Dataset
Chapter 3 of the Working Group I Contribution to the IPCC Sixth Assessment Report  data for Figure 3.34 (v20220104)
Abstract
Data for Figure 3.34 from Chapter 3 of the Working Group I (WGI) Contribution to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6).
Figure 3.34 shows attribution of observed seasonal trends in the annular modes to forcings.

How to cite this dataset

When citing this dataset, please include both the data citation below (under 'Citable as') and the following citation for the report component from which the figure originates:
Eyring, V., N.P. Gillett, K.M. Achuta Rao, R. Barimalala, M. Barreiro Parrillo, N. Bellouin, C. Cassou, P.J. Durack, Y. Kosaka, S. McGregor, S. Min, O. Morgenstern, and Y. Sun, 2021: Human Influence on the Climate System. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [MassonDelmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 423–552, doi:10.1017/9781009157896.005.

Figure subpanels

The figure has 3 panels, and all the data are provided in a single file named NAM_SAM_detection_attribution.nc.

List of data provided

This dataset contains
 Observed and simulated DJF NAM trends for 19582019
 Observed and simulated JJA NAM trends for 19582019
 Observed and simulated DJF SAM trends for 19792019
 Observed and simulated JJA SAM trends for 19792019
 Observed and simulated DJF SAM trends for 20002019
 Observed and simulated JJA SAM trends for 20002019
Simulations are from CMIP6 historical, histGHG, histaer, histnat, and histstratO3 simulations, and from equivalent time segments from CMIP6 piControl simulations (one segment from one model).
NAM: Northern Annular Mode
SAM: Southern Annular Mode
GHG: greenhouse gas
JJA: June, July, August
DJF: December, January, February

Data provided in relation to figure

Panel a:
 NAM_obs_DJF_1958_2019: grey horizontal lines in the left
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 NAM_piControl_DJF_62yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the left
 NAM_hist_DJF_1958_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the left, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the left
 NAM_GHG_DJF_1958_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the left
 NAM_aer_DJF_1958_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the left
 NAM_stratO3_DJF_1958_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the left
 NAM_nat_DJF_1958_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the left
 NAM_obs_JJA_1958_2019: grey horizontal lines in the right
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 NAM_piControl_JJA_62yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the right
 NAM_hist_JJA_1958_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the right, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the right
 NAM_GHG_JJA_1958_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the right
 NAM_aer_JJA_1958_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the right
 NAM_stratO3_JJA_1958_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the right
 NAM_nat_JJA_1958_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the right
Panel b:
 SAM_obs_DJF_1979_2019: grey horizontal lines in the left
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 SAM_piControl_DJF_41yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the left
 SAM_hist_DJF_1979_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the left, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the left
 SAM_GHG_DJF_1979_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the left
 SAM_aer_DJF_1979_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the left
 SAM_stratO3_DJF_1979_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the left
 SAM_nat_DJF_1979_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the left
 SAM_obs_JJA_1979_2019: grey horizontal lines in the right
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 SAM_piControl_JJA_41yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the right
 SAM_hist_JJA_1979_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the right, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the right
 SAM_GHG_JJA_1979_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the right
 SAM_aer_JJA_1979_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the right
 SAM_stratO3_JJA_1979_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the right
 SAM_nat_JJA_1979_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the right
Panel c:
 SAM_obs_DJF_2000_2019: grey horizontal lines in the left
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 SAM_piControl_DJF_20yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the left
 SAM_hist_DJF_2000_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the left, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the left
 SAM_GHG_DJF_2000_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the left
 SAM_aer_DJF_2000_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the left
 SAM_stratO3_DJF_2000_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the left
 SAM_nat_DJF_2000_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the left
 SAM_obs_JJA_2000_2019: grey horizontal lines in the right
>ERA5: obs_dataset = 0\n
>JRA55: obs_dataset = 1\n
 SAM_piControl_JJA_20yrs: multimodel ensemble mean and percentiles for blue open boxwhisker in the right
 SAM_hist_JJA_2000_2019: multimodel ensemble mean and percentiles for red open boxwhisker in the right, and multimodel ensemble mean and confidence interval for red filled box, with ensemble means of individual models for black dots, in the right
 SAM_GHG_JJA_2000_2019: multimodel ensemble mean and confidence interval for brown filled box, with ensemble means of individual models for black dots, in the right
 SAM_aer_JJA_2000_2019: multimodel ensemble mean and confidence interval for light blue filled box, with ensemble means of individual models for black dots, in the right
 SAM_stratO3_JJA_2000_2019: multimodel ensemble mean and confidence interval for purple filled box, with ensemble means of individual models for black dots, in the right
 SAM_nat_JJA_2000_2019: multimodel ensemble mean and confidence interval for green filled box, with ensemble means of individual models for black dots, in the right

Notes on reproducing the figure from the provided data

Multimodel ensemble means, interquartile ranges and 5th and 95th percentiles of historical and hist* simulations are calculated after weighting individual members with the inverse of the ensemble size of the same model. The weight is given as the weight attribute of each variable. The weighting is not applied to piControl simulations.
Filled boxes and black dots are evaluated based on the models with minimum 3 ensemble members. ensemble_assign attribute in each variable provides the model number to which each ensemble member belongs. For the confidence interval, first the ensemble average of individual models (with minimum 3 ensemble members) are calculated and then the confidence interval is evaluated based on t statistic.

Sources of additional information

The following weblinks are provided in the Related Documents section of this catalogue record:
 Link to the report component containing the figure (Chapter 3)
 Link to the Supplementary Material for Chapter 3, which contains supporting information on the figure in Section and details on the input data used in Table 3.SM.1
 Link to the code for the figure, archived on Zenodo
 Link to the figure on the IPCC AR6 website
Details
Previous Info: 
No news update for this record


Previously used record identifiers: 
No related previous identifiers.

Access rules: 
Public data: access to these data is available to both registered and nonregistered users.
Use of these data is covered by the following licence: http://creativecommons.org/licenses/by/4.0/. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. 
Data lineage: 
Data produced by Intergovernmental Panel on Climate Change (IPCC) authors and supplied for archiving at the Centre for Environmental Data Analysis (CEDA) by the Technical Support Unit (TSU) for IPCC Working Group I (WGI). 
Data Quality: 
Data as provided by the IPCC

File Format: 
txt, netCDF

Related Documents
Process overview
Title  Caption for Figure 3.34 from Chapter 3 of the Working Group I (WGI) Contribution to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) 
Abstract  Attribution of observed seasonal trends in the annular modes to forcings. Simulated and observed trends in NAM indices over 1958–2019 (a) and in SAM indices over 1979–2019 (b) and over 2000–2019 (c) for boreal winter (December–February average; DJF) and summer (June–August average; JJA). The indices are based on the difference of the normalized zonally averaged monthly mean sea level pressure between 35ºN and 65ºN for the NAM and between 40ºS and 65ºS for the SAM as defined in Jianping and Wang (2003) and Gong and Wang (1999), respectively; the unit is decade–1. Ensemble mean, interquartile ranges and 5th and 95th percentiles are represented by empty boxes and whiskers for preindustrial control simulations and historical simulations. The number of ensemble members and models used for computing the distribution is given in the upperleft legend. Grey lines show observed trends from the ERA5 and JRA55 reanalyses. Multimodel multimember ensemble means of the forced component of the trends as well as their 5–95% confidence intervals assessed from tstatistics, are represented by filled boxes, based on CMIP6 individual forcing simulations from DAMIP ensembles; greenhouse gases in brown, aerosols in light blue, stratospheric ozone in purple and natural forcing in green. Models with at least three ensemble members are used for the filled boxes, with black dots representing the ensemble means of individual models. Further details on data sources and processing are available in the chapter data table (Table 3.SM.1). 
Input Description  None 
Output Description  None 
Software Reference  None 
 var_id: NAM_GHG_DJF_1958_2019
 units: decade^1
 units: decade^1
 var_id: NAM_GHG_JJA_1958_2019
 units: decade^1
 var_id: NAM_aer_DJF_1958_2019
 units: decade^1
 var_id: NAM_aer_JJA_1958_2019
 units: decade^1
 var_id: NAM_hist_DJF_1958_2019
 units: decade^1
 var_id: NAM_hist_JJA_1958_2019
 units: decade^1
 var_id: NAM_nat_DJF_1958_2019
 units: decade^1
 var_id: NAM_nat_JJA_1958_2019
 units: decade^1
 var_id: NAM_obs_DJF_1958_2019
 units: decade^1
 var_id: NAM_obs_JJA_1958_2019
 units: decade^1
 var_id: NAM_piControl_DJF_62yrs
 units: decade^1
 var_id: NAM_piControl_JJA_62yrs
 units: decade^1
 var_id: NAM_stratO3_DJF_1958_2019
 units: decade^1
 var_id: NAM_stratO3_JJA_1958_2019
 units: decade^1
 var_id: SAM_GHG_DJF_1979_2019
 units: decade^1
 var_id: SAM_GHG_DJF_2000_2019
 units: decade^1
 var_id: SAM_GHG_JJA_1979_2019
 units: decade^1
 var_id: SAM_GHG_JJA_2000_2019
 units: decade^1
 var_id: SAM_aer_DJF_1979_2019
 units: decade^1
 var_id: SAM_aer_DJF_2000_2019
 units: decade^1
 var_id: SAM_aer_JJA_1979_2019
 units: decade^1
 var_id: SAM_aer_JJA_2000_2019
 units: decade^1
 var_id: SAM_hist_DJF_1979_2019
 units: decade^1
 var_id: SAM_hist_DJF_2000_2019
 units: decade^1
 var_id: SAM_hist_JJA_1979_2019
 units: decade^1
 var_id: SAM_hist_JJA_2000_2019
 units: decade^1
 var_id: SAM_nat_DJF_1979_2019
 units: decade^1
 var_id: SAM_nat_DJF_2000_2019
 units: decade^1
 var_id: SAM_nat_JJA_1979_2019
 units: decade^1
 var_id: SAM_nat_JJA_2000_2019
 units: decade^1
 var_id: SAM_obs_DJF_1979_2019
 units: decade^1
 var_id: SAM_obs_DJF_2000_2019
 units: decade^1
 var_id: SAM_obs_JJA_1979_2019
 units: decade^1
 var_id: SAM_obs_JJA_2000_2019
 units: decade^1
 var_id: SAM_piControl_DJF_20yrs
 units: decade^1
 var_id: SAM_piControl_DJF_41yrs
 units: decade^1
 var_id: SAM_piControl_JJA_20yrs
 units: decade^1
 var_id: SAM_piControl_JJA_41yrs
 units: decade^1
 var_id: SAM_stratO3_DJF_1979_2019
 units: decade^1
 var_id: SAM_stratO3_DJF_2000_2019
 units: decade^1
 var_id: SAM_stratO3_JJA_1979_2019
 units: decade^1
 var_id: SAM_stratO3_JJA_2000_2019
 var_id: ensemble_GHG
 var_id: ensemble_aer
 var_id: ensemble_hist
 var_id: ensemble_nat
 var_id: ensemble_stratO3
 var_id: model_ctl
 var_id: obs_dataset
Coordinate Variables
Temporal Range
19580101T12:00:00
20191231T12:00:00
Geographic Extent
90.0000° 

180.0000° 
180.0000° 

90.0000° 