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https://doi.org/10.1175/JCLI-D-17-0783.s112Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Supplemental Material

34How well do we know ENSO’s climate impacts over North America,

5and how do we evaluate models accordingly?

678

Clara Deser*, Isla R. Simpson, Adam. S. Phillips and Karen A. McKinnon

9National Center for Atmospheric Research

10Boulder, CO USA

1112
13

J. Climate

14

Submitted 15 November 2017

15

Revised 12 February 2018

16
17
18
19

*Corresponding author address: Dr. Clara Deser, Climate and Global Dynamics Division,

20

National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 USA.

21

Email cdeser@ucar.edu; Tel 303-497-1359; Fax 303-497-1333.

22

(a)
El Niño

30/31

40/41

41/42

57/58

63/64

65/66

68/69

72/73

82/83

86/87

87/88

91/92

94/95

97/98

02/03

06/07

09/10

UQ 18

NW SAT 10-

-

1-

1

12-

12--

1

312-

311NW SAT 90

11-

2

13-

1-

-

12-

13-

-

211SE SAT 10----

1

2132-

221-

2-

1

111SE SAT 90

1224

111-----

12111-

12PNW PR 10-

21-

2311-

121-

111-

113PNW PR 90

--

1-

421-

11-

-

1

1111312

GULF PR 10

322-

11-

2

112-----

2

111

GULF PR 90

1-

1

112-

1

3

13---

31-

-

11CA PR 10-

2-

2-

11-

1

1

121-

1

12213CA PR 90

11-

12-

23211-

1-

1-

1

113(b)
La Niña

24/25

33/34

38/39

42/43

49/50

55/5673/74

75/76

84/85

88/89

98/99

99/00

07/08

10/11

UQ 14

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

25/26

https://doi.org/10.1175/JCLI-D-17-0783.s1

NW SAT 10

113-

2-

1-

1--

1

139NW SAT 90

-

31-

131-

1-

211-

9SE SAT 10-

212-

21---

41-

18SE SAT 90

-

2-

1--

231-

-2-

37PNW PR 10

141-

22---

111-

19PNW PR 90

122111--1--

212

10GULF PR 1011112-

121-

112-

11

GULF PR 90

2-1--

2-

1-

2222-

8CA PR 10

12-

11-

21--

2

11210CA PR 90

2---

1

111132-

-

2

923

24
25
26
272829

Table S1. (a) The 18 El Niño events used for the ENSO composites, identified by theyears spanning the season December-February (e.g., ‘‘25/26’’ indicates the El Niño
event of 1925/26). Shown are the number of times each event was sampled in thesynthetic observational ENSO composites based on the 10th- and 90th-percentile
values of the: Northwest SAT Index (NW SAT), Southeast SAT Index (SE SAT), Pacific1

https://doi.org/10.1175/JCLI-D-17-0783.s1

30
3132
33
34

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Northwest Precipitation Index (PNW PR), Gulf States Precipitation Index (GULF PR)
and the California Precipitation Index (CA PR). The last column (bold font, labeledUQ18) shows the number of unique events in each composite. (b) As in (a) but forthe 14 La Niña events.

2https://doi.org/10.1175/JCLI-D-17-0783.s1

353637383940
41

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S1. ENSO composites of DJF SAT (°C) from each of the 10 CM2.1 Pacemakersimulations (labeled 1 through 10) and from observations (lower right panel). Eachcomposite is based on the same set of 18 El Niño events minus 14 La Niña events
during 1920-2013. Values not significant at the 10% confidence level based on a 2sided t-test are stippled.

3https://doi.org/10.1175/JCLI-D-17-0783.s1

42434445
46
4748

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S2. ENSO composites of DJF SAT (°C) from each of the 5 MIROC5 Pacemakersimulations (labeled 1 through 5) and from observations (lower right panel). Eachcomposite is based on the same set of 18 El Niño events minus 14 La Niña events
during 1920-2013. Values not significant at the 10% confidence level based on a 2sided t-test are stippled.

4https://doi.org/10.1175/JCLI-D-17-0783.s1

49505152535455

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S3. ENSO composites of DJF SAT (°C) from each of the 10 CESM1 TOGA
simulations (labeled 1 through 10) and from observations (lower right panel). Eachcomposite is based on the same set of 18 El Niño events minus 14 La Niña events
during 1920-2013. Values not significant at the 10% confidence level based on a 2sided t-test are stippled.

5https://doi.org/10.1175/JCLI-D-17-0783.s1565758

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S4. As in Fig. S1 but for precipitation (mm d-1).

6https://doi.org/10.1175/JCLI-D-17-0783.s1

5960
61

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S5. As in Fig. S2 but for precipitation (mm d-1).

7https://doi.org/10.1175/JCLI-D-17-0783.s1

626364

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S6. As in Fig. S3 but for precipitation (mm d-1).

8https://doi.org/10.1175/JCLI-D-17-0783.s1

6566676869

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S7. 5-95% confidence intervals (CI; °C) on the SAT ENSO composites basedon 2000 bootstrapped samples for each of the 10 CESM1 Pacemaker simulations(labeled 1-10).

9https://doi.org/10.1175/JCLI-D-17-0783.s1

707172

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S8. As in Fig. S7 but for precipitation (mm d-1).

10https://doi.org/10.1175/JCLI-D-17-0783.s1

73747576

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S9. Percent contribution of ENSO to the observed CIs on ENSO composites ofDJF (a) SAT and (b) precipitation. See main text for details.

11https://doi.org/10.1175/JCLI-D-17-0783.s1

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

77787980
8182838485

Figure S10. Observed ENSO composites of FMA (a) SAT (°C) and (b) precipitation(mm d-1) based on 18 El Niño events minus 14 La Niña events during 1920-2013.
Values not significant at the 10% confidence level based on a 2-sided t-test arestippled.

12https://doi.org/10.1175/JCLI-D-17-0783.s1

8687
88
89
90
91
92
93
94

Deser, C., I. R. Simpson, A. S. Phillips, and K. A. McKinnon

Figure S11. Observed ENSO composites of DJF (a) SAT (°C) and (b) precipitation(mm d-1) based on 18 El Niño events minus 14 La Niña events during 1920-2013.
Stippling indicates where values are within the 5-95% confidence interval based on
2000 bootstrapped samples after removing the linear dependence on the composite
Nino3.4 SST Index. See main text for details.

13