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HIWC - HAIC Coordination Meeting. Falcon 20 instrumentation for HAIC / HIWC AIRBUS, CNRS, BOM. Payload & status. HIWC - HAIC. Motivation to use F20. HIWC - HAIC.
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HIWC - HAIC Coordination Meeting Falcon 20 instrumentation for HAIC / HIWC AIRBUS, CNRS, BOM Payload & status HIWC - HAIC EASA.2011.OP.28
Motivation to use F20 HIWC - HAIC EASA.2011.OP.28 • Objective: Define the most adequate instrumental payload for the Falcon 20 in order to fully meet the objectives of the HIWC / HAIC study. • Recall: The main HighIWC aircraft (G-II) will particularly be instrumented with in-situ cloud microphysics instruments and focus on the in-situ characterization of high IWC regions. • Our strategy in the HAIC / HIWC project is: (i) to validate the Doppler cloud radar (on F20) estimates of IWC in HighIWC regions (retrieved from reflectivity and Doppler velocity) using the state-of-the-art in-situ microphysical measurements from G-II and Falcon 20 aircraft. (ii) then to use the validated radar estimates to take advantage of the vertical resolution of the cloud radar to extrapolate the IWC & PSD in situ data (G II & F20 trajectories) for the new icing envelope calculations.
Falcon 20 and basic instrumentation Aircraft : Falcon 20 (200 ms-1, 3.5 hours endurance, 12 km ceiling) Limitation to 4 single pods Deployment: Period: Jan 15 – Feb 15 2013. 49 flight hours Flightsperformed in IFR (instrumented flight rules) mode Airportat Darwin, Australia. HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC Task: choose in situ microphysics instrumentation • 4 under-wing pods available for best instrumental configuration. • No single instrument covers the range from 1m to several mm. • Payload alternations are possible during campaign CDP CPI Optical spectrometers ParticleImagers Bulk TWC / IWC devices Robust CAPS 2D-S AI Nephelometer CIP HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC Mergingdifferent instruments to retrieve total PSD 4 10 PIP CIP 2DS 2 10 PSD composition 0 10 #/L/µm -2 10 -4 10 -6 10 0 1 2 3 4 10 10 10 10 10 Deq(µm) In situ microphysics instrumentation: Complete PSD… PSD composition from 2D-S + CIP + PIP (MT-I data) « Pristine » range fit (80 µm,250 µm) « Drizzle » range fit (250 µm,1500 µm) Precipitation range fit (1500 µm,5000 µm) HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: Requirements • What are the requirements for High-IWC instrumental in situ payload? • Measurement of small ice particle properties (<100μm, if possible) • Avoidance of possible small ice crystals contamination on spectrometer data due to ice particle shattering. Reduction of the possible artifacts created by particle breakups and bouncing off surfaces ahead of the instrumentation sample volume. • Interarrival time analysis. • Discrimination of phases of particles (solid/liquid). • Enhancement of IWC measurements (Total amount). • A selection of adequate instrumentation will be deployed to cover the range for ice crystals measurement HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC • Cloud remote sensing on Falcon 20 : • Sophisticated 94 GHz cloud radar RASTA • In-situ microphysics : Most likely configuration • Pod 1: ROBUST Probe combined to CDP (Cloud Droplet Probe) • Pod 2: 2D-Stereo Probe (10-1280 µm; 10 µm pixel resolution) • Pod 3: CPI Cloud Particle Imager (10-2300 µm; 2.3 µm pixel resolution) • Pod 4: PIPPrecipitation Imaging Probe (100-6400 µm; 100 µm pixel resolution) • Fuselage hard points: Rosemount Aerospace Model 0871LM Series, Nevzorov Probe • Alternative probes: We want to change initial configuration during campaign!! • HSI High Speed Imaging Probe (5-2500 µm) • CPSD Cloud Particle Spectrometer with Depolarization (CPSD) • Backup probes: CAS-DPOL, CIP, 2D-Grey, 2D-P, FSSP-100 ... HIWC - HAIC EASA.2011.OP.28
Sum up: Whatdoes F20 add to HIWC HIWC - HAIC EASA.2011.OP.28 • Radar RASTA: Access to dynamics and macrophysicalcloudproperties • In-situ: Detailed information limited to aircrafttrajectory, use of radar to extrapolate the in situ data to entirecloudfield (particularly vertical extension) • Detailedmeasurement of cloudmicrophysics on a second flight level (first level by G-II)
Specific instrumentation on F20 for HighIWC Cloud radar RASTA • RASTA 94 GHz cloud radar (6 antennas): • Doppler velocity measurement • 3 radar beams looking down • 3 radar beams looking up • Sensitivity: -38 dBZ @ 1 km (down) / -32 dBZ @ 1 km (up) • “3D” (antenna directions!) wind retrieval (Papazzoni 2010) • Terminal fall speed retrieval • Combining reflectivity and fall speed to retrieve microphysics from cloud radar: IWC, extinction, effective radius, NT(Delanoë et al. 2007) HIWC - HAIC
Specific instrumentation on F20 for HighIWC Cloud radar RASTA & CLOUDSAT Comparison allows to check retrieved microphysical properties from CloudSat / CALIPSO. HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC Cloud radar RASTA RASTA vertical velocity retrievals compared to Falcon 20 in situ velocity In-situ In-situ HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ probes Do we need PIP size range for HIWC? - Acquisition of up to 12000 particles/s - On average 40% of icecrystal mass beyond 1 mm for continental tropical convection (Megha-Tropiques I, 2010 West Africa) and 20 % for oceanic convection (Megha-Tropiques II, 2011 IndianOcean) , respectively. HIWC - HAIC EASA.2011.OP.28
Falcon 20 validation flightswithin MT Typicalicecrystal images in tropical convection Right: PIP probe images over Indian Ocean (2011) Mixture of graupels and aggregates, due to strong updraft Much more pristine ice crystals due to moderate updraft 1cm 1cm 2 mm 2 mm HIWC - HAIC EASA.2011.OP.28 Left: PIP probe images over African continent (2010)
Specific instrumentation on F20 for HighIWC In situ probes • 2DS (10 µm resolution) versus CIP (25 µm resolution)? • Good overlap of different probes • Reconstruction of PSD between 50 and 6400 µm • CIP does not preciselyfollow 2D-S beyond 200 µm • For the moment: no interarrival time analysis of CIP; only 2D-S! HIWC - HAIC EASA.2011.OP.28
Falcon 20 validation flightswithin MT Interarrival time analysis and PSD correction for 2D-S Interarrival times (Delta t) HIWC - HAIC EASA.2011.OP.28
Results: IWC from radar reflectivity and µF Mass-diameterrelationship Flight nr. 18 - 2010 • = f (h) • = 2,1 HIWC - HAIC EASA.2011.OP.28 Mass-diameter relationship: m(D) = a Db Area-diameter relationship: A(D) = g Dh
Results: IWC from radar reflectivity and µF Mass-diameterrelationship Flight nr. 20 - 2010 • = f (h) • = 2,1 Mass-diameterrelationship Mass-diameter relationship: m(D) = a Db Area-diameter relationship: A(D) = g Dh HIWC - HAIC EASA.2011.OP.28
Conclusions and remarks • A selection of adequate Falcon 20 instrumentation will be deployed within HIWC international F/T campaign 2013 • Measurement of small ice particle properties at least down to 100μm is possible: CPI, CPSD, …. • Significant improvement of cloud particle phase discrimination: ROBUST & RICE probes, CPSD! • Enhancement of capability of total TWC & IWC measurements: ROBUST probe for the first time on Falcon 20 • Important refinements of mass – diameter relationships working on radar – in situ closure. Use of ROBUST probe bulk TWC measurements will enormously help!! • Access to GII data will enhance the valuable dataset HIWC - HAIC EASA.2011.OP.28
HIWC - HAIC EASA.2011.OP.28 ANNEXE
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: Imaging probes HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: CPI plate needles collumns needles HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: Optical spectrometers Standard FSSP-100 Supercooled water Response to ice HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: Optical spectrometers Cloud Particle Spectrometer with Depolarisation (CPSD) The CAS-DPOL / CPSD. Below response of the depolarization detector as a function of time and particle diameter. The white trace is the temperature. The color shows the intensity of depolarization. Higher depolarization indicates higher probability of ice. Above: CPSD Below: CAS - DPOL Courtsey: Bruce Gandrud HIWC - HAIC EASA.2011.OP.28
Specific instrumentation on F20 for HighIWC In situ microphysics instrumentation: Bulk TWC / IWC probes • RICE Probe • Principle : • Measures amount of ice mass accumulation on a metal cylinder. • As ice accretes on the cylinder, frequency of the vibration changes. • Supercooled LWC calculated from vibration frequency variation with time. • Principle: • Hydrometeors impact on sensor (4mm half cylinder). • The sensor element is heated in order to maintain a constant temperature, typically 140 °C. • The power level set by the control system to maintain temperature is converted into TWC. TWC LWC IWC = TWC - LWC Combination of Robust and RICE probes will provide a measurement of IWC. HIWC - HAIC EASA.2011.OP.28 • ROBUST Probe
Confrontation des CWC restituer par les 2 méthodes de calculs du pré-facteur α 2011 Vol 45 Forte probabilité d’enrichissement de la mesure CWC Nevzorov: Lié à la position de la sonde Nevzorov à l’arrière de l’Avion (proche fuselage). Pb supplémentaire: Saturation de la sonde Nevzorov (grand offset non réglable avec 3g par m3 comme max. CWC, sans offset)! Dispersion moins importantes pour le Code Mie. Avec l‘approximation des effets de Mie, les CWC sont sous-estimer par rapport à un code plus strict (Boudala). Mais , ils restent proportionnel l’un par rapport à l’autre ! Vol 46 HIWC - HAIC