Lake Superior Weather Trends

I didn't get a chance to go out hiking yesterday so for today's blog posting I decided to research Lake Superior's weather and temperature trends. I was talking with a friend yesterday and we realized that we have not yet had any snow. In other years I have cross country skied in October, and certainly in early November. Instead this year the temperatures have been in the 40s and 50s with no snow in sight. We barely have even had any frost.

I checked various web pages to see how typical or atypical this is. The data that is available is for Marquette. The earliest date to receive at least an inch of snow was September 22, 1974. The earliest date to receive at least 1/10 of an inch was September 19, 1956. According to the historical data, there has been at least a trace of snow in every month of the year. In the mid 1980s I saw snow flakes on the Grand Marais breakwall on July 5th. The latest date in Marquette for receiving at least 1/10 of an inch was November 19, 1994. The latest date to receive at least an inch of snow was December 11, 2006. It remains to be seen if we break the record for the latest date to receive snow this year.

The average amount of snow for Marquette over the last 65 years is:

January 30.5 inches
February 25.1 inches
March 23.7 inches
April 9.2 inches
May 1.4 inches
June trace
July trace
August trace
September .2 inches
October 4.4 inches
November 17.9 inches
December 28.6 inches
TOTAL 141 inches

Here are some charts showing weather trends for Marquette.  First a chart showing average snowfall per month.  Notice how high Marquette is (dark green line) compared to the national average (shaded light green).  For Grand Marais, the total snowfall figures would be a bit higher. We probably average around 200 inches of snow per year.

As would be expected, the daily high, low, and average temperatures also fall below the national average.

According to the chart below, only around 15 percent of the days in Marquette are clear of clouds.

One of the impacts on snowfall is the average temperature of Lake Superior's water. I was curious what the long term trend has been. The lake’s surface water temperatures have only been monitored for 31 years when a series of buoys were placed around the lake by the National Oceanic Atmospheric Administration (NOAA) in 1979. 

Here is a satellite view of Lake Superior as well as a chart showing the depth variation.

The average temperature of Lake Superior's water over a 12 month period is 39 degrees. Last year, Lake Superior hit a 31-year high mark in the daily average temperature of its surface waters on August 11 when the average for that day on several monitoring buoys on the open lake tallied 68.7°F (20.4°C). The previous high for daily average surface water temperature was set on August 14, 1998, at 67.5°F (19.7C).

Conditions can change quickly on Lake Superior. A couple of days after the record was set -- on August 14 and 15 last year -- the strongest sustained summer wind event on record occurred, mixing the warm surface waters with cooler waters below, dramatically cooling off the surface of the lake, which dropped from 68.7 to 59°F (15°C) in just two days.” The established average water surface temperature for Lake Superior in August is 56°F (13.4°C).  Below is a chart showing the trends leading up to August 11th last year.

The chart below shows that the warming trend of Lake Superior's water temperature continued in 2011.

The warmer lake caused stratification of hot and cold waters by June in 2010, a month or so earlier than usual. In summer, the colder water sinks as warmer water stays near the surface. The early warming in 2010 relates to the lack of ice cover the previous winter. With little ice cover, the lake, just like a giant solar panel, absorbed energy (and heat) from the sun.

Data collected at the power plant in Sault Saint Marie confirms the fact that the lake's average temperature, as well as the average air temperature in the region, are both increasing. Researchers have acknowledged these long-term increases in average air temperatures, but have also noted that Lake Superior's water temperature is heating up at a rate almost double that of the air.

While researchers know what happened with the water temperatures, they don’t know exactly how it will influence the lake’s complex eco-systems and water circulation. Warmer waters may drive some fish, like lake trout, deeper while certain invasive species, such a zebra mussels, kept in check by the lake’s usually chilly temperatures, may have get a better foothold.

Lake Superior was not the only large lake in hot water. Lake Michigan exceeded its all-time record temperature and Lake Huron tied its previous record. Lakes Ontario and Erie did not exceed previous records.

Just for comparison purposes, the following chart shows the temperature differences between the great lakes.

Other data comparing the five great lakes is below.

Average Depth
Lake Superior 483 feet (147 m)
Lake Michigan 279 feet (85 m)
Lake Huron 195 feet (59 m)
Lake Erie 62 feet (19 m)
Lake Ontario 283 feet (86 m)

Maximum Depth
Lake Superior 1332 feet (406 m)
Lake Michigan 925 feet (281 m)
Lake Huron 750 feet (229 m)
Lake Erie 210 feet (64 m)
Lake Ontario 802 feet (244 m)

Shore Length
Lake Superior 2726 miles (191 km)
Lake Michigan 1638 miles (2633 km)
Lake Huron 3827 miles (6157 km)
Lake Erie 871 miles (1402 km)
Lake Ontario 712 miles (1146 km)

Retention of water (time for all the lake water to be replaced)
Lake Superior 191 years
Lake Michigan 99 years
Lake Huron 22 years
Lake Erie 2.6 years
Lake Ontario 6 years

The two biggest influences on Lake Superior's water temperature is winter ice cover and summer air temperatures. One of the main reasons why Lake Superior's average water temperature is increasing is because of the decrease in ice cover during the winter months. The annual ice cycle for Lake Superior consists of a period of increasing shore ice in December and January leading to seasonal maximum ice which occurs sometime between mid-February and the first week in March, followed by decreasing ice and a loss of all ice cover that occurs between mid-to-late March and mid-to-late April. With the exception of portions of the east lake basin in January, ice cover on Lake Superior has varied over the last 40 years from less than 10 percent to over 90 percent.  Below is a chart showing the ice cover in 1973.

Here is an actual satellite photo taken in early March 2010 showing the lack of ice on Lake Superior.

Here is a chart also showing the lack of ice cover

For comparison, here is a picture taken in 2009 showing that most of the lake was covered.

Here is a chart showing the ice cover in 2009.

It will be interesting to see what the 2011-12 winter will bring. 

Hike in the Pictured Rocks National Park Forest

Despite having a rib injury from slipping on wet leaves while I was down state, I just had to get out and  hike yesterday.  It was sunny with temperatures in the 50s -- feeling more like September than November.  I chose to carefully walk the flat trail between H58 and the Log Slide (Masse Homestead Trail).  When I left to go down state a couple of weeks ago, the trees still had their leaves.  Now it certainly looks like late fall. 

As I walked toward the logslide, I noticed that the character of the forest changed.  Here are a few examples:

After I arrived at the log slide, I took the old trail east back to the western edge of the Grand Sable Dunes.  Notice the hiker in the middle of the sand bowl.

It was a calm day on the waters of Lake Superior.  Here is a shot looking east toward Grand Marais. 

I notice along the trail one of the most colorful shelf fungi I have ever seen.

Yesterday morning the deer were eating the apples in my yard.  I was able to capture a few photos.

Fantastic Rock Collection

While down state I visited with a friend to see his rock collection. To protect the collection, I will not even reveal the name. Wow. His collection rivals many museum collections.

Here is a huge Mexican agate that has shadow banding as well as plume formation.

This Brazilian agate has an interesting calcite crystal, around which chalcedony bands formed.  You can see the crystal just right of center.

He had thousands of Lake Superior agates, including this dandy eye agate.

The shadow in this Mexican Laguna agate just danced.

There were more cases of rocks than I could count, including this case that features mostly Mexican agates.

The top row on the shelf below included Coyamito agates from Mexico. 

Here is a close up of one of the Coyamito agates.  Double wow.

I just love the translucency of the Brazilian enhydro agates.  These specimens have water that became trapped as the agate formed.

You might think that the photo below is of a Brazilian geode agate.  It is actually an extremely rare Lake Superior agate.

I just love this Kentucky agate.

The agate below is a Mexican thunder egg.

He had a couple of terrific specimens of Labadorite, including the one below.

UofM Football Game

Last Saturday I attended a reunion with friends I met during my first year of college at the University of Michigan. Most of us worked in the cafeteria of our dorm. It is great to still spend time with this great bunch of people over 30 years later. Thank you to George for coordinating the logistics and getting the tickets.

Since the game was at noon, we didn't have much time to tail gate. However we spent a few minutes and grabbed something to eat. Thanks to Steve and Kathy for putting out the spread of food and drink.

The game was terrific as Michigan played well to beat Purdue decisively. It is always interesting to be part of the crowd numbering over 112,000. I must admit though, that with tight security the people in the stands are not nearly as entertaining as they were back in the 70s when we went to school.  But since it was homecoming, we were entertained by the alumni band, various celebrations of well-known alumni, as well as the alumni cheerleaders.

More Photos from my Lower Michigan Trip

Today I'll post a few more pictures from my trip to Lower Michigan.

Before going over to set up for the Gitche Gumee Gathering at the Rock Shoppe in Plymouth, friends Marsha and Robbie suggested that we stop by the Botanical Gardens to see and walk the new labyrinth.

Earlier in the day we walked around Marsha's yard.  I had to capture this cool bridge over a creek.

Here are a couple of shots of my booth at the Mason show.  It is by far the largest booth I have at any show with eight 8x3 tables plus one I brought that is a 4 x 2 table.  Thanks to all those who purchased things at this show to make it the best I have ever had.

While having breakfast before the Mason show with friends, I captured a shot of this hot air balloon and swans over Lake Lansing.