Clouds and precipitation in the initial phase of marine cold air outbreaks as observed by airborne remote sensing

• DOI: 10.5194/egusphere-egu24-5220
• Publication Date: 2024-03-08T14:37:51Z
• Authors: Imke Schirmacher; Sabrina Schnitt; Marcus Klingebiel; Nina Maherndl; Benjamin Kirbus; Susanne Crewell

During Arctic marine cold air outbreaks (MCAOs), and dry flows from the central southward over open ocean. There, cloud streets form that transform to cellular convection downstream under extreme surface heat fluxes. MCAOs strongly affect water cycle through large-scale mass transformations can lead weather conditions at mid-latitudes. The description of is still challenging partly because previous observations do not resolve fine scales lack information about microphysical properties. Therefore, we focus on crucial initial phase development within first 170 km two MCAO events with different strengths observed during HALO-(AC)3 campaign. Both times POLAR 5 6 aircraft flew several legs along same track perpendicular crossing sea ice edge allow a quasi-Lagrangian perspective. Based high-resolution remote sensing in-situ measurements, boundary layer, formation clouds, onset precipitation, riming are studied. We establish novel approach based radar reflectivity measurements only detect roll circulation forms streets. For event stonger contrast between 850 hPa potential temperature (MCAO index), tops higher, more liquid-topped clouds exist, liquid layer top wider, path, mean reflectivity, amount rime mass, precipitation rate occurrence larger compared weaker event. However, width similar for both events. All parameters, moreover, evolve distance water, as deepens heights rise. Cloud after traveling 15 water. After 20 km, cover increases just below 100 % around 30 forms. find maxima in have horizontal scale circulation. presentation will highlight how macro- parameters vary explain differences