Microphysics observations from MICRO-SCOPE J. Crosier, Z. Liu, J. Taylor, K. Bower, T. Choularton University of Manchester COPE meeting - Leeds - April 2014

Probe NameRoleProviderStatus CDP Cloud droplet size distribution 1 – 50 µm FAAMBADC CAS Cloud droplet size distribution 0.7 – 50 µm Phase discrimination UoM CIP15 CIP100 Cloud particle size distribution µm (100 – 7000 µm) Shadow imaging UoM/FAAMBADC 2DS Cloud particle size distribution µm Shadow imaging Dual channel UoMBADC CPI High resolution particle imageryUoM Nevzorov Bulk Liquid/Ice water contentUKMO/FAAMBADC SID-2 Particle size distribution Phase discrimination 1 – 50 µm UKMO??

COPE meeting - Leeds - April 2014 Probe NameRoleProviderStatus CDP Cloud droplet size distribution 1 – 50 µm FAAMBADC CAS Cloud droplet size distribution 0.7 – 50 µm Phase discrimination UoMUnknown CIP15 CIP100 Cloud particle size distribution µm (100 – 7000 µm) Shadow imaging UoM/FAAMBADC 2DS Cloud particle size distribution µm Shadow imaging Dual channel UoMBADC CPI High resolution particle imageryUoMIn progess Nevzorov Bulk Liquid/Ice water contentUKMO/FAAMBADC SID-2 Particle size distribution Phase discrimination 1 – 50 µm UKMO??

COPE meeting - Leeds - April DS and CIP Optical Array Probes Heymsfield and Parrish 1978, JAM

COPE meeting - Leeds - April DS and CIP Optical Array Probes CIP, -11°C, convective region within frontal cloud

COPE meeting - Leeds - April DS and CIP Optical Array Probes 2DS, -13°C, frontal cloud

2DS and CIP Optical Array Probes COPE meeting - Leeds - April DS “Stereo” probe NamePixel Res.Num. pixelsArm SepComments CIP1515 µm6470 mm2 bit images Anti-shatter tips CIP µm6470 mmAnti-shatter tips 2DS10 µm12863 mmDual channel Anti-shatter tips CIP probe

Data processing COPE meeting - Leeds - April 2014 DyDy DxDx D mean = 0.5 * (D y + D x ) Sample volume We use “Centre In” method Increases sample volume of large particles compared to “All-In” Determination of particle size Heymfield and Parrish 1978

“Centre-In” vs “All-in” COPE meeting - Leeds - April 2014 Heymfield and Parrish 1978 All-In No end diodes activated Entire particle is imaged Unambigous particle size Most large particle rejected Centre-In Predict size for partially imaged particles Assumptions on particle shape/symmetry Increased sample volume for larger particles

Particle shape analysis COPE meeting - Leeds - April 2014 Circularity = Perimeter 2 / (4 * Pi * Area) 1 for a perfect circle, >1 for non-circular By setting a suitable threshold of shape factor, we get an estimate of ice particle concentrations However, there is no perfect threshold, and we frequently see “miss-classification”. We are working to improve/quantify this. Determination of particle shape

Sampling artefacts COPE meeting - Leeds - April 2014 Spurious counts can be recorded due to shattering/splashing of ice/liquid particle on instrument tips The use of inter-arrival time and image processing can remove this bias. Can remove some “good” particles. New anti-shatter tips greatly reduce the shattering problem.

Sampling artefacts COPE meeting - Leeds - April 2014 Spurious counts can be recorded due to shattering/splashing of ice/liquid particle on instrument tips The use of inter-arrival time and image processing can remove this bias. Can remove some “good” particles. New anti-shatter tips greatly reduce the shattering problem.

Data availability COPE meeting - Leeds - April 2014 FlightCIP15CIP1002DS*CPI images B783BADC To do B785UnusableBADC To do B786BADC To do B788BADC To do B789BADC Technical delayTo do B790BADC To do B791BADC To do B792BADC (1)Particle images are also available on BADC (2)Particle images from 2DS are from channel 1. Channel 2 will be uploaded by June (3)Due to error in 2DS sample volume, all 2DS concentrations are a factor of 2 too high

Example CPI images COPE meeting - Leeds - April 2014

Revise 2DS dataset to correct for Svol error Finish exporting of CPI images Improve particle classification for OAP probes Any additional data products required? CAS/SID analysis? COPE meeting - Leeds - April 2014 To do…..