Cloudnet meeting Oct Martial Haeffelin SIRTA Cloud and Radiation Observatory M. Haeffelin, A. Armstrong, L. Barthès, O. Bock, C. Boitel, D. Bouniol, M. Chiriaco, J. Delanoe, P. Drobinski, J-L. Dufresne, C. Flamant, M. Grall, F. Hourdin, F. Lapouge, Y. Lemaître, A. Mathieu, Y. Morille, V. Noel, J. Pelon, C. Pietras, A. Protat, B. Romand, G. Scialom, R. Vautard, Y. Wanherdrick Institut Pierre Simon Laplace Algorithms

Cloudnet meeting Oct Martial Haeffelin LIDARCloud and aerosol vertical structure Multi-test algorithm applied on 532-nm channel to identify cloud layers, aerosol layers, molecular layers, and boundary layer height (Morille et al., 2004) Optical depthMulti-retrieval algorithm applied on 532-nm channel to retrieve optical depth of cloud or aerosol layers (Cadet et al., 2004) Depolarization and color ratio Multi-wavelength algorithms using linear and cross-polarized 532-nm and linear 1064-nm channels to discriminate particle shape (Noel et al., 2002) RADARCloud structure Ice/water content Particle size distribution Mean particle diameter from radar reflectivity and doppler velocity Size distribution related to mean diameter Extinction and ice water content function of reflectivity and size distribution Retrieval uncertainties estimated 50% CEILOME TER Cloud-base height Vaisala proprietary algorithm RADIATI- VE FLUX STATION Fraction of cloud cover Shortwave and longwave clear- sky fluxes Clear-sky models derived from measurements. Threshold to identify cloud cover fraction. (Long and Ackerman 2000) MWRIntegrated water vapor and liquid water content Brightness temperatures simulated from radiosonde profiles to calibrate MWR. Water vapor and liquid water contents inverted using the Kummerow and Weinman (1988) algorithm. Data Products

Cloudnet meeting Oct Martial Haeffelin Lidar Data Products Wavelet transform method: Search for high correlation between a wavelet and the lidar signal Mexican hat for particle layers in the free troposphere Step function for boundary layer Cloud / aerosol separation based on PR2 peak-to-base ratio Distinction between true noise (no more photons) and apparent noise (no more scatterers) Cloud and aerosol vertical structure

Cloudnet meeting Oct Martial Haeffelin Lidar Data Products L0: Lidar back-scattered power L1: Quality flag Monitoring noise L2: Atmospheric Mask (Clouds, aerosols, Boundary layer, Particle-free zone, Noise Cloud thermodynamic phase Cloud and aerosol layer optical depth L3: Time and layer -average data

Cloudnet meeting Oct Martial Haeffelin Radar-Lidar Cloud Products Combine Reading classification with LNA classification

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Processed LNA Lidar data: 10/ /2004 Cloud, aerosol mask Time averaged data

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Frequency of occurrence of cloud fraction and vertical distribution of cloud layers Palaiseau 10/ /2004 LNA Lidar

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Frequency of occurrence of single and multiple cloud layers Palaiseau 10/ /2004 LNA Lidar

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Frequency of occurrence of cloud thickness and vertical distribution Palaiseau 10/ /2004 LNA Lidar

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Palaiseau 10/ /2004 LNA Lidar Relative occurrence of cloud altitude (monthly variations)

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Palaiseau 10/ /2004 LNA Lidar Relative occurrence of cloud altitude (seasonal variations) Vertical Extent of Clouds

Cloudnet meeting Oct Martial Haeffelin Cloud Product Dataset Analysis Relative occurrence of cloud-base altitude (seasonal variations) Palaiseau 10/ /2004 LNA Lidar Occurrence of Cloud Base

Cloudnet meeting Oct Martial Haeffelin Lidar Data Products Mixed phase Liquid water Ice water Normalization problem Cloud thermodynamic phase Based on lidar depolarization ratio +  threshold Requires normalization in particle-free zone (2.74%)

Cloudnet meeting Oct Martial Haeffelin Lidar Data Products Molecular Integration method:  = ∫  (z)dz Integrated extinction = power loss between theoretical molecular return below the cloud and molecular return above the cloud Cloud optical depth Particle Integration method:  = LR eff ∫ (R(z)-1)  m (z)dz where R(z)=(  m (z)+  c (z))/  m (z) LR eff prescribed: 18 sr LR eff opt derived from MI method Cadet et al. 2004

Cloudnet meeting Oct Martial Haeffelin Lidar Data Products Cloud optical depth Cadet et al. 2004

Cloudnet meeting Oct Martial Haeffelin Radiative Flux Station LWSW Operations: 18 months of Global SW + LW SW Direct + Diffuse missing 12/03-02/04

Cloudnet meeting Oct Martial Haeffelin Radiative Flux Dataset Analysis SW Direct May 2004 SW Diffuse SW Global LW Down

Cloudnet meeting Oct Martial Haeffelin Radiative Flux Dataset Analysis Shortwave radiative impact of cloud layers Clear-sky reference from F = a cos(  ) b May 2004 Single-layer high-altitude clouds

Cloudnet meeting Oct Martial Haeffelin Produce 2-year radar-lidar L3 products Pursue analysis of vertical structure Pursue developments of lidar-only retrievals and combination Develop clear-sky flux and radiative forcing products, and analyse in relation to the cloud data base Perspectives Institutes and programs supporting SIRTA: