WMO Aircraft-Based Observations Newsletter

Contents

1. Welcome from the Chair of the JET-ABO
2. A word from the outgoing scientific officer
3. Status of Aircraft Based Observations
4. Regional program status and developments
5. ABOP Water Vapor Measurement
6. WMO Uncrewed Aircraft Systems Demonstration Campaign
7. RA-I Task Team on Aircraft-Based Observations and WICAP Workshop, December 2022
8. JET-ABO and Coordination Group on WICAP Priority Activities
9. ADS B as a Source of Global Aircraft-based Observations Data
10. Synoptic Data’s Role in the Aircraft-Based Observations Community
11. Development of the Aircraft Based Observations Metadata Repository
12. Contacts
13. Subscription & Links

Welcome from the Chair of the JET-ABO

On behalf of the JET-ABO co-chairs and the WMO Secretariat, welcome to the April 2023 edition of the WMO Aircraft-Based Observations Newsletter.  

As many of you are aware, after 12 years with WMO, Dean Lockett, Scientific Officer, has accepted a position with the Bureau of Meteorology and will return to Australia in early June. Dean has been more than a Scientific Officer. He has been the global leader for ABO for more than a decade, coordinating our many activities, shepherding through WMO and its members significant advances and growth in the scope of our important contributions to the world meteorological community. There is no one else with Dean’s intricate technical and programmatic knowledge of the many facets of ABO, across governments, in international bodies, our partners in the aviation industry, and beyond. Dean is creative, passionate, and dedicated to anything he puts his mind to. 

Dean, we will miss you sorely and no doubt be at a loss for a while as we try to carry forward the work of the JET-ABO and the global programme, We wish you and Kath all the best in this next chapter of your lives.

In this edition of the newsletter, we provide updates on the status of regional programmes, and a selection of articles featuring contemporary topics. Especially of interest are plans and priorities for the JET ABO and a contribution on the evolving status of ADS-B as a source of meteorological data. Also included are updates on water vapor measurement and turbulence monitoring as well as a look at Synoptic Data’s role in the ABO programme. 

In the last year we have increasingly returned to in-person engagement and meetings.  For the rest of 2023, we can look forward to more events, including a planned meeting with an emphasis on stakeholder engagement with the broader components of the aviation industry important to ABO, such as avionics and communications providers. Also, a meeting planned for late in the year to be hosted by Deutschr Wetterdienst, Germany, will focus on future strategies for water vapor measurements. We also will take stock of the outcome of the WMO Congress in May and June and its impacts on our membership and work.

We thank the authors of the articles for their time and effort and all involved in assembling this newsletter, with particular thanks to the newsletter editor, Mr Carl Weiss.

Curtis Marshall, Chair, JET-ABO

A word from the outgoing scientific officer

Firstly, thank you to Curtis for his very kind words in the welcoming article above.

It has been my great privilege to have, over the past 12 years, had the role as a scientific officer, to coordinate the WMO Aircraft Based Observations Programme as one of my primary responsibilities. This has been one of the most satisfying and rewarding roles that I have had in my career of over 30 years in science and meteorology. I have been very fortunate to have been offered this opportunity, which has included, and been highlighted by, the privilege of working and collaborating with so many professional, dedicated and friendly international colleagues on this still developing area of observational meteorology. Together, we have achieved a great deal, and yet, of course, there is still so much more to do to improve and expand upon this important component of the WMO Integrated Global Observing Systems.

In terms of the output of the programme, the achievements we have made together over the past 12 years include:

• The integration of the former AMDAR Panel into WMO and its technical commissions.
• The development and publication of many 100s of pages of guidance, technical and promotional materials, including the publication of WMO No. 1200, Guide to Aircraft-based Observations.
• Expansion of the volume of ABO data on the WIS from around 230k in 2011, to a peak of around 860k observations per day in 2019.
• The establishment of the WMO, IATA working arrangement on AMDAR development.

In this role, great support has been given and faith shown by WMO Member NMHS, who have supported the programme through contribution of resources to the AMDAR Operating Fund and through provision of time and effort of their own experts, without which nothing would have been achieved.

Additionally, much support has been shown and given to both the programme and to me by my Secretariat colleagues and managers.

I wish to sincerely thank all my colleagues for their wonderful support and collegiality over my time with WMO. I look forward to a continued connection with at least some of you in my new role with the Australian Bureau of Meteorology.

Thank you.

Dean Lockett, Scientific Officer, WMO Secretariat.

Status of Aircraft Based Observations

The graphic below shows the smoothed monthly average of daily aircraft-based observations (single point measurements in space and time, mainly of air temperature and wind speed and direction, made by an aircraft) transmitted on the World Meteorological Organization (WMO) Global Telecommunications System (GTS) since 2007 up to October 2022, as contributed by:

• All aircraft and all systems (black);
• From the AMDAR Programme with reports submitted in binary format (BUFR, red);
• From ICAO data sources (AIREP and ADS, purple); and,
• From the FLYHT AFIRS system (blue).

The observations from the WMO AMDAR observing system are the output from 12 operational AMDAR national and regional programmes in cooperation with some 43 national and international participating airlines, as listed on the WMO website.

ABO Data Volumes and Coverage

The graph shows that recently towards the end of 2019 and start of 2020, aircraft-based observations data volumes had increased to a historical maximum of more than 850k observations per day on the GTS, with AMDAR observations making up the majority of these at around 750k observations per day.

From March 2020, as a direct result of the impact of COVID-19 on the aviation industry and airlines, the volume of aircraft-based observations overall fell to around 245k observations per day and to 230k for AMDAR  - around 30% of December data volumes for both. The biggest monthly reduction occurred in May 2020, with only an average of 210k observations per day available.

Since then, data levels have gradually increased overall with mean daily total observations at around 670k observations per day in April 2023, which is around 80% of the December 2020 data volume.

The graphic above, courtesy of NOAA, provides an indicative coverage of the full ABO observing system over a 4-hour period on 22 May 2023, with around 12% of available observations shown on the map. The colour provides an indication of the altitude of the observation, ranging from red at low altitudes when aircraft are taking off or landing, to light blue, indicating altitudes at cruise levels.

Thanks to Program Partners

WMO and its Members are grateful to our aviation industry and airline partners for their continued contribution to the WMO Aircraft-based Observing System and the AMDAR Programme. The data that are produced from this collaboration are utilized within many meteorological applications and forecasts, benefiting aviation operations and safety, other application areas and the wider general public. 

For more information on aircraft-based observations data statistics visit the WMO Community Platform Aircraft-Based Observations site.

Regional program status and developments

WMO Region I, Africa, ABO Status

Kenya

WMO, Kenya Meteorological Department (KMD) and Kenya Airways (KQ) have recently established a new agreement for the continued operation of the Kenya Airways AMDAR system for the period 2023 - 2024. This implementation arrangement provides for WMO to support the ongoing communications costs for the 2 B737 reporting aircraft, and also to allow for the expansion of the fleet to include equipping the rest of the KQ B737 and Embraer 190 fleet, subject to required funding becoming available to support both the implementation and communications costs.

Ethiopia

As reported in this newsletter, a meeting of the RA-I Task Team on Aircraft-Based Observations (TT-ABO) and a workshop on WICAP was held in Addis Ababa, Ethiopia in December 2022. Representatives of both Ethiopian Airlines and the Ethiopia Meteorological Institute (EMI) attended the workshop where there was enthusiasm shown by both parties to work towards future establishment of an AMDAR programme. Discussion continues between the parties and the Regional Office for Africa to establish a way forward to implement the programme, subject to funding availability to support the implementation and ongoing communications costs. EMI expressed an interest in developing a future capability to receive and process AMDAR data in-house.

Morocco

EUMETNET, Royal Air Maroc (RAM) and Météo Maroc have recently recommenced the process of integrating RAM into the EUMETNET E-AMDAR programme based on equipping RAM's B738 fleet. An initial equipping of 5 aircraft would be undertaken with a larger rollout to take place when plans for integrating the fleet into the E-AMDAR data optimisation system were complete. A timeline for this development is not yet established.

WMO Region III, South America, ABO Status

Since December 2021, LATAM Airlines has halted AMDAR data provision for all its branches across South America.  Hence, there are no operational airlines providing this data in RA-III currently.  However, several meetings have been held with Avianca Airlines in order to start a new regional program in Region III under WICAP with support from the US-ABO program.

TT-ABO III activities

During Q1 2023, the Chairs of Task Team on Aircraft-based Observation for Region III (TT-ABO III) and Expert Team on Surface-based observations and WICAP for Region IV (ET-SBW) met several times to work together under a new WICAP program for the Americas.  This collaboration will enhance data provision from new participating airlines and will improve ABO coverage in data sparse areas of Central and South America.

Argentina (AR)-AMDAR

Communications with Aerolíneas Argentina have been reestablished in Q1 2023.  Changes in their aircraft avionics are required to install AMDAR onboard Software (AOS) and to report data under WMO No.1200 requirements.

Brazil (BR)-ABO 

The Brazilian ABO program also has not escaped the effects of the pandemic and the resulting cessation of LATAM AMDAR provision (fig. 1).  While ADS-C data delivery is increasing during austral summer, AMDAR data from former TAM airlines have fallen to zero since January 2022.

Figure 1.   Brazilian ABO program data during 2022 and first two months of 2023.  Blue bars represent ADS-C data. Source: Quilson Aragao Santos (DECEA - Brazil).

US LATAM Program

Because of pandemic-forced border and airspace closings since March 2020, the LATAM program has been seriously affected due to the bankruptcy of the airline.  This, plus increased downlink regional costs and irregular economic recovery of the airlines, forced LATAM to stop providing data permanently as of December 2021.  The US will continue to support the LATAM data stream processing when the airline is ready to start providing data again as the economy recovers.

Nicolás Rivaben, Vice Chair, JET-ABO, Chair, TT-ABO III

WMO Region IV, North and Central America, ABO Update

The RA-IV Program consists of the USA and USA-based AMDAR enabled airlines and FLYHT TAMDAR and AFIRS-AMDAR as well as Mexico and AeroMexico, and Canada and Canadian data sources from FLYHT.  The USA AMDAR program additionally provides ADS-C enroute wind and temperature reports approximately every 14 minutes on transonceanic and long-haul routes around the globe.  

As of April 2023, the USA, in partnership with RA-III and WMO, continues to pursue a replacement for the loss of LATAM in South America with a particular emphasis on Avianca.  Additionally, following the outcome of the RA-I ABO workshop in Addis Ababa, Ethiopia in December 2022, the USA continues to support the WMO Secretariat and RA-I members to potentially obtain and provide AMDAR data from Ethiopian Airways and Kenya Airways.  

The USA ABO and National Mesonet Program secured funding through April 2024 to continue providing a test feed of Mode-S data from FlightAware as well as TAMDAR and AFIRS-AMDAR observations from FLYHT.

Canada is working actively to expand their AMDAR program through partnerships with data providers and airlines to increase the number of reporting aircraft by 150%.  Implementation of new aircraft to the program could be completed by the end of this fiscal year, but technical difficulties have delayed the initial timelines. More details will be available later this year.

With the support of the regional Secretariat, on April 21st, the RA-IV Expert Team for Surface-base Observations and WICAP (ET-SBW) distributed a survey (RA IV Online Survey on AMDAR/WICAP and Surface-Based Observations) to region members seeking increased participation in the ET.  A larger membership is recommended to coordinate ET activities both within RA-IV and to increase collaboration with RA-III.  As such, RA-III and RA-IV ABO Experts have met twice recently to discuss coordination of activities between their regions to better plan and support WICAP implementation within the Americas.

Curtis Marshall, USA AMDAR Program Lead
Frederic Lenormand, Canada AMDAR Program Manager

WMO Region V, Southwest Pacific, ABO Update 

The first (virtual) meeting of the RA-V Expert Team on WICAP (ET – WICAP) was held on 5th April 2023, with representatives from Fiji, New Zealand, Samoa, Papua New Guinea, Australia, Malaysia and the WMO RA-V Secretariat participating.

One of ET-WICAP’s first objectives  is  to understand the current status of aircraft-based observations within the Region.  To assist, data from a typical day (in this case, 18th September 2022) were compared with the WMO's Rolling Review of Requirements for Global Numerical Weather Prediction: 

In the figure below, RA-V has been divided into 200km x 200km boxes (due to the map projection, the boxes appear larger in the south, but all are the same size.  

The box colour scheme is as follows:

This analysis did not include data available from FLYHT (TAMDAR, AFIRS).  This data will be added into the analysis ahead of the next ET meeting.

While not all NMHSs in the Region run NWP models, these types of visualisation assist in determining areas for further investigation of potential sources of aircraft-based observations. 

Dr. Doug Body, Bureau of Meteorology

WMO Region VI, Europe, ABO Update

Highlights

While the number of observations from the long-haul fleets is still low, the total observations from all ABO types (below) are back to normal.  However, both area and airport coverage still are falling short of minimum requirements due to the continuing reduced airline schedules.

Total monthly ABO by type in EUCOS area (90° to 10°N, 40°E to 70°W)

• While not all performance criteria have been met, all have continued to improve compared with the previous winter period .
• All nine of the WVSS-II aircraft are back in operation.
• As indicated in the figure below, huge numbers (currently 33million wind and 21 million temperature per day) of Mode-S EHS quality-controlled data now are being generated routinely and made available to users.

• The Russian/Ukraine conflict and subsequent flight bans continue (along with the data gap) and are impacting severely some airline routes, most notably Finnair and SAS on their Asian routes.  Despite this, Obs-SET members have not noticed any impact on global models or upper-air wind forecasts – which should be reassuring to stakeholders!  
• The temperature reporting issue from the Polish Airline LOT Embraer fleet is still unresolved and likely needs further input from Honeywell. 
• Meanwhile, work to integrate Turkish Airlines (THY) into the E-ADOS optimisation system continues at a slower than ideal pace.  Nevertheless, five THY aircraft continue to provide un-optimised data (see figure below), which include some coverage in Russian airspace.

• The EUMETNET ABO Programme has restarted discussions with a number of airlines (TAP, KLM, Brussels Airlines, RAM and DHL) that were initiated before COVID-19 about participation in AMDAR/WICAP.
• Programme requirements for the next phase of E-ABO (2024 to 2028) have been prepared. Any further information required on this can be obtained from the E-ABO Team.  The UK Met Office fully intends to bid to run the E-ABO Programme in this next phase, with the Invitation to Tender (ITT) expected to be issued late May/June.
• Work on WICAP and its implementation has continued at a slow pace, with a number of issues affecting the programme.  It has become clear that, unlike EUMETNET, each WMO regional association faces problems with establishing a collaboration between NMHSs to fund and manage a regional AMDAR programme, preferring instead to remain with individual national programmes where they already exist.  Even in RA-VI, there are issues caused by the political implications of the Russia/Ukraine conflict which means WICAP currently cannot move forward for the entire Region.
• Irrespective of region, engagement with the airlines still is needed to take WICAP forward but until they return to a sustainable footing, opportunity to work with some of the target airlines may be limited.  However, the WICAP Airline Agreement that will be used by the UK Met Office in dealing with E-AMDAR airlines has been agreed to and talks with existing and new airlines about migrating to the new agreement have started.
• A recent study comparing the quality and usefulness of the EMADDC Mode-S data and AMDAR, concluded with the main result being that Mode-S can replace some AMDAR data at some airports and in some circumstances.  It is hoped that this finding will lead to the release of some funding that could be better spent in more remote regions, such as Africa, where the impact of aircraft data would provide greater benefit to NWP.

Issues

• The airline industry is still in crisis mode and not expected to recover to 2019 levels until the end of 2023, more likely 2024, according to the latest review by EUROCONTROL.  This continues to impact developments with only those considered critical to their operations being given any form of approval.  Unfortunately, this means that many of the originally planned regional E-ABO developments are still on hold.
• An issue with AMDAR location data during the first part of ascents was identified through comparison with Mode-S data generated from the same aircraft.  This seems to affect aircraft reporting using ARINC620 v3 or lower.  The E-ABO management team is liaising with airlines and avionics vendors on software upgrades to potentially address this issue.
• The strong US dollar vs the Euro remains an issue for the affordability of AMDAR data.  Fortunately, the dollar has weakened slightly against the Euro over recent months so there is no immediate need to cut-back on the amount of AMDAR data generated within the region!
• European economies are struggling and most NMHS budgets are under increasing pressure to make spending cuts, or at least maintain current funding levels over the next five years. While it is hoped that Mode-S may free-up some funds, it cannot be assumed that this money will be re-invested back into ABO.  Some difficult budget decisions must be made over the coming months, but ABO funding should be finalised by the end of 2023.

Steve Stringer, E-ABO Programme Manager and RA-VI TT-ABO Lead

ABOP Water Vapor Measurement

Global Water Vapor Measurement Summary and Update

After three years of reduced aircraft-based observations (ABO) of water vapour due to the COVID-19 pandemic, operations of water vapour sensor-equipped aircraft are mostly back to normal.  During the last two decades, two distinct sensor systems have been used to make these measurements: the Second-Generation Water Vapor Sensing System (WVSS-II) and Tropospheric Airborne Meteorological DAta Reporting (TAMDAR).

WVSS-II

No new installations of WVSS-II occurred during the last year. The number of functioning WVSS-II units on commercial aircraft in RA-VI (Europe) remained constant at nine.  Operationally equipped aircraft in RA-IV (North America) also held steady at 131 since the October 2022 newsletter.  The table below shows the breakdown of WVSS-II reporting aircraft across all WMO Regions.

UPS and Southwest Airlines operate the WVSS-II-equipped aircraft in North America and Lufthansa in Europe.

As in the past, the NOAA/NWS and EUMETNET-ABO (E-ABO) networks provide water vapour measurements (WVM) predominantly from their respective geographic regions (RA-IV and RA-VI).  However, the participating airlines routinely travel outside the confines of their home territory, providing ABO WVM data over regions with otherwise no WVSS-II data, e.g., Region I (Africa) and Region III (South America). 

The following figure shows 24-hour global WVSS-II data coverage on March 29, 2023.

Regional Coverage of Water Vapour Measurement

Under the USA ABO programme, RA IV continues to have 131 aircraft from Southwest Airlines and the United Parcel Service equipped with WVSS-II sensors.  Typical daily water vapor profile numbers remain at approximately 1000.

All nine WVSS-II-equipped aircraft (all A321 airframes) in RA-VI are back in service.  E-ABO and airline partner Lufthansa Group share operations within the E-ABO network.  The following figure shows the RA-VI coverage of WVSS-II data over a one-week period (March 23–29, 2023).

The main hubs for these aircraft are Frankfurt and Munich, each with a relatively high density of vertical profiles.  However, these aircraft also fly to most countries within Europe on a routine basis.

The UK Met Office is investing in new observation data sources to support its developments in supercomputing and high-resolution modelling to improve weather and climate forecasting.  This includes plans to increase humidity measurements by installing sensors on commercial aircraft which would provide profiles similar to those already measured in the AMDAR programme and improve the coverage and frequency of measurements over the UK. 

TAMDAR

FLYHT currently collects data from 129 active TAMDAR-equipped commercial aircraft.  The breakdown of active TAMDAR aircraft by WMO region is shown below.

In February 2023, these aircraft generated on average 581 TAMDAR soundings per day with the highest concentration of profiles found over the Southwest Pacific and Asia followed by North America.  Sixty-six of the 129 active aircraft reported TAMDAR observations in February.

The map below shows the TAMDAR observations for February 2023.

Carmen Emmel, Deutscher Wetterdienst (DWD), ABO Coordinator

WMO Uncrewed Aircraft Systems Demonstration Campaign

WMO, under the Joint Expert Team on Aircraft-Based Observing Systems has developed the scope and terms of reference for the WMO Uncrewed Aircraft Systems Demonstration Campaign (UAS-DC), for which the plan was endorsed by the WMO Commission for Observation, Infrastructure and Information Systems (INFCOM) Management Group in March 2022.

The UAS-DC will be held over March to August 2024 and aims to demonstrate the capability of UAS to provide data of sufficient quality and reliability on a routine operational basis in support of meeting requirements for upper-air observations, as a component system of the WIGOS Global Basic Observing Network (GBON).

Plans for the UAS-DC continue to develop, with interest being piqued by a number of media articles in the past several months.

• February 2023, Inside Unmanned Systems, WMO Plans UAS Demonstration Campaign.
• March 2023, WMO MeteoWorld, Call for participants: WMO Uncrewed Aircraft Systems (UAS) Demonstration Campaign.
• April 2023, Meteorological Technology International, High Expectations.

An important achievement earlier in 2023 has been the finalisation of the WMO White Paper, A Global Demonstration Campaign for Evaluating the Use of Uncrewed Aircraft Systems in Operational Meteorology, which describes in detail the current status of UAS technology and advancements required to ensure its readiness as a contributing observing system of the WMO Integrated Global Observing System (WIGOS). A pre-publication version of the White Paper is availble from the UAS-DC site.

Over the coming months the WMO UAS-DC Scoping Planning and Organising Committee will focus attention on advancing several key aspects of the campaign, including:

• Finalising UAS data representation formats.
• Developing detailed guidance for UAS operators to support understanding and some standardisation of flight planning and data sampling, processing and provision of data, and during and post-campaign reporting.
• Development by Synoptic Data, of the system to support UAS data provision from UAS operators and to data users.
• Increasing interaction with data user participants and increasing understanding of their important role in the UAS-DC.

More information about the UAS-DC is available from the WMO Community Platform site.

WMO can be contacted about the campaign via the email address uas-demo@wmo.int 

RA-I Task Team on Aircraft-Based Observations and WICAP Workshop, December 2022

The WMO Regional Office for Africa conducted a meeting of the RA-I, Africa, Task Team on Aircraft-Based Observations (TT-ABO) and a Workshop on the WMO-IATA Collaborative AMDAR Programme (WICAP) over 6 - 8 December, 2022 in Addis Ababa, Ethiopia. The meeting and workshop was held at the Hotel Elilly and kindly co-hosted by the Ethiopian Meteorological Institute (EMI). 

The workshop was opened by Mr Fetene Teshome, Director General of Ethiopian Meteorological Institute and Permanent Representative (PR) of Ethiopia with WMO, Mr. Amos Makarau, WMO Director of Regional Office for Africa, Mr Anthony Rea, WMO Director of Infrastructure Department (online) and Mr Abubakr Salih Babiker, WMO Technical Coordinator for Infrastructure in Africa.

The meeting of the RA I Task Team on Aircraft-Based Observations (TT-ABO), which preceded the workshop on WICAP, was chaired by Mr Mosetlho, South Africa. The purpose of the workshop following the meeting was to exchange experiences, best practices and status of national aircraft-based observations programmes, and to discuss the challenges and opportunities at the national and regional level for extending AMDAR under the developing RA-I WICAP programme in collaboration with IATA and regional airlines. 

National reports on aircraft-based observations were received from TT-ABO experts from South Africa, Egypt, Ethiopia, Morocco, Kenya and Cote D'Ivoire. 

The key recommendations that were proposed from the workshop are summarised below.

• Priority should be given by TT-ABO and WMO Coordination Group on WICAP (CG-WICAP) for advancing the onboarding of Ethiopian Airlines and Royal Air Morocco, along with Kenya Airways as new WICAP partner airlines over 2023 and 2024, in collaboration with the corresponding WMO Member NMHS.
• WMO & IATA should strongly promote and facilitate WICAP expansion in Africa as a priority WICAP development project.
• JET-ABO and TT-ABO experts should endeavour to increase basic technical understanding of AMDAR  and aircraft-based observations over the RA to faciliate wider implementation of ABO systems.
• The TT-ABO and the Regional Office for Africa (RAF) should work with the RA-I Task Team on Aeronautical Meteorology to support capacity development across the region leading to the wider use of aircraft-based observations in NWP and relevant now-casting forecast applications.
• The TT-ABO should work with the RAF and the RA-I to strengthen ties with AMCOMET so as to ensure strong support for WICAP development in Africa.
• TT-ABO and the CG-WICAP to work together on exploring possibilities to promote the deployment of water vapor measurement as a component of the RA-I AMDAR Programme.
• The RAF and TT-ABO to make plans for further meetings and workshop in support of wider support for the Africa WICAP Development Project.

JET-ABO and Coordination Group on WICAP Priority Activities

Over 2022 and taking into account the approach of the coming new WMO Congress and constituent body inter-sessional period (2024 to 2027), the Joint Expert Team on Aircraft-Based Observing Systems (JET-ABO) and the Coordination Group on the WMO-IATA Collaborative AMDAR Programme (CG-WICAP) have reviewed their respective work plans and have established some expected priorities to be addressed.

For the JET-ABO, as reported in the last newsletter, the priority activities associated with extension of aircraft-based observing systems will focus on:

• Continued efforts to develop the WMO-IATA Collaborative AMDAR Programme (WICAP), including the expansion of water vapour measurement and turbulence monitoring.
• Further collaboration and activities towards the operational integration of UAS observing platforms, initially focused through the holding of the UAS Demonstration Campaign (2024).
• Preparations and planning for the advent of ABO data derived from ADS-B.
• Extension of Mode S and Aircraft Derived Data globally.
• Continued maintenance and improvement of technical materials.

From a WMO programmatic and data management perspective, additional activities would be expected to include:

• Operational implementation of the Aircraft-Based Observations Metadata Repository, as a component of the WIGOS OSCAR/Surface system.
• Development of the functionality of the ABO Lead Centre role, currently filled by USA/NOAA, to more fully meet expectations of monitoring of aircraft-based observations in line with the WMO Data Quality Monitoring System.
• Full implementation of the ABO Global Data Centre, providing availability of long-term records of aircraft-based observations in support of climate programs.

For the CG-WICAP, which in particular has the role of supporting development of AMDAR over data-sparse areas, activities will focus on:

• Development of plans for two priority WICAP development projects: 1) Africa WICAP Development Project, and 2) Central and South America WICAP Development Project.
• Increasing efficiencies in AMDAR development and operation through wider availability of avionics software; transition to cheaper communications solutions, harmonization of reporting applications, and integration of water vapour monitoring as an aviation application.
• Ensuring better airline support for WICAP through improved realisation of the benefits of participation, which include improved national forecast and service provision arising from wider use of aircraft-based observations within aeronautical forecast applications.

WMO will in the future continue to seek support from Members for the ongoing development of the Aircraft-Based Observations Programme as a component of the activities of the Commission for Observation, Infrastructure and Information Systems (INFCOM).

Dean Lockett, Scientific Officer

ADS B as a Source of Global Aircraft-based Observations Data

In 2017, the Harvard Business Review reported that, “Every year, weather variability is estimated to cost $630 billion for the U.S. alone, or 3.5% of GDP.”  Forbes’ reporting on Deloitte’s 2021 Climate Check Survey, notes that, “Climate change and extreme weather events…have a direct impact on 70% of all economic sectors worldwide.”  Better anticipation of impending weather through greater understanding of the atmosphere is critical to mitigating the negative effects and taking advantage of the opportunities associated with weather.

Safe and efficient aircraft and aviation system operation requires knowledge of the atmosphere’s temperature, wind, icing, turbulence, and other parameters that are also critical to weather forecasting. Improved forecasting could increase aviation safety and capacity and reduce emissions by identifying hazardous weather and fuel-efficient routes. 

Often seen as part of the problem, aircraft operators can be part of the solution by sharing aircraft-based observations (ABO) data to lessen the impact of weather on the more than two-thirds of global economic sectors beyond aviation.

Of the many inputs to numerical weather prediction models, ABO have one of the highest impacts of all observing systems, increasing both forecast accuracy and extending that accuracy in time.  This makes possible earlier and more confident decisions related to weather and its impacts.  ABO also provide an important record for climate change monitoring and prediction.

Automatic Dependent Surveillance – Broadcast (ADS B) is a surveillance data link used by aircraft to broadcast their position, velocity, and other information in support of air traffic control and management. ADS B version 2 (V2) is required for aircraft operating in controlled airspace in Europe, in the United States, and in many other countries across the globe.  ADS B version 3 (V3) standards that incorporate new requirements for ADS B Weather (ADS B Wx) were finalized for both 1090 MHz and Universal Access Transceiver (UAT) avionics in 2022.  ADS B Wx enables the collection of ABO data using aircraft avionics and air traffic surveillance networks and could dramatically increase ABO availability and markedly reduce their cost.

ADS B Wx is comprised of two independent capabilities, each of which is specified as optional for ADS B V3 avionics.  ADS B Wx Air Reports (AIREP) use automated input from onboard systems to continuously broadcast meteorological and other information without action by the flight crew.  ADS B Wx Pilot Reports (PIREP) rely on the flight crew to manually confirm input data prior to its broadcast by ADS B avionics.

1090 MHz ADS B Wx AIREP messages are automatically and continuously broadcast for use by ground-based weather forecasting and air traffic applications and by flight-deck based applications for hazardous flight condition avoidance and air traffic management.  The raw data in ADS B Wx PIREP messages require ground-based processing to validate their data, correlate them in space and time, and generate standardized reports for dissemination to users through existing networks, including via ground-to-air data link services such as Flight Information Services – Broadcast (FIS B).  ADS B Wx PIREP could also increase pilot weather reports while reducing human error, controller workload, and processing times associated with their collection and dissemination.

The following table shows the ADS-B Wx AIREP parameters and their broadcast interval, by message, for 1090 MHz ADS-B V3.  UAT ADS B V3 avionics broadcast similar ADS B AIREP information at rates that provide comparable reception probability to 1090 MHz ADS B systems.  When equipped with ADS-B Wx AIREP capable avionics, aircraft are expected to broadcast only those parameters for which they are equipped.

ADS B Wx development was coordinated with the meteorological community, research and standards organizations, aircraft and avionics manufacturers, aircraft operators, and other stakeholders. These efforts resulted in international consensus on ADS B Wx requirements and support for its implementation.

The U.S. Federal Aviation Administration (FAA) has published Technical Standards Orders (TSO) that incorporate the ADS B Wx AIREP and PIREP capabilities and are necessary for certification of ADS B V3 avionics.  The FAA is working to modify the U.S. ADS B Rule to allow the use of ADS B V3 avionics to comply with rule requirements.  Europe is working on similar initiatives.  18 months after the U.S. rule change, manufacturers will no longer be able to seek U.S. certification of ADS B V2 avionics.  International Civil Aviation Organization requirements for ADS B V3, including those for ADS B Wx AIREP and PIREP, are expected to become effective in 2026.

Avionics manufacturers are developing ADS B V3 avionics.  Mode S transponders operated in European airspace are currently required to implement both the ADS B V2 and Enhanced Surveillance (EHS) optional capabilities.  Mode S transponders implementing ADS B V3 and EHS, but not ADS-B Wx AIREP, are required to broadcast the ADS B Wx AIREP Alternate Weather State message, which will allow air navigation service providers with ADS B receiver networks to eliminate Mode S interrogations for those data, reducing 1090 MHz spectrum congestion.

The FAA is working to enable the U.S. ADS B ground receiver network to receive and process ADS B V3 messages, including ADS B Wx messages, in 2024.  Aireon, LLC, has already modified its satellite payloads that provide global, space-based ADS B message reception to receive ADS B V3 messages, making global reception of ABO possible, including in areas without ground-based infrastructure.

The U.S. National Transportation Safety Board (NTSB) has recommended that the FAA require air carriers to operate with ADS B Wx capable avionics. United Airlines and the Air Line Pilots Association have recommended that ADS B Wx functionality be specified as required, rather than optional, for ADS-B V3 avionics. The World Meteorological Organization, the U.S. National Weather Service and its Aviation Weather Center, and others, have made similar avionics requirements recommendations to the FAA and support the NTSB ADS B Wx implementation recommendations.

Stephen Darr, Dynamic Aerospace Inc.

Synoptic Data’s Role in the Aircraft-Based Observations Community

As the JET-ABO community is well aware, aircraft-based observations (ABO) are one of 
the top five inputs to numerical weather prediction. They provide vital upper-air 
observations in a critical area of the atmosphere that is generally under-observed, 
outside of satellites, weather balloons, and ground-based profilers. Given this, Synoptic 
has partnered with key aviation companies to collect and make broadly available these 
ABO data sets via our role in NOAA’s National Mesonet Program and relationships with 
various National Meteorological and Hydrological Services (NMHSs). 

Synoptic Data is a leader in environmental data aggregation with data from more than 
300 public and private networks across the globe. With a focus on weather, Synoptic 
gathers surface, upper-air, roadway, aircraft, and ocean data to provide a one-stop shop 
of both real-time and archived data back to the late 90s for certain networks. As a Public 
Benefit Corporation (PBC), Synoptic is committed to providing expanded access to 
environmental data for all user groups and is obligated to operate in a responsible and 
sustainable manner that balances our financial interests with our public benefit mission. 

As the prime subcontractor of the National Mesonet Program, a preeminent public-private-academic partnership, Synoptic aggregates data from 50+ partners across the 
United States, including aircraft data from FLYHT (TAMDAR and AMDAR-over-AFIRS) 
and FlightAware (Mode S). Synoptic has partnered with both companies to provide 
these data sets to NOAA, with FLYHT data being shared internationally through 
Synoptic’s collaboration with the Met Office. Recently, Synoptic worked with the 
Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin -
Madison and Texas Tech University on Mode S data quality and numerical weather 
prediction impacts. With the advent of the EMADDC and the JET-ABO expert group on 
aircraft-derived data, Synoptic hopes to further support this important research to help 
make this data set more easily accessible and beneficial for NMHSs and the private 
sector. 

Synoptic continues to engage with like-minded individuals both domestically and 
internationally on matters important to the ABO community including helping to expand 
the current universe of ABO providers as well as supporting and advocating for aviation 
weather sensor policies and requirements. Synoptic is honored to be involved with the 
JET-ABO and the meaningful work they are doing to advance the use of aircraft data 
worldwide. We welcome future opportunities to work both with the JET-ABO and its 
partners to ensure this vital data set is available for years to come.

Elizabeth Wilson, Director of Weather Programs, Synoptic Data PBC 
https://synopticdata.com

Development of the Aircraft Based Observations Metadata Repository

Over the past 14 months, WMO has been working with developer Wishtree Technologies on the implementation of the ABO Metadata Repository (ABO-MR), which will support the provision by WMO members of aircraft-based observational metadata in line with the requirements established in WMO No. 12, Guide to Aircraft-based Observations, Appendix D, Guidance on Aircraft-based Observations Metadata Maintenance and Provision.

This initiative is being funded by contributions made to the AMDAR Operating Fund, with phase one of the development expected to cost around 100k CHF, providing the functionality to support:

• Provision of metadata for aircraft providing meteorological data for a range of aircraft-based observing systems, including AMDAR, ADS-C, Mode-S, TAMDAR, AFIRS.
• Support for provision of data via both the system user interface, as well as by machine-to-machine, Application Programming Interface.
• Public interface for reporting on ABO program implementation and coverage.

Phase 1 of the ABO-MR is expected to be completed by mid-2023, with training of program managers  on the use of the system expected to commence in 2024.

The ABO-MR has been developed to meet requirements of data users to be able to better trace the origin of ABO data, to report on data quality issues and to undertake application level quality control based on improved ABO metadata access.

Dean Lockett, Scientific Officer

Contacts

WMO INFCOM, Joint Expert Team on Aircraft-Based Observing Systems Contacts

Chair
Mr Curtis Marshall (USA)

Vice-chairs

Ms Carmen Emmel (Germany)

Mr Nicolas Rivaben (Argentina)

WMO AMDAR Observing System Newsletter Editor

Mr Carl Weiss (USA)

WMO Aircraft-based Observations

Mr Dean Lockett (Switzerland)

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