Met Office - Stratospheric Assimilated Data

General Info

Title:	Met Office - Stratospheric Assimilated Data
Type:	Data Entity
Sub-Type:	Analysis
Abbreviation:	Met Office - Assim
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_ASSIM

Summary
A brief description of the data.

Data concerning stratospheric temperature, geopotential height and wind components produced by the Stratospheric Data Assimilation System at the UK Met Office. The data assimilation system is a development of the scheme used at the Met Office for operational weather forecasting, which has been extended to cover the stratosphere. The primary product is a daily analysis (at 1200 UTC) which is produced using operational observations only. For short periods of particular interest the analyses are available at 6-hourly intervals. Assimilation experiments using UARS data in addition to operational meteorological observations have been carried out for limited periods.

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

These data consist of 3-dimensional gridpoint analyses of temperature, geopotential height and wind components fields at 2.5 x 3.75 degree resolution from the ground to 0.3 hPa (for the period from 17th October 1991 (UARS day 36) to 2006-03-13) and on a smaller grid size 0.5625 degree x 0.375 degree on 27 (or 26 depending on variable) pressure levels, (note, this does not apply for the UARS versions of the data files), for the period 2006-03-03 to present day.

An xml description of the file structure is available at http://badc.nerc.ac.uk/cgi-bin/data_browser/data_browser/badc/ukmo-assim/doc/ukmo-nwp-strat_gbl-std_2006032612_u-v-w-t-gph.html , along with a corresponding description of the old structure for comparison http://badc.nerc.ac.uk/cgi-bin/data_browser/data_browser/badc/ukmo-assim/doc/ppassm_operk_y06_m03_d13_h12.html

These files describe fully the variables, horizontal grids and vertical levels provided by the model data.

Restricted Data Access

The Met Office wish to monitor the use of this data and require an acknowledgement of the data source if they are used in any publication. The application for access to the Met Office Assimilated data includes the Met Office Agreement to be completed online. Please note that the Met Office data sets are available for bona fide academic research only (sorry no undergraduates), on a per person per project basis (i.e. all members on a same project who will be using the data must individually apply for access to the data). If you wish to access the Met Office data for commercial or personal purposes, please contact the Met Office directly.

Your application for accessing the Met Office Assimilated data will be processed within a day of receipt and you will receive a confirmation email. Provided your application is complete and fully meets the Met Office conditions, a web account will be activated to allow you access to the Met Office Assimilated data directories via your login account from the BADC WWW Browse Archive pages.

Please read the 00README file available under /badc/ukmo-assim/ directory to guide you through the tree structure and the data directory.

Data availability and file format

The data are provided in Unix (SUN/HP) IEEE binary files in Met Office "PP" format. These files replace the compressed ascii data derived from data held at the UARS Central Data Handling Facility (CDHF) at NASA Goddard.

A guide is available to help you retrieve the data. Software is also provided to read the data.

These data are also available via the BADC Data Extractor service : http://cdat.badc.nerc.ac.uk/cgi-bin/dxui.py

Notes on How to use the Data Extractor.

Please note:

These data are in the same byte order as they were on the Met Office systems, and as such they may require byte swapping before they can be read into existing software utilities such as XCONV on your systems. XCONV/convsh are able to read these data via a gui/command line respectively, and convert them to other formats, including NetCDF. Please see http://badc.nerc.ac.uk/help/software/xconv/index.html. for more information.

Software to unpack the data from wgdos packed format is also available from the BADC XCONV page.

NetCDF Version of the Assimilated data

Netcdf versions of the pp files created using xconv are available in the archive at : /badc/ukmo-assim/data/standard/[year]/netcdf/.

Documentation and Links to further information and references

The BADC provides comprehensive for this data set. The complete set of documents provided by the team at the Met Office are available as well as a help file compiled by the BADC.

This data set is documented in detail in a paper by Swinbank and O'Neill. (Mon. Weather Rev. 122, pp. 686-702, 1994).
We also provide a list of other references which give background information on the dataset and results of studies using the analyses.

These data are also available from the DAAC at NASA Goddard in IEEE binary format by FTP (from October 1991 to the present) or in a compressed ascii format on CD-ROM (from October 1991 to November 1994).

Citation

Date of citation

Who to contact

If you have queries about these pages or about obtaining the Met Office Assimilated data from the BADC then you should contact BADC Support. Your query should be answered within one working day. When follow-up work is required, the BADC support will carry out the work as quickly and efficiently as possible, and in any case, the user will be kept informed of progress.

The Principal Scientific Contact for the analyses is Richard Swinbank or other members of the Middle Atmosphere Group in the Numerical Weather Prediction Division at the Met Office.

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".

On 15 November 2000 the Implementation of 3DVAR for the Met Office Stratospheric Analyses took place.

On 28th October 2003, the assimilation system is to be changed to use the New Dynamics (ND) version of the Unified Model.

As described in the news item of 5/9/05: The Met Office Stratospheric Analyses are changing , after favourable comparisons between the the Met Office stratospheric model which produced the output for this dataset and the extended operational NWP output, the former was suddenly turned off on 13/3/06. This dataset is continuing to be populated by the BADC by data from the operational model, and differs from what has gone before by:

Smaller grid size; it is now 640x480 (or 640x481 depending on variable); 0.5625 deg x 0.375 deg .
Data are on 27 (or 26 depending on variable) pressure levels, not UARS. (upper levels are now 15, 10, 7, 5, 3, 2, 1, 0.5, 0.4 mb)
Due to the increased resolution, the files are now 10x larger than before (now ~40MB)
Filenames have changed, to differentiate them from the earlier model data. They are now of the form: /badc/ukmo-assim/data/standard/2006/ukmo-nwp-strat_gbl-std_2006032612_u-v-gph-t-w.pp
These were previously called ukmo-nwp-strat_gbl-std_2006032612_u-v-w-t-gph.pp, but the name has been changed to reflect the order of the variables within the files, and the fact that the vertical levels within the new files is now in monotonic decreasing order.
The Met. Office Stratospheric Assimilated data will continue to be stored as binary files in pp format.
The missing 20hPa level for w will be added to the model outputs by the Met Office sometime in June 2006.
Some of the fields are now WGDOS packed. If reading the files using your own software, the files will need to be unpacked before use.

Quality Statement
Description of the relative quality of the dataset.

See dataset associated documentation.

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
www.metoffice.gov.uk (Met Office)	enquiries@metoffice.gov.uk

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
Tools	BADC Data Extractor Service
Download	Stratospheric Assimilated Data Directory
Documentation	BADC Doc: Acquiring the Met Office Stratospheric Assimilated data
Documentation	BADC Doc: Stratospheric Assimilated data Indexed Documentation
Documentation	BADC Doc: Met Office Assimilated List of References
Documentation	BADC Doc: Help File: Met Office Assimilated Data
Apply for access	Apply for Access to Stratospheric Assimilated data
Logo	Met Office Logo

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

UZONALWINDSPEED	UPPERLEVELWINDS	ATMOSPHERICWINDS	ATMOSPHERE
EARTH SCIENCE	NULL	GEOPOTENTIALHEIGHT	ALTITUDE
TEMPERATURE	AIRTEMPERATURE	ATMOSPHERICTEMPERATURE	HEIGHT
VMERIDIONALWINDSPEED	VERTICALVELOCITY	VERTICALWINDMOTION

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
UZONALWINDSPEED	http://vocab.ndg.nerc.ac.uk/term/null	NULL
UPPERLEVELWINDS	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ATMOSPHERICWINDS	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
GEOPOTENTIALHEIGHT	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ALTITUDE	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
TEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
AIRTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ATMOSPHERICTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
HEIGHT	http://vocab.ndg.nerc.ac.uk/term/null	NULL
VMERIDIONALWINDSPEED	http://vocab.ndg.nerc.ac.uk/term/null	NULL
VERTICALVELOCITY	http://vocab.ndg.nerc.ac.uk/term/null	NULL
VERTICALWINDMOTION	http://vocab.ndg.nerc.ac.uk/term/null	NULL

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:	1991-10-17
End Date:

Spatial resolution

640x480 (or 640x481 depending on variable); 0.5625 deg x 0.375 deg

Vertical extent

31 pressure levels (not UARS).

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

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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