Preprints
https://doi.org/10.5194/amt-2022-132
https://doi.org/10.5194/amt-2022-132
 
06 Jul 2022
06 Jul 2022
Status: this preprint is currently under review for the journal AMT.

Atmospheric visibility inferred from continuous-wave Doppler wind lidar

Manuel Queißer1, Michael Harris1, and Steven Knoop2 Manuel Queißer et al.
  • 1ZX Lidars, The Old Barns, Fairoaks Farm, Hollybush, Ledbury, HR8 1EU, U.K.
  • 2Royal Netherlands Meteorological Institute (KNMI), Utrechtseweg 297, 3731 GA, De Bilt, the Netherlands

Abstract. Atmospheric visibility, or meteorological optical range (MOR), is governed by light extinction by aerosols. State-of-the-art visibility sensors, such as employed in meteorological observatories and airports, infer MOR by either measuring transmittance or scattering. While these sensors yield robust measurements with reasonable accuracy (10 % to 20 %), they measure in situ. MOR from these sensors may thus not be representative of MOR further away, for example, under conditions with stratified aerosol types. This includes off-shore sites near the sea surface during conditions with advection fog, sea spray or mist. Elastic backscatter lidar can be used to measure light extinction and has previously demonstrated to be a powerful method to infer visibility. Lidar can measure visibility not just near the instrument, but further away (remotely) and single-ended, whilst capable of measuring profiles of MOR along atmospheric slant paths. Continuous-wave (CW) Doppler wind lidar systems make up one of the most widespread type of elastic backscatter lidar and are typically used in wind resource assessment. Using these existing platforms for remote and single-ended measurement of MOR-profiles could allow for new and valuable applications. However, the low light extinction associated with this type of lidar excludes the use of the extinction coefficient for MOR retrieval, but leaves the backscatter coefficient as a possible proxy for MOR, though with an accuracy expected to be inferior to the former method. We analysed backscatter data from CW wind lidar and co-measured MOR from visibility sensors from two campaigns (Cabauw, Netherlands and Pershore, United Kingdom) and found backscatter from CW wind lidar to be a viable proxy of MOR if calibrated against a visibility sensor. The expected accuracy of the method is low and of order of few kilometres. This means MOR from CW wind lidar could be used in safety uncritical problems, such as assessment of visibility of man-made objects, including wind turbines. The high sensitivity of the lidar backscatter to aerosol type and size distribution could open up additional applications, such as volcanic plume monitoring.

Manuel Queißer et al.

Status: open (until 10 Aug 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on amt-2022-132', Anonymous Referee #2, 15 Jul 2022 reply
    • AC1: 'Reply on RC1', Manuel Queisser, 05 Aug 2022 reply
  • RC2: 'Comment on amt-2022-132', Anonymous Referee #1, 09 Aug 2022 reply

Manuel Queißer et al.

Manuel Queißer et al.

Viewed

Total article views: 278 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
230 40 8 278 1 1
  • HTML: 230
  • PDF: 40
  • XML: 8
  • Total: 278
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 06 Jul 2022)
Cumulative views and downloads (calculated since 06 Jul 2022)

Viewed (geographical distribution)

Total article views: 264 (including HTML, PDF, and XML) Thereof 264 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 09 Aug 2022
Download
Short summary
Visibility is how well we can see something. Visibility sensors, such as employed in meteorological observatories and airports measure at a point at the instrument location, which may not be representative of visibilities further away, e.g., near the sea surface during sea spray. Light detecting and ranging (lidar) can measure visibility further away. We find wind lidar to be a viable tool to measure visibility with low accuracy, which could suffice for safety uncritical applications.