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UTLS-Ozone SLIMCAT: Leeds University Three dimensional chemistry transport model (CTM) measurements Version 1

Update Frequency: Not Planned
Latest Data Update: 2002-03-18
Status: Completed
Online Status: ONLINE
Publication State: Published
Publication Date: 2007-03-13
Download Stats: last 12 months
Dataset Size: 12 Files | 61MB


The SLIMCAT Reference Atmosphere for UTLS-Ozone was a set of example output from the SLIMCAT three-dimensional chemical transport model (CTM). It includes three-dimensional global fields of chemical (and sometimes meteorological) variables as computed for twelve dates in 1997, near the middle of each month.

This data set includes 12 files, each of them corresponding to one output time near the middle of each month of Year 1997 (12 Jan, 11 Feb, 13 Mar, 12 Apr, 12 May, 11 Jun, 11 Jul, 10 Aug, 19 Sept, 19 Oct, 18 Nov, 18 Dec). Each file contains the calculated 3-D distribution of 37 chemical species or families and 6 meteorological variables. The model used is the SLIMCAT chemistry transport model (CTM). The model was run from October 1991 and forced by the UK Met Office analyses. The model used 18 isentropic levels. The vertical coordinate in the data files is the globally averaged altitude. The real lat/lon-dependent altitude is given in the ALT field recorded in the files. The THETA field gives the real model theta levels (which are constant with latitude/longitude).

Data from Martyn Chipperfield, University of Leeds. NERC Research Programme UTLS-Ozone (Upper Troposphere and Lower Stratosphere) and National Centre for Earth Observation (NCEO).

A newer version 2 dataset was produced in 2009 that supersedes this dataset.

Citable as:  NERC UTLS SLIMCAT campaign participants; University of Leeds; Chipperfield, M. (2007): UTLS-Ozone SLIMCAT: Leeds University Three dimensional chemistry transport model (CTM) measurements Version 1. NCAS British Atmospheric Data Centre, date of citation.
Abbreviation: Not defined
Keywords: UTLS, SLIMCAT, Model, Atmospheric chemistry


Previous Info:
No news update for this record
Previously used record identifiers:
Access rules:
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

New version of data created November 2009 to include parameter names and units in NetCDF files.
Directory v1.0/ contains original files provided by Martyn Chipperfield in 2002.
Top level slimcat data directory contains updated files.

Data Quality:
File Format:
Data are netCDF formatted.

Process overview

This dataset was generated by the computation detailed below.

SLIMCAT model deployed on Leeds computer


SLIMCAT model deployed on Leeds computer. SLIMCAT was a three-dimensional (3D) off-line chemical transport model (CTM). The model used winds and temperatures from meteorological analyses (e.g. from the UK Met Office or ECMWF) to specify the atmospheric transport and temperatures and calculates the abundances of chemical species in the troposphere and stratosphere. The model had the option of detailed chemical scheme(s) for the stratosphere and troposphere.

The model can be used to simulate the past and current atmosphere, help interpret observations, and to diagnose the extent of problems such as stratospheric ozone depletion or tropospheric pollution. This model was developed at the University of Leeds, UK.

== Introduction ==

Around 1995 Martyn Chipperfield (University of Leeds) wrote SLIMCAT. This was a stratosphere-only version of TOMCAT formulated on isentropic levels. At this time TOMCAT became a 'tropospheric' model and various people in Cambridge helped to add treatments of e.g. convection, boundary layer mixing, and tropospheric chemistry. Recently, SLIMCAT has been extended downwards to include the troposphere. As the two former models were so similar, it made maintenance/development easier to merge TOMCAT and SLIMCAT into a single library with a choice of vertical coordinate (and other things), so that one model covers all of the applications. Depending on the coordinate use, the model is still referred to as TOMCAT or SLIMCAT.

=== Key Details ===

- Variable resolution. Typical resolutions are 5 x 5 degrees for multiannual runs to up to 1 x 1 degree.
- Forced by meteorological analyses, usually ECMWF and sometimes UKMO.
-Options of detailed stratospheric or tropospheric chemistry schemes.
- Written in Fortran (f77, f90). Runs on most platforms (including vector machines). Parallelised using OpenMP and MPI.

Input Description


Output Description


Software Reference


  • var_id: Alt
  • var_id: Br
  • var_id: BrCl
  • var_id: BrO
  • var_id: BrONO2
  • var_id: Bry
  • var_id: CH2O
  • var_id: CH3OOH
  • var_id: CH4
  • var_id: CO
  • var_id: Cl
  • var_id: Cl2O2
  • var_id: ClO
  • var_id: ClONO2
  • var_id: ClOx
  • var_id: Cly
  • var_id: H
  • var_id: H2O
  • var_id: H2O2
  • var_id: HBr
  • var_id: HCl
  • var_id: HNO3
  • var_id: HNO4
  • var_id: HO2
  • var_id: HOBr
  • var_id: HOCl
  • var_id: Heat
  • units: degrees_north
  • var_id: LAT
  • units: degrees_east
  • var_id: LON
  • var_id: N
  • var_id: N2O
  • var_id: N2O5
  • units: kilometres
  • var_id: NIV
  • var_id: NO
  • var_id: NO2
  • var_id: NO3
  • var_id: NOy
  • var_id: O1D
  • var_id: O3
  • var_id: O3P
  • var_id: OClO
  • var_id: OH
  • var_id: PV
  • var_id: Pres
  • var_id: TIM
  • var_id: Temp
  • var_id: Theta

Co-ordinate Variables

Temporal Range
Start time:
End time:
Geographic Extent