NWS Meteorologists Guide to TAMDAR Weather Data

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NWS Meteorologists Guide to TAMDAR Weather Data
The Great Lakes Fleet Experiment Fall
2004-Spring 2005
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NWS Meteorologists Guide to TAMDAR

• Roger Smith
• General Forecaster
• Baltimore/Washington WFO
• Sterling, Virginia

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Brief History of NWS Acquisition of Upper Air
Data via Aircraft Flights

• NWS began regularly scheduled aircraft weather
  observations in 1919. Pilots were not paid unless
  they reached an altitude 13.5 k ft. Pilots
  received a bonus for every 1000 ft above 13.5 k
  ft.
• Aircraft obs were discontinued in the early
  1940's, when radiosondes were first employed by
  the NWS.
• ACARS ( Aircraft Communications, Addressing and
  Reporting System) was first used to report wind
  and temperature data in support of the Global
  Weather Experiment in August of 1979.
• TAMDAR deployed in Great Lakes Forecasting
  Experiment beginning in the fall of 2004.

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ACARS (Aircraft Communications Addressing and
Reporting System)

• While aircraft weather data is often commonly
  referred to as ACARS, it is also known as MDCRS
  (Meteorological Data Collection and Reporting
  System) and AMDAR (Aircraft Meteorological Data
  Report)
• American, Delta, Northwest and United Airlines
  and Federal Express and United Parcel Service
  supply ACARS data.
• Airlines agreed to allow NWS, airline and
  university meteorologists to use ACARS (MDCRS)
  data in 1997.
• Airline and NWS meteorologists have found
  ACARS/MDCRS data very useful in producing more
  accurate forecasts and warnings
• The NWS and United Parcel Service are evaluating
  a new water vapor sensor at the present time.

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TAMDAR Program Description
Tropospheric Airborne Meteorological Data Report

• As part of the Aviation Weather Safety Program
  initiative, NASA has contracted with AirDat LLC
  to design and build a low cost airborne
  instrument to measure temperature, moisture,
  pressure, wind, ice accretion and turbulence
• The goal is to determine if additional upper air
  observations will contribute to improved aviation
  and public weather forecasts and warnings.
• TAMDAR sensors were first installed on prop-jet
  aircraft that serve small and medium size
  airports.

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TAMDAR Program Description

• TAMDAR were installed on 64 Mesaba Airlines
  (Northwest Airlink) Saab 340 aircraft beginning
  in September 2004

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TAMDAR Instrument
UND Cessna Citation II
NASA Twin Otter
TAMDAR instruments
Pictures of TAMDAR units installed on NASA and
UND research aircraft
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AirDat operates a sensor network for collecting
upper air data in near real time. The
aircraft-mounted sensor, called TAMDAR
(Tropospheric Airborne Meteorological Data
Reporting), transmits observations via satellite
to AirDat's data center, where they are
processed, archived and distributed. TAMDAR
supplements existing data sources with improved
temporal and spatial coverage and richer data
sets for better weather reporting and
forecasting. AirDat is now deploying TAMDAR
sensors to provide upper air data for the
continental United States.
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TAMDAR Design Specifications

• Operating Temperature -70 C to 55 C Ambient
• Pressure Altitude Range -500 Ft. to 50,000 Ft.
• Airspeed Range lt Mach .82

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TAMDAR Overview

• TAMDAR (Tropospheric Airborne Meteorological Data
  Report) is the result of several NASA sponsored
  aviation weather safety initiatives. The goal is
  to design, build, and fly an inexpensive
  instrument that would measure meteorological
  variables from commuter aircraft flying to small
  and medium size cities. It is anticipated that
  TAMDAR will result in more accurate weather
  forecasts and reduce aircraft accidents and
  delays.
• NASA has partially funded the design and testing
  of the TAMDAR instrument. Airdat LLC has
  contributed towards the design and testing, as
  well as satellite communications capabilities,
  quality control, etc. Mesaba Airlines is
  providing access to, and modification of, their
  aircraft to install the TAMDAR sensor. National
  Weather Service (NWS) meteorologists used the
  data as part of the Great Lakes Fleet Experiment,
  and provide feedback on data quality,
  availability, and application to various weather
  phenomena.

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TAMDAR Overview

• TAMDAR data is retrieved from 64 Mesaba Airlines
  Saab 340 turboprop aircraft.
• The Saab 340 was chosen because it flies shorter
  flights at lower altitudes than most regional jet
  aircraft. The fact that there are shorter
  duration flights means that there are more
  takeoffs and landings, and therefore, more
  soundings.
• The fact that they fly at lower altitudes is also
  important, as data from the mid levels of the
  atmosphere is important for most meteorological
  processes. This also compliments the large
  commecial jets that provide a significant amount
  of ACARS/MDCRS data from the upper levels of the
  atmosphere.
• Even though TAMDAR will initially be used on the
  Saab 340, it can be installed on most any
  commercial aircraft, with FAA certification.

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TAMDAR Overview

• Data are generally available every 10 mb from the
  surface through the first 100 mb, and every 50 mb
  thereafter.
• Test flights indicate that TAMDAR temperatures
  are accurate
• within 1 deg C, humidity within 5, wind
  direction within 5
• degrees, and wind speed within 4 knots.

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TAMDAR and RAOB Sites ( through 08/06/2005)
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Data Availability

• Mesaba flies the Saab 340 aircraft to
  approximately 80 cities
• Since each of the 64 aircraft makes approximately
  seven flight segments per day, there are nearly
  1000 soundings per day.
• Data coverage is greatest in the Great Lakes
  region, but still considerable in parts of the
  Northeast, Southeast and northern Plains
  

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Data Availability

• Some destinations have nearly 100 soundings per
  day (MSP, DTW, MEM), while others have only a few
  (BGM, FNT)
• You can find TAMDAR flight schedules on the GLFE
  web page www.crh.noaa.gov/tamdar

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TAMDAR Program Description
TAMDAR Flights are In Green Notice that data is
also available beyond the Great Lakes region
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Why do we need TAMDAR?

• Numerical model skill improved greatly during the
  past twenty years due to improved model terrain,
  physics, grid sizes, as well as increased
  computational speed.
• Future improvements will likely be slower, unless
  more upper air data is acquired.

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Why do we need TAMDAR
In order to fill in some of the gaps in the
weather balloon network, the NWS uses other
useful sources of upper air data, such as
Wind Estimates from Doppler Radar
Wind Profilers
GOES and POES Satellites
Commercial aircraft
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Why do we need TAMDAR?

• The NWS Upper air network is nearly the same as
  it was in the 1940s.

A lot of weather occurs between radiosonde sites!
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Why do we need TAMDAR?
Current NWS radiosonde network east of the Rocky
Mountain States
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Why do we need TAMDAR?

• ACARS data from commercial jet aircraft are very
  helpful, but there are relatively few soundings
  from small cities

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Why do we need TAMDAR?
TAMDAR Soundings will fill many of the gaps in
the current upper air network!
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Great Lakes Fleet Experiment

• A NASA/AirDat funded six-nine month evaluation
  called the Great Lakes Fleet Experiment began
  November 1, 2004. The NWS was a major
  participant.
• The goal was to determine whether TAMDAR units
  are a reliable, cost effective means of gathering
  upper air data - and whether these data can
  improve warnings and forecasts

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Great Lakes Fleet Experiment

• NWS Meteorologists were asked to use the data and
  comment on its quality, timeliness and utility.
• TAMDAR has potential to significantly improve
  warnings and forecasts

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Great Lakes Fleet Experiment
NWS meteorologists can retrieve TAMDAR data from
the FSL aircraft data web page at
http//acweb.fsl.noaa.gov This interactive web
page can produce wind plots and soundings
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NWS Forecaster Role

• TAMDAR should be useful in many forecast
  applications

• Upper air analysis and verification of model
  forecasts
• Precipitation type forecasts
• Severe storm environments
• Fog formation (UPS method)
• Turbulence forecasts
• LLWS

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Upper Air Analysis
TAMDAR winds, temperature and dewpoints can be
compared to model initial analyses and forecasts
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Precipitation Type Forecasts
Real time data from the lower troposphere is
crucial when forecasting the precipitation type
of winter storms. TAMDAR could provide this
information at many locations
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Severe Storm Environments

• Research has shown that knowledge of the
  near-storm environment is essential to effective
  severe thunderstorm and tornado warnings.
• Wind profilers, WSR-88D VWP, and 18UTC special
  radiosonde releases are helpful in determining
  the potential for severe thunderstorm
  development, but there are still many spatial and
  temporal gaps in coverage.
• TAMDAR soundings will be useful in determining
  stable layers, lapse rates, winds aloft and
  moisture availability.
• Stability parameters such as CAPE and CIN can
  also be calculated.

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Low Ceiling and Visibility Forecasts

• Knowledge of the temperature, moisture and wind
  fields in the boundary layer is vital when
  forecasting low ceilings and visibilities. Little
  real time data is available at most airports, so
  model soundings and MOS guidance are often used
  when producing aviation forecasts.
• TAMDAR equipped aircraft will fly to and from
  nearly 80 airports in the central and eastern
  United States, and can provide the necessary data
  to produce more accurate forecasts of low
  ceilings and visibilities that adversely affect
  all airports.

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Low-level Wind Shear

• The presence of low-level wind shear should be
  easy to determine at airports with TAMDAR data.
• Wind speed and direction at 10mb vertical
  increments in the boundary layer, along with an
  airborne turbulence sensor, will provide the
  necessary information to make more accurate
  forecasts of LLWS.

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Temperature
Water Vapor Mixing Ratio
Vector Wind Magnitude
Key Blue-w/o TAMDAR Red-with TAMDAR Solid-analysi
s Dotted-6 hour forecast Dashed with triangles-12
hour forecast
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Great Lakes Fleet Experiment

• TAMDAR data can also be sent to AWIPS via FSLs
  MADIS data server. Instructions can be found on
  the GLFE web page http//www.crh.noaa.gov/tamdar

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NWS Forecaster Resources

• A web site http//www.crh.noaa.gov/tamdar has
  been established that will provide meteorologists
  with information on TAMDAR and the GLFE
• It contains the latest flight schedules so that
  you can determine when TAMDAR soundings are
  available in your area, a Forum where you can ask
  or answer questions, and people to contact for
  more information.

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References

• Comprehensive article on Aircraft Weather Data
• http//www.crh.noaa.gov/tamdar/papers/aircraft.pdf
  
• TAMDAR instrument details and flight tests
• http//www.crh.noaa.gov/tamdar/papers/TAMDARsensor
  .pdf
• NWP applications of TAMDAR
• http//www.crh.noaa.gov/tamdar/papers/RUC.pdf
• Impacts of aircraft data on FSL, NCEP and ECMWF
  models
• http//www.wmo.int/files/www/GOS/Alpbach2004/3B_3P
  etersenRalph.pdf
• Previous forecaster evaluations of aircraft
  weather data
• http//acweb.fsl.noaa.gov/docs/mamrosh-2000/p.pdf