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Your search keyword '"Bordi, Isabella"' showing total 134 results
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134 results on '"Bordi, Isabella"'

1. A new class of orbiting very large ultra-light orientable mw antennas in low earth orbits

Author

Perona, Giovanni, Meo, Angelo Raffaele, Allegretti, Marco, Bordi, Isabella, Marengo, Elena, Mazzetti, Bruno, and Scovazzi, Mario

Subjects
Electrical Engineering and Systems Science - Systems and Control
Abstract

The purpose of the following proposal is to create a new class of antennas of low weight but with a large transmitting and receiving surface made of metallized fabric. This class of antennas will be stationed in low satellite orbits, at about 2000 km from sea level and will be easily steerable by exploiting the interaction between the earth's magnetic field and an electromagnetic field generated on the antenna. The possibility of orienting very large ultra-light balloon-like MW antennas, orbiting in the Earth magnetic field, through electric currents flowing in conductive wires embedded in the antennas walls, are examined. It is shown that such currents may easily provide the needed forces without the necessity of mechanically orienting the antenna itself. The antenna is extremely light, inexpensive, easily directional. The antenna has the shape of a spheroid in which the southern hemisphere has a parabolic shape made of metallized fabric; the northern hemisphere, transparent to the electromagnetic radiation, has a radius of curvature such that the north pole coincides with the focus of the parabola.

Published
2023

19. Zonal flow regime changes in a GCM and in a simple quasi-geostrophic model: the role of stratospheric dynamics

Author

Bordi, Isabella, Fraedrich, Klaus, Ghil, Michael, and Sutera, Alfonso

Subjects
Atmospheric circulation -- Observations, Atmospheric physics -- Research, Eddies -- Environmental aspects, Earth sciences, Science and technology
Abstract

The atmospheric general circulation is characterized by both single- and double-jet patterns. The double-jet structure of the zonal mean zonal wind is analyzed in Southern Hemisphere observations for the two calendar months of November and April. The observed features are studied further in an idealized quasi-geostrophic and a simplified general circulation model (GCM). Results suggest that capturing the bimodality of the zonal mean flow requires the parameterization of momentum and heat fluxes associated with baroclinic instability of the three-dimensional fields. The role of eddy heat fluxes in generating the observed double-jet pattern is ascertained by using an analytical Eady model with stratospheric easterlies, in which a single wave disturbance interacts with the mean flow. In this model, the dual jets are generated by the zonal mean flow correction. Sensitivity of the results to the tropospheric vertical wind shear (or, equivalently, the meridional temperature gradient in the basic state's troposphere) is also studied in the Eady model and compared to related experiments using the simplified GCM.

Published
2009

36. Northern Hemisphere climate trends in reanalysis and forecast model predictions: The 500 hPa annual means

Author

Bordi, Isabella, Fraedrich, K., and Sutera, Alfonso

Abstract

The lead time dependent climates of the ECMWF weather prediction model, initialized with ERA-40 reanalysis, are analysed using 44 years of day-1 to day-10 forecasts of the northern hemispheric 500-hPa geopotential height fields. The study addresses the question whether short-term tendencies have an impact on long-term trends. Comparing climate trends of ERA-40 with those of the forecasts, it seems that the forecast model rapidly loses the memory of initial conditions creating its own climate. All forecast trends show a high degree of consistency. Comparison results suggest that: (i) Only centers characterized by an upward trend are statistical significant when increasing the lead time. (ii) In midilatitudes an upward trend larger than the one observed in the reanalysis characterizes the forecasts, while in the tropics there is a good agreement. (iii) The downward trend in reanalysis at high latitudes characterizes also the day-1 forecast which, however, increasing lead time approaches zero.

Published
2010

42. Noise in multiple sclerosis: unwanted and necessary

Author

Bordi, Isabella, primary, Ricigliano, Vito A. G., additional, Umeton, Renato, additional, Ristori, Giovanni, additional, Grassi, Francesca, additional, Crisanti, Andrea, additional, Sutera, Alfonso, additional, and Salvetti, Marco, additional

Published
2014
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45. CLOUDS - A cloud, arerosol, radiation and precipitation explorer

Author

Bizzarri, Bizzarro, Künzi, Klaus F., Alberoni, Pier Paolo, Bonsignori, Roberto, Bordi, Isabella, Bordi, Roberto, Coppo, Peter M., Desbois, Michel, Dietrich, E., Gasiewski, Albin J., Gobbi, G. P., Grant, Norman A., Harries, John E., Heygster, Georg C., Liberti, Gian Luigi, Maggi, E., Miao, Jungang, Mugnai, Alberto, Murray, Jonathan E., Naud, Catherine M., Petitta, Marcello, Rizzi, Rolando, Rose, Thomas W., Russell, Jacqueline E., Slingo, Anthony, Spera, Paolo, Standfuss, Carsten, Sutera, Alfonso, Tibaldi, S., Vial, L., and Zimmermann, Peter Jan

Subjects
business.industry, Aerospace Engineering, Environmental science, Cloud computing, Precipitation, Radiation, business, Atmospheric sciences
Abstract

The CLOUDS study defines a small satellite addressing the objective of cloud-radiation interaction monitoring for improved climate and weather prediction. The study was funded by the EC, and now various paths are explored to provide study continuation and eventual programme implementation. Only passive radiometers are included, covering the spectral range from UV to MW, with more polarisations and viewing geometries. There are six instruments, four (the optical ones) integrated into a single package, one in MW, one in Sub-mm waves. All instruments have conical scanning, with fore- and aft- views; one has multi-angle capability. The resolution is 5 or 10 or 40 km depending on the instrument, and the observing cycle is 24 h for measurement from TIR or MW, or 48 h for measurements which involve channels operating with solar radiation. Sizing parameters of CLOUDS are: mass ~ 900 kg, power ~ 1.6 kW, data rate 1.1 Mbps for direct read-out in S-band, 30 Mbps for global data in X-band, volume compatible with launch by Eurockot. © 2003 Published by Elsevier Science Ltd.

Published
2003

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