Wintertime Airborne Measurements of Ice Nucleating Particles in the High Arctic: A Hint to a Marine, Biogenic Source for Ice Nucleating Particles

M Hartmann,H Wex,A Hünerbein,S Willmes,F Stratmann,K Adachi,E Jäkel,A Herber,C Jentzsch,C Haas,R Holzinger,O Eppers,M Pinxteren

doi:10.1029/2020gl087770

Abstract

AbstractIce nucleating particles (INPs) affect the radiative properties of cold clouds. Knowledge concerning their concentration above ground level and their potential sources is scarce. Here we present the first highly temperature resolved ice nucleation spectra of airborne samples from an aircraft campaign during late winter in 2018. Most INP spectra featured low concentration levels (<3 · 10−4 L−1 at −15°C). However, we also found INP concentrations of up to 1.8·10−2 L−1 at −15°C and freezing onsets as high as −7.5°C for samples mainly from the marine boundary layer. Shape and onset temperature of the ice nucleation spectra of those samples as well as heat sensitivity hint at biogenic INP. Colocated measurements additionally indicate a local marine influence rather than long‐range transport. Our results suggest that even in late winter above 80°N a local marine source for biogenic INP, which can efficiently nucleate ice at high temperatures, is present.

Highlights

No other region on the Earth is affected more severely by global warming than the Arctic, a phenomenon which is typically referred to as Arctic amplification
The Ice nucleating particles (INPs) measurements made during PAMARCMiP provide the first continuous ice nucleation spectra of airborne INP in the Arctic
On 3 of 12 samples we found INP concentrations above those of the field blanks

Summary

Introduction

No other region on the Earth is affected more severely by global warming than the Arctic, a phenomenon which is typically referred to as Arctic amplification. The interaction, strength, and relative importance of the processes relevant for Arctic amplification are not yet fully understood, and models fail to reproduce and predict the changes in the Arctic (Pithan & Mauritsen, 2014; Serreze & Barry, 2011). Clouds play a significant role in the global climate system and are especially important for the energy budget of the Arctic boundary layer (Intrieri, 2002; IPCC, 2014). They can have a cooling effect by reflecting shortwave solar radiation or lead to a warming effect if they reflect terrestrial longwave radiation.

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