World Meteorological Organization

1. Introduction

Meteorological observations from upper air sources play a crucial role in the enhancement of Numerical Weather Prediction (NWP) products and severe weather forecasting. A notable data source in this regard is aircraft-based observations (ABO), which serve to complement the extant radiosonde network. ABO data has been identified as having the potential to significantly enhance the global NWP system, as outlined in the recommendations of the WMO NWP Impact Workshop.

A number of ABO sources have been developed by WMO Members and Air Navigation Services Providers (ANSP), with the objective of increasing upper-air observations. These include Automated Data Surveillance (ADS) and Secondary Radar (Mode S), among other systems developed by the aviation industry. Nevertheless, the most well-known system is the Aircraft Meteorological Data Relay (AMDAR), a WMO programme that utilises the existing aircraft avionics (or retrofitted with water-vapor sensors) for the collection of meteorological data. This information is then transmitted to the respective National Meteorological and Hydrological Services (NMHSs) to be exchanged in real time through the WMO Information System (WIS). This improves critical numerical weather prediction for aviation purposes and general community.

Since late 1990, there has been an increase in AMDAR data, which continued until 2020 due to economic issues caused by the global aviation industry's downturn related to the outbreak of the COVID19 pandemic. While the aviation sector has demonstrated notable resilience and recovery since then, AMDAR programmes have not yet regained their previous rate of observations.  

A significant challenge persists in accessing data from regions with limited data coverage, including Latin America, Africa, and certain parts of Asia. These concerns primarily stem from the limited availability of communications, technology, and support from meteorological and aviation stakeholders.

Despite these challenges, some stakeholders have made efforts to address these issues, albeit with limited success. The necessity for upper-air observations is paramount to the functioning of ABO programmes worldwide, and NMHS are collaborating closely with the aviation sector to mitigate and adapt the social impact of climate change through its contribution to the United Nations Early Warning for All Initiative (EW4ALL), pillar 2- Observations and Forecasting, among others.

Taking this into consideration, the main aims of this workshop are to:

• Generate a suitable space for discussion with global stakeholders on aircraft-based observations and for the integration of new emerging ABO platforms
• Strength synergies between meteorological communities and aviation-industry-related communities:
  • Improving the NWP systems which provides ICAO’s World Area Forecast Centres and aviation-meteorological-related services;
  • encourage the aviation standardization entities to support ABO standards;
  • exploring new ways of getting cost-effective ABO data using new platforms;
• Develop a new way of collaboration for monitoring environmental hazards related to aviation industry such as contrails and non-CO2 aviation emissions
• Demonstrate the contribution of ABO to support UNDRR Strategic Framework 2022-2025 and UNICEF initiatives: by joining the ABO programme, which will enhance coverage of upper-air-data over data sparse areas and will improve NWP products, contributing to the UN Early Warnings for All initiative (EW4All) initiative.

To facilitate the development of the regional ABO programme, WMO plans to host the Global Aviation Stakeholders meeting on 15, 16 and the morning of 17 September 2025 at WMO HQ in Geneva, Switzerland.  The ET-ABO Meeting is scheduled to take place in the same building in the afternoon of 17 September and the entire day of 18 September 2025.

2. Scope

The Global Aviation Stakeholders meeting will focus on the following five main areas:

I: Introduction of Aircraft-based Observations

• Overview about different ABO sources: in situ observations and derived data.
• Benefit for aviation, meteorological and general community.

II: Contribution of ABO in the EW4ALL initiative and social aspects:

• Contribution of ABO in the WMO-Integrated Observing System (WIGOS)
• Impact of ABO into WMO Integrated Processing and Prediction System (WIPPS)
• Contribution of WIGOS and WIPPS to the Early Warning Systems, including UN Early Warning for All Initiative

III: Technology evolution of ABO sources

• Progress on next generation of sensors
• Progress and regulations of datalink communications
• Progress on ABO data processing

IV: Contribution of ABO in environmental aspects

• Contribution of ABO in contrail avoidance
• Contribution of ABO on non-CO2 aviation emission monitoring
• Public-Private entities as key stakeholders on ABO.

V. New emerging ABO data sources

• Progress on Wx-UAS
• Wx-UAS regulations
• Outcomes of WMO UAS DC

In the other hand, the ET-ABO meeting will focus on: 

I: Reports from ET-ABO Leadership, Regional Leads and WMO Secretariat

II: Reports from the ET-ABO Subgroups

III: 2025-2027 Workplan and ABO Trust Fund discussion.

III: Strategies and approaches to recommendations of the Global Aviation Stakeholders on ABO Meeting

3. Expected Outcomes

The GASM is expected to deliver the following outcomes:

• Developing of key points of discussion about ABO programmes over data-sparse areas and reach the 2019 levels -at least- by 2027.
• Fostering collaboration regarding ABO among NMHSs, airlines, UN entities, and aviation industry through meetings led by the Expert Team on Aircraft-based Observations (ET-ABO) with key collaborations of ICAO, IATA, RTCA and EUROCAE.
• Key points for a document about social and environmental value of ABO for target airlines.
• Make recommendations to WMO ET-ABO

4. Participants

The Global Aviation Stakeholders meeting is expected to have maximum 40 participants.

Participants expected:

• Members of ET-ABO as well as WMO regional/national focal points of ABO around the world
• Representatives from airlines
• Representatives of ICAO, IATA, RTCA, EUROCAE and their related entities.
• Representatives from different Aviation Industry companies, and National Industry researchers

The ET-ABO meeting is expected to have a maximum of 25 people with participation of ET-ABO member.

5. Date and Venue

The Workshop will be organized as a three-day hybrid event and located at the WMO HQ Building, Geneva, Switzerland. The ET-ABO meeting will be one-day and half hybrid event as well.

6. Tentative Programme of the events

Tentative GASM agenda is available here.

The ET-ABO tentative agenda will be available soon

7. Registration of GASM

The registration form is available here. (online and in-person)

Please note the deadline for in-person attendance registration is 01 September 2025.

8. Information note

Information note for in-person participants is available here.