NOAA Technical Memorandum GLERL-174

https://doi.org/10.25923/88c9-hm22

____________________________________________________________________________

Great Lakes ice duration, winter severity index, 

cumulative freezing degree days, and atmospheric

teleconnection patterns, 1973 – 2018

Jia Wang1

, Ting-Yi Yang2,3, James Kessler1, Haoguo Hu3, and Philip Chu1

1 NOAA Great Lakes Environmental Research Laboratory

2 Geodetic Science, School of Earth Science, The Ohio State University

3 Cooperative Institute for Great Lake Lakes Research, University of Michigan

NOAA Great Lakes Environmental Research Laboratory

4840 S. State Road, Ann Arbor, Michigan

Tuesday, January 28, 2020

____________________________________________________________________________

 UNITED STATES NATIONAL OCEANIC AND

DEPARTMENT OF COMMERCE ATMOSPHERIC ADMINISTRATION

Wilbur L. Ross, Jr. Secretary Dr. Neil Jacobs, Acting Administrator
NOTICE

Mention of a commercial company or product does not constitute an endorsement by NOAA. 

Use of information from this publication concerning proprietary products or the tests of such 

products for publicity or advertising purposes is not authorized. This is GLERL Contribution No. 

1934 and CIGLR Contribution No. 1154. This publication is available as a PDF file and can be 

downloaded from GLERL’s web site: www.glerl.noaa.gov or by emailing GLERL Information 

Services at oar.pubs.glerl@noaa.gov.
i

TABLE OF CONTENTS

1.0 Introduction............................................................................................................................... 1

2.0 Data Sets ................................................................................................................................... 1

2.1 Ice coverage data................................................................................................................... 1

2.2 Air temperature data ............................................................................................................. 1

2.3 Atmospheric teleconnection indices (Wang et al., 2018) ..................................................... 2

3.0 Definition and methodology ..................................................................................................... 2

4.0 Results....................................................................................................................................... 5

4.1 Freeze-up and break-up dates ............................................................................................... 5

4.2 Ice duration ........................................................................................................................... 7

4.3 Cumulative freezing degree days (FDD)............................................................................ 10

4.4 WSI/WSI_CLERL vs. atmosphere (circulation) teleconnection patterns .......................... 13

4.5 AMIC vs. atmosphere (circulation) teleconnection patterns .............................................. 27

4.6 Duration vs. atmosphere (circulation) teleconnection patterns........................................... 34

4.7 AMIC vs. FDD and AMIC vs. WSI/WSI_GLERL............................................................ 41

5.0 Summary................................................................................................................................. 53

6.0 Acknowledgments................................................................................................................... 53

7.0 References............................................................................................................................... 54

Appendix: Great Lakes environmental parameters....................................................................... 55

LIST OF FIGURES

Fig. 1. Distribution of air temperature stations............................................................................... 3

Fig. 2. Freeze-up and break-up dates – (1). .................................................................................... 5

Fig. 3. Freeze-up and break-up dates – (2). .................................................................................... 6

Fig. 4. Ice Duration – (1). ............................................................................................................... 7

Fig. 5. Ice Duration – (2) ................................................................................................................ 8

Fig. 6. Correlation between duration and FDD – (1)...................................................................... 8

Fig. 7. Correlation between duration and FDD – (2)...................................................................... 9

Fig. 8. Comparison between FDD and WSI – (1)......................................................................... 10

Fig. 9. Comparison between FDD and WSI – (2)......................................................................... 11

Fig. 10. Comparison between FDD and WSI_GLERL – (1)........................................................ 11

Fig. 11. Comparison between FDD and WSI_GLERL – (2)........................................................ 12

Fig. 12. Comparison between WSI and atmospheric teleconnection patterns [Superior]. ........... 13
ii

Fig. 13. Comparison between WSI and atmospheric teleconnection patterns [Michigan]........... 14

Fig. 14. Comparison between WSI and atmospheric teleconnection patterns [Huron]................ 15

Fig. 15. Comparison between WSI and atmospheric teleconnection patterns [Erie]. .................. 16

Fig. 16. Comparison between WSI and atmospheric teleconnection patterns [Ontario].............. 17

Fig. 17. Comparison between WSI and atmospheric teleconnection patterns [St. Clair]............. 18

Fig. 18. Comparison between WSI and atmospheric teleconnection patterns [Great Lakes]....... 19

Fig. 19. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Superior].

....................................................................................................................................................... 20

Fig. 20. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Michigan].

....................................................................................................................................................... 21

Fig. 21. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Huron]. 22

Fig. 22. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Erie]. ... 23

Fig. 23. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Ontario].

....................................................................................................................................................... 24

Fig. 24. Comparison between WSI_GLERL and atmospheric teleconnection patterns [St. Clair].

....................................................................................................................................................... 25

Fig. 25. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Great 

Lakes]............................................................................................................................................ 26

Fig. 26. Comparison between AMIC and atmospheric teleconnection patterns [Superior]. ........ 27

Fig. 27. Comparison between AMIC and atmospheric teleconnection patterns [Michigan]........ 28

Fig. 28. Comparison between AMIC and atmospheric teleconnection patterns [Huron]............. 29

Fig. 29. Comparison between AMIC and atmospheric teleconnection patterns [Erie]. ............... 30

Fig. 30. Comparison between AMIC and atmospheric teleconnection patterns [Ontario]........... 31

Fig. 31. Comparison between AMIC and atmospheric teleconnection patterns [St. Clair].......... 32

Fig. 32. Comparison between AMIC and atmospheric teleconnection patterns [Great Lakes]. .. 33

Fig. 33. Comparison between duration and atmospheric teleconnection patterns [Superior]. ..... 34

Fig. 34. Comparison between duration and atmospheric teleconnection patterns [Michigan]..... 35

Fig. 35. Comparison between duration and atmospheric teleconnection patterns [Huron].......... 36

Fig. 36. Comparison between duration and atmospheric teleconnection patterns [Erie]. ............ 37

Fig. 37. Comparison between duration and atmospheric teleconnection patterns [Ontario]........ 38

Fig. 38. Comparison between duration and atmospheric teleconnection patterns [St. Clair]....... 39

Fig. 39. Comparison between duration and atmospheric teleconnection patterns [Great Lakes]. 40

Fig. 40. Comparison between AMIC and FDD – (1). .................................................................. 41

Fig. 41. Comparison between AMIC and FDD – (2). .................................................................. 42
iii

Fig. 42. Comparison between AMIC and WSI – (1). ................................................................... 42

Fig. 43. Comparison between AMIC and WSI – (2). ................................................................... 43

Fig. 44. Comparison between AMIC and WSI_CLERL – (1). .................................................... 44

Fig. 45. Comparison between AMIC and WSI_CLERL – (2). .................................................... 45

Fig. 46. Comparison between duration and AMIC – (1). ............................................................. 46

Fig. 47. Comparison between duration and AMIC – (2). ............................................................. 47

Fig. 48. Comparison between duration and FDD – (1). ............................................................... 48

Fig. 49. Comparison between duration and FDD – (2). ............................................................... 49

Fig. 50. Comparison between duration and WSI – (1). ................................................................ 49

Fig. 51. Comparison between duration and WSI – (2). ................................................................ 50

Fig. 52. Comparison between duration and WSI_GLERL – (1). ................................................. 51

Fig. 53. Comparison between duration and WSI_GLERL – (2). ................................................. 52

LIST OF TABLES

Table 1. List of selected meteorological stations............................................................................ 4

Table 2. Environmental parameters in Lake Superior. ................................................................. 55

Table 3. Environmental parameters in Lake Michigan................................................................. 56

Table 4. Environmental parameters in Lake Huron...................................................................... 57

Table 5. Environmental parameters in Lake Erie. ........................................................................ 58

Table 6. Environmental parameters in Lake Ontario.................................................................... 59

Table 7. Environmental parameters in Lake St. Clair................................................................... 60

Table 8. Environmental parameters in Great Lakes...................................................................... 61

Table 9. Atmospheric teleconnection indices. .............................................................................. 62
1

Great Lakes ice duration, winter severity index, 

cumulative freezing degree days, and atmospheric 

teleconnection patterns, 1973 – 2018

Jia Wang, Ting-Yi Yang, James Kessler, Haoguo Hu, and Philip Chu

1.0 Introduction

This report investigates interannual variability in ice coverage (Bai et al., 2012; Assel et al., 

1998; Assel et al., 2013). We conduct analyses of the ice coverage records—freeze-up date, 

break-up date, duration and annual maximum ice coverage (AMIC)—with air temperature —

cumulative freezing degree days (FDD), winter severity index (WSI)—and atmospheric 

teleconnections—El Niño–Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation

(AMO), North Atlantic Oscillation (NAO), and Pacific Decadal Oscillation (PDO). In addition, 

we use scatter plots and linear / non-linear regression, to determinate whether they have linear or 

quadratic relationships. The purpose of this report is to provide users with the Great Lakes

environmental parameters and in depth analyses that are easily digested and applied to resources 

management, projection, and planning.

2.0 Data Sets

2.1 Ice coverage data

The ice coverage ASCII gridded data is provided by national Ice Center (NIC) from November 

1972 until Jun 2018. Before May 2007, the ice data was mapped with Mercator projection

(Clarke 1866 ellipsoid) and re-sampled to a 510 x 516 pixels gridded data. Since November 

2007, the data was changed to 1024 x 1024 pixels grid (with Mercator projection and WGS 1984

ellipsoid), to improve the resolution from 2.55 km to 1.275 km (Wang et al., 2012; Wang et al., 

2017). In our process, the ice coverage data is averaged at each lake, so resampling method was 

not used for data before 2008 winter.

2.2 Air temperature data

GHCND (Global Historical Climate Network Daily, https://www.ncdc.noaa.gov/ghcn-dailydescription) long-term daily air temperature data was used. The pre-processing and data cleaning 

was done and organized by Hunter et al (2015). In our process, maximum and minimum 

temperature are utilized, because most of the station don’t have long-term averaged temperature. 

Therefore, averaging maximum and minimum temperature was used instead of averaged 

temperature. Because to there are around 700 stations around the Great Lakes, we set up some 

criteria to select the useful stations:

A. Stations within 50km outside the lake’s basin

B. Time span includes 1973 – 2018
2

C. Data coverage (observation over a period of observed time) is more than 90%. However, 

some regions do not have enough stations, e.g. north side of Lake Superior, low data 

coverage stations are included for better station distribution. 

The station locations are shown in Fig. 1 and the detail information is listed in Table 1.

2.3 Atmospheric teleconnection indices (Wang et al., 2018)

ENSO: is defined by the 3-month running mean of ERSST.v3 (Extended Reconstructed Sea 

Surface Temperature Version 3) SST anomalies in the Niño3.4 region (5°N-5°S, 120°-170°W. 

Data is obtained from the NOAA/CPC (Climate Prediction Center, 

http://www.cpc.noaa.gov/products/analysis monitoring/ensostuff/ensoyears.shtml). 

NAO: is defined as the normalized sea level pressure difference between Azores and Iceland. 

Record was obtained from the Climatic Research Unit, UK.

(http://www.cru.uea.ac.uk/cru/data/NAO.htm). 

PDO: is the standardized principal component time series of leading empirical orthogonal 

function (EOF) of monthly sea surface temperature anomalies (SSTA) over the North Pacific 

(poleward of 20° N) after the global mean SST has been removed. The PDO index is derived

from http://research.jisao.washington.edu/pdo/PDO latest; 

https://www.ncdc.noaa.gov/teleconnections/pdo/).

AMO: is defined from the patterns of SST variability in the North Atlantic once any linear trend 

has been removed. The AMO index is obtained from 

http://www.esrl.noaa.gov/psd/data/timeseries/AMO/.

3.0 Definition and methodology

A. Ice coverage: freeze-up date, break-up date, duration, and AMIC

1. Freeze-up and break-up date: Compute the mean for each lake and all Great Lakes 

area per data, and assign the free-up date and break-up date if this is the first/last date 

when the mean greater than 10%. NA is assigned if the mean of ice coverages are all 

less than 10% in that year.

2. Duration: subtract the break-up date by the freeze-up date. Duration is assigned to 1 if 

the freeze-up and break-up date are same.

3. AMIC: compute the mean for each lake and all the Great Lakes area per data, and 

assign the maximum mean as AMIC

B. Air temperature: cumulative FDD, WSI, and WSI_GLERL

For each lake, daily temperature is derived from averaging all station daily data.

1. FDD: calculate how many days (from November 1th through June 30th) during which

the averaged temperature is less than or equal to 0 °C.

2. WSI: is developed by C. R. Snider in an earlier study, to define the Great Lakes 

winter severity. It is defined as average of the monthly-mean temperatures from 

November 1th through February 28th (or 29th for leap year) (Bai et al., 2011).
3

3. WSI_GLERL: average of the monthly-mean temperatures from December 1th

through February 28th (or 29th for leap year).

C. Atmospheric teleconnections (ENSO, NAO, PDO, and AMO) are used to correlate with 

air temperature and ice coverage parameters.

Fig. 1. Distribution of air temperature stations

(Annotated number: denote percentage of the data coverage, colors in circle: the stations are used 

for each lake)
4

Table 1. List of selected meteorological stations.

Region Station ID Latitude

(deg)

Longitude

(deg)

First 

Year

Last 

year

Data Coverage 

(%)

Superior

CA006049443 48.3667 -89.1167 1967 2018 54

USC00205690 46.4122 -86.6625 1911 2018 95

USC00208043 46.6014 -85.2239 1968 2018 93

USC00213282 47.7517 -90.3283 1913 2018 85

USC00474953 46.7781 -90.7653 1944 2018 96

USC00472889 46.4856 -92.2875 1963 2018 93

USW00014858 47.1686 -88.4889 1948 2018 81

Michigan

USC00116616 41.4947 -87.6803 1952 2018 99

USC00201896 45.6414 -85.0142 1969 2018 98

USC00205065 44.2114 -86.2939 1888 2018 92

USC00207690 42.4014 -86.2825 1895 2018 93

USC00478905 45.3583 -86.8911 1944 2018 99

USW00014839 42.9550 -87.9044 1938 2018 100

USW00014840 43.1711 -86.2367 1896 2018 100

USW00014850 44.7408 -85.5825 1896 2018 100

USW00014898 44.4983 -88.1111 1886 2018 100

Huron

CA006111769 44.6333 -79.5333 1971 2018 93

CA006117684 44.4000 -79.6333 1973 2018 99

CA006124127 44.1667 -81.6167 1872 2018 36

USC00201492 45.6528 -84.4725 1891 2018 93

USC00200417 43.8081 -82.9939 1925 2018 98

USC00206680 42.9750 -82.4194 1933 2018 97

USW00014814 45.0606 -83.4281 1948 2018 98

USW00014845 43.5331 -84.0797 1898 2018 100

USW00014847 46.4794 -84.3572 1931 2018 100

Erie

CA006134190 42.0500 -82.6667 1968 2018 98

CA006135583 42.5167 -81.6333 1957 2018 99

CA006136606 42.8833 -79.2500 1964 2018 97

USC00336389 41.7525 -81.2956 1950 2018 99

USW00014846 41.4500 -82.7167 1936 2018 97

USW00014860 42.0800 -80.1825 1926 2018 100

Ontario

CA006155878 43.8667 -78.8333 1969 2018 97

CA006158733 43.6833 -79.6333 1937 2018 99

CA006150689 44.1500 -77.4000 1866 2018 73

USC00304844 43.1878 -78.6092 1893 2018 83

USC00306314 43.4622 -76.4933 1926 2018 100

USW00014768 43.1167 -77.6767 1926 2018 100

USW00094790 43.9922 -76.0217 1949 2018 100

St.Clair

USW00014804 42.6083 -82.8183 1896 2018 94

USW00014822 42.4092 -83.0100 1948 2018 100

USC00203477 42.4078 -82.8892 1950 2018 99
5

4.0 Results

4.1 Freeze-up and break-up dates

Fig. 2. Freeze-up and break-up dates – (1).
6

Fig. 3. Freeze-up and break-up dates – (2).
7

4.2 Ice duration

Fig. 4. Ice Duration – (1).
8

Fig. 5. Ice Duration – (2)

Fig. 6. Correlation between duration and FDD – (1).
9

Fig. 7. Correlation between duration and FDD – (2).
10

4.3 Cumulative freezing degree days (FDD) 

Fig. 8. Comparison between FDD and WSI – (1).

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
11

Fig. 9. Comparison between FDD and WSI – (2).

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].

Fig. 10. Comparison between FDD and WSI_GLERL – (1).

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
12

Fig. 11. Comparison between FDD and WSI_GLERL – (2).

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
13

4.4 WSI/WSI_CLERL vs. atmosphere (circulation) teleconnection patterns 

 

Fig. 12. Comparison between WSI and atmospheric teleconnection patterns [Superior].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
14

 

Fig. 13. Comparison between WSI and atmospheric teleconnection patterns [Michigan].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
15

 

Fig. 14. Comparison between WSI and atmospheric teleconnection patterns [Huron].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
16

Fig. 15. Comparison between WSI and atmospheric teleconnection patterns [Erie].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
17

Fig. 16. Comparison between WSI and atmospheric teleconnection patterns [Ontario].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
18

Fig. 17. Comparison between WSI and atmospheric teleconnection patterns [St. Clair].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
19

Fig. 18. Comparison between WSI and atmospheric teleconnection patterns [Great Lakes].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
20

Fig. 19. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Superior].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
21

Fig. 20. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Michigan].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
22

Fig. 21. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Huron].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
23

Fig. 22. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Erie].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
24

Fig. 23. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Ontario].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
25

Fig. 24. Comparison between WSI_GLERL and atmospheric teleconnection patterns [St. Clair].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
26

Fig. 25. Comparison between WSI_GLERL and atmospheric teleconnection patterns [Great Lakes].

[95% critical values for Pearson’s correlation coefficient (DoF=44): ±0.29].
27

4.5 AMIC vs. atmosphere (circulation) teleconnection patterns 

Fig. 26. Comparison between AMIC and atmospheric teleconnection patterns [Superior].
28

Fig. 27. Comparison between AMIC and atmospheric teleconnection patterns [Michigan].
29

Fig. 28. Comparison between AMIC and atmospheric teleconnection patterns [Huron].
30

Fig. 29. Comparison between AMIC and atmospheric teleconnection patterns [Erie].
31

Fig. 30. Comparison between AMIC and atmospheric teleconnection patterns [Ontario].
32

Fig. 31. Comparison between AMIC and atmospheric teleconnection patterns [St. Clair].
33

Fig. 32. Comparison between AMIC and atmospheric teleconnection patterns [Great Lakes].
34

4.6 Duration vs. atmosphere (circulation) teleconnection patterns 

Fig. 33. Comparison between duration and atmospheric teleconnection patterns [Superior].
35

Fig. 34. Comparison between duration and atmospheric teleconnection patterns [Michigan].
36

Fig. 35. Comparison between duration and atmospheric teleconnection patterns [Huron].
37

Fig. 36. Comparison between duration and atmospheric teleconnection patterns [Erie].
38

Fig. 37. Comparison between duration and atmospheric teleconnection patterns [Ontario].
39

Fig. 38. Comparison between duration and atmospheric teleconnection patterns [St. Clair].
40

Fig. 39. Comparison between duration and atmospheric teleconnection patterns [Great Lakes].
41

4.7 AMIC vs. FDD and AMIC vs. WSI/WSI_GLERL 

Fig. 40. Comparison between AMIC and FDD – (1).
42

Fig. 41. Comparison between AMIC and FDD – (2).

Fig. 42. Comparison between AMIC and WSI – (1).
43

Fig. 43. Comparison between AMIC and WSI – (2).
44

Fig. 44. Comparison between AMIC and WSI_CLERL – (1).
45

Fig. 45. Comparison between AMIC and WSI_CLERL – (2).
46

4.8 Duration vs. AMIC, duration vs. FDD and duration vs. WSI/WSI_GLERL

Fig. 46. Comparison between duration and AMIC – (1).
47

Fig. 47. Comparison between duration and AMIC – (2).
48

Fig. 48. Comparison between duration and FDD – (1).
49

Fig. 49. Comparison between duration and FDD – (2).

Fig. 50. Comparison between duration and WSI – (1).
50

Fig. 51. Comparison between duration and WSI – (2).
51

Fig. 52. Comparison between duration and WSI_GLERL – (1).
52

Fig. 53. Comparison between duration and WSI_GLERL – (2).
53

5.0 Summary

We have investigated in depth Great Lakes ice duration, winter severity index (WSI), cumulative 

freezing degree days (FDD), and atmospheric teleconnection patterns, 1973 – 2018 for all five 

individual lakes and the whole Great Lakes. We provided not only their time series, but also the 

individual linear scatter plots between ice duration/WSI/FDD and major four teleconnection 

patterns (ENSO, PDO, NAO, and AMO). Furthermore, when a linear relationship is weak, a 

quadratic (nonlinear) relationship was derived. Both linear correlation coefficients and linear and 

nonlinear regression models were provided.

Based on these relationships, we can estimate the ice duration using WSI and cumulative FFD 

using the linear regression equation (model). Furthermore, we can derive multi-variable 

statistical regression models to hindcast and forecast ice duration using WSI, and cumulative 

FDD, and using teleconnection patterns indices, which will be conducted in the near future.

6.0 Acknowledgments

We appreciate support from the Cooperative Institute of Great Lakes Research (CIGLR) 2018 

Summer Fellows program. This is GLERL Contribution No. 1934. Funding was awarded to 

Cooperative Institute for Great Lakes Research (CIGLR) through the NOAA

Cooperative Agreement with the University of Michigan (NA17OAR4320152). This CIGLR 

contribution number is 1154.
54

7.0 References

Assel, R.A., and S. Rodionov. Atmospheric teleconnections for annual maximum ice cover on 

the Laurentian Great Lakes. International Journal of Climatology 18:425-442 (1998).

http://www.glerl.noaa.gov/pubs/fulltext/1998/19980001.pdf

Assel, R.A, J. Wang, A. Clites, and X. Bai. Analysis of Great Lakes ice cover climatology: 

Winters 2006-2011. NOAA Technical Memorandum GLERL-157. NOAA Great Lakes 

Environmental Research Laboratory, Ann Arbor, MI, 26 pp. (2013). 

https://www.glerl.noaa.gov/pubs/tech_reports/glerl-157/tm-157.pdf

Bai, X., Wang, J., Liu, Q., Wang, D., & Liu, Y. Severe ice conditions in the Bohai Sea, China, 

and mild ice conditions in the Great Lakes during the 2009/10 winter: Links to El Niño and a 

strong negative Arctic Oscillation. Journal of Applied Meteorology and Climatology, 50(9), 

1922-1935. (DOI: 10.1175/2011JAMC2675.1) (2011).

https://journals.ametsoc.org/doi/abs/10.1175/2011JAMC2675.1

Bai, X., J. Wang, C.E. Sellinger, A.H. Clites, and R.A. Assel. Interannual variability of Great 

Lakes ice cover and its relationship to NAO and ENSO. Journal of Geophysical Research 

117(C03002):25 pp. (DOI:10.1029/2010JC006932) (2012).

http://www.agu.org/pubs/crossref/2012/2010JC006932.shtml

Hunter, T. S., A. H. Clites, K. B. Campbell, and, A. D. Gronewold. Development and application 

of a North American Great Lakes hydrometeorological database—Part I: Precipitation, 

evaporation, runoff, and air temperature. Journal of Great Lakes Research, 41(1): 65-77 pp.

(DOI: 10.1016/j.jglr.2014.12.006) (2015).

https://www.sciencedirect.com/science/article/pii/S0380133014002676

Wang, J., R. A. Assel, S. Walterscheid, A.H. Clites, and X. Bai. Great Lakes ice cover 

climatology update: Winters 2006-2011 description of the digital ice cover data set. NOAA 

Technical Memorandum GLERL-155, 45 pp (2012).

http://www.glerl.noaa.gov/ftp/publications/tech_reports/glerl-155/tm-155.pdf

Wang, J., James Kessler, Franky Hang, Haoguo Hu, Anne H. Clites, and Philip Chu. Analysis of 

Great Lakes Ice Cover Climatology: Winters 2012-2017. NOAA Technical Memorandum 

GLERL-171 (2017).

https://www.glerl.noaa.gov/ftp/publications/tech_reports/glerl-171/tm-171.pdf

Wang, J., James Kessler, Franky Hang, Haoguo Hu, Anne H. Clites, and Philip Chu. Great Lakes 

Ice Climatology Update of Winters 2012-2017: Seasonal Cycle, Interannual Variability, 

Decadal Variability, and Trend for the period 1973-2017. NOAA Technical Memorandum 

GLERL-170 (2017).

https://www.glerl.noaa.gov/ftp/publications/tech_reports/glerl-170/tm-170.pdf

Wang, J., James Kessler, Xuezhi Bai, Anne H. Clites, Brent Lofgren, Alexandre Assuncao, John 

Bratton, Philip Chu, and George Leshkevich. Decadal variability of Great Lakes ice cover in 

response to AMO and PDO, 1963-2017. Journal of Climate. (in press)
55

Appendix: Great Lakes environmental parameters

Table 2. Environmental parameters in Lake Superior.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1972-12-20 1973-03-13 83 71.131 118 -6.460 -8.404

1974 1973-12-31 1974-04-25 115 74.617 133 -6.989 -9.382

1975 1975-01-16 1975-04-03 77 66.058 138 -4.675 -6.481

1976 1976-01-06 1976-04-06 91 52.407 118 -5.728 -8.058

1977 1976-12-16 1977-04-20 125 96.036 131 -9.478 -11.600

1978 1977-12-28 1978-04-19 112 92.489 129 -7.169 -9.662

1979 1979-01-01 1979-05-14 133 97.110 141 -9.415 -12.336

1980 1980-01-02 1980-04-09 98 80.700 128 -5.665 -7.464

1981 1981-01-07 1981-04-08 91 85.572 113 -5.881 -7.973

1982 1982-01-04 1982-04-26 112 85.814 134 -7.219 -10.328

1983 1983-01-03 1983-03-30 86 23.317 114 -4.495 -5.653

1984 1983-12-20 1984-04-19 121 88.352 125 -6.561 -8.926

1985 1984-12-28 1985-04-06 99 82.073 122 -7.360 -9.735

1986 1985-12-21 1986-04-05 105 90.698 128 -8.780 -10.519

1987 1987-01-24 1987-02-21 28 15.680 117 -4.241 -4.832

1988 1988-01-10 1988-04-03 84 68.547 123 -6.236 -8.711

1989 1989-01-01 1989-04-23 112 87.734 128 -6.570 -8.896

1990 1989-12-27 1990-04-02 96 76.729 134 -7.147 -8.549

1991 1991-01-09 1991-03-29 79 91.134 115 -5.815 -8.248

1992 1992-01-17 1992-04-06 80 81.223 136 -5.638 -6.503

1993 1993-01-13 1993-04-05 82 79.473 133 -6.251 -7.992

1994 1994-01-03 1994-04-20 107 96.333 127 -9.095 -11.489

1995 1995-02-08 1995-03-20 40 34.657 115 -4.411 -6.548

1996 1996-01-12 1996-05-10 119 99.000 156 -8.943 -10.540

1997 1997-01-14 1997-04-29 105 88.618 146 -7.524 -8.961

1998 1998-01-16 1998-01-16 1 10.946 108 -3.083 -3.655

1999 1999-01-15 1999-03-09 53 18.121 105 -4.633 -6.838

2000 2000-01-28 2000-02-25 28 33.155 98 -4.021 -6.511

2001 2001-02-05 2001-04-09 63 46.774 130 -6.929 -9.494

2002 2002-03-18 2002-03-18 1 10.237 116 -2.150 -4.357

2003 2003-01-23 2003-04-14 81 95.548 136 -7.010 -8.850

2004 2004-01-22 2004-03-25 63 52.260 127 -5.924 -7.841

2005 2005-01-17 2005-03-31 73 55.711 118 -5.675 -8.265

2006 2006-03-02 2006-03-09 7 17.625 112 -4.066 -5.613

2007 2007-02-01 2007-03-22 49 52.680 112 -5.006 -7.196

2008 2008-01-28 2008-04-03 66 63.665 133 -6.511 -8.691

2009 2009-01-12 2009-04-16 94 93.722 134 -8.027 -10.795

2010 2010-02-04 2010-03-04 28 28.975 101 -5.112 -8.006

2011 2011-01-20 2011-04-03 73 33.647 130 -6.618 -9.072

2012 NA NA NA 8.510 103 -3.067 -4.668

2013 2013-01-25 2013-03-30 64 38.664 137 -5.698 -7.634

2014 2013-12-31 2014-05-16 136 95.816 143 -10.521 -13.717

2015 2015-01-02 2015-05-03 121 95.653 134 -8.877 -10.485

2016 2016-02-12 2016-03-06 23 22.705 111 -3.386 -5.519

2017 2017-02-17 2017-03-17 28 18.718 100 -3.328 -5.932

2018 2017-12-29 2018-04-15 107 77.172 150 -7.781 -9.844
56

Table 3. Environmental parameters in Lake Michigan.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1972-12-28 1973-03-06 68 36.960 87 -2.424 -4.114

1974 1974-01-10 1974-04-04 84 43.184 93 -2.819 -5.019

1975 1975-01-16 1975-04-03 77 29.019 104 -1.369 -3.088

1976 1975-12-30 1976-03-23 84 32.869 91 -1.429 -3.972

1977 1976-12-16 1977-04-13 118 93.287 116 -6.678 -8.798

1978 1977-12-28 1978-04-12 105 68.290 111 -4.681 -7.420

1979 1978-12-27 1979-04-23 117 92.395 118 -5.442 -8.318

1980 1980-01-16 1980-04-02 77 43.690 96 -2.575 -4.426

1981 1980-12-24 1981-04-01 98 55.792 84 -3.043 -5.056

1982 1982-01-11 1982-04-20 99 62.866 104 -4.086 -6.731

1983 1983-01-18 1983-03-15 56 24.949 80 -0.270 -1.504

1984 1983-12-27 1984-04-08 103 46.129 97 -3.274 -5.730

1985 1985-01-05 1985-03-30 84 44.541 89 -2.994 -5.195

1986 1985-12-21 1986-04-05 105 68.014 101 -3.923 -6.052

1987 1987-01-24 1987-03-14 49 24.855 79 -1.231 -2.192

1988 1988-01-10 1988-03-27 77 36.489 94 -2.268 -4.620

1989 1989-01-08 1989-04-16 98 39.352 89 -1.848 -3.964

1990 1989-12-18 1990-03-19 91 25.692 98 -2.735 -4.177

1991 1991-01-07 1991-03-15 67 28.008 74 -1.340 -3.744

1992 1992-01-20 1992-03-27 67 42.189 89 -1.395 -2.390

1993 1993-01-13 1993-03-26 72 36.344 99 -2.458 -3.945

1994 1994-01-03 1994-04-06 93 90.418 91 -4.298 -6.728

1995 1995-02-08 1995-03-20 40 23.599 76 -0.637 -2.699

1996 1996-01-03 1996-04-19 107 75.154 114 -4.396 -5.765

1997 1996-12-27 1997-04-04 98 37.711 107 -3.052 -4.263

1998 1998-01-16 1998-02-13 28 15.763 78 -0.148 -0.839

1999 1999-01-05 1999-03-12 66 23.362 75 -0.493 -2.468

2000 2000-01-21 2000-02-29 39 27.608 73 -0.881 -3.177

2001 2000-12-25 2001-03-22 87 29.953 110 -3.386 -5.556

2002 2002-02-11 2002-03-25 42 13.008 65 1.640 -0.378

2003 2003-01-13 2003-04-10 87 48.995 102 -3.198 -5.081

2004 2004-01-12 2004-03-29 77 36.773 85 -2.127 -4.266

2005 2004-12-27 2005-03-31 94 31.007 88 -1.448 -3.590

2006 2006-02-09 2006-03-13 32 17.585 82 -0.749 -2.502

2007 2007-01-22 2007-03-22 59 38.813 72 -1.086 -3.152

2008 2008-01-21 2008-04-03 73 35.115 103 -2.703 -4.615

2009 2008-12-22 2009-03-26 94 53.364 100 -3.790 -6.193

2010 2010-01-05 2010-03-14 68 25.144 88 -1.393 -4.006

2011 2010-12-18 2011-03-26 98 29.335 102 -2.617 -5.075

2012 2012-01-20 2012-03-05 45 16.712 52 0.633 -1.034

2013 2013-01-22 2013-03-23 60 24.423 93 -1.045 -2.667

2014 2013-12-14 2014-04-29 136 93.325 116 -5.644 -8.410

2015 2015-01-02 2015-04-10 98 72.910 105 -4.560 -6.169

2016 2016-01-17 2016-03-05 48 26.735 68 0.599 -1.320

2017 2017-01-06 2017-03-21 74 18.180 71 0.433 -1.894

2018 2017-12-28 2018-03-21 83 51.304 98 -2.660 -4.501
57

Table 4. Environmental parameters in Lake Huron.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1972-12-20 1973-03-21 91 68.242 97 -3.478 -5.222

1974 1974-01-10 1974-04-18 98 63.407 109 -3.837 -6.100

1975 1975-01-16 1975-04-24 98 57.277 119 -2.031 -3.715

1976 1975-12-23 1976-04-13 112 54.616 103 -2.825 -5.722

1977 1976-12-16 1977-04-27 132 95.031 120 -7.201 -9.397

1978 1977-12-21 1978-04-26 126 95.778 122 -5.208 -8.000

1979 1978-12-27 1979-04-23 117 96.409 120 -5.763 -8.563

1980 1980-01-02 1980-04-16 105 72.814 107 -3.317 -5.417

1981 1980-12-24 1981-04-08 105 95.326 103 -5.042 -7.163

1982 1982-01-04 1982-05-05 121 93.427 112 -4.955 -7.568

1983 1983-01-18 1983-04-05 77 35.588 90 -1.567 -3.121

1984 1983-12-20 1984-04-19 121 78.552 107 -4.330 -6.645

1985 1985-01-05 1985-04-20 105 87.868 100 -3.834 -5.909

1986 1985-12-21 1986-04-12 112 74.139 114 -4.637 -6.982

1987 1987-01-24 1987-04-05 71 46.083 106 -2.771 -3.961

1988 1988-01-10 1988-04-10 91 61.772 101 -3.249 -5.333

1989 1988-12-30 1989-04-24 115 86.376 100 -2.983 -5.251

1990 1989-12-15 1990-04-13 119 74.775 112 -4.554 -6.176

1991 1991-01-07 1991-04-01 84 40.358 88 -2.649 -4.909

1992 1992-01-13 1992-04-22 100 70.684 114 -3.230 -4.736

1993 1992-12-28 1993-04-19 112 78.903 110 -3.574 -5.381

1994 1993-12-27 1994-04-22 116 97.746 104 -6.381 -9.083

1995 1995-01-06 1995-03-31 84 44.828 83 -2.065 -4.217

1996 1995-12-11 1996-04-29 140 97.578 130 -5.694 -7.271

1997 1996-12-27 1997-04-29 123 65.242 112 -3.691 -5.000

1998 1998-01-02 1998-03-24 81 29.822 89 -0.993 -1.931

1999 1999-01-05 1999-04-02 87 36.451 82 -1.686 -3.760

2000 2000-01-14 2000-03-17 63 42.070 82 -1.819 -4.091

2001 2000-12-21 2001-04-12 112 46.453 117 -3.877 -6.118

2002 2002-02-04 2002-04-01 56 26.735 80 0.618 -1.350

2003 2003-01-06 2003-04-24 108 96.208 113 -4.629 -6.695

2004 2004-01-08 2004-04-12 95 64.913 98 -3.361 -5.772

2005 2004-12-23 2005-04-11 109 59.973 106 -3.246 -5.624

2006 2005-12-22 2006-04-03 102 33.387 99 -1.777 -3.647

2007 2007-01-18 2007-04-05 77 72.031 84 -1.935 -4.086

2008 2007-12-17 2008-04-16 121 60.504 113 -3.002 -4.715

2009 2008-12-18 2009-04-14 117 85.503 106 -4.352 -6.733

2010 2010-01-05 2010-03-18 72 38.972 90 -2.049 -4.631

2011 2010-12-16 2011-04-11 116 63.907 111 -3.787 -6.288

2012 2012-01-16 2012-03-08 52 23.370 64 -0.016 -1.855

2013 2013-01-18 2013-04-01 73 48.028 96 -1.855 -3.448

2014 2013-12-12 2014-05-06 145 96.431 123 -6.232 -8.851

2015 2014-12-20 2015-04-22 123 96.416 112 -5.613 -7.758

2016 2016-01-13 2016-03-15 62 48.144 75 0.382 -1.573

2017 2017-01-06 2017-03-31 84 35.549 77 0.038 -2.136

2018 2017-12-16 2018-04-04 109 81.452 109 -3.480 -5.438
58

Table 5. Environmental parameters in Lake Erie.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1973-01-09 1973-03-06 56 95.590 60 -0.398 -1.777

1974 1974-01-10 1974-03-14 63 88.219 71 -0.375 -2.453

1975 1975-01-23 1975-03-13 49 80.444 83 0.537 -1.108

1976 1975-12-23 1976-03-16 84 95.369 68 0.348 -2.295

1977 1976-12-16 1977-04-06 111 99.595 97 -4.810 -6.803

1978 1977-12-21 1978-04-19 119 100.000 96 -3.261 -6.420

1979 1978-12-27 1979-04-02 96 99.958 82 -2.583 -5.223

1980 1980-01-02 1980-04-09 98 93.828 82 -0.545 -2.649

1981 1980-12-24 1981-04-08 105 95.938 83 -1.909 -3.809

1982 1982-01-11 1982-04-13 92 98.920 89 -2.172 -4.550

1983 1983-01-18 1983-02-23 36 43.605 48 2.188 0.695

1984 1983-12-27 1984-04-19 114 95.720 78 -1.266 -3.692

1985 1985-01-05 1985-04-06 91 95.990 67 -0.543 -2.494

1986 1985-12-21 1986-04-05 105 95.416 75 -0.849 -3.502

1987 1987-01-24 1987-03-07 42 87.932 70 -0.063 -1.500

1988 1988-01-03 1988-04-10 98 91.562 68 0.210 -1.972

1989 1989-01-08 1989-03-24 75 95.000 69 0.408 -1.588

1990 1989-12-15 1990-03-19 94 85.541 74 -0.522 -2.118

1991 1991-01-11 1991-03-06 54 44.589 57 1.189 -0.737

1992 1992-01-20 1992-03-20 60 91.216 67 0.444 -0.751

1993 1993-01-20 1993-04-05 75 94.762 75 -0.178 -1.932

1994 1994-01-03 1994-04-15 102 98.811 79 -2.353 -4.742

1995 1995-01-06 1995-03-22 75 95.688 58 1.063 -1.227

1996 1995-12-11 1996-04-17 128 99.000 92 -2.135 -3.751

1997 1996-12-27 1997-03-25 88 98.613 70 -0.289 -1.161

1998 NA NA NA 5.445 50 1.742 1.060

1999 1999-01-05 1999-03-19 73 74.672 56 1.642 -0.139

2000 2000-01-04 2000-03-03 59 90.920 60 1.214 -0.867

2001 2000-12-21 2001-04-12 112 93.915 86 -0.996 -2.980

2002 2002-01-03 2002-01-21 18 14.583 44 3.398 1.447

2003 2002-12-30 2003-04-03 94 95.717 89 -1.873 -4.091

2004 2004-01-08 2004-04-01 84 95.409 71 -0.061 -2.532

2005 2004-12-27 2005-03-31 94 92.960 71 0.257 -1.934

2006 2005-12-12 2006-03-09 87 24.603 65 1.487 -0.328

2007 2007-01-29 2007-04-02 63 95.762 61 0.962 -1.015

2008 2008-01-21 2008-04-03 73 93.332 71 0.301 -1.327

2009 2008-12-22 2009-03-26 94 95.549 80 -1.091 -3.050

2010 2009-12-31 2010-03-18 77 93.138 74 0.001 -2.643

2011 2010-12-16 2011-04-03 108 95.835 91 -1.333 -3.723

2012 2012-01-21 2012-02-15 25 13.978 32 3.020 1.200

2013 2013-01-22 2013-03-12 49 83.747 67 0.966 -0.251

2014 2013-12-12 2014-04-22 131 96.456 91 -2.346 -4.561

2015 2015-01-02 2015-04-18 106 98.150 85 -2.271 -4.247

2016 2016-01-18 2016-03-06 48 78.749 40 3.412 1.608

2017 2016-12-17 2017-02-08 53 35.570 43 3.016 1.093

2018 2017-12-27 2018-03-31 94 95.125 74 0.078 -1.852
59

Table 6. Environmental parameters in Lake Ontario.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1973-01-09 1973-03-06 56 64.828 83 -2.518 -3.995

1974 1974-01-10 1974-03-14 63 29.391 89 -2.294 -4.541

1975 1975-02-06 1975-02-13 7 16.573 96 -0.780 -2.245

1976 1976-01-27 1976-02-17 21 20.801 84 -1.601 -4.552

1977 1976-12-30 1977-04-13 104 49.672 104 -5.313 -7.440

1978 1977-12-28 1978-04-05 98 60.072 106 -3.839 -6.854

1979 1979-01-15 1979-03-26 70 86.498 90 -3.777 -6.293

1980 1980-01-30 1980-03-26 56 36.303 88 -1.757 -4.119

1981 1981-01-07 1981-03-04 56 51.091 90 -3.730 -5.813

1982 1982-01-18 1982-04-06 78 54.014 103 -3.454 -5.866

1983 1983-01-25 1983-02-23 29 17.364 61 0.161 -1.522

1984 1984-01-03 1984-03-29 86 44.642 93 -2.535 -4.667

1985 1985-01-05 1985-03-23 77 42.285 82 -1.989 -3.926

1986 1986-01-04 1986-03-22 77 47.059 98 -2.758 -5.069

1987 1987-02-14 1987-02-21 7 13.895 83 -1.986 -3.491

1988 1988-01-10 1988-03-27 77 25.830 87 -1.364 -3.199

1989 1989-02-05 1989-03-24 47 22.959 85 -1.154 -3.319

1990 1989-12-27 1990-03-14 77 36.122 92 -2.564 -4.414

1991 1991-01-14 1991-03-01 46 16.660 71 -0.427 -2.289

1992 1992-01-29 1992-03-27 58 22.313 91 -1.599 -3.256

1993 1993-02-10 1993-03-24 42 27.931 98 -2.305 -4.250

1994 1994-01-10 1994-04-06 86 79.930 89 -4.338 -6.945

1995 1995-02-08 1995-03-08 28 22.839 73 -0.393 -2.624

1996 1996-01-12 1996-03-20 68 46.103 102 -3.661 -5.333

1997 1997-01-21 1997-03-11 49 26.973 95 -1.629 -2.546

1998 NA NA NA 7.308 74 -0.264 -1.226

1999 1999-01-05 1999-03-09 63 19.329 69 -0.288 -2.042

2000 2000-01-21 2000-02-18 28 23.734 71 -0.638 -2.977

2001 2001-01-08 2001-03-12 63 19.484 98 -2.653 -4.685

2002 NA NA NA 5.095 61 1.907 0.079

2003 2003-01-23 2003-03-27 63 50.654 103 -3.647 -6.015

2004 2004-01-15 2004-03-11 56 39.688 88 -2.497 -5.013

2005 2005-01-20 2005-03-21 60 40.521 85 -2.222 -4.552

2006 2006-02-27 2006-03-02 3 16.384 76 -0.314 -2.256

2007 2007-02-01 2007-03-12 39 26.478 72 -0.483 -2.678

2008 2008-02-11 2008-03-17 35 17.173 97 -1.459 -2.948

2009 2009-01-12 2009-03-05 52 29.199 94 -2.943 -5.027

2010 2010-02-04 2010-02-15 11 16.427 69 -1.178 -3.587

2011 2011-01-18 2011-03-08 49 32.287 94 -2.706 -5.062

2012 NA NA NA 3.389 53 1.372 -0.518

2013 2013-02-09 2013-03-03 22 17.067 68 -0.606 -1.979

2014 2014-01-03 2014-04-08 95 61.613 101 -3.826 -5.970

2015 2015-01-02 2015-04-09 97 82.709 101 -3.983 -6.407

2016 2016-02-14 2016-03-06 21 24.609 62 1.539 -0.290

2017 NA NA NA 6.799 62 1.132 -0.613

2018 2017-12-29 2018-02-23 56 25.934 83 -1.532 -3.414
60

Table 7. Environmental parameters in Lake St. Clair.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1972-12-20 1973-03-06 76 99.391 57 -0.165 -1.571

1974 1973-12-31 1974-03-28 87 100.000 66 -0.548 -2.574

1975 1975-01-16 1975-04-10 84 100.000 77 0.728 -0.915

1976 1975-12-23 1976-03-02 70 98.494 66 0.815 -1.853

1977 1976-12-16 1977-03-16 90 100.000 92 -4.244 -6.169

1978 1977-12-21 1978-04-12 112 100.000 97 -2.687 -5.521

1979 1978-12-18 1979-03-19 91 99.840 85 -2.740 -5.328

1980 1980-01-02 1980-03-26 84 98.526 75 -0.457 -2.240

1981 1980-12-24 1981-03-11 77 100.000 82 -1.785 -3.636

1982 1981-12-21 1982-04-13 113 100.000 87 -1.994 -4.525

1983 1983-01-03 1983-03-23 79 97.179 50 1.831 0.493

1984 1983-12-20 1984-04-26 128 100.000 80 -1.343 -3.622

1985 1984-12-28 1985-03-23 85 99.968 74 -0.918 -2.782

1986 1985-12-14 1986-03-22 98 99.744 79 -1.350 -3.823

1987 1987-01-17 1987-03-21 63 97.564 61 0.095 -1.165

1988 1988-01-03 1988-03-20 77 100.000 72 -0.203 -2.385

1989 1988-12-14 1989-03-24 100 95.000 66 0.353 -1.480

1990 1989-12-13 1990-03-21 98 96.128 78 -0.649 -2.264

1991 1990-12-28 1991-03-18 80 95.000 59 0.707 -1.270

1992 1991-12-20 1992-04-03 105 95.000 65 0.283 -0.829

1993 1992-12-28 1993-04-05 98 96.359 71 -0.034 -1.564

1994 1993-12-27 1994-04-08 102 99.000 78 -2.414 -4.679

1995 1995-01-06 1995-03-20 73 99.000 66 0.948 -1.225

1996 1995-12-11 1996-03-22 102 99.000 93 -1.863 -3.220

1997 1996-12-20 1997-03-07 77 99.000 71 -0.547 -1.532

1998 1998-01-02 1998-02-06 35 94.551 41 2.060 1.380

1999 1998-12-29 1999-03-19 80 99.000 54 1.468 -0.394

2000 1999-12-28 2000-03-03 66 98.147 56 1.073 -1.121

2001 2000-12-11 2001-03-15 94 99.000 90 -1.544 -3.619

2002 2001-12-31 2002-03-25 84 92.532 47 2.925 1.003

2003 2002-12-05 2003-03-27 112 100.000 95 -2.313 -4.386

2004 2003-12-15 2004-03-08 84 100.000 78 -0.680 -3.056

2005 2004-12-20 2005-03-31 101 99.872 75 -0.898 -3.205

2006 2005-12-12 2006-03-09 87 95.000 66 0.774 -1.062

2007 2007-01-18 2007-03-22 63 100.000 67 -0.031 -1.946

2008 2007-12-06 2008-04-01 117 100.000 90 -0.979 -2.644

2009 2008-12-08 2009-03-10 92 100.000 86 -2.337 -4.356

2010 2009-12-14 2010-03-25 101 100.000 81 -0.466 -2.938

2011 2010-12-09 2011-04-03 115 99.939 98 -2.270 -4.586

2012 2012-01-04 2012-02-22 49 94.154 44 2.048 0.377

2013 2012-12-27 2013-03-25 88 100.000 77 0.048 -1.209

2014 2013-11-29 2014-04-09 131 100.000 104 -3.757 -6.043

2015 2014-11-23 2015-04-04 132 100.000 94 -3.150 -4.969

2016 2016-01-05 2016-03-08 63 95.942 57 2.111 0.358

2017 2016-12-16 2017-03-23 97 92.618 57 1.839 -0.114

2018 2017-12-14 2018-03-02 78 100.000 79 -1.248 -3.103
61

Table 8. Environmental parameters in Great Lakes.

Year Freezeup

(date)

Breakup

(date)

Duration

(days)

AMIC

(%)

FDD

(days)

WSI

(°C)

WSI_GLERL

(°C)

1973 1972-12-20 1973-03-21 91 62.759 90 -2.574 -4.180

1974 1974-01-10 1974-04-18 98 61.457 98 -2.810 -5.012

1975 1975-01-16 1975-04-10 84 52.324 107 -1.265 -2.925

1976 1975-12-23 1976-03-30 98 42.328 93 -1.737 -4.409

1977 1976-12-16 1977-04-20 125 90.197 111 -6.287 -8.368

1978 1977-12-28 1978-04-19 112 83.832 111 -4.474 -7.313

1979 1978-12-27 1979-05-07 131 94.885 116 -4.953 -7.677

1980 1980-01-02 1980-04-09 98 66.987 92 -2.386 -4.386

1981 1980-12-24 1981-04-08 105 73.422 94 -3.565 -5.575

1982 1982-01-04 1982-04-26 112 76.753 106 -3.980 -6.595

1983 1983-01-18 1983-03-23 64 25.455 80 -0.359 -1.769

1984 1983-12-20 1984-04-19 121 67.106 96 -3.218 -5.547

1985 1984-12-28 1985-04-06 99 71.666 87 -2.940 -5.007

1986 1985-12-21 1986-04-05 105 77.868 104 -3.716 -5.991

1987 1987-01-24 1987-03-14 49 29.595 92 -1.699 -2.857

1988 1988-01-10 1988-04-03 84 56.153 90 -2.185 -4.370

1989 1989-01-01 1989-04-23 112 64.405 92 -1.966 -4.083

1990 1989-12-18 1990-03-30 102 59.872 98 -3.028 -4.616

1991 1991-01-07 1991-03-25 77 49.397 74 -1.389 -3.533

1992 1992-01-17 1992-04-06 80 50.921 98 -1.856 -3.077

1993 1993-01-13 1993-04-05 82 66.704 101 -2.466 -4.177

1994 1994-01-03 1994-04-18 105 90.914 91 -4.813 -7.278

1995 1995-01-30 1995-03-22 51 35.718 78 -0.916 -3.090

1996 1995-12-29 1996-04-26 119 82.306 118 -4.449 -5.980

1997 1997-01-14 1997-04-15 91 58.756 102 -2.789 -3.910

1998 1998-01-16 1998-02-13 28 14.506 76 -0.114 -0.868

1999 1999-01-05 1999-03-12 66 26.379 74 -0.665 -2.607

2000 2000-01-18 2000-02-29 42 35.090 71 -0.845 -3.124

2001 2000-12-25 2001-04-09 105 34.422 110 -3.231 -5.409

2002 2002-03-04 2002-03-25 21 12.373 68 1.390 -0.593

2003 2003-01-13 2003-04-14 91 80.222 105 -3.778 -5.853

2004 2004-01-08 2004-04-01 84 52.000 93 -2.442 -4.747

2005 2004-12-27 2005-03-31 94 45.215 92 -2.205 -4.528

2006 2006-02-09 2006-03-13 32 21.644 90 -0.774 -2.568

2007 2007-01-25 2007-03-29 63 56.398 79 -1.263 -3.345

2008 2008-01-21 2008-04-03 73 55.002 107 -2.392 -4.157

2009 2008-12-22 2009-04-07 106 74.631 99 -3.757 -6.026

2010 2010-01-05 2010-03-14 68 29.576 89 -1.699 -4.302

2011 2010-12-30 2011-04-03 94 40.455 102 -3.222 -5.634

2012 2012-01-20 2012-03-05 45 13.279 53 0.665 -1.083

2013 2013-01-22 2013-03-24 61 38.763 90 -1.365 -2.864

2014 2013-12-14 2014-05-10 147 92.562 115 -5.388 -7.925

2015 2015-01-02 2015-04-21 109 88.833 105 -4.742 -6.673

2016 2016-01-19 2016-03-06 47 34.174 71 0.776 -1.123

2017 2017-01-07 2017-03-20 72 19.614 70 0.521 -1.599

2018 2017-12-28 2018-04-11 104 69.172 102 -2.771 -4.692
62

Table 9. Atmospheric teleconnection indices.

Year ENSO

(°C) NAO AMO(°C)

 PDO

(°C) Year ENSO(°C) NAO AMO(°C)

 PDO

(°C) 

1951 -0.70 -0.08 0.07 -1.12 1985 -0.97 -0.70 -0.33 1.01 

1952 0.57 0.47 0.18 -1.38 1986 -0.47 0.11 -0.31 1.04 

1953 0.37 -0.20 0.27 -0.20 1987 1.20 -0.30 -0.28 1.80 

1954 0.70 0.21 0.20 -0.95 1988 0.80 0.70 -0.03 1.15 

1955 -0.67 -0.76 0.02 -0.61 1989 -1.63 1.26 -0.18 -0.80 

1956 -1.13 -0.39 0.18 -2.66 1990 0.07 0.43 -0.20 -0.39 

1957 -0.17 0.42 -0.05 -1.26 1991 0.37 0.71 -0.11 -1.81 

1958 1.73 -0.49 0.11 0.11 1992 1.60 0.47 -0.16 0.15 

1959 0.60 -0.30 0.15 0.37 1993 0.10 0.86 -0.24 0.26 

1960 -0.07 -0.91 0.17 0.29 1994 0.10 1.02 -0.30 0.96 

1961 0.03 0.31 0.09 0.59 1995 0.93 1.36 -0.06 -0.61 

1962 -0.20 -0.11 0.17 -1.71 1996 -0.90 -0.62 0.00 0.50 

1963 -0.33 -1.47 0.17 -0.48 1997 -0.47 -0.07 -0.09 0.16 

1964 1.00 -1.43 -0.04 -0.43 1998 2.17 -0.23 0.18 1.02 

1965 -0.57 -0.61 -0.17 -1.31 1999 -1.47 0.64 0.13 -0.47 

1966 1.43 -0.59 -0.06 -0.26 2000 -1.60 1.30 -0.04 -1.49 

1967 -0.40 0.01 0.08 -0.23 2001 -0.63 0.04 -0.09 0.47 

1968 -0.57 -0.54 -0.20 -0.58 2002 -0.13 0.24 0.19 -0.43 

1969 1.07 -1.26 -0.03 -1.16 2003 0.87 -0.05 0.01 1.98 

1970 0.47 -0.38 -0.03 0.81 2004 0.37 0.07 0.21 0.41 

1971 -1.30 -0.70 -0.25 -1.54 2005 0.63 0.89 0.14 0.36 

1972 -0.67 0.40 -0.34 -1.90 2006 -0.77 0.11 0.14 0.63 

1973 1.70 0.36 -0.37 -0.47 2007 0.63 0.36 0.19 0.06 

1974 -1.80 0.51 -0.27 -1.21 2008 -1.53 0.65 0.09 -0.78 

1975 -0.57 0.49 -0.32 -0.56 2009 -0.73 -0.08 -0.07 -1.27 

1976 -1.50 0.23 -0.38 -1.53 2010 1.47 -1.67 0.10 0.58 

1977 0.70 -1.04 -0.38 1.33 2011 -1.37 -0.68 0.15 -0.99 

1978 0.63 -0.85 -0.15 0.37 2012 -0.80 1.37 -0.03 -1.34 

1979 0.03 -1.21 -0.17 -0.78 2013 -0.30 0.02 0.13 -0.35 

1980 0.57 0.10 -0.04 0.26 2014 -0.37 0.86 -0.02 0.09 

1981 -0.27 0.69 -0.20 0.65 2015 0.63 1.66 0.02 2.42 

1982 0.00 0.08 -0.05 0.40 2016 2.43 1.31 0.21 1.43 

1983 2.10 0.95 -0.25 0.65 2017 -0.33 0.65 0.26 0.88 

1984 -0.63 0.89 -0.06 1.47 2018 -0.90 1.30 0.20 0.52