Adding confidence levels and error bars to mixing layer heights detected by ceilometer

Christoph Münkel; Klaus Schäfer; Stefan Emeis

doi:10.1117/12.898122

26 October 2011 Adding confidence levels and error bars to mixing layer heights detected by ceilometer

Christoph Münkel, Klaus Schäfer, Stefan Emeis

Proceedings Volume 8177, Remote Sensing of Clouds and the Atmosphere XVI; 817708 (2011) https://doi.org/10.1117/12.898122
Event: SPIE Remote Sensing, 2011, Prague, Czech Republic

Abstract

Eye-safe lidar ceilometers are reliable tools for unattended boundary layer structure monitoring around the clock. A single lens optical design enables precise assessment of inversion layers and nocturnal stable layers below 200 m. This design has been chosen for the Vaisala Ceilometers CL31 and CL51. Based on the gradient method, an automatic algorithm for online retrieval of boundary layer depth and additional residual structures has been developed. This robust all weather algorithm is part of the Vaisala boundary layer reporting and analysis tool BL-VIEW. The data averaging intervals used depend on range and signal noise; detection thresholds vary with signal amplitude. All layer heights reported are accomponied by a quality index. In most cases the lowest of these layers is a good measure for the mixing layer height. The continuous knowledge of this atmospheric parameter is supporting the understanding of processes directing air quality. The utility of mixing layer height values for air quality forecast can be further increased by additionally utilizing unaveraged profiles for gradient minima detection. Based on their variation from the result of the BL-VIEW algorithm, confidence levels and error bars can be calculated. Results are presented from campaigns at three different sites. Validation with mixing layer height values derived from co-located radiosoundings confirm the applicability of this novel method.

Citation Download Citation

Christoph Münkel, Klaus Schäfer, and Stefan Emeis "Adding confidence levels and error bars to mixing layer heights detected by ceilometer", Proc. SPIE 8177, Remote Sensing of Clouds and the Atmosphere XVI, 817708 (26 October 2011); https://doi.org/10.1117/12.898122

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available