The Climate Change Tower Integrated Project (CCT-IP) represents the guide lines of the italian research in the arctic and aims to study the interaction between all the components of the climate system in the Arctic. The Amundsen-Nobile Climate Change Tower (CCT) is the key infrastructure of the project, and provides continuous acquisition of the atmospheric parameters at different heights as well as at the interface between the surface and the atmosphere. Turbulent parameters are measured at the Amundsen-Nobile Climate Change Tower (CCT) by means of a Gill R3 sonic anemometer installed at 7.5 m from the ground since 2010. It measures the three components of the wind (u, v and w) and the sonic temperature at a rate of 20 Hz. These micro-meteorological measurements are complemented by standard meteorological ones at 4 levels: 2, 5, 10 and 33 m (acquisition time step equal to 1 minute). From these measurements, sensible heat flux, friction velocity and roughness length are calculated. Wind components and sonic temperature measurements were used to estimate friction velocity and kinematic heat flux. Before computing the micrometeorological parameters, a preliminary analysis is applied in order to assess the data quality and to remove low quality records. After the quality analysis application, mean values of the turbulence statistics were computed following two coordinate rotations to ensure the mean lateral and vertical velocities were zero (McMillen, 1988). Half-hour turbulent statistics (heat fluxes and friction velocity) were derived using two time-scales: a standard averaging time of 30 min and a reduced one (2 min) necessary for filtering out submeso motions contributions that can greatly alter the estimation of turbulent fluxes in a strong and long-lived stable BL. The short averaging time scale was evaluated on the basis of spectral analysis of data in order to include all turbulent scales, but excluding submeso motions (larger than turbulence). The turbulent statistics evaluated over the short subsets and then re-averaged over 30 min following Vickers and Mahrt (2006). Turbulent parameter relative to unfavorable wind direction ([150÷270] degrees) for which the tower was upwind of the sonic anemometer were not discarded but are flagged (flagdir=1) in the final dataset. More, the percentage of NaNs relative to each run is indicated. The wind speed vertical profile measured by slow response standard meteorological anemometers at 2, 5, 10 and 33 m was used for estimating the roughness length assuming a typical log wind profile under statically neutral conditions. Mahrt, L., 1998. Flux Sampling Errors for aircraft and towers. J. Atmos. Ocean. Technol. 15, 416-429. Mc Millen, R.T., 1988. An Eddy correlation technique with extended applicability to non-simple terrain. Boundary-Layer Meteorol. 43, 231-245. Vickers D, Mahrt L. 2006. A solution for flux contamination by mesoscale motions with very weak turbulence. Boundary-Layer Meteorol. 118: 431–447. https://doi.org/10.1007/s10546-005-9003-y. Zahn, E., Chor, T.L., Dias, N. L., 2016. A Simple Methodology for Quality Control of Micrometeorological Datasets. American Journal of Environmental Engineering 6(4A): 135-142 DOI: 10.5923/s.ajee.201601.20.

Aerosol sampling by a High-Volume Sampler (TECORA eco-highvol equipped with digital PM1 sampling inlet, nominal flow 500 lpm) for the collection of ambient aerosol particles with aerodynamic diameter < 1 μm (PM1) on pre-washed and pre-baked quartz-fiber filters (PALL, Ø= 18cm). Sampling time: 3-4 days per sample. A multi-technique analytical approach for the characterization of the sampled organic aerosol: Organic matter (OM) and Organic Nitrogen (ON). Analytical techniques employed are based on nuclear magnetic resonance spectroscopy (NMR) and Aerosol Mass Spectrometry (HR-TOF-AMS applied off-line) for the OM characterization, C and N elemental analysis (CN-EA) and ion chromatography (IC) for inorganic ions and alkyl-amines. -NMR functional groups (Aromatics, anomeric/vynilic, H-C-O, H-C-C=, H.C) -NMR tracers: Levoglucosan, Methane-sulphonic acid (MSA), Hydroxymethane-sulphonic acid (HMSA), Amines (mono-, di- and tri-methyl amines, etc.) -HR-TOF-AMS (off-line): main species (Org, SO4, NO3, NH4, Chl), elemental ratios (OM:OC, O:C, H:C) & tracer fragments (m/z43, 44, 60 etc.) -NMR & AMS OA source apportionment

Aerosol Flux in Arctic (ALFA) Evaluate aerosol dry deposition/emission in the Arctic on icy/snowy surface and its dependence on particle size and micrometeorological parameters. The measures of the particles exchange rate will be carried out with the technique of eddy-correlation at Ny Alesund in size-segregated mode (2-3000 nm) coupling a sonic anemometer, a CPC and an optical particle counter (OPC) that are able to detect fluctuations of the particles concentration at high frequency (1Hz).

Activities: - PM1 sampling by a High-Volume Sampler (TECORA eco-highvol equipped with digital PM1 sampling inlet, nominal flow 500 lpm) on pre-washed and pre-baked quartz-fiber filters (PALL, Ø= 18cm). Sampling time: 3-4 days per sample. - Off-line filter based AMS characterization of water soluble non-refractory sulfate, nitrate, ammonium, chloride, and organic mass (NR-PM1). - Off-line filter-based spectroscopic characterization of the water-soluble organic mass in term of chemical functional groups and specific markers by means of proton-Nuclear Magnetic Resonance spectroscopy (H-NMR). - Source apportionment of organic aerosol by means of multivariate statistical techniques (namely Positive Matrix Factorization, PMF, and other factor analysis methods) applied on both AMS and NMR spectral datasets. Available data: -NMR functional groups (Aromatics, anomeric/vynilic, H-C-O, H-C-C=, H-C) -NMR tracers: Levoglucosan, Methane-sulphonic acid (MSA), Hydroxymethane-sulphonic acid (HMSA), Amines (mono-, di- and tri-methyl amines, etc.) -HR-TOF-AMS (off-line): main species (Org, SO4, NO3, NH4, Chl), elemental ratios (OM:OC, O:C, H:C) & tracer fragments (m/z43, 44, 60 etc.) -NMR & AMS OA source apportionment

Ice Nuclei Particle Concentration (INP) Ice nucleating particle (INPs) concentration obtained in spring and summer campaigns in the Arctic Region. Sampling lines allow the aerosol particles collection onto the filters and the sampling line for the continuos measurements of size distribution with the OPC and SMPS. The aim is to improve our understanding of aerosol-cloud-climate interactions and representation of climate models.

Ice Nuclei Particle Concentration (INPAIR) INPAIR Svalbard' Chemistry and Physics of the Atmosphere: Ice nucleating particle (INPs) concentration obtained in spring and summer campaigns in the Arctic Region. Measurements of INPs concentrations and activation fraction of aerosol in Arctic (e.g. Gruvebadet observatory in Ny-Ãlesund). b) Correlating INPs concentration with meteorological parameters and physicochemical characterisations. Instrument: PM1 and PM10 sampling lines. DFPC chamber

Arctic Metrology (MeteoMet - Arcitc) Project start:2017-03-01 end: 2022-02-01 Field calibration of thermometers for air, soil, permafrost and water temperature measurements using special transportable chamber and dedicated calibration procedures. Evaluation of field measurement uncertainty. Calibration of different kind of instruments and sensors. Dedicated calibration procedures. Documented traceability to SI standards. Field measurement uncertainty evaluations.