NCAR BOM Julie Haggerty Rodney Potts

Julie Haggerty
     NCAR
 Rodney Potts
      BOM

   The High Ice Water Content (HIWC) hazard to
    aviation
   Experimental nowcasting products for
    avoidance of HIWC conditions
   Engaging with potential users
   Product evaluation in an operational setting
   Exercise goals

   Large concentrations of small ice crystals can exist in areas
    of convective clouds with low radar reflectivity
   Ice crystals stick to warm metal surfaces in jet engine low
    pressure compressor
    ◦ Ice accretes; accumulated ice can
      block flow into engine core or shed
      into high pressure compressor or
      combustor
    ◦ Result may be power surge, power
      loss, engine damage
   Aircraft data systems may
    also be affected by ingest of
    ice crystals into inlets
    ◦ Result may be errors in               Over 150 Ice Crystal Icing events
      temperature, air speed, and angle     confirmed to date
      of attack                             (Event locations provided by M. Bravin, Boeing, 2015)

   Engine modification
   Detection of ice crystals by pilots’ weather
    radar
   Identification of HIWC areas with standard
    meteorological data sets
    ◦ Products to enable avoidance of hazard
    ◦ Development efforts underway by multiple research
      teams

   Uses operationally available data as input
   Applies fuzzy logic methodology to blend input
    data
     Apply expert knowledge to create rule-based behavior
     Membership functions characterize the relationship of each
      variable to the possibility of HIWC conditions
     Blend data with adjustable weighting factors
   Provides a 3-dimensional estimate of HIWC
    potential
     0: minimum interest, no HIWC likely
     1: maximum interest, high likelihood of HIWC
     Currently uncalibrated

                                        *Research   sponsored by U.S. FAA

Operationally
available data

Blend via
algorithms
using fuzzy
logic rules/
membership
functions

Gridded field of
potential for
HIWC conditions

   Three field campaigns
    ◦ 23 flights based in Darwin,
      Australia
    ◦ 16 flights based in
      Cayenne, French Guiana
    ◦ 10 flights based in Florida,
      US
   IWC Measurements
    ◦ In situ Isokinetic Probe
    ◦ Cloud radar retrievals of
      IWC profiles                   HIWC Potential

   Machine Learning
    Technique for Algorithm
    Tuning
    ◦ Data set partitioned into
      Training and Verification
      subsets

ALPHA v2.1 Performance Statistics

 False
 Alarm
 Rate:
 20.6%                    PoD-yes: 77.3%

                          Misses: 22.7%

PoD-no:
79.4%

   Experimental
    ALPHA available
    in real-time over
    U.S. since 2016
   Informal
    feedback
    solicited from
    small set of
    users
   Currently no
    mechanism to
    obtain structured
    feedback on
    utility and
    performance or
    quantitative data
    for verification

HIWC Nowcasting Trial Exercise
   Joint effort with Australian Bureau of Meteorology
    (BOM), NCAR, and U.S. Federal Aviation
    Administration (FAA)
   Provide experimental HIWC products to aviation
    industry stakeholders for a discrete time period
       Qantas
       Virgin Australia
   Solicit feedback on product performance and
    utility during convective season
   Evaluate and modify ALPHA as indicated by user
    experience

HIWC Nowcasting Trial Exercise
   ALPHA
                                   ALPHA Domain
    implemented over
    northern Australia
    and maritime
    continent
   Initial trial during    Radar Data
                            Available
    monsoon
    convective
    season, Jan-Mar
    2018; second trial
    in 2019
   Monitor
    performance
    based on airline
    feedback

HIWC Nowcasting Trial:
Organizational Structure and Responsibilities

NCAR                  BOM                    Airlines
• Regional ALPHA      • Provide input data   • Access product and
  development            • ACCESS              integrate with other
• Implementation         • HIMAWARI-8          meteorological
                                               products
  on BOM server          • Radar
                                             • Monitor areas
• Scientific and      • Host server
                                               identified as HIWC
  technical support   • Prepare and          • Pilot education on
• Evaluate and          distribute             characteristics of
  incorporate           products               HIWC in flight
  feedback to         • Coordinate and       • Note suspected
  improve               analyze feedback       encounters with
  algorithms                                   HIWC
                                             • Provide feedback

HIWC Nowcasting Trial Exercise: Schedule
2017 May          Dec            2018 Jan       Mar

                                     Product
    ALPHA        Installation                    Post-trial
                                      Trial:
 Development      & Testing                      Workshop
                                     Phase I

2018 Jul         Dec             2019 Jan       Mar

                                     Product
    ALPHA         Installation                         Final
                                      Trial:
  Modification     & Testing                          Report
                                     Phase II

HIWC Nowcasting Trial: Expected Outcomes
    Provide the BOM with an experimental HIWC nowcasting
     capability.
    Provide NCAR and FAA with feedback on ALPHA
     performance in a region with frequent convection and ICI
     events.
    Provide information to be used for further improvements to
     ALPHA
    Inform FAA and BOM decision on feasibility of a fully
     operational HIWC nowcasting product.
    Progress the development of an international capability for
     HIWC detection and prediction that may be required by ICAO
     in the future.

This research is in response to requirements and
funding by the Federal Aviation Administration (FAA).
The views expressed are those of the authors and do
not necessarily represent the official policy or
position of the FAA.