Calibrated (in unit of solar disk brightness) measurements of the sky brightness at DOME C as obtained by the ESCAPE experiment during the campaign 2019-2020

Backscattering and depolarization data from a LIDAR positioned at Concordia Station (Dome C, Antarctica). Data are available on the INO-CNR server on request to Dr. Massimo Del Guasta. The main objective of the FIRCLOUDS projectis a complete spectral characterization of cirrus and mixed phase clouds in order to evaluate the radiative models in the FIR regime, where the clouds effect is very strong, and systematic spectral measurements are scarcely available. A backscattering/depolarization lidar contributes to the estimation of the clouds position and phase, and of the optical extinction profile.

Calibrated (in unit of solar disk brightness) measurements of the sky brightness at DOME C as obtained by the ESCAPE experiment during the campaign 2021-2022

Here we present the firn cores collected along the international EAIIST project traverse, which took place in 2019-2020 Antarctic Campaign. We report the number of firn cores collected, the depth of the samplings and their geographic information.

We will collect oral samples from the volunteers at the Mario Zucchelli Station at different time points, using safe and not harmfull kits. Samples will be analysed by shotgun metagenomic sequencing, considering only the microbial component.

This dataset reports the water stable isotope composition (d18O, dD, D-excess) of precipitation at the Concordia Station, Antarctica. Daily precipitations are collected on benches (height: 1 m) in the clean area 800 m from the Station by the Concordia winter-over personnel. All samples are analyzed with laser spectroscopy (CRDS) or mass spectrometry (IRMS). 2008-2017 data are available here: https://doi.org/10.5281/zenodo.10197160; 2017-2021 data are available here: https://doi.org/10.1594/PANGAEA.971486

Concentrations of major, minor and trace elements in particulate matter (PM10) samples, collected at Concordia with monthly time resolution, since January 2018, obtained by PIXE-PIGE and HR-ICP-MS measurements.

Terra Nova Bay (Ross Sea, Antarctica), characterized by a moltitude of ice tongues flowing from land to sea, represents an ideal study site for understanding the complex interaction between relative sea level variations and ice sheet dynamics during the Holocene. The DISGELI project, thanks to the combination of innovative technology and traditional methods for geomorphologic and stratigraphic analysis, aims to: i) reconstruct the local variations of the East Antarctic Ice Sheet after the Last Glacial Maximum; ii) provide a time constrain for the deglaciation processes along the coast; iii) reconstruct, with unprecedent detail, the relative sea level variations during Holocene in the Drygalski basin. The morpho-bathymetric and topographic data obtained through this study will be integrated using digital terrain models based on the analyses of key areas onland, where palaeo-coastlines and sea-level markers have been identified.

Antarctic ecosystems have a high number of species, that are closely linked to the presence of sea ice and seasonal cycles. This biodiversity is subject to anthropogenic and natural influences. Macrozoobenthic communities are the 'biological memory' of the ecosystem, structuring themselves as a function of environmental changes over the years. Macrozoobenthos samples were collected using suction dredging and scraping techniques, in soft and hard bottoms. Sampling occurred in 5 different sites.

The main goal of the project is the identification of well-characterized case studies aimed at a radiative self-consistency experiment of ice clouds and in mixed phase on the Antarctic Plateau, as well as the improvement of current spectral patterns in the far-infrared region. This can be achieved through the synergistic use of various measurement instruments operating in different bands of the electromagnetic spectrum and installed at the Concordia base, particularly at the Physics shelter. The infrared radiation emitted by the atmosphere and clouds is measured by the Fourier transform spectroradiometer REFIR-PAD (Radiation Explorer in Far Infrared - Prototype for Applications and Development) operating at Concordia since 2012 inside the DoCTOR PNRA project by Dr. Giovanni Bianchini (https://www.pnra.aq/it/project/330/dome-c-tropospheric-observer-osservatorio-troposferico-dome-c). The position and phase of clouds is estimated by the backscattering and depolarization LIDAR active since 2008. The particle size distribution can be estimated by an ICE- CAMERA, i.e., a kind of optical scanner that collects precipitating ice crystals on the shelter roof. As of the 2018-2019 campaign, a 24 GHz weather radar (Micro Rain Radar, MMR) operating continuously has been installed on the roof of Physics, which can provide an estimate of the precipitation rate of ice crystals and the falling velocities of those crystals. From these measurements, efforts are also being made to estimate the ice content in the case of precipitating ice clouds. Finally, during the last 2019-2020 campaign, a HALO-CAMERA was also installed, which can provide an estimate of the shape of ice crystals that can be used as a priori information in transfer models radiative suitable for simulating the effect of clouds. In order to complete the radiative closure (or self-consistency) experiment, the idea is to use the values of the parameters of the precipitating ice clouds, i.e., optical thickness and effective diameter, obtained from the inversion of the spectra produced by REFIR-PAD, to characterize the size distribution of the ice crystals and use the latter to calculate the reflectivity at the MRR radar wavelength, i.e., 24 GHz. The calculation of reflectivity obviously depends on the type of particles (habit) that are assumed, so the inversion procedure of the spectra produced by REFIR-PAD is repeated assuming different types of particles, thus using different optical property databases depending on whether aggregates, bullet rosettes, hexagonal columns, platelets or hollow columns are used. Consequently, the same habit assumptions will have to be made for the calculation of radar reflectivity. The reflectivity obtained can at this point be compared with the experimental reflectivity measured by MRR. Data analysis was carried out by Dr. Alessandro Bracci of ISAC-CNR and Giacomo Roversi of Ca' Foscari University of Venice, both belonging to the group led by Dr. Luca Baldini. Unfortunately, the very small size of the crystals at Concordia, due to the extremely low temperatures and very low humidity values, make it difficult to detect many of these crystals. For this reason, an initial work involved precisely the selection of optimal cases that could be analyzed. The work appears to be still in progress although positive results have already been obtained from the retrieval products of REFIR-PAD, which have allowed the estimation of the reflectivity at 24 GHz, which has been compared ,in the cases of best radar signal, with that measured by MRR obtaining a good agreement. The backscattering signal allows to derive the top and bottom elevations of the cloud to be fixed in the simulation of the radiative transfer. The depolarization signal makes it possible to discriminate the presence of ice, as water droplets do not produce depolarization signal. The lidar data, along with halo-camera and ice-camera data, are provided by Dr. Massimo Del Guasta.