Influence of cyclonic perturbations on surface winds around Dumont d'Urville, East Antarctica, using wavelet transform

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Naithani, Jaya, Mastrantonio, G, Argentini, S, Pettre, P
• Other Authors: UCL - SC/PHYS - Département de physique
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Geophysical Union 2001
• Subjects: Antarctic; Dumont d'Urville; Dumont-d'Urville; East Antarctica; The Antarctic; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2078.1/42569; https://doi.org/10.1029/2001JD900123

Wavelet analyses of the surface winds at Dumont d'Urville, an East Antarctic station, have been performed for the months April, June, September, and December 1993, representing autumn, winter, spring, and summer, respectively. The 3 hourly 10 min averaged meteorological station data have been used. The site is characterized by intense katabatic winds that arrive from the southeast. During the year 1993 the maximum occurrence of wind was from 160 degrees direction sector. The wavelet transform spectra of horizontal wind show prominent periodicities in the interval between 2 and 20 days. The spectral energies in the diurnal scale are comparatively very low even in summer. A comparison with wavelet spectra of pressure for synoptic scale (2-10 days) confirms the influence of synoptic disturbances that are frequent in coastal regions of the Antarctic continent. The same analysis carried out on the wind components, parallel and transverse to the main katabatic flow direction, reveals that these periodicities are mainly due to the katabatic flow behavior. Although the katabatic wind flow is the dominant force characterizing the day-to-day weather conditions, the influence of transient cyclones offshore cannot be ignored; in situations of considerable synoptic activity the intensity and duration of katabatic wind flow are prolonged.