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Stratospheric Nudging And Predictable Surface Impacts (SNAPSI): control data produced by the IFS model at ECMWF

Status: Ongoing
Online Status: ONLINE
Publication State: Working
Publication Date:
Download Stats: last 12 months
Dataset Size: 9.76K Files | 2TB


This dataset contains model data for SNAPSI experiment 'control' produced by scientists at ECMWF (European Centre for Medium-Range Weather Forecasts, United Kingdom). This dataset contains all ensemble members produced by the ECMWF IFS model.

The SNAPSI project is a model intercomparison project to study the role of the stratosphere in subseasonal forecasts following stratospheric sudden warmings and the representation of stratosphere-troposphere coupling in subseasonal forecast models.

The control experiment is a set of retrospective, 45-day, 50-member ensemble forecasts. Following the initial date, the stratospheric zonal mean temperatures and zonal winds are nudged towards the time-evolving climatological state. The forecasts are initialized on the date indicated by the sub-experiment id; for instance, the sub-experiment 's20180125' is initialized on 25 January 2018. The ocean, sea-ice, land-surface and ozone are all initialized and run prognostically.

Sources of additional information
The following web links are provided in the Details/Docs section of this catalogue record:
- Stratospheric Nudging And Predictable Surface Impacts (SNAPSI): A Protocol for Investigating the Role of the Stratospheric Polar Vortex in Subseasonal to Seasonal Forecasts
- New set of controlled numerical experiments: Stratospheric Nudging And Predictable Surface Impacts (SNAPSI)
- ECMWF IFS model reference publication

Citable as:  Hitchcock, P.; Polichtchouk, I.; Stockdale, T. (9999): Stratospheric Nudging And Predictable Surface Impacts (SNAPSI): control data produced by the IFS model at ECMWF. NERC EDS Centre for Environmental Data Analysis, date of citation.
Abbreviation: Not defined
Keywords: control, IFS, ECMWF, stratosphere, arctic, antarctic, stratospheric polar vortex, SNAPSI, SNAP


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Access rules:
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
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:

The data is based on pressure-level output from the IFS model provided by Inna Polichtchouk. It has been lightly processed to conform to the SNAPSI data request. The data has been published by the Centre for Environmental Data Analysis (CEDA).

Data Quality:
Quality control checks performed at CEDA confirmed that the data meets the SNAPSI metadata requirements.
File Format:
Files are Net-CDF formatted

Process overview

This dataset was generated by the computation detailed below.



The underlying data was produced by the ECMWF IFS model for the SNAPSI project.

Input Description


Output Description


Software Reference


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