Identifying Potential Convective Turbulence in Remote Oceanic Areas Convective Diagnosis Oceanic (CDO) vs. Eddy Dissipation Rate (EDR)

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1 Identifying Potential Convective Turbulence in Remote Oceanic Areas Convective Diagnosis Oceanic (CDO) vs. Eddy Dissipation Rate (EDR) Joe Grim, Cathy Kessinger, and Greg Meymaris RAL Retreat 5 Dec RAL Retreat 1

2 Eddy Dissipation Rate (EDR) Objective, aircraft-independent measure of turbulence Available only from some aircraft 15 or 20-min temporal resolution, 1-min in turbulence Primary fields mean EDR mean over past minute peak EDR peak over past minute Sharman et al. (2014) turbulence thresholds none = 0.00 (~41% of all peak EDR reports) light = (~58% of all peak EDR reports) moderate = (~1.6% of all peak EDR reports) severe 0.47 (~0.01% of all peak EDR reports) Units: m 2/3 s RAL Retreat 2

3 Convective Diagnosis Oceanic (CDO) Identifies probable areas of convection from several geostationary satellite products and lightning data Especially valuable over remote oceanic areas with no ground-based observations Value ranges 0 6; higher values indicate greater likelihood of convection Value is weighted combination of four scaled inputs: Cloud Top Height (CTH) Global Convective Diagnosis (GCD) Overshooting Tops (OTops) Earthnetworks lightning 2017 RAL Retreat 3

4 Example CDO image from recent 0.40 peak EDR turbulence case 24 November CDO scale RAL Retreat 4

5 cloud top heights GCD IR channel diff technique overshooting tops 0.40 peak EDR report Schematic showing algorithmic inputs into CDO lightning in past 15 minutes lightning lightning in past 60 minutes 2017 RAL Retreat 5

6 Goal of this study Use temporally and spatially co-located CDO values and EDR reports to determine CDO s ability to identify regions of potential convective turbulence, especially over remote oceanic areas 2017 RAL Retreat 6

7 light moderate severe Evolution of turbulence event CDO with peak EDR reports overlaid peak EDR mean EDR 2017 RAL Retreat 7

8 Expand CDO areas by 25 km using mit_storm_filter Input results into TITAN to create polygons 2017 RAL Retreat 8

9 Identify EDR reports from flights within CDO area within 25 km & 15 minutes CDO 2 EDR reports coincident and concurrent with CDO RAL Retreat 9

10 coincident and concurrent CDO & EDR objects are found for all CDO thresholds CDO=2 9 EDR reports CDO=3 5 EDR reports CDO=4 2 EDR reports CDO=5 1 EDR report CDO=6 0 EDR reports 2017 RAL Retreat 10

11 normalized After finding all coincident and concurrent CDO & EDR reports, calculated frequency of occurrence for CDO vs. EDR noise here from small sample size normalized peak EDR mean EDR similar to peak EDR histogram for this and all subsequent normalized histograms 0.1 incr. EDR w/ incr. EDR>0.15 { light moderate severe 2017 RAL Retreat 11

12 Map showing boundaries (red) used to delineate Oceanic, Continental and Transition areas flight areas with EDR data Transition = all EDR reports w/in 100 km of a boundary Continental = all EDR reports inside boundary, but not in Transition Oceanic = all other locations 2017 RAL Retreat 12

13 normalized all EDR not just those w/ CDO values On flight paths for these aircraft: lowest EDR for oceanic zones highest EDR for transition zones continental zones to all zones combined light moderate severe 2017 RAL Retreat 13

14 normalized normalized opposite seen when looking in CDO area within 2 CDO<3 areas, high EDR more common in oceanic zones than continental or transition zones *note: used wider bins due to small sample sizes light moderate severe 2017 RAL Retreat 14

15 similar results at higher CDO thresholds sample size too small at high EDR thresh sample size too small at high EDR thresh light moderate severe light moderate severe

16 Weather in the Cockpit Demonstrations to Display Convective Hazard Products Convective Diagnosis Oceanic (CDO) and Cloud Top Height (CTH) Pacific Ocean CDO CTH CDO CTH LIDO erm EFB BCI Viewer for Tablet 15 min updates Lufthansa Airlines demonstration FAA WTIC ROMIO demonstration with United Airlines, Delta Air Lines and American Airlines Uplink CDO and CTH products during operational flights 2015-current, Lufthansa Airlines in the B747 fleet and Brussels Airlines (~50 aircraft) FAA WTIC Remote Oceanic Meteorology Information Operational (ROMIO) demonstration to start phased rollout December 2017 with 9 month duration 2017 RAL Retreat 16

17 Major Conclusions All EDR reports Oceanic has a lower frequency of elevated EDR values than other zones Continental EDR histograms nearly identical to all zones histograms Transition Zone has a great frequency of high EDR values than other zones Within zones of higher CDO (e.g., CDO 2) Opposite is true: oceanic high EDR values occur at a greater frequency than other zones What can we take away from this? Areas of potential turbulence (i.e., higher CDO) over ocean are not as well observed as their land counterparts (e.g., no radar, fewer PIREPS) Therefore, it appears that planes might not be avoiding these areas of increased turbulence potential, because they re not aware of them. CDO would be nice low-bandwidth product for pilots to help reduce 2017 RAL Retreat 17 turbulence risk, especially over remote areas

18 Existing RAL/NCAR software employed in this study Leveraging existing technologies to develop products fuzzy_engine uses fuzzy logic techniques to calculate and combine values from other products mit_storm_filter manipulates and filters gridded data Titan (Thunderstorm Identification, Tracking, Analysis and Nowcasting) gives object properties (e.g., size, location, advection speed, and many others) Tstorms2Spdb converts Titan Tstorms file output to SPDB output for viewing Tstorm2Ascii converts SPDB data to ASCII format NCL (NCAR Command Language) very versatile programming language for processing and plotting data thousands of functions, including hundreds that are meteorology specific 2017 RAL Retreat 18

19 2017 RAL Retreat 19

20 Convective Diagnosis Oceanic (CDO) cloud top heights (CTH) linearly interpolated score for CTHs > 20,000 overshooting tops (OTs) similar linearly interpolated score to CTH Global Convective Diagnosis (GCD) uses IR channel differencing to identify possible liquid water in updrafts lightning in past 15 minutes lightning in past 30 minutes lightning in past 60 minutes } score = 1 for each if lightning, otherwise RAL Retreat 20