OHP02 gravity wave campaign in relation to optical turbulence
- 35 Downloads
Herein we present a campaign dedicated to the detection and the characterization of Gravity Waves (GW) in the Earth’s atmosphere in relation to the generation of Optical Turbulence (OT). The observations took place in France from 17 to 24 July 2002 at the Haute Provence Observatory (OHP) and simultaneously at the Sirene Observatory, some 20 km apart. From both sites, several balloons were launched that measured the classical PTU-Wind profiles and additionally the structure constant of the temperature field \(C_T^2\) vertical profiles. A Generalized Scidar (GS) technique was implemented at the 1.93 m-diameter OHP telescope, providing \(C_N^2(h)\) profiles every minute. From our observations, a significant amount of GW activity was observed at both sites, but without clear evidence of correlation between the two sites. It seems from our observations that a wide spectrum of GW is present at a given altitude and that this could result in a lack of correlation between observations made from two sites 20 km apart. Most GW are non-stationary with long horizontal wavelengths (λ ∼ 100–200 km), kilometric vertical wavelengths (λ ~ 0.5–2 km) and long intrinsic period (T ~ 2–15 h). They belong in the category of “hydrostatic rotating or non-rotating waves”. Layers of optical turbulence detected by balloons and the Scidar technique correlate well with regions of GW activity.
keywordsGravity waves Atmospheric optics Atmospheric turbulence effects
Unable to display preview. Download preview PDF.
- 1.Roddier F (1981). Progress in optics. North-Holland, Amsterdam Google Scholar
- 2.Vernin J (2002) Mechanism of formation of optical turbulence. In: Vernin J et al. (eds) Proceedings Astronomical site evaluation in the visible and radio range, 13–17 Nov, ASP, MarrakechGoogle Scholar
- 3.Avila R, Vernin J and Masciadri E (1997). Whole atmospheric-turbulence profiling with generalized scidar. Appl Opt 36: 7898–7905 Google Scholar
- 4.Gill A (1982) Atmosphere Ocean dynamics. Academic PressGoogle Scholar
- 7.Vernin J and Muñoz–Tuñón C (1994). Optical seeing at La Palma Observatory II. Intensive site testing campaign at the Nordic Optical Telescope. Astron. & Astrophys 284: 311–318 Google Scholar