Options
ENEA Casaccia, S. Maria di Galeria (RM), Italy
4 results
Now showing 1 - 4 of 4
- PublicationOpen AccessCharacterization of seismic signals recorded in Tethys Bay, Victoria Land (Antarctica): data from atmosphere-cryosphere-hydrosphere interaction(2017)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; In this paper, we analysed 3-component seismic signals recorded during 27 November 2016 - 10 January 2017 by two stations installed in Tethys Bay (Victoria Land, Antarctica), close to Mario Zucchelli Station. Due to the low noise levels, it was possible to identify three different kinds of signals: teleseismic earthquakes, microseisms, and icequakes. We focus on the latter two. A statistically significant relationship was found between microseism amplitude and both wind speed and sea swell. Thus, we suggest that the recorded microseism data are caused by waves at the shore close to the seismic stations rather than in the deep ocean during storms. In addition, we detected three icequakes, with dominant low frequencies (below 2 Hz), located in the David Glacier area with local magnitude of 2.4-2.6. These events were likely to have been generated at the rock-ice interface under the glacier. This work shows how seismic signals recorded in Antarctica provide insights on the interactions between the atmosphere-cryosphere- hydrosphere. Since climate patterns drive these interactions, investigations on Antarctic seismic signals could serve as a proxy indicator for estimating climate changes.1372 135 - PublicationOpen Access
25 10 - PublicationOpen AccessThe Impact of Precipitation and Sublimation Processes on Snow Accumulation: Preliminary Results(2008-07)
; ; ; ; ; ; ; ; ; ;Scarchilli, C.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy ;Frezzotti, M.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy ;Didonfrancesco, G.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy ;Valt, M.; A.R.P.A.V., Centro Valanghe di Arabba, Livinallongo del Col di Lana (Belluno) - Italy ;Urbini, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;De Silvestri, L.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy ;Dolci, S.; Consiglio Nazionale delle Ricerche, Rome - Italy ;Iaccarino, A.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy ;Grigioni, P.; Ente per le Nuove Tecnologie, l’Energia e l’Ambiente, ‘Progetto Speciale Clima Globale’, Rome - Italy; ; ; ; ; ; ; ; The need for climate change prediction has focused attention on the Surface Mass Balance (SMB) of the Antarctic continent and on how it influences the sea level. The SMB of the Antarctic plateau is governed by the equilibrium between precipitation and ablation processes such as sublimation and wind-borne snow redistribution. At scales of hundreds of kilometres snowfall variability dominates the snow accumulation process (Dery and Yau, 2002); at smaller scales, postdepositional process such as wind-borne redistribution, surface sublimation and snowdrift sublimation becomes more important. In recent years the sublimation phenomenon has received much attention from the glacial-meteorological community, and some theoretical studies have tried to model it (Bintanja, 1998; Dery & Yau, 2001b; Frezzotti, 2004). There are two different types of sublimation: surface sublimation and blowing snow sublimation. Surface sublimation is mostly determined by the continual exchange of water between the air (in the vapour phase) and the snow pack (in the solid phase) due to solar irradiance. Blowing snow sublimation is possibly the more effective of the two sublimation processes. It occurs when snow particles at the surface are blown by winds exceeding a certain threshold value. Particles suspended in the sub saturated Atmospheric Boundary Layer (ABL) sublimate at a relatively fast rate, cooling air mass transported by the wind and increasing the local atmospheric moisture content. When the first few meters of the ABL are completely saturated, the process is dumped. It takes a long time to meet this condition because katabatic winds transport saturated air masses to the coast, thereby reactivating sublimation. The role of sublimation in snow accumulation and its high variability at local scales are not fully understood due to the few available measurements in Antarctica. Further study and field experiments are required.304 219 - PublicationOpen AccessCould we find any signal of the stratosphere-ionosphere coupling in Antarctica?(2002)
; ; ; ; ; ;Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Kazimirovsky, E. S.; Institute of Solar-Terrestrial Physics, Russian Academy of Sciences, Irkutsk, Russia ;De Franceschi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Grigioni, P.; ENEA Casaccia, S. Maria di Galeria (RM), Italy ;Scotto, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; ; ; ; An investigation searching for a possible coupling between the lower ionosphere and the middle atmosphere in Antarctica is here performed on the basis of stratospheric vertical temperature profiles and ionospheric absorption data observed at the Antarctic Italian Base of Terra Nova Bay (74.69S, 164.12E) during local summer time. The result obtained by applying a multi-regression analysis and a Superimposed Epoch Analysis (SEA) shows a statistically significant ionosphere-stratosphere interaction. In particular, by selecting stratospheric temperature maxima occurring at different heights as the referring epoch for the SEA approach, the ionospheric absorption is found to show a positive and/or negative trend (several days) around it. The tendency for an increasing/decreasing absorption is obtained for temperature maxima occurring below/above the stratospheric level of about 17-19 km, respectively.567 355