A Workshop27 April 2006, 7 to 830 pm

CSU Atmospheric Science Department, Ft Collins, CO

A SYSTEM FOR PLANNING AND ANALYZING SOARING FLIGHTS IN COLORADO

Edward (Ward) HindmanThe City College of New York, New York City, NY USA

Visiting scholar (2005-06), Colorado State University, Ft. Collins CO USA

Stephen SaleebyColorado State University, Ft. Collins, CO USA

Olivier LiechtiAnalysen and Konzepte, Winterthur CH

William Cotton

Colorado State University, Ft. Collins, CO USA

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WORKSHOP CONTENTS

• Current situation: The weather information glider pilots need is on the Web but fragmented. The pilot must assemble and analyze the information and determine a feasible task.

• An operational European system for planning and analyzing soaring flights is being experimented with in Colorado: The Colorado State University Regional Atmospheric Modeling System (CSU-RAMS) produces the weather predictions (*.ram file) and the Liechti TopTask Competition (TTC) algorithm uses the predictions to determine the feasibility of a proposed task (*.cup file).

• Learn to use the RAMS-TTC system to plan and analyze your flights: You can “fly” a proposed task through a weather prediction to determine task-feasibility and analyze the resulting *.igc file for the task-speed compared to the ideal TTC speed.

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GLIDER PILOTS NEED TO KNOW:

• When the lift will start

• How strong it will be

• How deep it will be

• Where it will be

• How long it will last

• Wind speeds and directions

• Severe weather potential

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HINDMAN’S WEB-RESOURCES AND ANALYSIS TOOLS FOR PREPARING FORECASTS FOR

GLIDER CONTESTS

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EUROPEAN FLIGHT PLANNING SYSTEM

Hindman discovered the German Weather Service “pc_met” pilot self-briefing system at the 2003 World Gliding Championships, Leszno Poland. He decided, then, to work to bring the Liechti Toptherm glider forecasts and TopTask flight planning algortihm found in “pc_met” to USA glider pilots.

Demonstration of the Toptherm glider forecasts and TopTask flight planning algortihm in “pc_met” using software given to Hindman by E. Lorenzen the “pc_met” developer. More information on “pc_met” can be found at www.dwd.de/de/SundL/Luftfahrt/pcmet/pcmet.htm.

What you will experience in this workshop is the first step in the campaign to bring TopTherm/TopTask to the USA. You will learn to use TopTask Competition (TTC), a simplified version of the TopTask found in “pc_met”.

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CSU-RAMS THE SUITABLE ATMOSPHERC MODEL

• TopTask requires meteorological predictions at 30 minute intervals with 12 km spatial resolution which RAMS can easily produce.

• Hindman has a sabbatical to dedicate to the project plus a gracious host, Prof. Bill Cotton and capable associates Stephen Saleeby and Ray McAnelly.

• Hindman has a history with the RAMS:

The 5 July 2002, 1725 EST cloud pattern from NOAA-14. The track of WH is shown: warm colors are low altitudes (500 ft) while the cold colors are high altitudes (18,000 ft).

From Hindman, et al., 2006, Technical Soaring, in press

RAMS air flow at 850 mb for 1230 EST.The vertical motion is colored. The horizontalmotion is indicated by the wind barbs. The“checker board” vertical motion pattern reproduces the cloud pattern.

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THE STEPS TO CONNECT RAMS AND TTC

1. Construct “forecast regions” around OCGP using SeeYou:

OCGP

2. Identify the RAMS grid points in each forecast region:

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THE STEPS TO CONNECT RAMS AND TTC (contd.)

3. Adapted Olofsson (2005, OSTIV Met panel, Istanbul) procedures at each

grid point to analyze the predicted sounding:

– Dry thermal top or cloud base

Where dT = 0.4 x (1 + W/200) x 20/ff

W = net sensible heat flux near ground in W/m2 (if W > 200, W = 200, [Liechti (2006, personal communication]) ff = wind velocity near ground (10 m) in km/h (if ff < 20 (10 kts), ff = 20)

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THE STEPS TO CONNECT RAMS AND TTC (contd.)

3. continued

– Mean rate of climb (m/s)

Mean rate of climb = 0.75 x (h/1000) x W/200 x (1 - TADV/2) x 20/FF

• h = calculated thermal height or cloud base height in m AGL

• W = net sensible heat flux near ground in W/m2 (if W>200, W=200)

• TADV = temperature advection at 1000 m in C/h

• FF = wind velocity at 1000 m in knots (if ff < 20, ff = 20)

“gospel” per WMO TN158

0.75X(h/1000)

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THE STEPS TO CONNECT RAMS AND TTC (contd.)

4. Extract 1000 m AGL wind speed and direction at each grid point

5. Average derived values at all grid points in a forecast region to produce the yymmddhh.ram weather file used as input for TTC. Here are the values for the Wheatland Reservoir forecast region for 22 April 2006. Note, UTC times are really MST times.

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HOW DOES TTC WORK?

arrivée

descente

vol thermique

descente

A B C

moyen relief haut relief

VZ

VZ

plaine

A flight is simulated using the sailplanepolar and speed-to-fly-theory

A B C

départ

VZ

vol thermique

grimper

moyen relief haut relief

VZVZ

VZ

plaine

grimper

grimper VZ

VZ

Flight phases

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VERIFICATION OF RAMS-TTC FORECASTS

The fifty-three On-line-contest (OLC) 2004, 2005 and 2006 (thru 22 April) flights from OCGP reveal the average maximum achieved altitude is not significantly different from the RAMS-TTC value. Thus, RAMS is accurately predicting the depth of the convective boundary layer.

The twenty-seven Faris and Odehnal OLC flights for 2004, 2005, 2006 (thru 22 April) produced speeds almost identical to the TTC predicted speeds.

Scored = 101 +/- 3 kphRAMS-TTC = 99 +/- 3 kph

The RAMS-TTCSystem is ready to be used to plan and analyze flights from OCGP. But, you’ve got to fly like Bob and Gary!

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RAMS-TTC HOME PAGEThe URL for the yymmddhh.ram files is:

htttp://rams.atmos.colostate.edu/smsaleeb/ramsmodel/ramssoaring.html

Password: ramsttc

The file for the current day will be automatically posted at 7am MDT. If a blank box appears there has been a computer malfunction.

The other files you will need are posted on the page:–TopTaskCompetition.exe [executable program]–regtherm.dat [forecast regions map]–Owl Canyon Region 9 (Hindman tasks-1).cup [sample *.cup file]–64ec3r32.igc [sample *.igc file]–RAMS_TTC_Instructions.doc [description and instructions]–WorkShopPresentation.ppt [this briefing]

The remainder of the workshop will be learning to use TTC following the instructionsIn RAMS-TTC_Instructions.doc