Chemical and physical characterization of fertile soil-derived ice residuals from the Fifth International Ice Nucleation workshop in November 2014 (FIN-1)
EMSL Project ID
49302
Abstract
A minor fraction of the atmospheric aerosol, so-called ice nucleating particles (INPs), can have a major impact on clouds, precipitation and climate. In particular, fertile soil particles are recently found as an important INP due to their abundance and ice nucleation efficiency. The proposed research will utilize approaches of multi-modal chemical characterization of ice residual/aerosol samples from fertile soil dusts collected in the Fifth International Ice Nucleation workshop (FIN-1). FIN-1 was held at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) facility at Karlsruhe Institute of Technology (KIT), which is the world's foremost facility for studying ice clouds in a controlled setting, in November 2014 to comprehensively study the heterogeneous ice formation in the atmosphere with collaboration among 10 international groups that were funded through European consortium, NSF and USDOE agencies. During FIN-1, AIDA cloud expansion experiments were conducted to simulate mixed-phase and cirrus cloud conditions. Concurrently, ice crystal residual samples were collected using the ice-selecting pumped counterflow virtual impactor (IS-PCVI). IS-PCVI allowed to inertially separate ice crystals (>15 micro-m) from supercooled droplets (<15 micro-m) and interstistial particles (<2 micro-m). Accordingly, we collected ice crystal residuals of fertile soil on the TEM grids/boron substrates through a home-built multi-stage impactor deployed downstream of IS-PCVI. IS-PCVI also functioned as a particle concentrator with an enhancement factor up to 20 times, such that the concentrated residuals can be transported to the downstream analytical instruments and impactors for offline analysis. Our proposed research at EMSL will generate the unique dataset of a combination of TEM and two spectro-microscopy methods (CCSEM-EDX and micro-Raman) to provide the fundamental molecular level of understanding of ice-nucleating components in fertile soil that may be useful to interpret AIDA INP measurements in FIN-1. In addition, to complement these off-line analyses we will use EMSL's ice nucleation chamber and single particle mass spectrometer (SPLAT II) to characterize in real-time the soil particles that induced nucleation of ice. Through these unique measurements, we will obtain detailed information on ice residual surface and inner composition, morphology, phase and internal structure of individual particles. Our research will help understand how either morphology and/or composition influence ice nucleation. Such dataset has long been a missing piece in the study area of cloud microphysics and atmospheric chemistry and is of importance to improve atmospheric models of cloud feedbacks and determine their impact on climate. Currently, ice formation processes are very poorly represented in the climate models including DOE climate change model (ACME), and our study supports this DOE mission.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2017-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Related Publications
Hiranuma, N. et al., Chemical and physical characterization of fertile soil-derived ice residuals, 2018 European Geophysical Union Annual Meeting, 23-28 April, 2017, Vienna, Austria.