Urban air pollution, climate change and wildfires: The case study of an extended forest fire episode in northern Italy favoured by drought and warm weather conditions

The aim of the paper is to describe the spread forest fire event occurred in the Italian Alps in 2017 under extremely drought conditions. In the study the root causes of wildfires and their direct relapses to the air quality of the Western Po valley and the urban centre of Torino have been assessed by means of air pollution measurements (focused to particulate matter with reference samplers and optical particle counters OPCs), meteorological indicators and additional public data. Results show a good correlation among different urban sites and instrument technologies. Concentration data, compared with environmental conditions and historical values describe the clear impact of fires on both local and regional air quality. Indeed, the deferred impact of wildfires on the local wood biomass energy supply chain is briefly outlined. Keywords: Air quality, Biomass, Climate change, Forest fires, Particulate matter, Wildfire

Applying a probabilistic model of rainfall and snow days occurrence to daily series recorded in NW Italy.

Daily precipitation records exist spanning several decades. A valuable amount of climatic information exists in the time-series of interarrival times (IT), defined as the succession of times (number of days) elapsed from a rainy (or snowy) day to the one immediately preceding it.In a previous work, Agnese et al. (2014) have been successfully tested some probabilistic modelling of rain occurrence on Sicily rainfall data; particularly, the better fitting of IT’s observed frequencies was obtained by 3-parameter Lerch-series distribution. In this work thisdistribution is tested on 70 years of 20 precipitation time-series taken in the North-West Italy, both in the plain and in the mountains, up to the 2000 meters altitude. In such Mediterranean climatetwo markedly different behaviours were observed in the dry semester (April to September) and in the wet one (October to March). A better fit was obtained with that simple subdivision of the year, in comparison with the whole year modelling. However, the NW Italy climate is both more similar to the Central Europe one, and it is deeply influenced by the higher peaks of the Alps. Therefore the seasonality of daily precipitation data is much more complicated. Usually spring and fall are the seasons characterized by the higher precipitations, but the convective vs. frontal events also play a role in the IT distributions. In this work, different subdivisions were compared with the whole year fitting. The whole year Lerch distributions successfully fitted the data in a part of the time series, opening the way to interesting climate applications

Variations of Lys Glacier (Monte Rosa Massif, Italy) from the Little Ice Age to the Present from Historical and Remote Sensing Datasets

Alpine glaciers respond to climate imbalance by adjusting their mass and length. In turn, these changes modify the glacial and periglacial environment, leading to increased supraglacial debris cover, the development of glacial lakes and glacier fragmentation. In this research, we investigated the evolution of Lys Glacier (Monte Rosa Group), by studying length, area and volume changes, and evolution of its supraglacial debris cover and proglacial lakes by means of historical sources and high-resolution aerial and satellite orthophotos. Lys Glacier retreated almost continuously, by nearly 2 km, from its maximum Little Ice Age position. More recently, the glacier lost 11.91% of its area between 1975 and 2014 and underwent fragmentation in 2009. Over the same period, glacier fragmentation and tongue stagnation affected the formation and rapid growth of a series of ice-contact lakes and led to a non-linear debris cover evolution. The glacier was also subjected to strong volume losses, with more than 135 m thinning on the ablation tongue from 1991 to 2014. Analysis of the meteorological records (1927–present) from the closest weather station reveals a considerable increase in average annual temperatures by more than 1°C from the mean of 1971–1989 to the mean of 1990–2017

Ricostruzione del clima medioevale nelle Alpi occidentali tramite fonti archivistiche. Il progetto Archlim

Un échantillon significatif de sources d’archives publiées sur la période 800-1400 dans une région centrée sur les Alpes occidentales a été fouillé à la recherche de citations d’événements climatiques, grâce au soutien financier de la Compagnia di San Paolo de Turin (Projet Archlim). Environ 900 événements de froid intense, canicules, chutes de neige, tempêtes, inondations, sécheresses, conditions des cols alpins, dont 650 concernant les Alpes occidentales, ont été récensés et numerisés. Ce materiel a été validé et analysé aux moyens d’indices d’anomalie. Les résultats ramènent a des plus justes proportions la période chaude médiévale (Medieval Warm Period -MWP), auparavant considerée très douce et sans anomalies thermiques négatives, caractérisée au contraire par de fréquents épisodes froids (88 % des données) et par un important enneigement des cols alpins.Mercalli Luca, Cat Berro Daniele. Ricostruzione del clima medioevale nelle Alpi occidentali tramite fonti archivistiche. Il progetto Archlim. In: La Gazette des archives, n°230, 2013-2. Les sources d’archives pour l’étude du climat et de l’environnement. pp. 67-77

Long-term changes in the ionic composition of Italian alpine lakes, in relation with climate change

To estimate the effects of climate change on the ionic composition of Alpine lakes, we compared the analysis performed in the 1980\u27s and in the second decade of the 21th century on about fifty high mountain lakes located in the Western and Central Alps, Italy. In spite of a high lake-to-lake variability, a general increasing trend in conductivity and in most ionic concentrations was detected, particularly evident in the lakes with a higher solute content. An increase in the contribution of sulfate to the total ionic content was also found. Changes in the ionic composition were more marked in lakes having rock glaciers and/or retreating glaciers in their catchments: present concentrations of major ions generally resulted more than twice the values of the 1980s in the formers, and up to 4 times in the latters. To test the hypothesis that changes in snow and glacial cover in lake catchments were more important than temperature alone in affecting lake chemistry, we also analysed the relationship between year-to-year variability in lake water chemical composition and selected meteorological variables in 4 lakes in Ossola Valley (Central Alps), sampled almost every year from 1978 to 2015. Finally, a spring originating from a rock glacier and feeding one of these lakes was also studied in detail to identify the effects of short-term meteorological variability

Observed snow depth trends in the European Alps: 1971 to 2019

International audienc