The chance of freezing - a conceptional study to parameterize temperature-dependent freezing by including randomness of ice-nucleating particle concentrations
Artikel i vetenskaplig tidskrift, 2023

Ice-nucleating particle concentrations (INPCs) can spread over several orders of magnitude at any given temperature. However, this variability is rarely accounted for in heterogeneous ice-nucleation parameterizations. In this paper, we present an approach to incorporate the random variation in the INPC into the parameterization of immersion freezing and analyze this novel concept with various sensitivity tests. In the new scheme, the INPC is drawn from a relative frequency distribution of cumulative INPCs. At each temperature, this distribution describing the INPCs is expressed as a lognormal frequency distribution. The new parameterization scheme does not require aerosol information from the driving model to represent the heterogeneity of INPCs. The scheme's performance is tested in a large-eddy simulation of a relatively warm Arctic mixed-phase stratocumulus. We find that it leads to reasonable ice masses in the cloud, especially when compared to immersion freezing schemes that yield one fixed INPC per temperature and lead to almost no ice production in the simulated cloud. The scheme is sensitive to the median of the frequency distribution and highly sensitive to the standard deviation of the distribution, as well as to the frequency of drawing a new INPC and the resolution of the model. Generally, a higher probability of drawing large INPCs leads to substantially more ice in the simulated cloud. We expose inherent challenges to introducing such a parameterization and explore possible solutions and potential developments. Copyright:

Författare

Hannah Frostenberg

Chalmers, Rymd-, geo- och miljövetenskap, Geovetenskap och fjärranalys

André Welti

Finnish Meteorological Institute

Mikael Luhr

Stockholms universitet

Julien Savre

Ludwig-Maximilians-Universität München (LMU)

Erik S Thomson

Göteborgs universitet

Luisa Ickes

Chalmers, Rymd-, geo- och miljövetenskap, Geovetenskap och fjärranalys

Atmospheric Chemistry and Physics

1680-7316 (ISSN) 1680-7324 (eISSN)

Vol. 23 19 10883-10900

ModElling the Regional and Global Earth system (MERGE)

Lunds universitet (9945095), 2010-01-01 -- .

Mänsklig påverkan på nordiska och arktiska klimat och luft: sjöfart, vatten- och ismoln, och partiklar

Formas (2017-00564), 2018-01-01 -- 2020-12-31.

Ämneskategorier

Meteorologi och atmosfärforskning

DOI

10.5194/acp-23-10883-2023

Mer information

Senast uppdaterat

2024-10-11