This chapter wishes to propose a description of the statistical properties of midlatitude atmospheric waves for observational data-sets and state-of-the-arts climate models simulations. Therefore, a non-linear theory, accounting for a relevant part of the mid-latitude variability, has been revised in terms of its signature in observational and model data. Theoretical and observational arguments suggest that two main features of mid-latitude northern hemispheric winter variability can be somewhat unambiguously separated, both in terms of signal and physical processes. The synoptic phenomena, which are travelling waves characterized by time scales of the order of 2-7 days and by spatial scales of the order of few thousands Km., can be associated with release of available energy driven by conventional baroclinic conversion. At lower frequencies (10-40 days), the planetary scale variability is related to the non linear orographic resonance processes
Statistical properties of mid-latitude atmospheric variability / S. Calmanti; A. Dell’Aquila; V. Lucarini; P. M. Ruti; A. Speranza. - STAMPA. - (2007), pp. 369-391. (Intervento presentato al convegno 20 Years of Nonlinear Dynamics in Geosciences, tenutosi a Rhodes, Greece nel 11-16/6/2006).
Statistical properties of mid-latitude atmospheric variability
LUCARINI, VALERIO;
2007
Abstract
This chapter wishes to propose a description of the statistical properties of midlatitude atmospheric waves for observational data-sets and state-of-the-arts climate models simulations. Therefore, a non-linear theory, accounting for a relevant part of the mid-latitude variability, has been revised in terms of its signature in observational and model data. Theoretical and observational arguments suggest that two main features of mid-latitude northern hemispheric winter variability can be somewhat unambiguously separated, both in terms of signal and physical processes. The synoptic phenomena, which are travelling waves characterized by time scales of the order of 2-7 days and by spatial scales of the order of few thousands Km., can be associated with release of available energy driven by conventional baroclinic conversion. At lower frequencies (10-40 days), the planetary scale variability is related to the non linear orographic resonance processesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.