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Po Valley (po + valley)
Selected AbstractsAerosol Direct Radiative Impact Experiment (ADRIEX) overviewTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue S1 2007E. J. Highwood Abstract The Aerosol Direct Radiative Experiment (ADRIEX) took place over the Adriatic and Black Seas during August and September 2004 with the aim of characterizing anthropogenic aerosol in these regions in terms of its physical and optical properties and establishing its impact on radiative balance. Eight successful flights of the UK BAE-146 Facility for Atmospheric Airborne Measurements were completed together with surface-based lidar and AERONET measurements, in conjunction with satellite overpasses. This paper outlines the motivation for the campaign, the methodology and instruments used, describes the synoptic situation and provides an overview of the key results. ADRIEX successfully measured a range of aerosol conditions across the northern Adriatic, Po Valley and Black Sea. Generally two layers of aerosol were found in the vertical: in the flights over the Black Sea and the Po Valley these showed differences in chemical and microphysical properties, whilst over the Adriatic the layers were often more similar. Nitrate aerosol was found to be important in the Po Valley region. The use of new instruments to measure the aerosol chemistry and mixing state and to use this information in determining optical properties is demonstrated. These results are described in much more detail in the subsequent papers of this special issue. Copyright © 2007 Royal Meteorological Society [source] Effect of autumn and winter meteorological variables on spring aphid populations in the Po valley, Northern ItalyJOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2001D. Rongai Prediction of aphid populations is crucial to the successful application of control strategies. In previous studies clear relationships between aphid catches and meteorological variables were highlighted. The primary objective of this study was to quantify the effects of autumn and winter meteorological variables on the aphid species populations the following spring. The data on all the species caught at two Italian sites (Ozzano Emilia and Budrio) up to 31 May from 1992 to 1999 were used for this study. Different models were found according to the aphid biological cycle (i.e. holocycle, anholocycle, holo-anholocycle). A fourth group of minor species, designated as ,others', was properly modelled as holo-anholocycle species. A satisfactory fit was observed when holocycle species were plotted against minimum temperature and precipitation in October, anholocycle species against minimum temperature and precipitation in December,January, holo-anholocycle species and ,others' against wind speed and number of frosty days in November, and minimum temperature and precipitation in December,January. Model response was more consistent at Budrio (open flat site) than at Ozzano Emilia (flat site delimited by a hill). A coherent pattern was found with an overall comparison of the estimates against observations. The possibility offered by these empirical models for forecasting spring aphid populations of all species at a given site is clearly of interest. This first study encouraged further investigation aimed at validating models before applying them in practice. [source] Origins of the reversed flow over the windward Alpine foothills during MAP IOP3 and IOP8THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 615 2006N. Asencio Abstract The synoptic-scale situations during the two Intensive Observing Periods (IOPs) of the Mesoscale Alpine Programme (MAP) characterized by persisting precipitation and down-valley flow as observed by the Doppler on the wheel radar (DOW) over the two Alpine valleys (Toce and Ticino) were investigated. The first period (IOP3, 24,27 September 1999) was characterized by a south-westerly flow and convective precipitation, whereas the second period (IOP8, 20,21 October 1999) by a down-valley flow and stratiform precipitation. During IOP3, the down-valley northerly flow over the north-western part of the Po valley was confined within a thin layer of 200,300 m depth. During IOP8, the northerly flow extended from the Alps foothills to the Ligurian sea in a deep layer of 1,2 km height. The Meso-NH numerical model with a 2.5 km horizontal mesh grid reproduced the characteristics of both cases from the valley scale to the meso-, scale. Sensitivity experiments were, furthermore, performed in order to highlight the relationships between wet or dry drainage flow channelled by the Alpine orography, mesoscale upstream flow blocked by the Alps, and a regional cold pool at the foothills inside the Po valley. During IOP8, the diabatic processes were dominant at local scales in confirmation of Steiner results based on the DOW observations and they were significant at regional scales upstream of the Alps by maintaining a cold pool over the Po valley. The IOP3 low-level flow reversal occurred as the flow began to cross over the Alps instead of turning around. A downslope flow is associated with the blocked-regime period upstream of the Alps. Copyright © 2006 Royal Meteorological Society [source] Data assimilation of high-density observations.THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 605 2005II: Impact on the forecast of the precipitation for the MAP/SOP IOP2b Abstract The impact of the data assimilation of high-density (space and time) data on the precipitation forecast is evaluated by improving the initial conditions of a mesoscale model. The high-frequency data allow for improving the three-hourly initial and boundary conditions as well. The data assimilation is performed using initial objective analysis (Cressman and multiquadric schemes) and 3D-Var. The MM5 (version 3) mesoscale model from Penn State University/National Center for Atmospheric Research is used to evaluate the impact of the improved initial and boundary conditions on the model simulations. The comparison of model results with observations shows: (i) the forecast of the precipitation at high resolution produces better results than those without data assimilation only if three-hourly data are assimilated by multiquadric; (ii) the mean error of the model rainfall largely decreases only if 3D-Var is used, but no comparable improvement in the spatial distribution of the precipitation is found; (iii) the improvement for the rainfall is not as good as it is for the initial conditions for all experiments. Moreover, the observations ingested by objective analysis modify both the amount and the timing of the precipitation on the Po valley. On the other hand, 3D-Var modifies only the amount of the precipitation, but both techniques barely recover large-model failure. Copyright © 2005 Royal Meteorological Society [source] Fungal community diversity and soil health in intensive potato cropping systems of the east Po valley, northern ItalyANNALS OF APPLIED BIOLOGY, Issue 2 2009L.M. Manici Abstract An ecological approach was used to investigate the relationship between diversity of soil fungal communities and soil-borne pathogen inoculum in a potato growing area of northern Italy affected by yield decline. The study was performed in 14 sites with the same tillage management practices: 10 named ,potato sites', that for many years had been intensely cultivated with potatoes, and 4 named ,rotation sites', subject to a 4-year rotation without potatoes or any recurrent crop for many years. Fungal communities were recorded using conventional (soil fungi by plate count and endophytic fungi as infection frequency on pot-grown potato plant roots in soil samples) and molecular approaches [Basidiomycetes and Ascomycetes with specific and denaturing gradient gel electrophoresis (DGGE) analysis]. Diversity of fungal communities in potato sites was significantly lower than that in rotation sites. In addition, fungal communities in rotation sites showed lower Berger,Parker dominance than those in the potato sites, suggesting that rotation sites had a higher diversity as well as a better fungal community balance than potato sites. The ANalysis Of SIMilarity test of soil fungi and root endophytic fungi revealed that the two cropping systems differed significantly for species composition. Root endophytic fungal communities showed a greater ability to colonise potato roots in soil samples from potato sites than those from rotation sites. Moreover, the majority of endophytic root fungal community species in potato sites belonged to the potato root rot complex and storage disease (Colletotrichum coccodes, Fusarium solani and Fusarium oxysporum), while those in rotation sites were mainly ubiquitous or saprobic fungi. Soil rDNA analyses showed that Ascomycetes were much more frequent than Basidiomycetes in all the soils examined. DGGE analysis, with the Ascomycete-specific primer (ITS1F/ITS4A), did not reveal distinctions between the communities found at the potato and rotation sites, although the same analysis showed differences between the communities of Basidiomycetes (specific primer ITS1F/ITS4B). These findings showed that recurrent potato cropping affected diversity and composition of soil fungal communities and induced a shift in specialisation of the endophytic fungi towards potato. [source] | ||||||||||