Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.

 

Comparison of Modeled and Measured Ice Nucleating Particle Composition in a...

Ullrich, R., C. Hoose, D. Cziczo, K. Froyd, J. Schwarz, A. Perring, T. P. Bui, C. Schmitt, B. Vogel, D. Rieger, T. Leisner, and O. Möhler (2019), Comparison of Modeled and Measured Ice Nucleating Particle Composition in a Cirrus Cloud, J. Atmos. Sci., 76, 1015-1029, doi:10.1175/JAS-D-18-0034.1.
Abstract: 

The contribution of heterogeneous ice nucleation to the formation of cirrus cloud ice crystals is still not well quantified. This results in large uncertainties when predicting cirrus radiative effects and their role in Earth’s climate system. The goal of this case study is to simulate the composition, and thus activation conditions, of ice nucleating particles (INPs) to evaluate their contribution to heterogeneous cirrus ice formation in relation to homogeneous ice nucleation. For this, the regional model COSMO—Aerosols and Reactive Trace Gases (COSMO-ART) was used to simulate a synoptic cirrus cloud over Texas on 13 April 2011. The simulated INP composition was then compared to measured ice residual particle (IRP) composition from the actual event obtained during the NASA Midlatitude Airborne Cirrus Properties Experiment (MACPEX) aircraft campaign. These IRP measurements indicated that the dominance of heterogeneous ice nucleation was mainly driven by mineral dust with contributions from a variety of other particle types. Applying realistic activation thresholds and concentrations of airborne transported mineral dust and biomass-burning particles, the model implementing the heterogeneous ice nucleation parameterization scheme of Ullrich et al. is able to reproduce the overall dominating ice formation mechanism in contrast to the model simulation with the scheme of Phillips et al. However, the model showed flaws in reproducing the IRP composition.

PDF of Publication: 
Download from publisher's website.
Research Program: 
Radiation Science Program (RSP)
Upper Atmosphere Research Program (UARP)
Mission: 
MACPEX