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NA. Lake Pepin ice thickness data collected from 1994 through 2009 during winter stratified random sampling episodes. Measurements were collected within a three week window starting on Monday’s of the last full work week of January. - PowerPoint PPT Presentation
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1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Ice
Dep
th (
cm)
0
20
40
60
80
Lake Pepin ice thickness data collected from 1994 through 2009 during winter stratified random sampling episodes. Measurements were collected within a three week window starting on Monday’s of the last full work week of January. Sample size is 30 measurements per episode. Note there are zero values during some years where ice coverage did not exist in the upper part of Lake Pepin. No sampling occurred in 2003. Box plots indicate the 25 th and 75th
percentile, a line within the box marks the median, and the whiskers are the 10 th and 90th percentiles. Points indicateoutliers.
NA
Pearson correlation coefficientr = -0.809
Relationship between mean December through January air temperature and median ice depth measured during winter SRS episodes from 1995 though 2009. Air temperature data is a mean of temperatures measured daily at Lock&Dam 3 at 08:00, 16:00, and 24:00 hours. No ice data was collected in 2003.
0
10
20
30
40
50
60
70
0 5 10 15 20 25 30
Mean Dec/Jan Air Temperature
Med
ian
Ice
Dep
th (
cm)
0
10
20
30
40
50
60
70
0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
Mean January Discharge (cfs)
Me
dia
n I
ce
De
pth
(c
m)
Pearson correlation coefficientr = -0.027
Relationship between mean January discharge at Lock&Dam 3 and median ice depth measured during winter SRS episodes from 1995 though 2008. No ice data was collected in 2003.
