of measured dust, the ICE-L team was able to identify the source of the dus
|Contact: Robert Monroe or Mario Aguilera|
University of California - San Diego