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 [Masson-Delmotte, 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 1958-2019

- Observed and simulated JJA NAM trends for 1958-2019

- Observed and simulated DJF SAM trends for 1979-2019

- Observed and simulated JJA SAM trends for 1979-2019

- Observed and simulated DJF SAM trends for 2000-2019

- Observed and simulated JJA SAM trends for 2000-2019

Simulations are from CMIP6 historical, hist-GHG, hist-aer, hist-nat, and hist-stratO3 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

-->JRA-55: obs_dataset = 1\n

- NAM_piControl_DJF_62yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the left

- NAM_hist_DJF_1958_2019: multimodel ensemble mean and percentiles for red open box-whisker 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

-->JRA-55: obs_dataset = 1\n

- NAM_piControl_JJA_62yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the right

- NAM_hist_JJA_1958_2019: multimodel ensemble mean and percentiles for red open box-whisker 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

-->JRA-55: obs_dataset = 1\n

- SAM_piControl_DJF_41yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the left

- SAM_hist_DJF_1979_2019: multimodel ensemble mean and percentiles for red open box-whisker 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

-->JRA-55: obs_dataset = 1\n

- SAM_piControl_JJA_41yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the right

- SAM_hist_JJA_1979_2019: multimodel ensemble mean and percentiles for red open box-whisker 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

-->JRA-55: obs_dataset = 1\n

- SAM_piControl_DJF_20yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the left

- SAM_hist_DJF_2000_2019: multimodel ensemble mean and percentiles for red open box-whisker 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

-->JRA-55: obs_dataset = 1\n

- SAM_piControl_JJA_20yrs: multimodel ensemble mean and percentiles for blue open box-whisker in the right

- SAM_hist_JJA_2000_2019: multimodel ensemble mean and percentiles for red open box-whisker 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