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Dataset

 

IASI retrieval of sulphur dioxide (SO2) column amounts and altitude, 2014-09 to 2015-02, version 1.0

Update Frequency: Not Planned
Status: Completed
Online Status: ONLINE
Publication State: Published
Publication Date: 2019-03-04
Download Stats: last 12 months

Abstract

This dataset contains global retrieval of sulphur dioxide (SO2) column amounts and altitudes derived from the Infrared Atmospheric Sounding Interferometer (IASI) instrument on the METOP-A satellite. The data have been produced by the University of Oxford as part of the NERC Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET).

This dataset has been produced using the Carboni et al. (2012,2016) retrieval algorithm for the Infrared Atmospheric Sounding Interferometer which retrieve column amount and altitude (together with a comprehensive error budget for every pixel) using simultaneously all the IASI channels between 1000–1200 and 1300–1410 cm−1. It has a global coverage and includes the six-month-long Holuhraun eruption, from September 2014 to February 2015, together with other events during the same periods such as: volcanic activity on the Kamchatka peninsula, Etna and Capo verde eruptions, anthropogenic SO2 emissions from China.

The data presents the results of the retrieval for every IASI 'plume' pixels (e.g. that result positive to the IASI SO2 detection) including: column amount (in Dobson Unit - DU), altitude (in millibar and successively converted in km using meteorological profile), surface temperature. It also includes quality control parameters and quality flags: for generic use we recommend using data with flag = 1. Quality control parameters available are: degree of freedom, cost function, convergence. These quality control paramenters are also summarized in two 'stricted' and 'relaxed' quality control flags.

This dataset also includes location of all IASI pixels in the same orbit (non plume pixel) to allow regridding and comparison with other instruments and models.

Citable as:  Carboni, E.; Taylor, I.; Grainger, D. (2019): IASI retrieval of sulphur dioxide (SO2) column amounts and altitude, 2014-09 to 2015-02, version 1.0. Centre for Environmental Data Analysis, date of citation. https://catalogue.ceda.ac.uk/uuid/d40bf62899014582a72d24154a94d8e2
Abbreviation: Not defined
Keywords: IASI, SO2, volcanic emissions, satellite observation,

Details

Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
Use of these data is covered by the following licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

These data were produced by the Earth Observation Data Group, Atmospheric, Oceanic and Planetary Physics, University of Oxford, as part of the NERC Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). These data were then supplied to the Centre for Environmental Data Analysis (CEDA) to be archived.

Data Quality:
Data as provided by the Earth Observation Data Group, Atmospheric, Oceanic and Planetary Physics, University of Oxford.
File Format:
Data are NetCDF formatted.

Process overview

This dataset was generated by a combination of instruments deployed on platforms and computations as detailed below.

Instrument/Platform pairings

IASI Deployed on: Metop-A

Independent Instruments

IASI

Mobile platform operations

Mobile Platform Operation 1 Mobile Platform Operation for: Metop-A

Computation Element: 1

Title Global sulphur dioxide (SO2) column amounts from the Infrared Atmospheric Sounding Interferometer (IASI)
Abstract The Walker et al. (2011, 2012) linear retrieval developed for the Infrared Atmospheric Sounding Interferometer (IASI) on the Metop satellites has been used to process the IASI Metop-A data to produce an effect SO2 column amount. The linear retrieval output for each orbit has then been averaged for each month to obtain an average effective SO2 column amount in Dobson Units (DU). In this application, the retrieval uses the ν3 absorption band (centred at 7.3 μm) and SO2 was assumed to be evenly distributed between the surface and 20 km. Literature: Taylor et al. (2018) Exploring the utility of IASI for monitoring volcanic SO2 emissions, in review at JGR: Atmospheres. Walker et al. (2011) An effective method for the detection of trace species demonstrated using the MetOp Infrared Atmospheric Sounding Interferometer, Atmospheric Measurement Techniques, 4: 1567-1580, doi:10.5194/amt-4-1567-2011. Walker et al. (2012) Improved detection of sulphur dioxide in volcanic plumes using satellite-based hyperspectral infrared
Input Description None
Output Description None
Software Reference None
Output Description None
  • var_id: latitude
  • units: degrees north
  • long_name: Latitude of pixels negative to plume detection
  • names: Latitude of pixels negative to plume detection
  • var_id: longitude
  • units: degrees east
  • long_name: Longitude of pixels negative to plume detection
  • names: Longitude of pixels negative to plume detection
  • units: none
  • var_id: conv
  • long_name: convergence flag
  • names: convergence flag
  • var_id: day
  • units: none
  • long_name: degree of freedom
  • var_id: df
  • names: degree of freedom
  • units: DU
  • long_name: error of retrieved SO2 column amount
  • var_id: so2_col_err
  • names: error of retrieved SO2 column amount
  • units: millibar
  • long_name: error of retrieved SO2 plume altitude
  • var_id: dh_mb
  • names: error of retrieved SO2 plume altitude
  • units: K
  • long_name: error of retrieved surface temperature
  • var_id: dts
  • names: error of retrieved surface temperature
  • units: km
  • long_name: extrapolated SO2 plume altitude
  • var_id: so2_height
  • names: extrapolated SO2 plume altitude
  • units: km
  • long_name: extrapolated error of SO2 plume altitude
  • var_id: so2_height_err
  • names: extrapolated error of SO2 plume altitude
  • var_id: hour
  • var_id: lat_all
  • units: degrees
  • long_name: lat_min, lon_min, lat_max, lon_max
  • var_id: limit
  • names: lat_min, lon_min, lat_max, lon_max
  • var_id: lat_noplume
  • var_id: lon_all
  • var_id: lon_noplume
  • var_id: minute
  • var_id: month
  • units: none
  • long_name: normalized cost function
  • var_id: chi
  • names: normalized cost function
  • long_name: quality control flag (relaxed)
  • var_id: qc10
  • names: quality control flag (relaxed)
  • long_name: quality control flag (stricted)
  • var_id: qc2
  • names: quality control flag (stricted)
  • var_id: flag
  • long_name: quality control flag, bad=0 , good=1
  • names: quality control flag, bad=0 , good=1
  • units: DU
  • long_name: retrieved SO2 column amount
  • var_id: so2_col
  • names: retrieved SO2 column amount
  • units: millibar
  • long_name: retrieved SO2 plume altitude
  • var_id: h_mb
  • names: retrieved SO2 plume altitude
  • units: K
  • var_id: ts
  • long_name: retrieved surface temperature
  • names: retrieved surface temperature
  • var_id: second
  • var_id: time
  • long_name: time of IASI measurements
  • names: time of IASI measurements
  • units: deg.
  • var_id: vza
  • long_name: viewing zenith angle
  • names: viewing zenith angle
  • var_id: year

Co-ordinate Variables

Coverage
Temporal Range
Start time:
2014-08-31T23:00:00
End time:
2015-02-28T00:00:00
Geographic Extent

 
90.0000°
 
-180.0000°
 
180.0000°
 
-90.0000°