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

Global	Papua New Guinea
SO2 vertical column at orbit coordinates over the Dem.Rep. Congo on 1 Dec. 2006, based on SCIAMACHY measurements. The SO2 is related to an eruption of the Nyamuragira volcano which started late in the evening of 27 Nov. and lasted several days.	SO2 vertical column at orbit coordinates over the Western Indian Ocean on 8 April 2007, based on SCIAMACHY measurements. The SO2 is related to an eruption of the Piton de la Fournaise volcano which started on 30 March and lasted several days.

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 aerosol is based on IR measurements of the SEVIRI instrument aboard MSG (Meteosat 8).

data product instrument	off-line data archive	near-real-time processing and notification
		data archive	operational since	notification since
SO2 columns GOME	--	--	--	--
SO2 columns SCIAMACHY	Sep. 2004 - June 2008	Aug. 2007 - present	Sep. 2006	-- Feb. 2007
SO2 columns OMI	--	Oct. 2007 - present	Oct. 2007	--
SO2 columns GOME-2	--	Feb. 2008 - present	Feb. 2008	--
Volcanic ash indicator SEVIRI	--	--	--	--
Trajectories --	--	--	--	--

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
  • [to come]

• Trajectories
  • [to come]

Background information

• General introduction to the Support to Aviation Control Service

• General background information on the Volcanic & Air Quality SO2 Services

• Regions of the Volcanic SO2 Service

• 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 people and institutes:

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

Jos van Geffen, last modified: July 2008