Resursele de apă din România. Vulnerabilitate la activităţile antropice
[Water resources from Romania. Vulnerability to the pressure of man’s activities]

Conference Proceedings
ISBN: 978-606-8042-65-7

11-13 June 2010, Targoviste - Romania

Editors
Petre Gâştescu
Petre Breţcan

EVENIMENTE EXTREME (INUNDAŢII) PE CURSUL INFERIOR AL DUNĂRII ÎN CORELAŢIE CU OSCILAŢIA NORD-ATLANTICĂ (NAO) ŞI PRESIUNEA LA NIVELUL MĂRII (SLP)

Simona PĂTRUŢ^1,2,
¹ Universitatea din Bucureşti, Facultatea de Fizică, CP MG - 11, Bucureşti-Măgurele, patrut_simona@yahoo.com
²  Ministerul Mediului şi Pădurilor, Blv. Libertaţii, 12, sector 5, Bucuresti

Extreme events (floods) on the lower Danube in conjunction with the North Atlantic Oscillation (NAO) and the pressure at sea level (SLP)
Abstract: In the context of climate changes manifested in Romania in recent years and especially in 2006, there were atypical and dangerous weather phenomena with a special intensity. These extreme events that have occurred lately creates need more thorough study of atmospheric structure and also their associated physical processes that generate them. It has been studied the relationship between variability of Danube anomalies of discharge and the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO). Both strongly influence the NAO and ENSO of the Danube flow variability. Given the winter period 1900-1998, negative phase (positive) anomalies there are associated with the average annual discharge positive (negative) on the Danube. On the other hand, El Nino (La Nina) in the tropical Pacific in winter is associated with Danube positive anomalies (negative) in annual mean discharge. The results bring in line with the NAO and precipitation over Europe Enso [Cullen et al., 2002, Dai et al., 1997]. The influence that North Atlantic Oscillation (NAO) has on the circulation of air masses and the climate in Europe makes the connection between this index and hydrological conditions. Studies on weather anomalies and their influence on the Danube discharge, extreme hydrological phenomena have been performed regularly in recent times, most recently studies made by T. Andreeva (2008), Divac (2008), V.N. Mikhailov (2006). The study is the link between variability of Danube flow anomalies and the NAO index. NAO is known as one of the most important modes of variation of air masses in the northern hemisphere, which occurs in all seasons, has a great influence on weather and consequently the hydrological regime in the winter season. Using the average daily discharge at Orsova station, located on the lower Danube river, for a long time (1840-2005), for December, January, February (DJF), we aimed correlation behavior associated with extreme discharge (floods) with NAO index phase for the same period. Pressure structure on the anomalies associated with discharge anomalies was projected onto flow - pressure structure anomalies associated with the NAO index, using the method of composite maps.

Full text .PDF

© Asociatia Romana de Limnogeografie (2008)