How to obtain a large Database of Measurements on ...€¦ · ¾Dr. Andreas Dörnbrack/ German Aerospace Center (DLR) MWP- extended scientific team. 28/02/11. AGU Chapman Conference

28/02/11AGU Chapman Conference on

Atmospheric Gravity Waves

H ow to obtain a large D atabase of M easurem ents on atm ospheric

G ravity W aves

R. Heise, A. Ultsch, J. Hacker



5.000 hrs. over the Andes

45 World Records

M O U N TA IN W AVE PR O JEC T

over 10 years of study system Rotor-Wave

Flying in Waves - true to the forces of nature trusting and evidence of a well understanding of complex airflows and mesoscale patterns



Chief Scientist Prof. Joerg HackerAirborne Research Australia (ARA)

Chief Pilot Klaus OhlmannQuo Vadis International

Project-Director René HeiseGeoInformationService Bundeswehr- Staff Officer GAF

MWP- core team



Scientific support

Prof. Alfred Ultsch/ University Marburg

Dr. Erland Lorenzen/ German Weather Service (DWD)

Prof. Thomas Prenosil/ Bundeswehr Geoinformationservice

Dr. Andreas Dörnbrack/ German Aerospace Center (DLR)

MWP- extended scientific team



In 1998 the pilots Klaus Ohlmann and René Heise founded the MWP, a project for global classification and analysis of airflows and turbulences which cause very strong winds (e.g. Foehn, Mistral, Zonda) over the mountains.

MWP is an independent non-profit-project of the Scientific and Meteorological Section of the Organisation Scientifique et Technique Internationale du Vol à Voile (OSTIV) and is supported by the Fédération Aéronautique Internationale (FAI).

Mountain Wave Project (MWP)



The core of the MWP – measurement equipment was the so called Best Aircraft Turbulence (BAT)-probe used, a device, that measures the frequency of high pressure and temperature variations along the flight path and thus a highly accurate reconstruction of air movement or turbulence in the atmosphere possible.

Research Aircraft – Stemme S10 VT



MWP- main topics are:

• detection and determination of physical processes inthe atmosphere, as well as their associated synopticcharacteristics, which play a dominant role in the generation and development of mountain waves

• investigation of rotor bands, determination of theirlocation, spatial extension and classification of concomitant turbulence

• high resolution measurement of relevant meteorological variables (eg. potential temperature, turbulence parameters, vertical and horizontal wind, humidity...)



MWP- main topics are:

• Visualization of the rotors/regions of turbulence with a GeoInformationService (GIS).

• Statistical analysis of wave flights (IGC-files of GPS flight loggers) to develop an empirical GIS-based representation of wave and rotor locations

• Verification of mesoscale forecast models and fine tuning/ adjustment of the applied parameterisations

• Application of the acquired data, scientific results, andprediction tools to enhance the safety and effectiveness of air traffic route planning, and improve pilot training. Furthermore, assisting in the development and creation of focused training methodology, tools and simulator scenarios.



Synoptical patterns

• good developed Mountain Waves over the Andes we observed very often prefrontal of a cold front (CF approaching longitudinal the pacific coast line) => record flights

• disturbed MTW‘s conditions in combination with a wavingcold front latitudinal over Patagonia (moist airflow,unfavourablewindshear due to the jetstream)

wall of moisture nearEsquel, no VMC, problemswith the numerical wx-model

• good developed Mountain Waves over the Andes we observed very often prefrontal of a cold front (CF approaching longitudinal the pacific coast line) => record flights

• disturbed MTW‘s conditions in combination with a wavingcold front latitudinal over Patagonia (moist airflow,unfavourablewindshear due to the jetstream)



Synoptical patterns

• for a long straight distance flight over 2.000km

Using of the synoptical especialness the confluenceof Polarjet –Subtropical Jet

2003 Calafate- San Juan (ARG) –2.138 km



Synoptical patterns

special synoptical feature – Cold Front Wave

• prefrontal of a cold front we observing very often a long continuous wave with a length of ~1.200km

• moving slowly in direction of Pampa, combined with high waves (very often above 10.000m, not in connection with „classical“ wave structures

• Tsunami-like, caused by the amplification of the cold air obstacle/barrier in front of the Andes (west coast)

• Ohlmann flight 700km along this wave



Synoptical patterns

special synoptical feature – Breaking Waves

• rarely observed, the wave is tilting against the wind direction

• decreasing of windspeed and a large lift area allowed to make circles with the glider in the lift area

special synoptical feature – Waves in the Lee of Volcanos



With cross section flights “Visualization” of waves

black line –track; red – lift; blue - sink

1st wave

2nd wave

( Oct 10 2006- Waves of Tupungato- Aconcagua)

Vertical Wind Turbulence

Rotor

Geographical Information System (GIS)

• import und presentation of high resolution measurements flights (i.E. Vz, T, wind, turbulence; minimum resolution 50 Hz)Rsec Rsec0 Rmin0 Rhr0 Rlon Ralt Rlat turbAC turbAIR wairLB theta ddLB ffLB uairLB vairLB

taMLrec tdML terrain Rpch Rrll Rtrk Rgs Rw tasLB394425.58000 0.00000 0.00000 0.00000 -68.93490 2068.60044 -32.70385 0.44937 0.90778 -1.73520 28.23784 355.16780

2.76163 0.23263 -2.75181 8.50645 1.05244 1130.92002 7.58233 2.91778 332.29956 49.12085 4.73678 51.89057394426.08000 0.50000 0.00833 0.00014 -68.93502 2071.09933 -32.70366 0.44481 0.79329 -0.99783 28.23106 359.84046

2.37888 0.00662 -2.37887 8.47613 1.16880 1131.92337 7.30511 2.89878 332.54216 48.90114 5.13367 51.23301394426.58000 1.00000 0.01667 0.00028 -68.93514 2073.62356 -32.70346 0.45265 0.59171 -1.53921 28.15876 3.23546

2.11273 -0.11924 -2.10936 8.38461 1.21737 1132.98378 7.15844 3.15067 332.75599 48.72685 4.94111 50.79151….

Example measurement of wind in the SW of Uspallata

• Presentation of empirical positions (global ~ 200) with attributes (synopt. situation, Vz, turbulence-guidance, rotor height and references)

Example: position system Rotor –Wave of Monte Rosa (Italy)

Geographical Information System (GIS)

Ecrins (France)

BLM/RBL-forecast tool operational daily available via self-briefing system (pcmet) for Pilots of DWD

Adobe –Tool (SVG-Viewer)with wind direction (FL100)

Modell areas => Europe, Argentina, Tibet, Afghan., Antarctica

Example: Local Model Forcast – WX-Satellite - Track

record flight Satellite imagery(vis;14:45 UTC);flight track (black);position aircraft(15:00UTC)

Local model forcastRLMK~ 2.8 kmvertical velocity [m/s]dissolving of wave structures

The flight path of the 2,256 km world gliding record flight in a straight distance demonstrates good correlation with the bands of statistically derived areas of prevalent wave climbs (using ~ 3,500 analyzed wave climbs) in the mountain waves. Red turbulence symbols designate moderate to heavy turbulence with vertical speeds of 6 to 10 m/s.Purple symbols depict extreme turbulence with over 10 m/s. Maximizing the use of these wave bands enabled the record flight from El Calafate, Argentina to San Juan, Argentina on January 12, 2010,

Example: Turbulence Overview for Aviation



Summary: MWP- Highlights

MWP- Expedition Argentina `99 (ARG) - several 1000km wave flights- record flight from San Martin to Rio Grande (Fireland)

MWP- Expedition Jaca 2003 (ESP)- numerous wave flights over the Pyrenees

MWP- Expedition Op Mendoza 2006 (ARG)- first scientific measurment flights of turbulence over the Andes

- 12.500km flights up to the lower edge of Stratosphere

T-REX Sierra Nevada 2006 (USA)- Reviewer NSF and participation on Field Experiment 2006



Within the pilots world - we find a simple imagination of Mountain Waves- Lee Waves

http://mwp.flightplanner.info/images/Projpicture/OSTIV_MWP_Wave.jpg



… but the real world – the atmosphere is complex

First questions were:

1. Where are the strongest waves in direction of wave lift, of spatial lenght and height?=> Looking for an ideal atmospheric lab for waves

2. How we can use empirical data of wave flights?

3. How we can use objective data of new flight recorders



one personal experience in connection IOP‘s with T-REX was, for a better understanding of complex mechanism of rotor and wave you need a timely and spatial flexibility of airborne measurements- as the wave as well.

The best solution is the using of a glider/motorglider:

- no cross country flights without a lift - the aircraft is perfect evidence

- high spatial and timely resolution of flights- low cost for airborne measurements

Problem: scientific specialist and meteorologist are needed



Additional data source in connection with glider flights-using of flight data of the Soaring Community (OLC)

2010• over 100.000 flights all over the world• over 17 Mill. of miles • over 13.000 pilots

Documentation of the air sport flights via GPS flight recorder (GNSS-Flight Recorder certified by the Federation Aeronautique Internationale ( FAI )



Data base

Motivation:

Data evaluation of ~ 126 MWP- Flights (1999-2010) over the Andes (region San Juan – Fireland, 2.500km) to filter out Structures of Waveclimbs in IGC-Files

IGC-Logger: GPS – logger to storaging the time, geographical longitude/latitude (WGS-84), GPS-height, barometric height in a data format of the International Gliding Commission (IGC;1995) with a time lag of 1-15 sec.

www.mountain-wave-project.com/w/index.php?title=Datei:Logger.jpg&filetimestamp=20061201165407



Data base

Motivation:

Determination of vertical velocity Vz using IGC- Files

• in contrast to high resolution airborne measurements we like to derive Vz in IGC-Files with an use of a statistical analysis.

• in connection with measurements of Vz it is necessary to know exactly the real flight attitude and the upstream flow angle with an accuracy of tents degree and a time resolution at least of 10Hz

• Location of climbs in an IGC-file

With a tool we are identify Climbs-times, where we ascend due to lifts (thermals/wave/ridge).

MWP IGC - evaluation process (Ultsch/Heise)

Climb-feed points (green point)Climb-top points (red point)as well as midpoints

IGC-Filewith

32 Climbs

• Calculation of distance within the climb

I.e. has the climbs 10 a distance of d = 13 km.

NorthSouth

East


• Estimation of limits for determination between wave and thermalsThe distinction is made on the basis of the climb in the distance traveled d and the height of the base points.To calculate a decision boundary for the distribution of d we are using a Gaussian mixture. As a decision limit are taken the Bayes decision boundary.

Decision limit for d is by ~ 2.8 km.


• Estimation of limits for the determination between waves and thermals

…contains the search for plausible separating functions!


Decision limit for base points of climbs

The decision limit for base points is by~ 2500 m.


Classification of climb rates

From all IGC-Files we are searching for fixes, which we can find in a climb:whose base points are > 2.500 m,whose covered a distance > 2.8 km

This fixes will be considered as points which we founded and used as a wave.


As limits to climb classes can therefore apply: 2.0, 5.0 und 7.5 m/s



Error estimation:

• limited data base of IGC-files (only spring/summer time, only mwp-flights)

• using of GPS altitiude, accuracy 10m, temporally 100m• using of the barometric height allowed an accuracy of + 0,1 hPa

• Vz aircraft is a function of the airspeed• improvement of a filtering of ridge lift only with a better digital elevation model (actual SRTM30 in use)

Here are some graphics for the region of the Andes…


More than 4.083 wave climbs –over the Andes (Nov - Jan; 1999-2010)

Climatology of Waves – over the Andes

w ≤ 2.5 ms-1w ≤ 4.5 ms-1w ≤ 5.5 ms-1w > 5.5 ms-1

vertical speed



Altitude band of wave climbs

≤ 3.500m



3.500 ≤ 5.100m 5.100 ≤ 6.600m 6.600 ≤ 7.500m



7.500 ≤ 9.500m



Wave Climbs – vertical velocity

Volcán Lanín



Presentation via GIS

wave climbs-vertical speed

& track world record

01/12/2010

…and using forflight planning of record flights !!!

Climatology of Andes

w ≤ 2.5 ms-1

w ≤ 4.5 ms-1

w ≤ 5.5 ms-1

w > 5.5 ms-1



Wave Climb Density

Volcán Lanín

DensCls(Dens<10) = yellow DensCls(Dens>10) = red DensCls(Dens>20) = green DensCls(Dens>50) = magenta

local frequency of wave climbs



Summary

• the accurate prediction of Mountain Waves is a challenge for meteorological forecasting

• to measure precise data on Mountain Waves to verify meteorological predictions is costly and only sparsely available

• this work presents the first steps in the exploitation of large databases of flights made by glider pilots of theMountain Wave Project over the Andes. It was a first step in direction of a wave climatology

• the region of Cordillera del Viento appears to be favourable area with good developed wave structures, high value ofvertical speed (continous lift with 16m/s) and high momentum transport in the stratosphere



Summary

• waves over south part of the Andes are very often weakly and not reached the height more than 10.000m

• the wave structures over the Tupungato-Aconcagua region is temporally affected by a windshear due to the (easterly) thermal anabatical flow and a westerly upper gradient wind

• the data base of wave points (points of a high density of wave climbs) allowed to developed an MOS-forecast by using ofparameter fields of a global model as a first step for a local turbulence forecast in combination with a non hydrostatical model



What next … - see

www.mountain-wave-project.com

Documents

How to obtain a large Database of Measurements on ...€¦ · ¾Dr. Andreas Dörnbrack/ German Aerospace Center (DLR) MWP- extended scientific team. 28/02/11. AGU Chapman Conference