NERC Data Catalogue Service
Lagrangian Dry Point data regarding the sensitivity of stratospheric water vapour to variability in tropical tropopause temperatures and large-scale transport
This dataset contains results in support of a publication that investigates processes affecting water vapour entry to the stratosphere. The back trajectories were calculated using the OFFLINE trajectory model. Past publications have shown the key processes are temperatures in the tropical tropopause layer and large-scale transport into the stratosphere using trajectory methods. Lagrangian Dry Points (LDPs) are normally calculated as the minimum water vapour saturation mixing ratio experienced along a back-trajectory that has traversed from troposphere to tropical lower stratosphere in its recorded history.
This study separated the two key processes by sampling alternative temperatures. These alternative temperatures are either time-shifted or averaged in time or longitude. This method is applied for two meteorological datasets: ERA-Interim (ERA-I) reanalysis for the period 1999-2009, and the UM-UKCA chemistry-climate model for eleven years of a repeat-year-2000 forcing scenario. The ERA-I trajectories were calculated by S Fueglistaler and S Liu for separate publications. The UM-UKCA climate model scenario was conducted by A Maycock. This dataset contains only the LDPs resulting from alternative-temperature sampling.
The directory UM-UKCA/LDP-original-T/ provides a simple view of the original unmodified method to calculate LDPs.
LDP-alt-T/ directories contain LDPs determined with time-shifted alternative temperature samplings. The time-shift is identified by the alternative initialisation date, denoted in the filename and file metadata.
LDP-ave-T/ directories contain LDPs determine with averaged alternative temperature samplings. The averaging is identified by the variable name and metadata. In the variable names, shorthand and full-name identifiers include 6h (6 hourly instantaneous), ZM (zonal mean), 30DZM (30-day rolling window mean and zonal mean), 120DM, 90DM, 60DM, 30DM, 15DM, 14DM, 8DM, 7DM, 4DM, 2DM, 1DM (rolling window 120 day mean, 90 day mean, etc.).
Note that various alternative temperatures are recorded at each LDP calculated from each alternative temperature.
For more information on the directory structure, file naming conventions, variable naming conventions and attribute conventions please see the README.txt.
Default
Identification info
- Metadata Language
- English (en)
- Dataset Reference Date ()
- 2020-11-30T14:07:13
- Dataset Reference Date ()
- 2020-11-30T14:07:13
- Identifier
- Centre for Environmental Data Analysis (CEDA) / c6b2f1ca5f8e4c5285fb4f69d1514a03
- Identifier
- doi / 10.5285/c6b2f1ca5f8e4c5285fb4f69d1514a03
- Maintenance and update frequency
- unknown
- Update scope
- dataset
- Keywords
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- OFFLINE
- stratospheric
- ERA
- UM-UKCA
- trajectories
- GEMET - INSPIRE themes, version 1.0 ()
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- atmospheric conditions
- Limitations on Public Access
- otherRestrictions
- Other constraints
- Public data: access to these data is available to both registered and non-registered users.
- Use constraints
- otherRestrictions
- Spatial representation type
- grid
- Topic category
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- Climatology, meteorology, atmosphere
))
- Begin date
- 1999-01-01T00:00:00
- End date
- 2009-12-31T23:59:59
- Code
- WGS 84
Distribution Information
- Data format
-
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Data are provided in NetCDF formats.
()
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Data are provided in NetCDF formats.
()
- Resource Locator
-
CEDA Data Catalogue Page
Detail and access information for the resource
- Resource Locator
-
DOWNLOAD
Download Data
- Resource Locator
-
Smith, J. W., Haynes, P. H., Maycock, A. C., Butchart, N., and Bushell, A. C.: Sensitivity of stratospheric water vapour to variability in tropical tropopause temperatures and large-scale transport, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-934, in review, 2020.
No further details.
- Resource Locator
-
CEDA Data Catalogue Page
Detail and access information for the resource
- Resource Locator
-
DOWNLOAD
Download Data
- Resource Locator
-
Smith, J. W., Haynes, P. H., Maycock, A. C., Butchart, N., and Bushell, A. C.: Sensitivity of stratospheric water vapour to variability in tropical tropopause temperatures and large-scale transport, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-934, in review, 2020.
No further details.
- Quality Scope
- dataset
Report
- Dataset Reference Date ()
- 2010-12-08
- Statement
- Diabatic trajectories subjected to ERA-I meteorology were obtained from S Liu and S Fueglistaler. Kinematic trajectories subjected to UM-UKCA meteorology were calculated using the OFFLINE trajectory model (Methven et al. 1997, Liu et al. 2009) in a from modified by S Liu and by the data provider. Trajectories are initialised every 2 degrees longitude and latitude between 30 N - 30 S on a surface above the tropical tropopause layer (83 hPa surface for ERA-I and 400K potential temperature surface for UM-UKCA). Alternative temperature sampling was also calculated using OFFLINE. Lagrangian Dry Points were calculated using python processing scripts by the data provider. Data has been converted to CF-netCDF using python processing scripts by the data provider, and then passed on to the Centre for Environmental Data Analysis (CEDA).
Metadata
- File identifier
- c6b2f1ca5f8e4c5285fb4f69d1514a03 XML
- Metadata Language
- English (en)
- Character set
- 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646
- Resource type
- dataset
- Metadata Date
- 2022-07-18T23:26:54
- Metadata standard name
- UK GEMINI
- Metadata standard version
- 2.3
