Preliminary Results from ICE-Preliminary Results from ICE-TT

Paul LawsonPaul Lawson

Summary of Learjet ICE-T MissionsSummary of Learjet ICE-T Missions

Lear flew a total of 12 ICE-T Missions.

10 of the 12 Learjet Missions were in Conjunction with the C-130 and one (30 July) was a Coordinated Formation Flight.

Approximately 150 Penetrations of Cloud Turrets with Temperatures between +22 C and -24 C.

Most Cloud Penetrations were between 0 C and -20 C, with the Major Focus on the Region between -5 C and -20 C.

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2D Images do Not have Sufficient Fidelity 2D Images do Not have Sufficient Fidelity

to Separate to Separate

Water Drops from Ice Particles in ICE-T Water Drops from Ice Particles in ICE-T CloudsClouds

Growing ICE-T Tropical Cumulus Clouds are Growing ICE-T Tropical Cumulus Clouds are Typically Mixed-Phase from about Typically Mixed-Phase from about

– – 10 C to – 20 C.10 C to – 20 C.

2D-S Images in Decaying Turret 2D-S Images in Decaying Turret Appear to be All Ice (Rice Probe Appear to be All Ice (Rice Probe

Indicates no SLWC)Indicates no SLWC)

CPI Images at Same Time Show CPI Images at Same Time Show Low Concentration of Low Concentration of Supercooled DropsSupercooled Drops

Another Example of 2D-S Another Example of 2D-S Images in the Middle of the Images in the Middle of the

Decaying Turret Decaying Turret

CPI Images at the Same Time CPI Images at the Same Time Show Several Supercooled Show Several Supercooled Drops (No Activity on Rice)Drops (No Activity on Rice)

3V-CPI (CPI Portion) Images are used 3V-CPI (CPI Portion) Images are used

in Conjunction with 2D-S Image Data in Conjunction with 2D-S Image Data

to Provide Quantitative Water Drop to Provide Quantitative Water Drop

and Ice Particle Size Distributions and Ice Particle Size Distributions

and Derived Quantitiesand Derived Quantities

Examples of CPI Images in Mixed-Phase at -17 CExamples of CPI Images in Mixed-Phase at -17 C

Examples of CPI Images in Mixed-Phase at -17 CExamples of CPI Images in Mixed-Phase at -17 C

Examples of CPI Images in Mixed-Phase at -17 C Examples of CPI Images in Mixed-Phase at -17 C

Examples of CPI Images in Mixed-Phase at -17 C Examples of CPI Images in Mixed-Phase at -17 C

CPI Images in Mixed-Phase Automatically Separated CPI Images in Mixed-Phase Automatically Separated

into:into: Water and IceWater and Ice

Particle Size Distributions from Various ProbesParticle Size Distributions from Various Probes

Using CPI Automatic Image Recognition to Generate FFSSP 2D-Using CPI Automatic Image Recognition to Generate FFSSP 2D-

S HVPS Water and Ice Size Distributions in Mixed-PhaseS HVPS Water and Ice Size Distributions in Mixed-Phase

Example Comparison of Lear and C-130 Example Comparison of Lear and C-130

in situ Measurements with Remote in situ Measurements with Remote ObservationsObservations

Shown are Results from a Cloud Penetration when the Learjet flew in trail about 400 m beneath the C-130. The purpose was to compare C-130 UW cloud radar with Lear in situ measurements.

The C-130 Entered 11-s Ahead of the Lear in a Rising Turret with strong updraft and mostly SLW followed by an older decaying mixed-phase region that transitions to mostly ice. The two types of cloud can be seen in the Lear cockpit video photos. The CPI part of the Lear 3CV-CPI* malfunctioned during this cloud penetration and no images are available, so the absence of cloud drops cannot be confirmed in the mixed-phase cloud.

* The 3V-CPI was made available courtesy of the US Navy Center for Interdisciplinary Remotely Piloted Aircraft Studies

Lear (purple) and C-130 (yellow) Flight Tracks Lear (purple) and C-130 (yellow) Flight Tracks

During Coordinated Penetrations on 30 July 2011During Coordinated Penetrations on 30 July 2011

Lear Cockpit Time-Lapse Photos Showing Rising Lear Cockpit Time-Lapse Photos Showing Rising

Turret and Older Cloud Behind that C-130 Turret and Older Cloud Behind that C-130 Penetrated and Lear Penetrated 11-s later and Penetrated and Lear Penetrated 11-s later and

1,500 ft Below C-1301,500 ft Below C-130

2D-S Images of Supercooled Drops in Turret Updraft2D-S Images of Supercooled Drops in Turret Updraft

2D-S Images of Ice Particles in the Old Cloud Region2D-S Images of Ice Particles in the Old Cloud Region

C-130 UW Cloud Radar Data for 1726 Cloud PenetrationC-130 UW Cloud Radar Data for 1726 Cloud Penetration

Lear and C-130 3V-CPI Particle Size DistributionsLear and C-130 3V-CPI Particle Size Distributions

First Ice in Tropical Cumulus First Ice in Tropical Cumulus CloudsClouds

Paul LawsonPaul Lawson

A Simple Methodology to Analyze A Simple Methodology to Analyze First IceFirst Ice

I. Automatically categorize water drops and ice crystals for each cloud penetration with working CPI data.

II. Classify clouds having number concentrations of < 2% ice crystals with a mean size < 50 µm as being those containing first ice.

III. Evaluate the amount and type of first ice as a function of cloud temperature, updraft speed, aerosols, cloud appearance, etc.

CaveatsCaveats Care must be taken not to include old cloud fragments

outside of growing turrets

Care must be taken to correct any misclassified water drops and ice particles.

Example of First Ice Observed by Learjet Example of First Ice Observed by Learjet

in Cloud at -12 C in Cloud at -12 C

on 11 July from 190615 – 190625…on 11 July from 190615 – 190625…

All Water Drops Observed during First 7 s of Cloud Penetration All Water Drops Observed during First 7 s of Cloud Penetration

(One Second – about 300 images: 190615.6 – 190616.6 shown below)(One Second – about 300 images: 190615.6 – 190616.6 shown below)

190616.6 – 190617 and 190618 – 190618.6 shown below 190616.6 – 190617 and 190618 – 190618.6 shown below

……then skip 5 –s then skip 5 –s

First Ice at -12 C Observed at 190623First Ice at -12 C Observed at 190623

More Examples of First Ice at -12 CMore Examples of First Ice at -12 C

Particle Size Distributions from Various ProbesParticle Size Distributions from Various Probes

Composite Water Drop Size Distribution from FFSSP, 2D-S, & HVPS Composite Water Drop Size Distribution from FFSSP, 2D-S, & HVPS

and CPI Images of First Ice (1.3% of total particles) at – 12 Cand CPI Images of First Ice (1.3% of total particles) at – 12 C