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Topic 11 New Sensors, Platforms, Analysis Techniques and Integrated Systems for Measuring Ice Cloud Properties. D. Baumgardner M. Maahn Z. Wang Co-Leaders. A. Abdelmonem H. Bieligk U. Bundke J. Crosier, M. Gallagher I. Gulteppe M. Hamilton R. Jackson A. Johnson A. Korolev

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Topic 11

New Sensors, Platforms, Analysis Techniques and Integrated Systems for Measuring Ice Cloud Properties

D. Baumgardner M. Maahn Z. Wang

Co-Leaders

A. Abdelmonem

H. Bieligk

U. Bundke

J. Crosier,

M. Gallagher

I. Gulteppe

M. Hamilton

R. Jackson

A. Johnson

A. Korolev

P. Kupiszewski

P. Lawson

A. Mensah

B. Sierau

J. Stith

J. Ulanowski

E. Weingartner

Workshop on Measurement Problems in Ice Clouds

Zurich, Switzerland

July 5-6, 2013


Presentation Guide

Topic Theme and Objectives of the Working Group

Brief Status of this Topic after the July, 2010 workshop

What progress has been made in the last three years?

What are the remaining unknowns and uncertainties and how do they impact our fundamental understanding of the atmosphere, climate change, weather and society in general?


Presentation Guide

Topic Theme and Objectives of the Working Group

Brief Status of this Topic after the July, 2010 workshop (see BAMS article)

What progress has been made in the last three years?

What are the remaining unknowns and uncertainties and how do they impact our fundamental understanding of the atmosphere, climate change, weather and society in general?


  • The central focus of Topic 11 is the assessment of new and evolving technology for measuring and analyzing the properties of ice in clouds and precipitation, including in situ and remote sensing techniques, ground based, airborne and space borne platforms and integrated suites of sensors.

  • The objectives of the working group are to:

  • summarize the strengths and weaknesses of current technology;

  • assess the technological progress that has made since June, 2010; and

  • identify gaps in our measurement capabilities where new technology or measurement approaches are needed.


Presentation Guide evolving technology for measuring and analyzing the properties of ice in clouds and precipitation, including in situ and remote sensing techniques, ground based, airborne and space borne platforms and integrated suites of sensors.

Topic Theme and Objectives of the Working Group

Brief Status of this Topic after the July, 2010 workshop

What progress has been made in the last three years?

What are the remaining unknowns and uncertainties and how do they impact our fundamental understanding of the atmosphere, climate change, weather and society in general?


As of June 30, 2010, from the BAMS meeting summary, issues related to measurement capabilities.

3) Currently available instruments are limited by problems caused by ice crystal shattering and sample volume uncertainties for cloud particles smaller than 50 μm. Although consistent and reliable measurements of ice crystal size distributions can be obtained for particles larger than 400 μm, given sufficiently long integration times, large uncertainties still remain at smaller sizes.

4) New instruments are becoming available to differentiate liquid droplets from ice crystals at sizes less than 50 μm by detecting their shapes from forward light scattering and depolarization signals.


Presentation Guide related to measurement capabilities.

Topic Theme and Objectives of the Working Group

Brief Status of this Topic after the July, 2010 workshop (see BAMS article)

What progress has been made in the last three years?

What are the remaining unknowns and uncertainties and how do they impact our fundamental understanding of the atmosphere, climate change, weather and society in general?


  • Measurement Issues related to measurement capabilities.

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Avoiding Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted and commercial aircraft)

  • Issues related to passive and active remote sensing


  • Measurement Issues related to measurement capabilities.

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Avoiding Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted and commercial aircraft)


In Situ Related to Small Ice, Water/Ice Discrimination related to measurement capabilities.(Needs editing. )

Maturing Sensors (How far back do we go?)

SID-3,2H (introduced 20??) – Results from ICE-T (Johnson/Field)

Holodec (Introduced 2004?) – Anything new? (Contact Jacob)

CAS-POL (Introduced 2008) – Lab/Aircraft results (Jessica/Martin)

PN (Introduced 1997) -

New Sensors

BCP (Introduced 2011) – Airbus results (Darrel)

BCP-POL (Introduced 2012) – BAE-146 results (Darrel/Martin)

CPSPD (Introduced 2011

3V-CPI (Introduced 2010) – ICE-T? (Paul L.)

Hawkeye (Introduced 201?) –Global Hawk? (Paul L.)

PHIPS-HALO (Introduced 2011)

MASC (Introduced 2012) – Results from Tim Garrett

Polarsonde (Introduced 2012?)


Sid 2h vs fssp

SID-2H vs. FSSP related to measurement capabilities.


Sid 2h vs fssp 100 all ice and water cases
SID-2H vs. FSSP-100: related to measurement capabilities.All Ice and Water Cases

RF11 cloud pass at -13°C (all ice)

RF04 cloud pass at 7°C (all water)

  • Penetration at base of shallow maritime cumuli

  • 2D-C images = small water drops

  • FSSP-100 >> SID-2H concentration

    • SID-2H shouldn’t be trusted in warm clouds

  • SID-2H derived particles shape dominated by spheres, small number of irregular particles

  • Penetration through dying cloud

  • 2D-C images = small ice particles; mostly aggregates aswell as rimed columns & dendrites, very few drops

  • SID-2H ~ FSSP-100 concentration

  • SID-2H derived particles shapes dominated by spheres and irregular particles


Sid 2h vs fssp 100 first detectable ice case
SID-2H vs. FSSP-100: related to measurement capabilities.‘First Detectable Ice’ Case

RF04 cloud pass at -5°C

  • Penetration within 500 m of cloud top

  • 2D-C images = drops, no ice

  • FSSP-100 >> SID-2H concentration

  • SID-2H derived particles shapes, irregular particles, and columns

  • Ice predominately observed by SID-2H in updraft/downdraft interfaces

Data from Johnson et. al – Submitted to J. Tech.


200µm related to measurement capabilities.

500µm

500µm

500µm

500µm

Polar Nephelometer : phase discrimination

Case study : Nimbostratus arctic cloud


Results from BCP related to measurement capabilities.


Change in Polarization State related to measurement capabilities.

to Detect Water Phase Changes

Implementation in CAS-POL and CPSPD


PHIPS-HALO: Particle Habit Imaging and Polar Scattering Probe

PHIPS-HALO is an optical sensor designed to measure, simultaneously, the 3D morphology and the corresponding optical properties of individual cloud particles. It is composed of two combined optical systems. The first system measures the polar scattered light from cloud particles with a resolution of 1° for forward scattering directions (from 1° to 10°) and 8° for side and backscattering directions (from 18° to 170°). The second system is a stereo imaging system composed of two identical camera-telescope assemblies and a pulsed flash Laser. The images are produced as particles shadows on the CCD of each camera. The measured particle size range is 5 to 800 µm


Sample result: Probe

Cam.2

Cam.1

Abdelmonem et al.

Atmos. Meas. Tech., 4, 2125–2142, 2011





Polarsonde a low cost polarisation backscatter sonde
Polarsonde Probe : A low-cost polarisation backscatter sonde

  • A probe for cloud ice/ supercooled liquid

  • Originally conceived for support of aviation forecasting

  • Potentially useful for study of cloud structure and for support of modelling

  • Transmits linearly polarised light from LED (6 kHz mod’n.)

  • Photodiodes with perp. and parallel polarisers

    • and lock-in amplifiers

  • Measures linear “depolarisation”

  • Interfaces to RS92SGP radiosonde

  • Uses Vaisala RSA921 Ozonesonde interface

Murray Hamilton, Huichao Luo; University of Adelaide


Launch at summit camp 18 july 2012 cloud present at ca 3400 m and ca 5500 m
Launch at Summit Camp: 18 July 2012 Probe Cloud present at ca 3400 m and ca 5500 m


data from 10 m on tower at Summit Probe Large depolarisation implies ice, small (ca 0.3?) implies liquid. (temp and RH for 1st week Nov. follow)

After 24-hr darkness …

did not behave well in sunlight.

Fog monitor (faulty) and particle size spectrometer also at 10 m

Modified since to be insensitive to sunlight.


Validation of polarsonde
Validation of polarsonde Probe

  • Cloud particle microscope; Huichao Luo

    • Relatively low-cost … Light weight … balloon borne

  • Collaboration with ICECAPS and Greenland Isotope projects.

  • Monte-Carlo modeling of scattering in cloud

    • Multiple scattering is a significant confounding process

    • Uses Mie theory for liquid droplets

      • typical linear depolarisation

      • Approx. equal contributions to depolarisation from geometry and multiple scattering

    • Model for ice crystals in progress – guidance is sought at Zurich workshop!


Remote Sensing Related to Small Ice, Water/Ice Discrimination (Needs editing. )

Maturing Sensors (How far back do we go?)

New Sensors (Need descriptions and example results)


  • Measurement Issues Discrimination

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Avoiding Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted and commercial aircraft)


Maturing Sensors Discrimination

CDP (introduced 2004)

Probes with Korolev Tips (introduced 2000)

FSSP Inlet removed

HOLODEC

New Sensors

BCP

CPSPD

Analysis techniques?


  • Measurement Issues Discrimination

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Light Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted and commercial aircraft)


In Situ Total Water Discrimination

Maturing Sensors (Anything New? Which ones do we keep?)

Nevzorov Probes (introduced ????)

FISH (introduced 1990)

Cloud Extinction Probe (CEP) (introduced 2006)

New Sensors

IKP


  • Remote Sensing Discrimination (Needs editing with specific examples)

  • (Cloud) Radars

  • New technologies:

  • multi-wavelength (also form space -> GPM)

  • Exploiting higher moments or even full Doppler Spectrum

  • Attenuation proportional to ice at mm wavelengths

  • Polarization

  • shorter averaging times to reduce influence of turbulence

  • Challenges:

  • Absolute Calibration

  • processing of large data amounts


Z swc relations for radar

SWC: snow water content

Z – SWC relations for radar

Z mm6m-3

Liu, 2008:

SWC gm-3

M. Kullie, Univ. of Madison


Multi frequency approach
Multi Frequency approach distribution

  • Dependency of differential reflectivity on particle type:

Kneifel et al., JGR, 2011

Difference Ka and Ku band [dB]

Difference Ka and W band [dB]


Exploration of higher radar moments
Exploration of higher radar moments distribution

  • Doppler radar measure not only reflectivity, but also Doppler spectrum and higher moments, such as Spectral Width, Skewness and Kurtosis

  • Shape depends on particle density, shape, fall velocity, PSD and turbulence


Exploiting attenuation
Exploiting attenuation distribution

Petty and Huang, JAS, 2010

  • Extinction has less variability in respect to particle habits, but stable connection to mass.

  • Only for high MW frequencies (> W-band)

  • Measurement:

    • 2nd, not attenuated frequency (e.g. Kband)

    • Radio link


  • Remote Sensing distribution(Needs editing with specific examples)

  • Radiometers

  • New technologies:

  • Polarization

  • Exploiting higher frequencies

  • Increasing number of observations from space

  • Challenges:

  • receiver calibration

  • inversion of forward models (retrieval)

  • getting climatologies for retrieval

  • going beyond path properties


Passive microwave signals during snowfall

TB: brightness temperature (= intensity of radiation) distribution

  • Snow/ice scatters thermal surface emissions:

  • TB depression measured from space

  • TB enhancement measured from ground

Passive microwave signals during snowfall

U. Löhnert, U. Cologne


Microwave spectrum during snowfall

typical winter case distribution

Microwave spectrum during snowfall

sensitivity to particle habit

U. Löhnert, U. Cologne

  • Frequencies > 120 GHz needed for detection of snow and ice

  • Signal sensitive to ice AND water

  • Sensitivity: ~ 8 - 10 K per 0.1 kgm-2 SWP at 150 GHz


Polarization
Polarization distribution

Long term statistics of measurements taken at Mnt. Zugspitze at150 GHz, elev= 34.5°

Polarization due to non-spherical shape of ice particles.

Signal only visible, if SCLW is not present!

Xie et al., JGR, 2012

Polarization Difference = TBv - TBh


Remote Sensing distribution(Needs editing with specific examples)

Lidars, passive vis & IR

Lidars:

Elastic lidar (all platform): backscattering and depolarization

Raman lidar (ground +airborne): cloud extinction + ice water content+ effective size

High spectral resolution lidar: cloud extinction + depolarization

Passive:

VIS+IR: MODIS improved ice cloud retrievals after intercomparison with CALIPSO optical depth

Microwave: AMSR-E, IWP


  • To be added: distribution

  • New Analysis Techniques

    • Multi-sensor retrievals

    • Multi-probe synergy

    • IC-PCA

  • New and emerging measurement platforms

    • UAV

    • Balloon-borne

  • New integrated measurement techniques

    • Multi-sensor integrations from ground, airborne, and satellite.

    • Airborne integration of remote sensing and in situ sampling.


  • New observatory of cloud and precipitation properties from ground-based remote sensing in East Antarctica (HYDRANT project, ees.kuleuven.be/hydrant):

  • Equipment: ground-based remote sensing using low-maintenance and robust instruments (ceilometer, infrared pyrometer and MRR)

  • Products: cloud height, distinction of ice vs liquid-containing clouds, precipitation intensity and height (including virga), precip vs blowing snow

  • Integrated measurements: combined with meteorology, radiation, accumulation (=> effects on SMB/SEB) + Regional Climate Model evaluation + potential for CALIPSO/CloudSat collocated analysis

  • Contact: N. Van Lipzig, I. Gorodetskaya (KUL, Belgium)

Princess Elisabeth base

Powered by wind and solar E

Unmanned during March-Nov

(satellite connection)

CL31 Ceilometer (910 nm)

Infrared pyrometer (8-14 µm)

Micro-rain radar (24 GHz)

AWS: meteorology,

radiative fluxes,

accumulation

Webcam:

Weather and

instrument

monitoring

Automatic Weather

Station


Ice clouds with virga case at pe e antarctica

MRR Ze from new algorithm of Maahn et al. 2012: can detect virga (sensitivity down to -14 dBZ)

Ice clouds with virga case at PE, E Antarctica

Webcam

2012-02-20 16 UTC

Ceilometer : attenuated backscatter

20 Feb 2012

I. Gorodetskaya, KULeuven


Snowfall followed by virga case at pe e antarctica

MRR Ze (from -14 dBZ), W, spectral width from new algorithm virga (sensitivity down to -14 dBZ)

of Maahn et al. 2012:

Snowfall followed by virga case at PE, E Antarctica

Webcam

2012-02-28 14UTC

Ceilometer : attenuated backscatter

28 Feb 2012

I. Gorodetskaya, KULeuven


Mixed phase clouds cases at pe e antarctica

Liquid-containing clouds are detected with threshold virga (sensitivity down to -14 dBZ)βatt > 102.8 x 10-9 sr-1 m-1

determined using cloud structure + LWin

Mixed-phase cloudscases at PE, E Antarctica

Ceilometer : 7 Feb 2012

Webcam

2012-02-07 04:39UTC

Ceilometer : 8 Mar 2010

Ceilometer : 17 Mar 2010

I. Gorodetskaya, KULeuven


Cloud sw forcing all vs mixed phase

Cloud effects on radiative fluxes using simultaneous measurements

Cloud SW forcing(all vs mixed phase):

Cloud LW forcing

(all vs mixed phase):

I. Gorodetskaya, KULeuven


  • Measurement Issues measurements

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted and commercial aircraft)


In Situ ( measurementsCovered in Topic 8?)

Maturing Sensors (Anything new since 2010?)

CVI + SP2

CVI + ATOFMS

CVI + AMS

CFDC (Introduced 1996)

New Sensors (Anything new?)

SPIN

ISI


Deployed inlets for measurementsthe extraction of ice nuclei:

Addressed question:

Study the physico-chemical characteristics of atmospheric ice nuclei in mixed-phase clouds under ambient conditions as a function of air mass origin and as a function of cloud type and cloud properties.

CLACE2013 : Intensive measurement campaign (Jan-Feb 2013) at the high alpine site Jungfraujoch in the Swiss Alps

Participating groups:

Ice-CVI from TROPOS

ISI from PSI


Ice Selective Inlet (ISI) measurements

The ISI extracts small ice crystals from mixed-phase clouds, simultaneously counting, sizing and imaging the hydrometeors contained in the cloud with the use of Welas optical particle counters (OPC) and a Particle Phase Discriminator (PPD).

Separation of ice crystals from supercooled droplets is in the airborne state – no physical impaction!


ISI: Droplet evaporation unit measurements

Ice-coated inner-walls

SVP (ice) < SVP (liquid)

 Flux of water vapor from liquid droplets to ice surface


Particle Phase Discriminator (PPD2) measurements

Scattering chamber.

Sensitive volume:

d = 2.5mm

h = 150µm

Camera:

f = 20Hz

Trigger sensor: f = 1kHz

Laser: 100mW @ 532nm

Source: University of Hertfordshire

PPD2 CLACE 2013 data:

Hexagonal ice plate (left);

droplet (middle);

irregularly shaped ice particle (right)



Clace 2013 ice residual analysis
CLACE 2013: Ice residual analysis measurements

Normalized dry size distributions of the total aerosol (red) and ice residuals (blue) measured with a single particle soot photometer

Chemical composition of typical ice residuals measured with the ALABAMA single particle mass spectrometer

Courtesy of J. Schneider, T. Klimach and S. Schmidt, MPI


  • Measurement Issues measurements

  • Small ice properties (< 100 μm), water/ice discrimination, Low concentrations (poor sampling statistics)

  • Shattering and Splashing

  • Liquid/Solid/Total Water, Ice Water Separation, Extinction

  • Composition/Concentration of Ice Nuclei

  • Platform dependent issues (e.g., high speed, rotary wing, unpiloted or commercial aircraft)


In Situ measurements

Maturing Sensors (Anything new since 2010?)

Fast 2D-C (Faster response – NCAR/RAF)

2D-S (Faster response)

Fast FSSP (Faster Response)

New Sensors

Fast CDP (Faster response)

BCP (Commercial aircraft)

BCPD (Commercial aircraft)


Presentation Guide measurements

Topic Theme and Objectives of the Working Group

Brief Status of this Topic after the July, 2010 workshop (see BAMS article)

What progress has been made in the last three years?

What are the remaining unknowns and uncertainties and how do they impact our fundamental understanding of the atmosphere, climate change, weather and society in general?


  • Remote Sensing measurements(Needs editing)

  • General

  • Challenges:

  • realistic scattering properties of hydrometeors

  • good size descriptor

  • joined datasets based on remote sensing & in situ instruments

  • good forward models

  • Combining measurements of various instruments with different spatial and temporal footprints

  • Global coverage with polar orbiting satellites


  • Continuing Issues and recommendations measurements(Needs Editing)

  • Many new instruments since 2002, how can they be validated/referenced to older instruments?

  • Many new instruments developed at research institutes – how do we make them available to broader community?

  • Modifications/improvements continue to be made on existing, individual instruments – how to implement on other similar sensors?

  • Still no analysis package with common features.

  • Single particle polarization measurements – How to quantify?

  • SID-2H – Other ways to analyze images? Sensitivity analysis?

  • How can we encourage new developments by young investigators?

  • Should there be stronger links between private business and research institutes?


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