0176460 - UFA-U 20033506 RIV CZ eng J - Článek v odborném periodiku
Kašpar, Marek
Objective frontal analysis techniques applied to extreme/non-extreme precipitation events.
Studia geophysica et geodaetica. Roč. 47, - (2003), s. 605-631. ISSN 0039-3169. E-ISSN 1573-1626
Grant CEP: GA ČR GA205/00/1451
Výzkumný záměr: CEZ:AV0Z3042911
Klíčová slova: NWP model * synoptic scale * objective analysis * atmospheric front * frontogenesis
Kód oboru RIV: DG - Vědy o atmosféře, meteorologie
Impakt faktor: 0.426, rok: 2003

A simple method of the objective frontal analysis (OFA) based on a thermal definition of atmospheric fronts is proposed for the area of Central Europe with the aid of gridded numerical weather prediction model (NWP model) outputs. The OFA includes both mathematical and graphical techniques that enable a computer to draw fronts entirely automatically in atmospheric cross-sections by means of one locating equation and four masking criteria. The OFA also enables to analyse the frontal wave position and the type, activity, and future development of fronts. The OFA is applied to two synoptically analogous cold-frontal situations, which occurred over the Czech Republic in summer season and were characterised by quite different precipitation amounts. The outputs (12h, 18h, and 24h forecasts) of the NWP model Europa Modell/Deutschland Modell are used in computations. The equivalent potential temperature is considered as an input thermal parameter of the OFA. The impact of applying and changing the OFA masking criteria is various and among others also depends on synoptic situation. The comparison between the objective and subjective analysed fronts subserves to evaluate the values of masking threshold constants. Some obtained results of the analysis of the extreme precipitation situation support the possibility of enhanced precipitation amounts. The analysis of the second non-extreme precipitation situation revealed a few different features that do not support the forecast of enhanced precipitation amounts. The results show the OFA could contribute to the improvement of the general short-range weather forecast.
Trvalý link: http://hdl.handle.net/11104/0073436