Radar & lidar observations of clouds

UWERN Cloud systems and Orography meeting

Robin HoganUniversity of Reading, UK

1. Current and future Chilbolton capabilities2. Cloud physics and model evaluation work at

Chilbolton3. Global model evaluation and cloud radiative

properties from A-train data (CloudSat, Calipso and Aqua)

Chilbolton capabilitiesCAMRa 3 GHz Precipitation, clouds Scanning: Z, Doppler, polarization

UFAM Acrobat 1 GHz Boundary-layer dynamics Scanning: Z, clear-air Doppler

UFAM Copernicus 35 GHz Clouds Vertical: Z, Doppler, LDR, 24/7 operation

Galileo 94 GHz Clouds Vertical: Z, Doppler

Viper New! 3 GHz Clouds, precipitation Vertical: Z, 24/7 operation

Rothamstead VLR 10 GHz Insects Vertical: Insect properties, 24/7 operation

RAMAN 355 nm Humidity, temperature Vertical, case study operation

Vaisala ceilometer 905 nm Clouds, aerosols Vertical, 24/7 operation

Leosphere New! 355 nm Clouds, aerosols Vertical/45º, polarization, 24/7 operation

Halo New! 1.6 m Boundary-layer dynamics Vert./scanning, Doppler, 24/7 operation

Radars

Lidars

CIMEL Sun photometer: Aerosol optical depth & size 24/7

Dual-wavelength microwave radiometers: Liquid water path and water vapour path 24/7

Sonic anemometer & open-path H2O probe New! Sensible and latent heat flux, momentum flux 24/7

Standard met instruments including distrometer: Temperature, raindrop size distribution etc. 24/7

Pyranometer and pyrgeometer: Downwelling shortwave and longwave irradiance 24/7

UFAM Tethered balloon? Proposal submitted to CAA: In-situ measurements to ~1.2 km

Radiosondes: 25 km from Larkhill, which can launch extra sondes during case studies

Meteosat Second Generation: GERB fluxes, SEVIRI radiances & cloud products archived over site 24/7

Models: Forecasts from seven operational European models archived over site as part of Cloudnet 24/7

Radiation, surface energy budget, aerosols, models, satellite…

Cloud physics and model evaluation

1. Field campaigns and FAAM/Chilbolton experiments- Present & proposed NERC campaigns: CSIP, CWVC, ICEPIC, APPRAISE…- Met Office campaigns: CAESAR, MICROMIX, evaluation of 1, 4 km model- New capabilities at Chilbolton and FAAM will allow more detailed study

of cloud physics & aerosol (e.g. APPRAISE, POL45), Sc dynamics (NERC Sc)…

2. Cloud physics work comparing radar to CRM- Detailed case studies have been performed with deep convection

(Brown and Swann 1997), cirrus (Marsham and Dobbie 2005) and mixed-phase cloud (Clark et al. 2005, Marsham et al. 2006)

- CRM still in need of detailed evaluation! Need to test new prognostic IN scheme, drizzle formation, simulation of cloud inhomogeneities etc.

3. Long-term evaluation of forecast models- In Cloudnet (EU FP5) led by Chilbolton/Reading, seven operational

forecast models have been evaluated over three years & three sites- First ever long-term evaluation of model cloud fraction, LWC and IWC- Substantial differences found, but continued funding is needed to test

and improve the latest versions of models and new parameterizations

• NCAS-2 proposal Theme T2 includes

– Postdoc to process the raw data to obtain cloud products for rapid evaluation of clouds in models

– This would include algorithm development and support for other uses of the data: LEM studies, evaluation of satellite retrievals etc.

Observations

Models

Illingworth, Hogan, O’Connor et al.(BAMS, accepted for publication)

Global cloud observations from the A-train: CloudSat, Calipso,

MODIS and CERES• First two sentences of S9 theme stress

– Representation of clouds in climate models, particularly cloud physics and radiation

– This issue should be one of the key links between NCAS Weather and NCAS Climate

• The A-train of satellites offers the perfect opportunity to

– Put Cloudnet in space: global evaluation of clouds in ECMWF and MO climate models

– Calculate the radiative effect of each cloud type globally and evaluate climate models in more detail than ever before

• NERC-funded A-train work at Reading– Hogan, Illingworth, Delanoe + 2 PhDs– Collaboration with Met Office and

ECMWF – Consortium proposal with NCAS Climate

to evaluate high-res simulations of the tropics

Cloudsat radar and Calipso lidar launched in April 2006 behind the Aqua satellite

Eastern RussiaJapanSea of JapanEast China Sea

Calipso lidar

CloudSat radar 5500 km

Molecular scattering

Aerosol from China?

Cirrus

Mixed-phase altocumulus

Drizzling stratocumulus

Non-drizzling stratocumulus

Rain

Stratospheric aerosol

“First light” data from Cloudsat and Calipso on 7 June 2006

• Work is progressing to develop a variational radar/lidar/radiometer retrieval scheme; cloud products will be available to the community

– UK is providing the scientific leadership for the approved 2012 ESA “EarthCARE” mission, to carry radar & lidar on same platform; it is the only Earth Explorer mission (out of 5) dealing with physical processes in the atmosphere

• Liquid water content evaluation 2004, 3 sites, 7 models

• Ice water content comparison

Illingworth, Hogan, O’Connor et al. (accepted for publication in BAMS)

LEM/radar mixed-phase comparisons

• Radar/lidar observations of glaciating altocumulus

Marsham et al. (QJ 2006)

Supercooled water• LEM simulates many aspects well butunderestimates LWP

• Need to conduct experiments with prognostic ice nuclei to allow for depletion (Cotton and Brown)Role of Hallett-Mossop demonstrated by Clark et al. (QJ 2005)