Articles | Volume 6, issue 8
Atmos. Meas. Tech., 6, 2055–2064, 2013
https://doi.org/10.5194/amt-6-2055-2013
Atmos. Meas. Tech., 6, 2055–2064, 2013
https://doi.org/10.5194/amt-6-2055-2013

Research article 15 Aug 2013

Research article | 15 Aug 2013

Nadir airborne lidar observations of deep aerosol layers

F. Marenco F. Marenco
  • Observational Based Research, Met Office, Exeter, UK

Abstract. The observation of deep and optically thick aerosol layers by a nadir-pointing lidar poses a challenge in terms of the signal inversion into a geophysically meaningful quantity such as extinction coefficient. A far-end reference molecular layer will usually be unavailable if the observed layer is near the surface, and using a near-end reference results in an unstable mathematical solution. In this paper, it is demonstrated that a far-end reference, taken within the aerosol layer, yields a better solution, and that the influence of the reference reduces strongly when coming inward, so that 1–2 km above reference the solution can be trusted. A method is developed to set the reference using the assumption of a well-mixed layer near the surface, and its effect is tested on data collected during recent aircraft-based campaigns. The method is also tested on simulated profiles in order to verify its limits and accuracy. The assumption of a well-mixed layer can be relaxed if one is able to set the reference well within a layer rather than at its boundaries.

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