Factors controlling atmospheric DMS and its oxidation products (MSA and nssSO(4)(2-)) in the aerosol at Terra Nova Bay, Antarctica

This paper presents the results of simultaneous high time-resolution measurements of biogenic aerosol (methane sulfonic acid (MSA), non-sea salt sulfate nssSO(4)(2-)) with its gaseous precursor dimethylsulfide (DMS), performed at the Italian coastal base Mario Zucchelli Station (MZS) in Terra Nova Bay (MZS) during two summer campaigns (2018-2019 and 2019-2020). Data on atmospheric DMS concentration are scarce, especially in Antarctica. The DMS maximum at MZS occurs in December, one month earlier than at other Antarctic stations. The maximum of DMS concentration is connected with the phytoplanktonic senescent phase following the bloom of Phaeocystis antarctica that occurs in the polynya when sea ice opens up. The second plankton bloom occurs in January and, despite the high dimethylsufoniopropionate (DMSP) concentration in seawater, atmospheric DMS remains low, probably due to its fast biological turnover in seawater in this period. The intensity and timing of the DMS evolution during the two years suggest that only the portion of the polynya close to the sampling site produces a discernible effect on the measured DMS. The closeness to the DMS source area and the occurrence of air masses containing DMS and freshly formed oxidation products allow us to study the kinetic of biogenic aerosol formation and the reliable derivation of the branch ratio between MSA and nssSO(4)(2-) from DMS oxidation that is estimated to be 0.84 +/- 0.06. Conversely, for aged air masses with low DMS content, an enrichment of nssSO(4)(2-) with respect to MSA, is observed. We estimate that the mean contribution of freshly formed biogenic aerosol to PM10 is 17 % with a maximum of 56 %. The high contribution of biogenic aerosol to the total PM10 mass in summer in this area highlights the dominant role of the polynya on biogenic aerosol formation. Finally, due to the regional and year-to-year variability of DMS and related biogenic aerosol formation, we stress the need for long-term measurements of seawater and atmospheric DMS and biogenic aerosol along the Antarctic coast and in the Southern Ocean

La fenologia per la viticoltura: esempio applicativo nelle varieta Chardonnay e Garganega nei Colli Berici della Regione Veneto nel 2005

English journal title: Italian Journal of AgrometeorologyI Colli Berici sono una formazione collinare, situata nella Regione Veneto e compresa interamente nella provincia di Vicenza, dove la viticoltura è molto diffusa. Il caso studio si riferisce a due varietà, Chardonnay e Garganega, coltivate in tre aziende coinvolte nel progetto di ricerca Aquavitis. Obiettivo di questo lavoro è l’analisi dei rilievi fenologici raccolti durante il primo anno di ricerca e l’interpolazione di questi con i dati meteo, forniti dalle stazioni meteorologiche di proprietà dell’ARPA Veneto. I risultati mostrano come la fenologia, ancora una volta, possa trovare vari campi di applicazione poiché molte tecniche di coltivazione sono strettamente legate allo sviluppo ontogenico vegetale e, come questa disciplina costituisca un valido strumento di supporto agli operatori del settore.A. Bonamano, R. De Bei and M. Borinhttp://www.arpa.veneto.it/temi-ambientali/agrometeo/file-e-allegati/documenti/fenologia/AQUAVITIS%202%20AIAM%202006.pdf/vie

Influenza della disponibilita idrica sull'accrescimento delle bacche e sulla composizione del mosto dei vitigni Garganega e Chardonnay

Le variazioni quanti-qualitative delle produzioni viticole sono spesso legate a fattori ambientali e agronomici. In particolare, le precipitazioni, agendo sullo stato idrico della pianta, influenzano la crescita delle bacche e la composizione del mosto e del vino. Nel presente lavoro si è voluto verificare l’influenza dell’irrigazione sull’attività produttiva dei vitigni Garganega e Chardonnay in ambiente collinare. È stata monitorata la crescita delle bacche e dall’invaiatura sono stati misurati i parametri della maturazione. Nel vitigno Garganega, uno stress idrico, anche moderato, nel primo periodo di crescita della bacca, ha influenzato in modo irreversibile il volume finale delle bacche. Alla vendemmia nella Garganega non sono state osservate differenze sui parametri produttivi e qualitativi mentre nello Chardonnay le uve delle viti irrigate hanno presentato un grado rifrattometrico superiore.R. De Bei, G. Ponchia and A. Bonaman

Short-term climate change effects on maize phenological phases in Northeast Italy

This study evaluates the response of maize growing cycle length to meteorological variables at regional scale particularly, in the short-term period, considering global climate change. The experiment was carried out in Veneto Region (Northeast Italy) where maize phenological data collected by the regional network from 2005 to 2007 were combined with temperature data to analyse the relationship between BBCH stages and thermal sum. The effects of climatic changes in the near and medium term on maize phenology and on water requirements were also evaluated over a grid of climatic data obtained from different climatic models. The piecewise analysis gave the best fitting between BBCH and Growing Degree Days observed data characterized by two lines with different slopes with BBCH 70 (beginning of fruit develop-ment) as changing stage. The angular coefficient of the first line was 2.6 times than the second one (0.028) suggesting that the early stages of the growing cycle are more sensitive to air temperature. The simulation of maize phenology evolution highlights a modest variation at the 2020-time horizon, while an expected reduction of maize growing cycle of about 10 days has been estimated for 2030-time horizon. Long-term phenological observation are desirable to confirm our findings and to improve the strength of dataset