Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI)

General Info

Title:	Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI)
Type:	Data Entity
Sub-Type:	Measurement
Abbreviation:	TOMS_OMI
Publication State:	published
The publication state of this metadata: 'old' - for redundant records; 'working' - for new/in progress records; 'published' - for records approaching maturity, which may still change, but should be available via the discovery services; and 'Published' for mature records that are unlikely to change and should be available via the discovery services.

URI:	http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_TOMS

Summary
A brief description of the data.

TOMS are a series of instruments on board the NASA NIMBUS 7, Meteor-3, Earth Probe and ADEOS satellites which measure column ozone. Gridded, global data available daily between November 1979 - December 1994 from NIMBUS and Meteor-3. Also available for this period are daily GIF files of hemispheric plots, video sequence of the GIFS showing the ozone hole development for educational purposes plus NASA CD-ROM of image data. Also available are data from the Earth-Probe and ADEOS satellites, launched in July and August 1996. TOMS data are available from November 1978 to December 2006. Following failure from EP TOMS, OMI Ozone data from the AURA spacecraft are now available from the BADC for the period August 2004 to present. These datasets are public.

Content
The actual data being described by this document. NB, in the case of data granules, this content may just be a reference to an ingested CSML or CDML file.

Introduction

The Total Ozone Mapping Spectrometer (TOMS) is an instrument built and operated by the National Aeronautics and Space Administration (NASA). The instrument uses backscattered ultraviolet radiance to infer total column ozone measurements. The data consists of daily gridded averages of total ozone covering the entire globe. The original Nimbus-7 TOMS operated from November 1978 until May 1993. Meteor-3 TOMS was launched in August 1991 and operated until December 1994.

After a gap of one and a half years, two new TOMS instruments began operation in 1996: Earth-Probe TOMS was launched on 2nd July 1996 and started to produce data on 25th July. ADEOS TOMS was launched on 17th August 1996 and started producing data on 11th September. The satellites were originally placed in different orbits, giving complete global coverage with the ADEOS data, while Earth-Probe had complete coverage at the poles with an increased ability to measure UV-absorbing aerosols in the troposphere. ADEOS failed in June 1997 and Earth-Probe was subsequently placed in a higher orbit to give global coverage.

On Saturday, december 2, 2006, contact with Earth Probe was lost. There has been no communication with the spacecraft since. The spacecraft is intact and Earth-oriented which mean that it is still operational and maintaining attitude. On Wednesday December 6, the spacecraft was commanded to go to SAFE mode, in which it points at the sun, which will maintain power indefinitely. The spacecraft is now sun-pointing, indicating that the receiver and processor are working. Earth Probe has been operating on its backup transmitter since 1998 when the primary failed. The operations team tried to switching to the zenith antenna in hopes that the problem was the nadir antenna, but still no signal was received. This likely means that the transmitter has failed. At this point the probability of recovering looks poor but the Earth Probe team is still trying.

Before contact was lost with Earth Probe, there were calibration problems with EP TOMS and so in the view of the good performance of the Ozone Monitoring Instrument (OMI) on the AURA spacecraft, OMI data of ozone are now available for the entire OMI mission beginning with August 17, 2004 through the most recent data.

In addition to ozone data, OMI data for aerosol and reflectivity are available from August 17, 2004; images are available from here.

Data Access

This dataset is public and can be accessed from the BADC archives

Data availability

The BADC holds the entire TOMS and OMI datasets online in daily ASCII files. The Nimbus-7 data includes monthly and zonal averages. The data can be freely transferred using WWW or anonymous FTP. GIF images are also available. Note that these datasets are not fully validated. Software to read the data is available.

Also available from the BADC is a VHS video compiled from the GIF images of Northern and Southern hemisphere ozone plots for the 1978-1994 TOMS data. The Nimbus-7 and Meteor-3 data, processing version 8, are also available on CD-ROM from NASA.

Documentation, Links to further information and references

BADC documentation on the TOMS instrument and data products.
OMI Ozone README doc from the NASA TOMS Home page.
References. A few good starting points in TOMS literature.
You can find the latest news about the TOMS instruments at NASA's TOMS home page.

Citation

Date of citation

Who to contact

If you'd like to know more about TOMS instruments, data or how to get TOMS data from the BADC, contact the BADC support line or Dr. Richard McPeters (mcpeters@wrabbit.gsfc.nasa.gov), head of the Ozone Processing Team.

Lineage
Summary of the origins of the dataset, e.g.: "Dataset produced from NASA MODIS instrument on Terra and collected at the University of York's groundstation 1999-2003 and a copy provided to NEODC in June 2007".

TOMS data was mirrored from GSFC NASA until saturday December 2, 2006, when contact with Earth Probe was lost. OMI data is continuously being mirrored at the BADC from NASA (since 2004).

Quality Statement
Description of the relative quality of the dataset.

Data quality controlled by NASA. TOMS - Total Calibration Error - The Version 8 algorithm is now used for all TOMS data. For data beginning in year 2000, the calibration has been stabilized relative to NOAA-16 SBUV/2 in the equatorial zone. Because of continuing changes in the optical properties of the front scan mirror that are not well understood, we are now seeing a latitude dependent error that cannot be corrected by a simple calibration correction. The calibration appears to be stable near the equator. But by 50 degrees latitude, there is now a -2% to -4% error in TOMS, a bit larger in the northern hemisphere than in the southern hemisphere. Because of this error, data since 2002 should NOT be used for trend analysis.

Author
The principal author of the actual underlying data. Only one author can be specified per atom; if there are multiple authors, these should be specified as 'contributors'. NB, an atom MUST have an author specified.

Name	email
NASA GSFC

Online References
Online references with a specific relationship to the data being described here. NB, if links are supplied they must be valid and include the transport protocol - e.g. 'http://blah.co.uk'. Also, note, three online references can be added at once; after these are added a further three may be specified - and so on.

Relation	Title
Download	AURA OMI Data Directory
Download	EarthProbe TOMS Data Directory
Logo	TOMS-OMI Ozone Logo
Documentation	BADC Doc: The TOMS instrument and data products
Documentation	TOMS List of References
Documentation	TOMS/OMI Homepage at NASA

Parent Data Entity
Define the parent of this record. There should probably only be one parent, but this is not enforced.

No data specified at present

Sub Data Entities
Lists all entities which have the current entity as their parent.

None

Associated Deployments

Parameters - summary

TOTALOZONECOLUMN	OZONE	OXYGENCOMPOUNDS	ATMOSPHERICCHEMISTRY
ATMOSPHERE	EARTH SCIENCE	NULL

Parameters - details
Parameters to describe the data - with vocab URL and term IDs for further classification. Note, three parameters can be added at once; after these are added a further three may be specified - and so on.

Label	Vocab Term URL	Vocab Term ID
TOTALOZONECOLUMN	http://vocab.ndg.nerc.ac.uk/term/null	NULL
OZONE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
OXYGENCOMPOUNDS	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ATMOSPHERICCHEMISTRY	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
ATMOSPHERE	http://vocab.ndg.nerc.ac.uk/term/P131	NULL
EARTH SCIENCE	http://vocab.ndg.nerc.ac.uk/term/P111	GCAT0001
NULL	general_units	0

Data Coverage
Summary of the temporal and spatial data coverage for the data.

Spatial coverage
Max Y: 90.0
Min X: -180.0	Max X 180.0
Min Y -90.0

Temporal coverage
Start Date:	1978-11-01
End Date:	2005-12-31

Spatial resolution

No spatial resoultion information available.

Vertical extent

No vertical extent information available.

Responsible Parties
Parties responsible for the metadata - e.g. data curator. Responsible parties can have a role specified to make their function clearer. Multiple responsible parties can be specified.

Role	Name	URI
Data Curator	badc.nerc.ac.uk	http://badc.nerc.ac.uk

Other Info
Other miscellaneous information. Note, update frequency relates to the update frequency of the underlying data, not the metadata.

Dataset language

English

Update frequency

OMI data updated daily

Links and Services
	Downloadable XML version of this record

Not all information in this record may be rendered in this view. Please see the XML version for complete content

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