ICE COVER STUDY

Green Lake
Township of Madawaska Valley
Barry's Bay, Ontario, Canada

Latitude    45o 23.5'                    Longitude      77o 38.5'

This small (~1 km2) land-locked lake is largely spring fed with no above-ground exit and is sheltered from heavy winds.
The Lake level is relatively constant, varying with weather and the seasons rather than with any flood-control program.
The ice generally melts in place rather than being pushed ashore, so the freeze and thaw is more directly dependent on temperature
than is the case with larger lakes exposed to more variables.

graph


The slope now shows the ice cover per year to be receding at a rate of about 1 day per year;
however, in 1997, the trend actually indicated increasing ice cover days.
More significant perhaps, is the trend toward more chaotic behavior in the last half of the sample.

doug@dougdelamatter.com

For more data on more lakes see the Environment Canada site
(EMAN section "IceWatch") http://www.naturewatch.ca

Green Lake Data:
© D. De La Matter May 15, 2011

Year

Freeze Over

Thawed

Ice Covered

Ice Free

Date

Julian Day

Date

Julian Day

Days

Days
                   

1980

23-Nov

328

   

1981

30-Nov

334

 

5-Apr

95

 

132

  

239

1982

11-Dec

345

 

27-Apr

117

 

148

  

228

1983

6-Dec

340

 

24-Apr

114

 

134

  

226

1984

5-Dec

340

 

21-Apr

112

 

137

  

228

1985

4-Dec

338

 

24-Apr

114

 

139

  

224

1986

1-Dec

335

 

7-Apr

97

 

124

  

238

1987

17-Dec

351

 

12-Apr

102

 

132

  

249

1988

9-Dec

334

 

13-Apr

104

 

118

  

240

1989

24-Nov

328

 

21-Apr

111

 

132

  

217

1990

11-Dec

345

 

20-Apr

110

 

147

  

235

1991

5-Dec

339

 

10-Apr

100

 

120

  

239

1992

6-Dec

341

 

3-May

124

 

115

  

217

1993

26-Nov

330

 

25-Apr

115

 

139

  

215

1994

16-Dec

350

 

18-Apr

108

 

143

  

242

1995

9-Dec

343

 

2-Apr

92

 

107

  

251

1996

25-Nov

330

 

27-Apr

118

 

140

  

212

1997

20-Dec

354

 

27-Apr

117

 

152

  

237

1998

1-Dec

335

 

13-Apr

103

 

114

  

232

1999

18-Dec

352

 

12-Apr

102

 

132

  

250

2000

3-Dec

338

 

2-Apr

93

 

106

  

245

2001

26-Dec

360

 

19-Apr

109

 

136

  

251

2002

28-Nov

332

 

12-Apr

102

 

107

  

230

2003

3-Dec

337

 

16-Apr

104

 

137

  

233

2004

6-Dec

341

 

17-Apr

108

 

136

  

233

2005

6-Dec

340

 

22-Apr

112

 

136

  

228

2006

28-Dec

362

 

14-Apr

104

 

129

  

258

2007

11-Dec

345

 

16-Apr

106

 

109

  

239

2008

6-Dec

341

 

21-Apr

112

 

132

  

229

2009

12-Dec

341

 

12-Apr

102

 

126

  

244

2010

9-Dec

343

 

3-Apr

93

 

112

  

250

2011

18-Dec

349

 

18-Apr

108

 

130

  

241

2012

12-Dec

347

 

25-Mar

85

 

101

  

262

2013

 

 

 

23-Apr

113

 

131

  

ice-free