A block diagram of the joint airport weather studies program is presented. Background leading to the development of the program is reviewed. Basic studies, aircraft performance, and detection and warning techniques used to develop fine scale structure of thunderstorm dynamics and kinematics in the vicinity of a major airport; effect of thunderstorm low level wind shear on aircraft performance; and development of real time testing of flow level wind shear detection and warning techniques and displays are described

Fujita, T. T.

Mccarthy, J.

Wilson, J.

English

NASA Technical Reports Server

TITLE : The Joint Airport Weather Studies (JAWS) Project 
RESEARCH INVESTIGATORS: John McCarthy .--- - 
and 
James Wilson 
Field Observing Facility 
National Center for Atmospheric Research 
Boulder, CO 80307 
Dr. T. Theodore Fujita 
Dept. of Geophysical Sciences 
University of Chicago 
Chicago, IL 60637 
SIGNIFICANT ACCOMPLISHMENT TO DATE IN FY-83: 
The Joint Airport Weather Studies (JAWS) Project, formed in 1980, conducted 
a major field investigation during the summer of 1982 (15 May to 13 August, inclusive) 
in and around Denver, Colorado. The project is jointly conducted by the National 
Center for Atmospheric Research (NCAR) and the University of Chicago. The 
principal objective of JAWS was to examine convectively driven downdrafts and result- 
ing outflows near the earth’s surface known as microbursts, a term coined by Dr. 
Fujita of the University of Chicago, Microbursts can be lethal for jet aircraft on 
takeoff or landing because of the extreme magnitude of the flows. 
The JAWS effort has concentrated on three aspects of microburst-induced, low- 
level wind shear: basic scientific investigation of microburst origins, lifecycles, and 
velocity structures; various aspects of aircraft performance, including numerical’ 
models, manned flight simulators, instrumented research aircraft response, and 
operational air carrier performance; and low-level wind shear detection and warning 
using surface sensing, airborne systems, and radar sensing. 
The data collection phase was truly extraordinary. Of 91 possible operational 
days, 75 had convective weather on which at least one of 38 pre-planned JAWS 
experiments could be conducted. We expected to observe 10 to 12 microbursts with 
more than one Doppler radar, but saw 87! We collected many data sets not only on 
wind shear events but on mesocyclones, tornadoes, gust fronts, hailstorms, and flash 
floods. Our collection also included a broad data set on operational uses of Doppler 
weather radar, which will be used to support the Next Generation Radar (NEXRAD) 
Doppler development and procurement in the United States. 
During FY-83, we prepared a 276 page report “The JAWS Project, Operations 
Summary 1982, ‘I which was distributed to sponsoring agencies and interested scien- 
tists. The report contains an up-to-date summary of the available JAWS data, 
instruction on how to obtain them, and a daily summary of data collection. We 
describe the meteorology of each day and the weather event highlights, and discuss 
each significant experiment conducted. For each operational. day, a table shows the 
operating hours of each observing system (i.e. , radars, lidars, aircraft, surface 
network, etc. ) Finally, on days of significant JAWS weather, a map of the network 
showing the event location is included. Table 1 indicates the complete scientist, 
institution and sensor involvement in the JAWS field experiment. Complete details 
can be obtained first from the Operations Summary or from the individuals listed as 
appropriate in the Table 1. 
https://ntrs.nasa.gov/search.jsp?R=19830028318 2020-03-21T00:37:31+00:00Z
While the data set was extraordinary in its extent and number of significant 
weather events, the summary, aIthough not exhaustive, identifies events of principal 
interest to the many JAWS objectives. 
CURRENT FOCUS OF RESEARCH WORK: 
At present, we are concentrating on an evaluation of the low-level wind shear 
alert system (LLWSAS), on preparation of four dimensional multiple Doppler radar 
fields on the capability of a single Doppler radar to identify microburst and shear 
events, and development with assistance from the Federal Aviation Administration of 
a wind shear information film. 
We have just compiled a prioritized list of the most interesting microburst cases 
for multiple Doppler editing and analysis using an over-determined dual Doppler 
analysis (ODDAN) program which is currently being made user friendly. 
Work by subcontractor (FWG Associates, Inc.) is progressing on the develop- 
ment of a six-degree of freedom aircraft performance model. Under a subcontract 
with NOAA, Al Bedard has constructed programs to analyze and display low-level wind 
shear alert system (LLWSAS) and Portable Automated Mesonet (PAM) data and to 
produce plots combining PAM/LLWSAS data showing wind vectors sequentially for 
selected case studies. 
Working with scientists from NASA and NOAA, JAWS personnel are modifying 
computer programs to help prepare dual-lidar analysis comparisons. 
NCAR Doppler radar data are being used to support the NASA’s B-57B Gust 
Gradient effort to identify both longitudinal and internal gust components of turbu- 
lence and wind shear. 
We are preparing nine papers for the 21st Conference on Radar Meteorology: 
(1) “Dynamic Interpretation of Notches, WERS, and Mesocyclones Simulated in a 
Numerical Cloud Model”; (2) “Analysis of Bias Measurements in Relation to Small- 
Scale Meteorological Events”; (3) “The Structure of a Microburst: As Observed by 
Ground-Based and Airborne Doppler Radar” ; (4) “Aircraft and Doppler Air Motion 
Comparisons in a JAWS Microburst”; (5) “Weighted Least Squares Methods for Multiple 
Doppler Radar Analysis” ; (6) “Microburst Wind Structure Using Doppler Radar, PAM 
and LLWSAS Data”; (7) “JAWS Data Collection, Analysis Highlights, and Microbursts 
Statistics” ; (8) “Aircraft Performance in a JAWS Microburst”; and (9) “Evaluation of 
Doppler Radar for Airport Wind Shear Detection.” 
PLANS FOR FY-84 & 85: 
A very brief outline of the complete complement of tasks being addressed in 
FY-83 & 84 is given in Table 2. More details are available by calling the JAWS 
Project Office on (303) 497-0651. 
New NASA research objectives for FY-84 & 85 that should be addressed focus 
around manned flight simulation theory and practice in wind shear conditions. The 
current work of Frost (FWG Associates) and at NASA Langley Research Center, 
utilizing high resolution JAWS wind shear data to better understand aircraft per- 
formance, leads to the following projected tasks for FY-84 & 85: 
6 
(1) Research and training simulator: frequency response to wind shear input 
visuals. 
(2) A careful study of simulator equations of motion with regard to wind shear. 
(3) Extensive communication with simulator technology experts regarding the 
findings of (1) and (2). 
These tasks need to be refined and examined, not only through JAWS and NASA 
research, but through a close association with airborne and flight simulator manu- 
facturers. 
RECENT PUBLICATIONS: 
“The NCAR Research Aviation Facility Fleet Workshop, 18-19 February 1982, 
Boulder, Colorado,” Bull. Amer. Meteor. Sot., to be published in May 1983 by P. H. 
Hildebrand and J. McCarthy. 
“Low-Level Wind Shear Detection and Warning - A Systems Update,” AIAA 21st 
Aerospace Sciences Meeting, Jan. 10-13, 1983, Reno, Nevada, by J. McCarthy and 
J. W. Wilson. 
“Applications of Doppler Radar to Aviation Operations - JAWS Experiences,” 
AIAA 21st Aerospace Sciences Meeting, Jan. 10-13, 1983, Reno, Nevada by J. McCarthy 
and J. W. Wilson. 
“The Joint Airport Weather Studies, ” 17th Annual Southern Methodist University 
Air Law Symposium, March 3-5, 1983, Dallas, Texas by J. McCarthy. 
“The JAWS Project Operations Summary 1983,” printed in February 1983 by the 
National Center for Atmospheric Research, limited distribution, copies available upon 
request. 
7 
TABLE 1. ORGANIZATIONS AND EQUIPMENT IN JAWS 
Organizations Participating in JAWS 
Federal Government 
National Science Foundation 
Contact for Data Sensors/Equipment Comments 
o National Center for Atmospheric 
Research 
- Convective Storms Division Ed Zipser 
Pete Johnson 
NCAR Sabreliner 
Multiple Aircraft Positioning System 
Mesoscale Analysis 
Calculates aircraft location 
using interferometry 
- Field Observing Facility Phyllis 0’ Rourke Portable Automated Mesonet (PAM) 
Doppler Radars 
27 Stations 
two 5-cm and one lo-cm 
Federal Aviation Administration Marty Natchipolsky Low-level Wind Shear Alert System Funding agency 
(LLWSAS) 
National Aeronautics & Space Administration Funding agency 
o Marshall Space Flight Center (MSFC) Dennis Camp 
Warren Campbell 
B-57B Aircraft, CO2 Doppler Lidar 
George Fichtl 
o Langley Air Research Center B-57B Aircraft, Manual Flight Simulator 
o Dryden Flight Research Facility B- 57B Aircraft 
National Oceanic & Atmospheric Administration 
o Program for Regional Observing & 
Forecasting Services (PROFS) 
Ron Valdez Mesoscale Surface Network 
Ron Valdez AFOS Products 
Ron Valdez Limon & Cheyenne Radars 
Ron Valdez Lightning Detection Array 
Ron Alberty Satellite Data 
TABLE 1. (Concluded) 
Organizations Participating in JAWS 
o Wave Propagation Laboratory (WPL) 
Contact for Data 
Freeman Hall 
Al Bedard 
Al Bedard 
John Gaynor 
Ron Valdez 
Sensors/Equipment 
CO Doppler Lidar 
LL&AS Analysis 
Pressure Jump System Data Collection 
and Analysis 
Boulder Atmospheric Observatory Tower 
Atmospheric Profiler 
Comments 
o Weather Research Program 
o National Hurricane & Experimental 
Meteorological Laboratory /NCAR 
o National Weather Service 
Fernando Caracena Microburst ForecastinglNowcasting 
Techniques 
Dave Jorgensen NOAA P- 3 Aircraft /Airborne Doppler Joint NOAA /NCAR 
Peter Hildebrand Experiment 
Phyllis O’Rourke Rawinsonde (4 daily, 2 regular, 
2 special) 
o PROFS /JAWS /CSD 
Transportation Systems Center 
(Dept. of Transportation) 
Universities and Colleges 
University of Chicago 
University of Wyoming 
Mary McCoy Cooperative Storm Intercept Group 
Lloyd Stevenson Air Traffic Control Data 
T. Theodore Fujita Whole Sky Camera 
Al Rodi King Air Aircraft /Microphysics 
Instrumentation 
Photograph & verify 
weather hazards identified 
by Doppler radar 
Study effects of weather 
on terminal air traffic 
Photographed from CP-2 
Aircraft leased to NCAR 
Dartmouth College 
Foreign 
United Kingdom 
o Royal Aircraft Establishment 
o Royal Signals and Radar Establishment 
Robert Crane 
Alan Woodfield 
Michael Vaughan 
Hawker-Siddeley 125 Aircraft 
Airborne CO2 Doppler Lidar 
Test Crane cell tracking 
and turbulence algorithms 
=: TABLE 2. A VERY BRIEF SUMMARY OF TASKS BEING ADDRESSED AT NCAR BY THE JAWS PROJECT 
1. 
2. 
3. 
4. 
5. 
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
Physical Mechanisms Definitions & Statistics Techniques 
Microburst Climatology 
Microphysical Interactions 
with Microburst Negative Buoyancy 
Microburst Precipitation Physics i 
Dynamics Feedback 
Microburst Cloud Modeling (Klemp) 
Boundary Layer Interactions in 
Microburst Situations 
1. 
7 a. 
3. 
Variability of Microbursts in 
Time & Space (Radar and PAM) 
Microburst /Downburst Scales 
Terminology /Definitions - 
Wet vs. Dry Microbursts 
1. 
2. 
3. 
4. 
1. 
2. 
3. 
4. 
5. 
Kinematic Fields in Microburst 
Analysis 
Complete Multiple Doppler 
Synthesis Program 
Sensor Intercomparison 
3 Airborne/Surface Doppler 
Synthesis 
Aircraft Performance Detection and Warning 
Flight Simulation Using Multiple 
Doppler Data 
Doppler Derived Turbulence 
Aircraft Performance in 
Microbursts 
Penetration Techniques for 
Microbursts 
Flight Simulator Fidelity in 
Microbursts 
B- 57B Correlation Synthesis 
Heavy Rain Aircraft Performance 
Rotocraft Performance in Microbursts 
1. 
2. 
Redesign of LLWSAS 
Radar Siting for Terminal Doppler 
Radar 
3. 
4. 
5. 
Airport-Located Doppler Radar 
Microburst Detection Techniques 
Airborne Detection & Warning Synthesis 
Observational Precursors for 
Microbursts 
6. 
7. 
Avoidance Techniques (Pilot) for 
Microbursts 
Evaluation of Detection & Warning 
Concepts 
Evolution of Crane Cell Tracking and 
Turbulence Algorithms 
Microburst Pilot Forecast Advisories 
Sampling Theory /Detection Using 
Surface Arrays 
Lidar Surface Detection & Warning 
IR Radiometer Detection of 
Microbursts 
8. 
9. 
10. 
11. 
12. 
Miscellaneous 
Prioritization of Cases 
Wind Shear Information Film 
for Pilots 
Analysis of Meteorological 
Features Affecting Formation 
of Microbursts 
Terminal Air Traffic (TSC) 
Impacts Due to Convective 
Storms 
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The Joint Airport Weather Studies (JAWS) project

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