Lidar difficulties, retrievals, and successes Franco Marenco

The 146 lidar story Mevex (2009) – first use – qualitative Laser frozen – six months for servicing First version of on-board viewer (Lidardisplay) Volcanic ash (2010) – quantitative – fully analysed FENNEC (Apr+May 2011) – quantitative data analysis planned Sept 2011 – loss of power – 4 months servicing DIAMET (Nov-Dec 2011) – Manchester instrument – was poor → servicing PIK&MIX (Jan-Feb 2012) – loan lidar from Leosphere (weak) MEVALI (March 2012) – lidar back from Leosphere – weaker signal April 2012 – tested in the lab for T dependence – no result Water spill preventers + lidar breather installed FENNEC (June 2012) – quantitative data analysis planned July 2012 – laser broken – “self fix” (new laser) – good and strong signal SAMBBA (Sept-Oct 2012) - quantitative data analysis planned ALS450 out of production

Temperature effect Ground-based In flight

iButtons: temperature effect proven RED – ground based GREEN – COALESC BLUE - FENNEC Rayleigh scattering constant (m=0.00415)

iButtons for housekeeping To what temperature cycle are we exposing the lidar? Something happened on Thursday, 29 September 2011 at 15:45!

Lidar upgrade In collaboration with Patrick Chazette (LSCE) New “better” polarising beam splitters Paris, January 2013 ?

Finding molecular layers: is the contour plot adequate? Is this blue (low signal) due to aerosols or Rayleigh scattering? Fennec

Finding molecular layers: is the contour plot adequate? aerosols or alignment problem? this slope is very different from Rayleigh scattering: must be aerosols!!

Inversion of lidar signals Range corrected signal Aerosol extinction coefficient 1 2 3 4 5 Reference Height 1 Height 2 backscatter extinction LIDAR RATIO

Setting layers manually for analysis accept/reject surface spike aerosol and depol calibration ranges cloud tops ch0: yellow ch1: brown

Volcanic ash: extinction coefficient retrievals spatially resolved detection ~ 30% uncertainty quantitative signal inversion 17 May lidar ratio 60 sr ~1800 lidar profiles inspected + analysed (6 flights)

Ash concentration estimates courtesy of B. Johnson, J. Dorsey and M. Gallagher Date fc Kext (m2/g) 4 May 0.52 0.92 5 May 0.72 0.65 14 May 0.97 0.62 16 May 0.78 0.82 17 May 18 May 0.75 0.74 Uncertainty: ~ factor of 2

Volcanic ash Lidar vs. NAME courtesy of H. Webster (Atmospheric Dispersion Group) Volcanic ash Lidar vs. NAME reasonable overall magnitude positional errors sometimes model uncertainties: source term, meteorology, sub-scale processes

Volcanic ash - Lidar vs. SEVIRI courtesy of P. Francis and M. Cooke (Satellite Applications) 17 May

ACEMED: validation of CALIPSO In collaboration with V. Amiridis, A. Tsekeri and E. Marinou (National Observatory of Athens)

In collaboration with H. Jones (U. Manchester) COSIC: contrails In collaboration with H. Jones (U. Manchester)

Verification of cirrus model Courtesy of A. Baran

SAMBBA

SAMBBA

FENNEC

Questions and answers