Abstract. Various aerosols, including mineral dust, soot, and biological particles, can act as ice nuclei, initiating the freezing of supercooled cloud droplets. Cloud droplet significantly impacts properties and, consequently, weather climate. Some nuclei exhibit exceptionally high nucleation temperatures close to 0 °C. Ice-nucleating macromolecules (INMs) found on pollen are typically not considered among most active nuclei. Still, they be highly abundant, especially for species such...

Abstract. Within the last years pollen grains have gained increasing attention due to their cloud-forming potential. Especially discovery that ice nucleating macromolecules (INMs) or subpollen particles (SPPs) obtained from are able initiate freezing has stirred up interest in pollen. INMs and SPPs much smaller potentially more numerous than could significantly affect cloud formation atmosphere. However, not clearly distinguished. This motivated present study, which focuses on birch...

Scots pine (Pinus sylvestris) is the most widespread species in world. It grows largest forest system northern hemisphere and, together with birch trees, occupies a major part of boreal forests. Recently, trees have been discovered as important emission sources terrestrial ice-nucleating macromolecules (INMs) coming from pollen, bark, leaves, petioles, branches, and stem surfaces. known that pollen nucleate ice; however, potential other tree parts releasing INMs contributing to ice-active...

Ice-nucleating proteins (INpro) trigger the freezing of supercooled water droplets relevant to atmospheric, biological, and technological applications. The high ice nucleation activity INpro isolated from bacteria

Terrestrial ecosystems can influence atmospheric processes by contributing a huge variety of biological aerosols (bioaerosols) to the environment. Several types particles, such as pollen grains, fungal spores, and bacteria cells, trigger freezing in super-cooled cloud droplets, contribute hydrological cycle. Even though biogenic particles are known most active form ice nucleation (INPs), transport high tropospheric altitudes, well occurrence clouds, remains understudied. Thus, from land...

In alpine environments, many plants, bacteria, and fungi contain ice nuclei (IN) that control freezing events, providing survival benefits. Once airborne, IN could trigger nucleation in cloud droplets, influencing the radiation budget hydrological cycle. To estimate atmospheric relevance of IN, investigations near emission sources are inevitable. this study, we collected 14 aerosol samples over three days August 2019 at a single site Austrian Alps, close to forest silver birches, which known...

Organic matter can initiate heterogeneous ice nucleation in supercooled water droplets, thereby influencing atmospheric cloud glaciation. Predicting the ability of organic matter-containing droplets is challenging due to unknown mechanism for templating ice. Here, we observed presence nanoparticles aqueous samples known ice-nucleating biopolymers cellulose and lignin, as well newly identified xylan laminarin. Using our drop Freezing Ice Nuclei Counter (FINC), measured median temperature...

Abstract. Silver birch (Betula pendula) is known to contain ice-nucleating macromolecules (INMs) survive in harsh environments. However, little about the release and transport of INMs from trees into atmosphere. In this study, we conducted situ vivo investigations on nine birches growing an alpine valley (Ötztal, Austria). A detailed analysis drill cores showed that INM concentration increases towards outer layers, reaching its maximum near surface. Aqueous extracts surfaces leaves, bark,...

Abstract. Within the last years pollen grains have gained increasing attention due to their cloud forming potential. Especially discovery that ice nucleating macromolecules (INM) or subpollen particles (SPP) obtained from are able initiate freezing has stirred up interest in pollen. INM SPP much smaller and potentially more numerous than could significantly affect formation atmosphere. However, not clearly distinguished explanations on how these materials distribute atmosphere missing. In...

Ice-nucleating proteins (INpro) trigger the freezing of supercooled water droplets relevant to atmospheric, biological, and technological applications. The high ice nucleation activity INpro isolated from bacteria Pseudomonas syringae has been suggested occur by aggregation at bacterial membrane or air-water interface (AWI) droplets. Here, we show direct evidence this proposed mechanism. We monitored droplets, between two hydrophobic glass slides, with a high-speed camera on cryo-microscope....

Ice-nucleating proteins (INpro) trigger the freezing of supercooled water droplets relevant to atmospheric, biological, and technological applications. Ice nucleation caused by INpro from bacteria Pseudomonas syringae has been suggested initiate at bacterial membrane or air-water interface (AWI) droplets. Here, we show direct evidence this proposed mechanism. We monitored droplets, between two hydrophobic glass slides, with a high-speed camera on cryo-microscope. Onset sites sterilized P....

Abstract. Organic matter in agricultural soil dust can enhance dust's ice-nucleating ability relative to mineral dust, and thus impact local cloud formation. But how is this organic able nucleate ice? We hypothesised that hydrophobic interfaces, such as the air-water interface, influence nucleates ice, which be quantified by measuring surface tension. Here, we investigated correlations between surfactant properties activities of amphiphilic macromolecules common soils known ice nucleators,...

A wide range of aerosols, including dust, soot, and biological particles, can serve as ice nuclei, initiating the freezing supercooled cloud droplets. This process significantly impacts characteristics, consequently, weather climate. Among some exhibit exceptionally high nucleation temperatures. While Ice Nucleating Macromolecules (INMs) found on pollen are typically not among most active they abundant, evidenced by their presence throughout tissues trees. Notably, recent studies have shown...

Due to the changing climate, wildfires globally have been increasing in size and intensity. With increase of these biomass burning events there is a surge organic aerosols present atmosphere. Recent evidence from our group community suggests that can catalyze heterogeneous ice nucleation.1–3 Currently, nucleation largest source uncertainty climate models as it governs formation mixed-phase clouds, important regulators linked annual precipitation global cloud coverage. We are...

Organic matter can initiate heterogeneous ice nucleation in supercooled water droplets, thereby influencing atmospheric cloud glaciation. Atmospheric organic includes biopolymers, which are emitted as primary bioaerosols, biomass burning aerosols, soil dust and sea spray aerosols nucleate the absence of a solid surface like mineral dust. There is evidence that biopolymers could form aggregates solution, creating ice-nucleating sites. However, submicron size heterogeneity these creates...

Abstract. Various aerosols, including mineral dust, soot, and biological particles, can act as ice nuclei, initiating the freezing of supercooled cloud droplets. Cloud droplet significantly impacts properties and, consequently, weather climate. Some nuclei exhibit exceptionally high nucleation temperatures close to 0 °C. Ice Nucleating Macromolecules (INMs) found on pollen are typically not considered among most active nuclei. Still, they be highly abundant, especially for species such...

<p>Wind pollinated trees such as birch release large amounts of pollen to the atmosphere during their blooming season in early spring. Due size (birch diameter: 20-25 µm) and short residence time atmosphere, impact on cloud formation was believed be negligible. However, recent years studies have shown that ice nucleating materials, so called macromolecules (INM), much smaller can extracted from pollen. At same there is evidence medical rupture under conditions high...

Scots pine (Pinus sylvestris) is the most widespread species in world. It a major tree found northern hemisphere and large parts of boreal forest. In recent studies, birch trees, another notable forest, have been identified as an important emission source ice-nucleating macromolecules (INMs). The INMs were pollen1 all over tree’s tissue (e.g., branch wood, bark, petioles, leaves)2,3. Similarly, pollen to be ice nucleation active, but until now, no further investigation from other...