VAAC London QVA Gridded Data API

The VAAC London QVA Gridded Data API supplies meteorological gridded data in response to tailored API requests.

Data is provided under the remit of the International Civil Aviation Organisation (ICAO) and can be used to support activities related to aviation. Specifically, it enables aviation end users operate more effectively in airspaces affected by volcanic eruptions emanating from Iceland.

This API includes two collections in netCDF format as response payloads:

  • the probabilistic collection forecasts the likelihood of ash concentration exceeding four set thresholds in mg/m3: ≥0.2, ≥2.0, ≥5.0 and ≥10.0. It includes four separate datasets (one per threshold).
  • the deterministic collection forecasts the expected ash concentration as a deterministic gridded forecast for a specific timestep. It includes one dataset.
Operations

The VAAC London QVA Gridded Data API provides gridded meteorological forecasts in netCDF files in response to tailored API requests.

It also provides end users the ability to request metadata about the meteorological forecast included in the forecasts, returning a response in .JSON format.

Synchronous: Transactions are synchronous.

TI Protocol Method: HTTP GET

Precondition: Consumers must be authenticated and authorised via the Met Office API Management (APIM) Developer portal.

Processing consideration: The service shall provide only the latest available data.

Idempotent
IDEMPOTENT
Operation Message

This endpoint returns metadata in JSON format about the "qva_probabilistic" and "qva_deterministic" collections that are available to be queried. Metadata includes:

  • Collection "id", "title" and "description"
  • Geospatial information
  • Forecast intervals (timesteps)
  • Vertical atmospheric slices
  • a list of "volcano_id" and associated metadata
Resource Type
REST_RESOURCE
  • Get information about the "qva_probabilistic" {collectionId}. Response is a JSON file. It is the ‘source of truth’ to check which data has been generated and is ready to download. This is the endpoint that you can query to find out the applicable "volcano_id" for which forecast data is available. You can then use "volcano_id" to build your API request: https://gateway.api-management.metoffice.cloud/vaac-london-qva-gridded-…
  • Get information about the "qva_deterministic" {collectionId}. Response is a JSON file. It is the ‘source of truth’ to check which data has been generated and is ready to download. This is the endpoint that you can query to find out the applicable "volcano_id" for which forecast data is available. You can then use "volcano_id" to build your API request: https://gateway.api-management.metoffice.cloud/vaac-london-qva-gridded-…

 

Resource Type
REST_RESOURCE

This is also the endpoint that you can query to find out the applicable volcano for which forecast data is available. If forecasts are available for multiple volcanic eruptions, then multiple "volcano_id" may be listed.

Response is a JSON file.

Resource Type
REST_RESOURCE

This is the endpoint you query to retrieve the volcanic ash forecast in a specific collection {collectionId} for a specific volcano_id {locationId}.

For example, requesting data in the ‘qva_probabilistic’ collection for volcano_id 372070 (Hekla in Iceland): https://gateway.api-management.metoffice.cloud/vaac-london-qva-gridded-data/1.0/collections/qva_probabilistic/locations/372070

For example, requesting data in the ‘qva_probabilistic’ collection for volcano_id 372070 (Hekla in Iceland): https://gateway.api-management.metoffice.cloud/vaac-london-qva-gridded-data/1.0/collections/qva_deterministic/locations/372070 

A successful request for data will return a “302 Found” response code with a redirect link in the Location header of the response, which you can use to download the requested dataset. The link is valid for one hour.

The payload response is in netCDF format. When following the Redirected URL, you will get a 200 response and the requested binary netCDF data, which you can save as an .nc file in your systems.

Resource Type
REST_RESOURCE

The Service Interface Binding is SWIM Yellow Profile Compliant, using WS Light enabling HTTP GET requests and associated responses.

  • The Service shall return a .JSON response for metadata requests:
    • OpenAPI:
      • / gets the EDR root data entrypoint
      • /api gets the EDR spec for exposed endpoints
    • /conformance gets the conformance data for the API
    • Collections data:
      • /collections gets the end point that contains information about all the collections available
      • /collections/{collectionId} gets the end point that contains information about an individual collection {collectionId}
    • Location data: /collections/{collectionId}/locations gets the end point that contains information about the volcanoes for which ash forecast data is available in an individual collection {collectionId}
    •  
  • Request for meteorological forecast data shall return a response as a 302 URL redirect to the payload, either in netCDF or IWXXM format:
    • Ash concentration forecast for a specific Volcano (locationId}: /collections/{collectionId}/locations/{locationId} gets the end point for forecast data for a specific volcano (locationId} contained in an individual collection {collectionId}

The Service implementation conforms with IPV4_SECURE_UNICAST as part of SWIM Yellow Profile requirements.

Interface Provision Side
TI Primitive Message Exchange Pattern