International Cooperation for Space Weather Service Delivery for Aviation

The PECASUS (Pan-European Consortium for Aviation Space weather User Services) initiative is a global space weather service based on seamless and committed collaboration by European institutes possessing leading expertise in the space weather by Finland (Lead), Belgium, UK, Poland, Germany, Netherlands, Italy, Austria, and Cyprus.

The users of PECASUS space weather (SWx) information service center (SWxC) are Flight Crew, Air Navigation Service Providers (ANSPs), Operators, and Civil Aviation Authorities. SWx advisories will enhance the overall situational awareness of ANSPs while managing multiple flights in a coordinated manner. For Operators the advisories will be a useful additional asset when planning potential rerouting and consequent impacts on fuel consumption and crew scheduling. Experiences gathered in SWxC operations will guide Civil Aviation Authorities in their regulations for national investments to minimize SWx related risks in civil aviation.

PECASUS SWxC will provide information on prevailing and forthcoming SWx in advisories compatible with the standardized ICAO formats. The advisories will be given by a 24/7 service and in the areas of

1. High Frequency (HF) communications
2. Communications via Satellite
3. Navigation and surveillance based on Global Navigation Satellite Systems (GNSS), and
4. Radiation exposure at flight altitudes

Advisories will be based on Near-Real-Time (NRT) observations of

• Coronal mass ejections (CMEs) and high-speed streams
• Geomagnetic storms
• Solar radiation storms
• Solar flares
• Solar radio bursts
• Ionospheric activity

The Main Hub (Finland) is responsible for management and verification aspects of the network and serves as the master gateway for international dissemination according to the ICAO regulations. It performs quality and sanity check of the outgoing advisories and maintains the PECASUS website with content contributed by the PECASUS partners.

The Advisory Production Hub (Belgium) is responsible for the scientific and technical production of the advisories, which are composed from input by the Expert Groups (EGs). The Advisory Production Hub collects the status of the components in the network, identifies malfunctions and contacts the responsible parties for their corrections. The Advisory Hub maintains also the primary, internal FTP-site for internal PECASUS communications.

The Resilient Operations Hub (UK) provides the PECASUS backup services in the cases of malfunction of the Main Hub or Advisory Production Hub. The Resilient Operations Hub can use support from the EGs in its services, but can survive also without them. In the latter case the quality of the service may be somewhat lower than that of the primary service.

The nowcasting and forecasting methods will be operated by the following EGs:

• EG for Flight Radiation
• EG for Satellite Communications
• EG for HF Aviation Services
• EG for GNSS Aviation Services
• EG for Solar & Heliospheric Services

Radiation environment at aviation altitudes is controlled by galactic cosmic radiation and solar phenomena like solar flares or Coronal Mass Ejections (CMEs). In EG RAD radiation conditions are characterized with the AVIDOS tool. The updated model AVIDOS 2.0 provides forecasting of radiation exposure due to galactic cosmic radiation for up to one year ahead. The new version gives also nowcasts on the radiation exposure due to solar energetic particles.

The NRT proxy for the official Kp-index provided by GFZ Potsdam (Germany) will be used to support EGs in RAD, HF, and GNSS. In addition, several partners in the PECASUS consortium are maintaining magnetometer observatories and stations that allow NRT monitoring of the evolution of geomagnetic storms.

Continuous riometer measurements will be conducted in the Northern Fennoscandia and Svalbard in order to spot potential Polar Cap Absorption events in HF-communication. In addition to actual riometer measurements the D-RAP model will be used in PECASUS in order to get NRT estimates of global absorption conditions in the ionosphere. The model has been validated against riometer data and is used in routine manner both in NOAA/SWPC and in UK Met Office. D-RAP uses as input X-ray flux data from the GOES geostationary satellites maintained by NOAA.

Time and space variations of MUF are monitored and forecasted with methodologies developed in SRC and INGV. The approaches use advanced kriging techniques and are based on both NRT ionospheric observations and monthly average conditions in ionospheric electron density.

To detect threshold violations within the scintillation domain EG GNSS provides S4 and Sigma-Phi nowcasts based on DLR’s and INGV’s high rate (50-100 Hz) GNSS receivers that are globally distributed. The update rate of the contributed scintillation products will be in the range from 1 to 15 minutes. For geographical mapping the estimated scintillation indices are projected to ionospheric pierce points by applying a single ionospheric layer approach. To improve the spatial coverage and forecast capabilities EG GNSS will monitor also the maximum Rate of TEC Index (ROTI) which is a proxy for scintillation measurements.

Global and European TEC nowcasts will be provided with the GNSS receiver data processing routines used in DLR’s IMPC. GNSS input data is acquired and processed in real time from several global and regional GNSS receiver networks. The update rate of the PECASUS TEC maps will be 5 min and the latency less than 5 minutes. DLR’s activities will be supported by INGV and STCE for enhanced reliability and availability of EG GNSS. In addition to nowcasts EG GNSS will provide also climatological TEC forecasts. DLR will produce TEC forecasts for global and European region based on the TEC nowcast, its 27-day median and rate. The lead time of DLR’s TEC forecasts is one hour. Furthermore, INGV will provide short term forecast maps of TEC for the Central Mediterranean and European region. The lead time of INGV’s short term TEC forecasts will be 30 minutes.

Notifications by EG SOL will wake up the other parts of SWxC to follow up the evolution of enhanced solar activity. In the cases of several subsequent activations, SOL EG will provide input also to the remarks part of the SWxC advisories. In the current plans the EG SOL contribution consists of eight different products (Forecasts, Summaries, Notifications) characterizing e.g. solar flaring source regions, flare peak intensity and duration, CME arrival times and their geoefficiency (impact in Near-Earth space and ground-based technologies).