RT info:eu-repo/semantics/article
T1 An environmental synoptic analysis of tropical transitions in the central and Eastern North Atlantic
A1 Calvo Sancho, Carlos
A1 González Alemán, Juan Jesús
A1 Bolgiani, Pedro
A1 Santos Muñoz, Daniel
A1 Farrán Martín, José Ignacio
A1 Martín Pérez, María Luisa
K1 Atmospheric research
K1 Investigación atmosférica
K1 Tropical transitions
K1 Transiciones tropicales
AB A tropical transition (TT) is the process whereby a baroclinic, high-to-moderate vertical wind shear, extratropical or subtropical cyclone is transformed into a warm-core, low vertical wind shear, tropical cyclone. Thirty TT events were identified over the central and eastern North Atlantic basin during the period 1979–2019. The TT process is here studied from a synoptic storm-centered composite climatology and an environmental classification perspective. The aim is to study their common features and highlight their differences. The storm-centered composite analysis reveals that a westerlies meridional trough with quasigeostrophic forcig acts as precursor. TT environments are characterized by a trough at 300 hPa geopotential and the increase of the 1000–500 hPa thickness, i.e., the system evolves into a warm-core, and a strong anticyclone is located north of the surface cyclone. The transition is accompanied by a large latent heat release which promotes the vertical redistribution of potential vorticity and a reduction of the 850–300 hPa vertical wind shear. The identified TTs in the central North Atlantic predominantly developed in environments with warm sea surface temperatures (> 25 °C) and low-to-moderate wind shear (10–15 m s−1). In contrast, the eastern North Atlantic TTs transitioned in low sea surface temperature values (< 25 °C) and high wind shear (> 15 m s−1). Finally, the statistically significant differences in the environmental classification encouraged further analysis of their environments via storm-centered composites, revealing that eastern North Atlantic cyclones have a more defined extratropical structure, while central North Atlantic cyclones show more tropical characteristics.
PB Elsevier
SN 0169-8095
YR 2022
FD 2022
LK https://uvadoc.uva.es/handle/10324/54512
UL https://uvadoc.uva.es/handle/10324/54512
LA eng
NO Atmospheric Research, 2022, vol. 278, 106353
NO Producción Científica
DS UVaDOC
RD 17-jul-2024