Support to Aviation Control Service

Introduction

The aim of the Support to Aviation Control Service (SACS for short) is to deliver in near-real-time data derived from satellite measurements regarding SO2 and aerosol emissions possibly related to volcanic eruptions, and where possible to track volcanic plumes. The service provides the data in the form of global as well as regional maps.
In the event of an exceptional SO2 emission, an e-mail alert is sent to interested parties, pointing them to dedicated web pages.

Example results

Alaska	Indonesia
SO2 concentrations as measured by the GOME-2 instrument on 10 August 2008 south of Alaska. The SO2 was released by the Kasatochi volcano (52.17N, 175.51W; summit 314 m), which erupted late in the evening of 7 August and brought the SO2 up into the stratosphere.	SO2 concentrations as measured by the OMI instrument on 7 June 2008 over the Indonesian island Sulawesi. The SO2 was released by the Soputan volcano (1.11N, 124.73E; summit 1784 m), which erupted on 6 June; winds have transported the SO2 to the Southwest.

Data delivery

SO2 slant column data is derived with a DOAS technique from measurements by satellite instruments such as GOME, SCIAMACHY, OMI, and GOME-2. Combining this data with an appropriate air-mass factor (AMF) gives SO2 total vertical column data.
A volcanic ash indicator for volcanic aerosols is based on IR measurements of the SEVIRI instrument aboard MSG (Meteosat 8).

NOTICE:   the service has been reconstructed; the archive is not fully (re)processed yet.

data product instrument	off-line data archive	near-real-time processing and notification
		data archive	operational	notifications
SO2 columns GOME-1	--	[n/a]	[n/a]	[n/a]
SO2 columns SCIAMACHY	Jan 2004 - Sep 2010	May 2009 - present	Sep 2006	Feb 2007
SO2 columns Aerosol index OMI	Aug 2004 - Sep 2010 --	Jul 2009 - present Jul 2009 - present	Oct 2007 Jul 2008	-- [n/a]
SO2 columns GOME-2	Jan 2007 - Sep 2010	May 2009 - present	Feb 2008	--
Volcanic ash SEVIRI	--	--	--	--
Trajectories [n/a]	--	--	--	[n/a]

Notes:

• Near-real-time service
  Provides daily SO2 column data in the form of maps of the world and selected geographic regions, and as data files covering the whole world. In the event of an exceptional SO2 emission, an e-mail alert is sent to interested parties, pointing them to dedicated web pages.

• Off-line data archive service
  Provides daily, 3-day composite and monthly SO2 column data in the form of maps of the world and selected geographic regions, and as data files covering the whole world.

• Data files
  Daily data at satellite orbit coordinates are given in the form of ASCII files, with the orbits of one day in a zip archive.
  Daily, 3-day composite and monthly data are given on a latitude-longitude grid in HDF files; these are not available in the near-real-time service.

• SO2 related to anthropogenic activities
  This is covered by the Global SO2 monitoring from satellite, part of the Air Quality Record Service.

Documentation

• SO2 column densities
  • On-line product information with detailed background information on the retrieval methods, on the data file format, etc.
  • Downloadable documentation, which includes a print of the on-line product information and a report based on that: "Sulphur dioxide monitoring within TEMIS", which also applies to the SO2 data provided within PROMOTE.
  • References to papers related to SO2 retrieval

• Volcanic ash indicator (VAI)
  • Due to delays in setting up the VAI processing chain and the various aspects of SACS, the VAI is not implemented during the time of PROMOTE. Similar data products will be provided by the SAVAA project, to which the extention of SACS will link.

• Trajectories
  • Due to delays in setting up the various aspects of SACS, there will be no trajectory system implemented during the time of PROMOTE. Similar data products will be provided by the SAVAA project, to which the extention of SACS will link.

Background information

• General introduction to the Support to Aviation Control Service

• General background information on SO2 in the Earth's atmosphere

• Predefined regions of the Service and the volcanoes located therein

• On-line product information

Core users

The Volcanic Ash Advisory Centres (VAACs) are the official organisations to gather information on volcanic ash clouds and on the basis of that issue advices and alerts to air line and air traffic control organisations on the possible danger of volcanic clouds. The VAACs are part of an international system set up by the International Civil Aviation Organization (ICAO) called the International Airways Volcano Watch (IAVW).

Participating institutes and main people there

• BIRA-IASB -- Jos van Geffen, Michel Van Roozendael -- contact form
• CGS -- Walter Di Nicolantonio, Lucia Tampellini
• DLR -- Pieter Valks, Thilo Erbertsede
• KNMI -- Ronald van der A

Jos van Geffen, last modified: July 2009