Dataset
Lagrangian Dry Point data regarding the sensitivity of stratospheric water vapour to variability in tropical tropopause temperatures and large-scale transport
Abstract
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.
Details
| Previous Info: |
No news update for this record
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| Previously used record identifiers: |
No related previous identifiers.
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| 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: 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: |
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). |
| Data Quality: |
Data are as given by the data provider, no quality control has been performed by the Centre for Environmental Data Analysis (CEDA)
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| File Format: |
Data are provided in NetCDF formats.
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Process overview
| Title | Combination of UM-UKCA deployed on unknown computer, OFFLINE deployed on linux machines at DAMTP, University of Cambridge, and python processing scripts deployed on data provider's computer. |
| Abstract | Combination of Met Office Unified Model with active chemistry components (UM-UKCA) deployed on unknown computer, OFFLINE deployed on linux machines at DAMTP, University of Cambridge, and python processing scripts deployed on data provider's computer. The python scripts for processing and visualisation are not provided. |
| Input Description | None |
| Output Description | None |
| Software Reference | None |
- units: 1
- long_name: Lagrangian Dry Point for each trajectory
- var_id: point
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP
- var_id: air_potential_temperature_at_LDP
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_14DM
- var_id: air_potential_temperature_at_LDP_14DM
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_1DM
- var_id: air_potential_temperature_at_LDP_1DM
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_30DM
- var_id: air_potential_temperature_at_LDP_30DM
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_30DZM
- var_id: air_potential_temperature_at_LDP_30DZM
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_7DM
- var_id: air_potential_temperature_at_LDP_7DM
- units: K
- standard_name: air_potential_temperature
- long_name: air_potential_temperature_at_LDP_ZM
- var_id: air_potential_temperature_at_LDP_ZM
- units: hPa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP
- var_id: pressure_ldp_ZM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_14DM
- var_id: air_pressure_at_LDP_14DM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_1DM
- var_id: air_pressure_at_LDP_1DM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_30DM
- var_id: air_pressure_at_LDP_30DM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_30DZM
- var_id: air_pressure_at_LDP_30DZM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_6h
- var_id: air_pressure_at_LDP_6h
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_7DM
- var_id: air_pressure_at_LDP_7DM
- units: Pa
- standard_name: air_pressure
- long_name: air_pressure_at_LDP_ZM
- var_id: air_pressure_at_LDP_ZM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_14DM_at_LDP_14DM
- var_id: air_temperature_14DM_at_LDP_14DM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_14DM_at_LDP_6h
- var_id: air_temperature_14DM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_1DM_at_LDP_1DM
- var_id: air_temperature_1DM_at_LDP_1DM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_1DM_at_LDP_6h
- var_id: air_temperature_1DM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_30DM_at_LDP_30DM
- var_id: air_temperature_30DM_at_LDP_30DM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_30DM_at_LDP_6h
- var_id: air_temperature_30DM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_30DZM_at_LDP_30DZM
- var_id: air_temperature_30DZM_at_LDP_30DZM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_30DZM_at_LDP_6h
- var_id: air_temperature_30DZM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_6h_at_LDP_6h
- var_id: air_temperature_6h_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_7DM_at_LDP_6h
- var_id: air_temperature_7DM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_7DM_at_LDP_7DM
- var_id: air_temperature_7DM_at_LDP_7DM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_ZM_at_LDP_6h
- var_id: air_temperature_ZM_at_LDP_6h
- units: K
- standard_name: air_temperature
- long_name: air_temperature_ZM_at_LDP_ZM
- var_id: air_temperature_ZM_at_LDP_ZM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_at_LDP
- var_id: temperature_ZM_ldp_ZM
- units: K
- standard_name: air_temperature
- long_name: air_temperature_initialised_with_wind_at_LDP
- var_id: air_temperature_initialised_with_wind_at_LDP
- units: K
- standard_name: air_temperature
- long_name: air_temperature_time_shifted_from_wind_at_LDP
- var_id: air_temperature_time_shifted_from_wind_at_LDP
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP
- var_id: geopotential_height_at_LDP
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_14DM
- var_id: geopotential_height_at_LDP_14DM
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_1DM
- var_id: geopotential_height_at_LDP_1DM
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_30DM
- var_id: geopotential_height_at_LDP_30DM
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_30DZM
- var_id: geopotential_height_at_LDP_30DZM
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_7DM
- var_id: geopotential_height_at_LDP_7DM
- units: m
- standard_name: geopotential_height
- long_name: geopotential_height_at_LDP_ZM
- var_id: geopotential_height_at_LDP_ZM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP
- var_id: hybrid_height_at_LDP
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_14DM
- var_id: hybrid_height_at_LDP_14DM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_1DM
- var_id: hybrid_height_at_LDP_1DM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_30DM
- var_id: hybrid_height_at_LDP_30DM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_30DZM
- var_id: hybrid_height_at_LDP_30DZM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_7DM
- var_id: hybrid_height_at_LDP_7DM
- units: m
- standard_name: atmosphere_hybrid_height_coordinate
- long_name: hybrid_height_at_LDP_ZM
- var_id: hybrid_height_at_LDP_ZM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_14DM_at_LDP_14DM
- var_id: saturation_mixing_ratio_ppmv_14DM_at_LDP_14DM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_14DM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_14DM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_1DM_at_LDP_1DM
- var_id: saturation_mixing_ratio_ppmv_1DM_at_LDP_1DM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_1DM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_1DM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_30DM_at_LDP_30DM
- var_id: saturation_mixing_ratio_ppmv_30DM_at_LDP_30DM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_30DM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_30DM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_30DZM_at_LDP_30DZM
- var_id: saturation_mixing_ratio_ppmv_30DZM_at_LDP_30DZM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_30DZM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_30DZM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_6h_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_6h_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_7DM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_7DM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_7DM_at_LDP_7DM
- var_id: saturation_mixing_ratio_ppmv_7DM_at_LDP_7DM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_ZM_at_LDP_6h
- var_id: saturation_mixing_ratio_ppmv_ZM_at_LDP_6h
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_ZM_at_LDP_ZM
- var_id: saturation_mixing_ratio_ppmv_ZM_at_LDP_ZM
- units: 1
- standard_name: humidity_mixing_ratio
- long_name: saturation_mixing_ratio_ppmv_at_LDP
- var_id: smr_ZM_ldp_ZM
Co-ordinate Variables
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP
- var_id: latitude_ldp_ZM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_14DM
- var_id: latitude_at_LDP_14DM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_1DM
- var_id: latitude_at_LDP_1DM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_30DM
- var_id: latitude_at_LDP_30DM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_30DZM
- var_id: latitude_at_LDP_30DZM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_7DM
- var_id: latitude_at_LDP_7DM
- units: degrees_north
- standard_name: latitude
- long_name: latitude_at_LDP_ZM
- var_id: latitude_at_LDP_ZM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP
- var_id: longitude_ldp_ZM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_14DM
- var_id: longitude_at_LDP_14DM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_1DM
- var_id: longitude_at_LDP_1DM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_30DM
- var_id: longitude_at_LDP_30DM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_30DZM
- var_id: longitude_at_LDP_30DZM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_7DM
- var_id: longitude_at_LDP_7DM
- units: degrees_east
- standard_name: longitude
- long_name: longitude_at_LDP_ZM
- var_id: longitude_at_LDP_ZM
- standard_name: time
- var_id: time
- standard_name: time
- long_name: time_at_LDP
- var_id: t_ldp_ZM
- standard_name: time
- long_name: time_at_LDP_14DM
- var_id: time_at_LDP_14DM
- standard_name: time
- long_name: time_at_LDP_1DM
- var_id: time_at_LDP_1DM
- standard_name: time
- long_name: time_at_LDP_30DM
- var_id: time_at_LDP_30DM
- standard_name: time
- long_name: time_at_LDP_30DZM
- var_id: time_at_LDP_30DZM
- standard_name: time
- long_name: time_at_LDP_6h
- var_id: time_at_LDP_6h
- standard_name: time
- long_name: time_at_LDP_7DM
- var_id: time_at_LDP_7DM
- standard_name: time
- long_name: time_at_LDP_ZM
- var_id: time_at_LDP_ZM
- standard_name: time
- long_name: time_of_windseries_at_LDP
- var_id: time_of_windseries_at_LDP
- standard_name: time
- long_name: time_reaching_troposphere
- var_id: time_reaching_troposphere
Temporal Range
1999-01-01T00:00:00
2009-12-31T23:59:59
Geographic Extent
30.0000° |
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-180.0000° |
180.0000° |
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-30.0000° |