Progetti Finanziati

L'esperimento ALPACA (ALaskan Pollution And Chemical Analysis), coordinato dall'Università dell'Alaska in Fairbanks, è il primo grande esperimento internazionale sulla qualità dell'aria nelle città artiche. La campagna sperimentale, che ha avuto luogo tra gennaio e febbraio 2022 a Fairbanks, ha cercato di delineare le cause degli eventi critici di inquinamento da particolato atmosferico (PM) delle città artiche nei periodi di alta pressione durante i mesi invernali. Sono state considerate le possibili sorgenti da combustione (dal riscaldamento domestico alle centrali termiche) e le variabili meteorologiche tipiche dei mesi freddi alle alte latitudini. Sono state inoltre caratterizzate le deposizioni nevose. Infine, il progetto ha coinvolto associazioni di cittadini interessate al miglioramento della qualità dell'aria a Fairbanks, nonché enti regolatori e di monitoraggio (EPA).

The Arctic is experiencing the most dramatic impact of t he present climate change, amplifying and driving changes elsewhere in the Earth system. This “Arctic Amplification” is due to peculiar feedbacks between climate forcings and environmental responses, especially involving large changes in surface albedo, over land, sea and long-range transport patterns of air pollutants. A detailed knowledge of the atmospheric processes at different scales can help to define the main causes of “Arctic Amplification”. In this scenario, vertical structure of the Arctic Boundary Layer (ABL) is a key element that can influence aerosol size distribution, chemical composition and its Svalbard is Norway’s northernmost region, and the archipelago is one of the northernmost land-areas in the world. In this archipelago is Ny-Ålesund, a small research town hosting several national and international institutions and their long-term research programmes and projects. This site is a perfect opportunity to investigate ABL thanks to the availability of these three essential facilities in the same place: Gruvebadet (GVB) atmospheric observatory, Zeppelin (ZEP) station and Amundsen-Nobile Climate Change Tower (CCT).
GVB (78.918°N, 11.895°E; 61 m above sea level) is located 800 m south-west of the Ny-Ålesund and it is managed by ISP-CNR. It is an atmospheric laboratory dedicated to the chemical and physical monitoring of atmospheric aerosol begun in 2010 and is still ongoing; the sampling was normally performed from March to October for each year, but since winter 2018/2019, all-year-round samplings have started. Moreover, several campaigns were performed using a tethered balloon equipped also with an optical particle counter (OPC) and meteorological sensors to investigate size-segregated particle samples at ground level and in the free atmosphere and to provide aerosol profiles in and above the boundary layer.
The ZEP observatory (78.908°N, 11.881°E; 474 m above sea level) is located at the top of the Zeppelin mountain, about 3 km from the coast of the fjord and 1 km from GVB. It is owned and managed by the Norwegian Polar Institute and is part of the Global Atmospheric Watch network. Compared to stations closer to sea level, the ZEP station is less affected by local anthropogenic aerosol and pollution sources and by local air flow phenomena such as katabatic winds.
The CCT was installed at the end of 2009 about 2 km west of Ny-Ålesund on the southern coast of Kongsfjorden. The tower is 34-m high and the main sensors are sonic anemometers and low-frequency thermo-hygrometers and anemometers. CCT was conceived to provide a scientific platform for atmospheric monitoring activities in an orographically complex area, to complement other researches, and to host new experiments and instruments devoted to the study of the ABL dynamics, in different atmospheric conditions.
Aerosol plays a relevant role on climate by scattering and absorbing the solar radiation and by influencing cloud formation (i.e. cloud condensation nuclei). Aerosol particles are transported from the middle latitude influencing the composition of Arctic atmosphere, with consequent effects on cloud formation, albedo or sea ice. Several aspects remain poorly known, representing the challenge of the recent aerosol research. For example, organic compounds have notable consequences for atmospheric chemistry and cloud formation, but limited information about the sources of key compound classes such as sugars were produced. On the other hand, the positive forcing of black carbon (BC) is well known because it enhances light absorption processes in the atmosphere, especially in the Arctic, and after its deposition over the glaciers, where triggers and accelerates melting processes. However, the dynamics of BC entertainment in the ABL are still a poorly understood process and may have a wide variability depending on local conditions.
The key challenge of BETHA-NyÅ is to set up an inter-comparison aerosols measurement experiment between GVB and ZEP stations to understand the ABL dynamic effects on the aerosol composition in the Arctic region. The composition data obtained at the two stations will be integrated with meteorological information obtained at CCT and through radiosondes. The sampling alignment in a long-term scenario will be crucial to obtain statistical significant conclusions about the impact of ABL on the atmospheric composition in the Arctic.

The project aims at quantifying the impact of precipitation on the surface distribution of ice and snow and on the surface radiation budget. The goal will be achieved by means of an integrated approach based on ground-based, in situ, and satellite-based measurements in combination with a regional climate model. Observations will be used also to improve model representations of key physical processes. Field activities will take place at the Thule High Arctic Atmospheric Observatory, Greenland.