Progetti di ricerca

Atmospheric mineral dust (hereby ’dust’) is a key component of the Earth system and has widespread climatic impacts. Dust affects the global climate and environment through, for example, radiative forcing, cloud formation, and nutrient cycles1,2, but its parametrisation in global climate and… Leggi tutto Earth system models is defective3-5. Recently, the current net effect of dust direct radiative forcing on global climate was calculated as most likely negative, although potentially slightly positive given the large uncertainty on this estimate (-0.2 ± 0.5 W m-2 with 90% confidence interval5 ). Many uncertainties remain in such calculations, largely caused by incomplete data on the chemical and physical properties of dust particles, and on the meteorological processes and driving mechanisms behind dust emission, transport, and deposition (‘dust cycle’). While climate models have become increasingly complex, the parametrisation of dust processes, although also improving, lags behind this development, and its uncertainties amplify as models get more sophisticated4 . This limits our understanding on the Earth system as a whole and hampers the ability of models to predict the effects of climate changes on the natural world and societies. A necessary first step to enhance models is to have more observational data on dust properties. The arid and semi-arid East Asia is one of the key global dust sources, but, for example, observational studies on East Asian dust mineralogy were ~50% less than those from the northern African region by 20156 . Compared to other major global dust sources, East Asia is unique in that it also hosts a globally exceptional geologic archive of windblown dust from the past ~25 million years, the Chinese Loess Plateau (CLP; Fig. 1). Extensive research, especially provenance studies, on the CLP dust deposits has been a key in revealing the long-term, two-way link between dust and climate changes in the Earth’s history7-10 . Dust provenance analysis is, in fact, one of the few methods that simultaneously provide information on all the steps of the dust cycle (emission, transport, deposition). Because of the scarcity of interdisciplinary studies involving both atmospheric scientists and geologists, the CLP region has much unused potential to establish a link between past and present dust activity to better understand both and to enhance the modelling aspects of dust11-13 . In this project, I study the properties and provenance of dust collected by active and passive samplers in East Asia during 2019–2023.

Extreme events in Europe have been shown to affect forest health status and they will likely increase in frequency, causing significant impacts. Super-sites integrating long-term ground observations and multi- scale spectral information need to be established across biogeographical regions, focusing on key… Leggi tutto forest types that have already shown significant degradation (such as evergreen and deciduous oak forests, and southern European pine forests). In this context, the FlyFor will combine hyperspectral and solar-induced chlorophyll fluorescence airborne measurements to determine tree stress responses along a stress severity axis, to upscale current and possible future climate impacts on forests. A biogeographical west-European transect including three super-sites (in forest ecosystems which are showing mild to severe signs of decline) was designed including: i) Mediterranean evergreen oak forests, ii) continental deciduous oak forests, iii) low altitude alpine pine forests. Ground-truth data available at the selected super sites (Eddy Covariance, defoliation, sap flow, canopy hyperspectral reflectance and SIF) will be integrated with additional FlyForSIF measurements (airborne SIF, Leaf Area Index, Leaf Water Content, Specific Leaf Area, leaf pigment content and leaf Pulse-Amplitude- Modulation-PAM fluorescence). Pigments (including xanthophylls) will be measured at selected trees during the summer of 2025. Flight campaigns will be carried out with IBIS-CASI-SASI hyperspectral sensors. The ability of single-tree spectral information to detect tree stress will be tested and upscaled to the satellite level using PlanetScope imagery. In the FORWARDS initiative context, the expected results will act as a proof of concept for the future implementation of a multi-scale tool for long-term detection of climate change impacts on European forests.