Climate change occurs in the Arctic faster than elsewhere in the world. Observations indicate continuing trends in the state of several key physical components of the Arctic system, including the atmosphere, ocean, sea ice cover, and land (Richter-Menge et al. 2006). The temporal extent of the data provides a multidecadal perspective and confirms the sensitivity of the Arctic to changes.
Complex interplay of the atmosphere, the ocean and the criosphere (sea ice) at a whole spectre of time scales take on a fundamental role in determining a quite complex picture, the amplitude of changes and their spatial and temporal behaviour. As a consequence, climate models reliability is often particularly poor in Arctic regions, when their parameterizations are based on observations at lower latitudes, and extensive long term measurements of key climate parameters, as studies deepening our knowledge on the complex interactions/processes above described, are needed as basis for model upgrade.
As contribution to the vision of Ny Alesund as a supersite allowing investigating the complex Arctic System with a multidisciplinary approach, and to reinforce cooperation and research activities of Italian research Institutions at Ny Alesund, the Department of Earth and Environment (CNR-DTA) promoted in 2008 the Climate Change Tower Integrated Project (CCT-IP – www.isac.cnr.it/~radiclim/CCTower), with general aim to realize a multidisciplinary experimental platform to investigate energy budget and processes at the snow/air/soil interface and in the Arctic ABL. Thanks to CNR support and a previous approved PRIN project (PRIN07 – Dirigibile Italia) key elements of this integrated platform, the 34 m height Amundsen-Nobile Climate Change Tower (CCT) and the physico-chemical Lab at sea level (Gruvebadet), have been put on place and equipped with a large set of instrumentation, and a first test campaign is carrying out during 2010 (March-September). Research activities herein proposed will permit our Research Unit (CNR-RU) to
finalize efforts and scientific work performed in the last three years. Participation to the CNR-RU of several Institutes and than disposability of many different abilities and equipments will allow our Unit to provide a large contribution to all WPs grouping research activities of the whole proposal. In particular:
Measurements of all components of the energy budget and their temporal variation will be continuously performed thanks to the instruments mounted on the CCT, and data will allow to assess our knowledge on several processes in which energy (radiation, heat) partition and behaviour play a key role.
Vertical profiles (5 levels) of temperature and humidity, acquired by the CCT since September 2009 will provide an important set of data useful to characterise the vertical structure of the ABL, for stable conditions characterizing the Arctic atmosphere. In spring, vertical profiles of meteorological parameters will be obtained by a tether-sounding system operating near the CCT site to provide vertical profiles of temperature, humidity and wind at 6 levels up to 600 meters.
Several procedures applied to radiation data will allow to obtain information on cloud amount and cloud forcing along the whole year, while spectral and broadband measurements of up-welling fluxes able us to determine the surface reflectance behaviour, as well as its dependency from cloudiness and solar elevation.
High resolute information on the aerosol vertical profile in the lower troposphere will be supplied by a two wavelengths (532, 1064 nm) micro-lidar., Measurements will allow an estimate of the profile of crystal size and load inside the ABL and of the ABL height. Lidar data will be constrained thanks to AOD evaluations supplied by other groups.
In order to assess the skill of global models in reproducing the complex chemical and physical processes involving aerosols and the composition and distribution patterns of aerosols in the Arctic, we will compare measurements from artic sites in the period 1974-2006 with numerical simulations generated by a state-of-the-art global model of the aerosol-climate system (ECHAM5-HAM).
Chemical and Physical processes at the air/snow/soil interface will be deeply investigated through the measure of a large number of chemical compounds (concentration and fluxes): NO, NO2, HONO, HNO3, PAN, PPN, nitrate and nitrite particles, carbonyl compounds. Role that snow morphology, impurity, and reflectance characteristics play in the complex exchange processes at the interface, will be also largely investigated through systematic measurements.
Finally, biomass burning episodes and long range transport will be identified and investigated by means specific molecular marker as levoglucosan, acrilamide and amino acids, trace elements (TE), rare earth elements (REE) and lead isotope ratio measurements (Pb-IR).