On the dynamics of a case study of explosive cyclogenesis in the Mediterranean

Abstract

In this study, a case of explosive cyclogenesis over the central Mediterranean is examined with the aid of the MS Cyclone Detection and Tracking Scheme along with the Vertical Tracing Software and the Parcel Trajectory Software that were developed in Melbourne University, employing a regular 0.5°9 0.5°latitude-longitude grid of the ERA-Interim dataset. It is found that the explosive cyclogenesis occurred as a result of the downward intrusion of high-PV cold stratospheric air into the upper troposphere combined with a low-level warm environment surrounded by the bent-back structure of the cold front in the poleward side of a jet streak. The positive effect of the diabatic processes in explosive cyclogenesis is demonstrated. When cold air masses cross the warmer sea of the central Mediterranean, positive surface sensible and latent heat fluxes generate a low-level warm and moist environment, favorable for convective activity.

A Three-Dimensional Perspective on Extratropical Cyclone Impacts

“…While each method has advantages and disadvantages, for this paper we use the well-established University of Melbourne cyclone tracking scheme (Murray and Simmonds 1991;Simmonds et al 1999;Simmonds and Keay 2000). This method has been widely used for studies of cyclone behavior across the globe (Jones and Simmonds 1993;Pezza and Ambrizzi 2003;Allen et al 2010;Grieger et al 2014;Pinto et al 2005;Mesquita et al 2009;Simmonds and Rudeva 2014), including studies of the vertical structure of cyclones with altitude (Lim and Simmonds 2007;Kouroutzoglou et al 2012Kouroutzoglou et al , 2015.…”

“…of the atmosphere, despite the importance of upper cyclonicity for surface cyclone development (Keable et al 2002;Fuenzalida et al 2005;Lim and Simmonds 2007). The University of Melbourne cyclone tracking scheme applied in this paper has previously been used for vertical tracking in the Southern Hemisphere (Lim and Simmonds 2007) and for explosive cyclones in the Mediterranean (Kouroutzoglou et al 2012(Kouroutzoglou et al , 2015. For the Southern Hemisphere, Lim and Simmonds (2007) showed that cyclones are most common at the surface and at 500 hPa, with a minimum in cyclone frequency at 700 hPa, and that 52% of Southern Hemisphere cyclones can be considered ''vertically well organized,'' extending from the surface up to 500 hPa.…”

From Tropospheric Folding to Khamsin and Foehn Winds: How Atmospheric Dynamics Advanced a Record-Breaking Dust Episode in Crete

“…level PV-θ anomaly, baroclinic trough propagation, lower troposphere baroclinicity) is responsible for the formation and intensification of East Mediterranean cyclones and for the generation of dust storms [64][65][66][67].…”

Extratropical cyclone classification and its use in climate studies

“…For example, Upper level forcing may be associated with upper level PV anomalies [e.g., Elsberry and Kirchoffer , ; Wang and Rogers , ; Dacre and Gray , ; Kouroutzoglou et al , ], potentially caused by either cyclonic or anticyclonic Rossby wave breaking [ Gómara et al , ] and this seems to be more important in the east Atlantic than the west Atlantic [ Wang and Rogers , ; Dacre and Gray , ]. Air‐sea interaction involves the flux of energy from the ocean to the atmosphere, resulting in heating and moistening of the atmosphere and reduced stability, which is important prior to and during the explosive development [ Davis and Emanuel , ; Kuo et al , ; Reed et al , ]. Moisture from the ocean may be transported onshore, contributing to latent heating in the cyclones [ Brennan and Lackmann , ] and it may be evaporated by drier airstreams within the cyclones, leading to enhanced latent heat release in the warm conveyor belt region of the cyclone [ Booth et al , ; Hirata et al , ]. Latent heat release (diabatic heating) can be very important in the generation and/or development of explosive cyclones [ Anthes et al , ; Manobianco , ; Lim and Simmonds , ; Heo et al , ; Kouroutzoglou et al , ]. Heo et al [] find that the latent heat released in an explosive cyclone could account for around half of the intensification seen during the initial phase of cyclone development.…”