INoVA · Geochemical Controls on the Ice Nucleating Efficiency of Volcanic Ash
„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“
- Период
- 2018-01-22 → 2020-01-21
- Финансиране от ЕС
- 183 455 €
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- MSCA-IF-EF-ST
Линиите свързват координатора с партньорите.
Накратко на български
Вулканичната пепел и нейният химичен състав се изследват, за да се разбере как частиците от нея стимулират образуването на лед в облаците. Това помага за по-доброто разбиране на атмосферните процеси и влиянието им върху климата на Земята.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Geochemical Controls on the Ice Nucleating Efficiency of Volcanic Ash
Ice formation has a major impact on the properties and lifetime of clouds yet remains one of the least well understood processes indirectly affecting the Earth’s climate. Ice-nucleating particles (INPs) promote ice formation in supercooled water droplets at temperatures down to ~-38 °C. Although the abundance of INPs in the atmosphere is low - typically comprising only one in a million particles - they exert a profound influence on clouds. Research that seeks to describe how well and explain why different airborne particles nucleate ice is thus central to our understanding of the atmosphere and climate. While desert dust lofted by wind is considered one of the most important INP types globally, an impact of volcanic ash from explosive eruptions on ice formation is increasingly recognised, with airborne ash sporadically dominating INP populations. Ash is made up of aluminosilicate glass and minerals and iron(-titanium) oxide minerals. Previous field and laboratory studies present conflicting evidence on the ice-nucleating activity (INA) of ash, and it is not clear what drives the large variation observed. Studies on dust suggest that factors such as chemical composition, crystallinity, and mineralogy of the solid particles can influence their INA; the same may be true for ash but this has not been systematically investigated before now. The overarching objective of the INoVA project was to quantify the INA of volcanic ash and to relate this to geochemical factors including ash properties and history. Specifically, the following hypotheses were tested: the INA of ash is (H1) influenced by its chemical composition, crystallinity, and mineralogy as determined by the source magma conditions, (H2) reduced by interaction with acidic gases at high temperatures in the eruption plume and cloud, and (H3) reduced by exposure to acidic condensates at ambient temperature in the atmosphere. These hypotheses were studied by combining laboratory approaches (experiments and analyses) across geochemistry and atmospheric science disciplines, providing new insights on factors potentially affecting the role of airborne ash in ice nucleation.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Ice formation in the atmosphere has a major impact on the properties and lifetime of clouds yet is one of the least well understood processes indirectly affecting the Earth’s climate. Heterogeneous ice nucleation by airborne solid particles (‘ice nuclei’) exerts a profound influence on clouds by raising the temperature at which ice can form relative to by homogeneous freezing of supercooled water droplets. Volcanic ash from explosive eruptions is increasingly recognised to be capable of acting as ice nuclei but factors determining the ash ice nucleating efficiency have yet to be elucidated. As for mineral dust from arid and semi-arid regions, physicochemical properties of the solid particles such as crystallinity, mineralogy and composition likely play a role in their ice nucleating efficiency, but this remains poorly understood and has not been systematically investigated for volcanic ash. In addition, the influence of thermochemical processes/conditions in the source magma, in the eruption plume and cloud, and in the ambient atmosphere on ash ice nucleating efficiency is not known. The proposed research will address this gap in knowledge through an experimental approach uniquely bridging volcanic geochemistry and atmospheric science, to establish the link between ash ice nucleating efficiency and its physicochemical properties and magmatic, eruptive and atmospheric history. A range of natural ash and synthetic ash, generated and treated under controlled laboratory conditions, will be studied. Experimental data will be parameterised for use in model simulations to predict regional ice nuclei concentrations based on an Icelandic eruption scenario. Collectively, the proposed research, training and knowledge transfer activities will enhance the future prospects of both the Fellow and host, while contributing to the greater benefit of society by improving understanding of the potential impacts of ash emissions from explosive eruptions on the atmosphere and on climate.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITY OF LEEDS · LeedsКоординаторОбединеното кралство
Връзки
Данни: CORDIS, © Европейски съюз