Mesoscale Predictability ExperimentMPEX

National Center for Atmospheric Research

Research Aviation Facility

MPEX Overview

• 15 May – 15 Jun 2013• ≈ 12 Flights 7 hrs duration• High Altitude FL 400 – FL 410• Early Morning Operations– 0900 – 1600Z

• ≈ 30 Drop Sondes Each Flight• Predefined Drop Points

MPEX Area of Interest

4

• Single Aircraft• RVSM Certified• Research Speed Mach .80

N677F

MPEX Research Aircraft

MPEXGeneral Science Objective

• Improved forecast of the timing and location of convection initiation and the development of severe thunderstorms or storm complexes to the lee of the Rocky Mountains onto the High Plains within the MPEX domain

MPEX Measurement Strategy

• Use numerical models and observations to forecast a region within MPEX domain that would benefit from added soundings through the atmosphere

• Select subset (30-40) of available pre-defined drop points and fly late night N677F missions

• Launch 30-40 dropsonde from aircraft to measure winds, temperature and moisture

• Send these data to National Weather Service and researchers in real-time for use in operational and research models and by forecasters

• Evaluate improvement in severe weather forecasts within the MPEX domain

Airborne Vertical Atmospheric Profiling System(AVAPS)

Drop Sonde System

FAR Applicability

• No Specific “Drop Sonde” Guidance but……..• Subchapter F Subpart A: General Applicability

Unmanned Aerial balloons – 101.1 Carries a payload package that weighs more than

four pounds and has a weight/size ratio of more than 3 oz per square inch on any surface of the package, determined by dividing the total weight in oz of the payload package by the area in square inches of its smallest surface.

Old Drop Sonde

3.02 oz per sq inch 13.7 oz Overall

AVAPS SONDE

2.5 oz per sq inch 5.89 oz Overall

Drop Sonde Comparability

Length Diameter Weight

Old Sonde 16” 2.75” 13.7 Oz

New Sonde (AVAPS)

12” 1.875” 5.89 Oz

Sonde Evolution

AVAPS

Sonde Fall Time

0 2 4 6 8 10 12 14 160

10,000

20,000

30,000

40,000

50,000

60,000

Mini SondeFall Time vs Altitude

Fall Time (minutes)

Drop

Alti

tude

(Fee

t)

Sonde Descent Velocity

2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 6,0000

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

Mini SondeDescent Velocity vs Altitude

Vertical Velocity (ft/min)

Altit

ude

(feet

)

Data From NASA Global Hawk(Distribution of horizontal distance traveled by

sondes from drop point)

Weather Balloon Contrast

NWS Weather Balloon “Upsonde””

Upsonde Comparison

• Similar Weight as AVAPS Dropsonde• Ascends to Approx 100,000 ft• Balloon Bursts Allowing Sonde to Descend via

parachute• Similar Descent Rate as AVAPS Drop Sonde • 180 NM Drift vs AVAPS 26 NM Max Drift• Over 6,000 Upsondes per Month Launched in

USA• Only 300 AVAPS Sondes During MPEX

Overall Drop Points

• 102 Total Points• Defined by Intersection or Radial/DME

Denver Center

Albuquerque Center

Kansas City Center

Minneapolis Center

Salt Lake Center

Example Flight Plan

Example Flight Plan

FAR 91.15

“No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.”

Reasonable Precautions

• Utilize ITT Exelis Symphony Air Traffic Management System

ITT Exelis

• Near “Real-Time” Web Based Application• Accessible Onboard the Aircraft• Dedicated Operator During Flight

Reasonable Precautions (cont.)

• Aircraft TCAS• Strategic Drop Point Placement (Deconfliction)– Major Airports– Approach Facilities and Corridors– Cities– Sensitive Ground Areas (e.g. Indian Reservations)

Reasonable Precautions (cont)

• ATC – Normal Traffic Advisories

• Miniaturized Drop Sonde Design• Drop Time of Day– Early Morning (3 AM – 9 AM)

Operations

• Responsibility Rests With the Pilot in Command and NCAR

• Not Seeking Drop “Clearance” from Any Controller

• Will Cease Operations Anytime When Directed by ATC

• Will Immediately Follow ATC Instructions

Coordination Procedures

• Flt plans Normally Filed NLT 2 hrs prior • Flight Plan Remarks• Briefing Books for All Centers– Drop Points – Intersections, Radial DME and

Coordinates– Will Always File with Intersection or Radial/DME

Letter of No Objection

• Preflight Telephone Coordination?– Required Timelines

• Finalized Flight Plan Drop Points– Required Timelines

• NOTAMS?– Required Timelines

• Required Radio Calls?

Contact Information

Scotty McClain 720-234-2696ncar-pilots@eol.ucar.edu

Jim Moorejmoore@ucar.edu

Questions?Discussion