European Facility For Airborne Research

European Facility For Airborne Research Aug. 20, 2018, 05:46

Document

Description
Title Multiparameter Raman Lidar Measurements for the Characterization of a Dry Stratospheric Intrusion Event
Type Publication
Abstract:

The University of Basilicata Raman lidar system (BASIL) is operational in Potenza, Italy, and it is capable of performing high-resolution and accurate measurements of atmospheric temperature and water vapor based on the application of the rotational and vibrational Raman lidar techniques in the ultraviolet region. BASIL was recently involved in the 2005 International Lindenberg campaign for Assessment of Humidity and Cloud Profiling Systems and Its Impact on High-Resolution Modeling (LAUNCH 2005) experiment held from 12 September to 31 October 2005. A thorough description of the technical characteristics, measurement capabilities, and performances of BASIL is given in this paper. Measurements were continuously run between 1 and 3 October 2005, covering a dry stratospheric intrusion episode associated with a tropopause folding event. The measurements in this paper represent the first simultaneous Raman lidar measurements of atmospheric temperature, water vapor mixing ratio, and thus relative humidity reported for an extensive observation period (32 h).
The use of water vapor to trace intruded stratospheric air allows the clear identification of a dry structure (∼1 km thick) originating in the stratosphere and descending in the free troposphere down to ∼3 km. A similar feature is present in the temperature field, with lower temperature values detected within the dry-air tongue. Relative humidity measurements reveal values as small as 0.5%–1% within the intruded air. The stratospheric origin of the observed dry layer has been verified by the application of a Lagrangian trajectory model. The subsidence of the intruding heavy dry air may be responsible for the gravity wave activity observed beneath the dry layer.
Lidar measurements have been compared with the output of both the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) and the European Centre for Medium-Range Weather Forecasts (ECMWF) global model. Comparisons in terms of water vapor reveal the capability of MM5 to reproduce the dynamical structures associated with the stratospheric intrusion episode and to simulate the deep penetration into the troposphere of the dry intruded layer. Moreover, lidar measurements of potential temperature are compared with MM5 output, whereas potential vorticities from both the ECMWF model and MM5 are compared with estimates obtained combining MM5 model vorticity and lidar measurements of potential temperature.

Available from http://journals.ametsoc.org/doi/abs/10.1175/2009JTECHA1253.1
Author
DI GIROLAMO Paolo
DONATO Summa
FERRETTI Rossella
Reference
Journal Journal of Atmospheric and Oceanic Technology
Volume 26
Pages 1742-1762
Year 2009
Times cited 0
Institute country Italy
Type of science
  • Atmospheric dynamics (includes thermodynamics)
Field of science
  • Stratosphere
  • Troposphere
File details
Added Sept. 28, 2011, 00:00
Last update April 25, 2016, 15:38
Size 6.8 MB
File name 1253_JTECH_Sept-2009_20110928215347.pdf
Visibility Public
Links with specific subjects

Go to the document list

Back to top
EUFAR
EU

This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 312609

Copyright © 2018 EUFAR All rights reserved.