OPTIMice-close: Optimal combination of Polarimetric and Triple frequency radar techniques for Improving Microphysical process understanding of cold clouds and associated rainfall

• Applicant: Dr. Stefan Kneifel
• Subject Area: Atmospheric Science
• Term: from 2016 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290611444

• Final Report Year: 2023

Final Report Abstract

The main objective of the OPTIMIce project was to improve our understanding and ability to realistically model ice microphysical processes, such as aggregation, riming, secondary ice processes, and melting. In order to achieve this ambitious goal, we needed to make progress and optimally combine the following three main work areas: 1) Obtain a synergistic dataset of triplefrequency radar, Doppler spectra, and polarimetric radar observations of mid-latitude winter clouds; 2) Further develop a radar forward operator in combination with realistic scattering assumptions for ice and snow particles; 3) Combine long-term numerical weather prediction model simulations and innovative 1D Lagrangian super-particle modelling in order to understand deficiencies identified by the radar observations in the bulk model and for developing improved parametrizations.

Publications

• Assessing the uncertainties of the Discrete Dipole Approximation in case of melting ice particles, J. Quant. Spectrosc. Radiat. Transfer, 217, 396-406
  Ori, D., and S. Kneifel
  
• The TRIple-frequency and Polarimetric radar Experiment for improving process observation of winter precipitation, Earth Syst. Sci. Data, 11, 845-863
  Dias Neto, J., S. Kneifel, D. Ori, S. Trömel, J. Handwerker, B. Bohn, K. Mühlbauer, M. Lenefer, and C. Simmer
  
• Evaluation of ice particle growth in ICON using statistics of multi-frequency Doppler cloud radar observations, Q. J. Roy. Meteor. Soc., 146, 3830-3849
  Ori, D., V. Schemann, M. Karrer, J. Dias Neto, L. von Terzi, A. Seifert, and S. Kneifel
  
• Ice Particle Properties inferred from Aggregation Modelling, Journal of Advances in Modeling Earth System, 12, e2020MS002066
  Karrer, M., A. Seifert, C. Siewert, D. Ori, A. von Lerber, and S. Kneifel
  
• Long-term statistics of riming in non-convective clouds derived from ground-based Doppler cloud radar observations, J. Atmos. Sci., 77, 3495-3508
  Kneifel, S., and D. Moisseev
  
• Scattering of Hydrometeors. In V. Levizzani, C. Kidd, D. B. Kirschbaum, C. D. Kummerow, K. Nakamura, and F. J. Turk (Ed.), Satellite Precipitation Measurement (Vol. 1), New York: Springer
  Kneifel, S., J. Leinonen, J. Tyynelä, D. Ori, and A. Battaglia
  
• Improving the Representation of Aggregation in a Two-moment Microphysical Scheme with Statistics of Multi-frequency Doppler Radar Observations, Atmos. Chem. Phys., 21, 17133–17166
  Karrer, M., A. Seifert, D. Ori, and S. Kneifel
  
• snowScatt 1.0: Consistent model of microphysical and scattering properties of rimed and unrimed snowflakes based on the self-similar Rayleigh-Gans Approximation, Geosci. Model Dev., 14, 1511-1531
  Ori, D., L. von Terzi, M. Karrer, and S. Kneifel
  
• Ice microphysical processes in the dendritic growth layer: A statistical analysis combining multi-frequency and polarimetric Doppler cloud radar observations, Atmos. Chem. Phys., 22, 11795–11821
  von Terzi, L., J. Dias Neto, D. Ori, A. Myagkov, and S. Kneifel
  
• Melting behavior of rimed and unrimed snowflakes investigated with statistics of Triple-frequency Doppler radar observations, J. Geophys. Res.: Atmos., 127
  Karrer, M., J. Dias Neto, L. von Terzi, and S. Kneifel