April 16, 2021: Today’s Photos / News

These aerial photographs were taken just before noon today, by MAG Canada‘s Justin Martin.

You can click on these pictures to see a larger, zoomable version.

Hay Island.

Looking north west along Hay Island towards Middle Island and Scotty Island. Needle Point is at the lower right corner.

Pine Portage Bay, Sultana Island, Bald Indian Bay.

This same pan of ice was photographed yesterday afternoon by Quinn Wilson. It looks thinner now. It also shrank noticeably in the span of twenty hours, and lost some of the smaller pans that surrounded it.

Pine Portage Bay, including Northern Harbour.

I waited a bit to see if I got any late arriving photos, or if one of the satellites managed to catch a break in the cloud cover, but it looks like that’s it for today.

Oh. No it’s not. I forgot to check the news today. This Covid-19 update about provincial border checkpoints from CBC News. 

We’re just days away from full ice-out now, and some popular areas of the lake are already reachable.

For the rest, a lot may depend on our weekend weather. As if to keep the suspense going, it’s a mixed bag. The Weather Network says we’re looking at a crisp -7°C tonight, but temperatures should rebound to 10° by Saturday afternoon.


April 16, 2021: New Aerials / Big Changes

A week of cloud and snow has left us all wondering what’s happening on the lake. But poor flying weather and cloud cover that blocked the satellites from seeing anything left us all in the dark. Until yesterday.

First, it cleared up enough yesterday afternoon that NASA’s Aqua satellite managed to image most of Lake of the Woods.

If you click on this picture, you’ll see a version with some landmarks tagged.

Aqua satellite’s image from April 15, 2021, in false colour.

There are clearly areas of ice on Shoal Lake, and both north and south of the Barrier Islands. Closer to Kenora, cloud cover makes it hard to be confident, but it looks like mostly open water. The south end of the lake looks completely clear. This is possible, it was down to free-floating sheets of ice five days ago, and that stuff is very vulnerable to wind action.

Let’s follow up with some aerial photography to get a more detailed picture of how it’s going. My friend Quinn Wilson was out for a training flight in one of the MAG Canada fire detection planes, a Cessna 337. He took these pictures on Thursday afternoon.

If you click on these pictures, you’ll see a larger full screen version.

Bigstone Bay, Hay Island.

In this shot, the camera is pointing south across Bigstone Bay at Hay Island. Interestingly, the east end of the bay is mostly water, but there are extensive ice sheets west of Copper Island. In the distance, Moore Bay appears open, but Andrew Bay and everything further south look icy.

Pine Portage Bay.

From the other side of the plane, Pine Portage Bay, home of Northern Harbour. The marina is just visible at the right edge.

Town Island, Keewatin Channel, Second Channel, The Tangle.

Looking north. Town Island is at the lower right, and the picture is roughly centered on Shragge’s Island. It looks like the water is open from Kenora all the way to Leisure Island now.

The Manitou.

In the other direction, the Manitou is still covered in ice. I don’t know the name of the island in the foreground; it’s next door to Hough’s. Whiskey Island is at the right, and the Barrier Islands are in the distance.

Welcome Channel.

Welcome Channel is still frozen over, but the shorelines are starting to let go.

Poplar Bay.

The strange track-like feature is just a reflection of the upholstery stitching in side the plane.

Abbott Island, Cross Island, Turnbull Island, Rheault Bay.

West of Keewatin, there’s still pan ice close to town.

Crowe Island, Anglican Island Channel Island, Shragges Island, Keewatin Channel, Second Channel, Canoe Channel.

As you can see, this area is open except for where the ice roads ran, but there’s still plenty of ice further out on the lake. Quinn says all that ice looks poor, though. Thanks, Quinn!

Only days now until the lake is fully open.

I’ve got more photos coming in, taken this morning, but while I receive them and sort them out, I’ll put this batch up for people to see.

I’ll put the newest photos up in a separate post later today.


April 11, 2021: New Aerials

Kelly Belair and his kids have contributed aerial photos starting last year. Here’s what he sent me today.

We’ll start with the ones taken yesterday, Saturday April 10.

You can click on these pictures to see the full-size version.

The Elbow.

Kelly flies a Maule, and the photographer on this flight was his daughter, Taylor Belair. So this shot looks south at the Elbow, which is the gap in the Barrier Islands between Allie Island, on the left, and Mather Island on the right.

French Narrows.

Here’s another passage through the Barrier Islands: French Narrows lies between East Allie Island (the twin points at the left of the photo) and the mainland of the Eastern Peninsula. This shot looks north, with Andrew Bay in the corner to the right of the wing strut.

Poplar Bay, Holmstrom’s Marsh, The Tangle.

North east over Poplar Bay, with The Tangle near the center of the shot and Holmstrom’s Marsh at the right edge. Kenora is near the upper left corner.

Then this lovely shot.

Water bomber near Cross Island.

It’s not very often I have to figure out the location of someone’s photo that doesn’t have even one whole island in it, but we’re looking roughly north west, and that’s Cross Island with Turnbull Island in the background. (I don’t actually know all 14,000 islands; Kelly gave me a hint, he said it was near Keewatin.)

Lower Black Sturgeon. 

Looking north or north west at Lower Black Sturgeon, with Black Sturgeon Narrows out of frame at the right edge.

For fun, Kelly also sent me this picture he took on April 5 of last year.

Holmstrom’s Marsh, Welcome Channel.

Haha, you say: look at all the ice.

Well, it’s probably going to snow tonight. Plus other lovely forms of precipitation like drizzle and freezing drizzle. Because I put the summer tires on ten days ago. Luckily, I’m not travelling much.

Even with that, we’re still doing much better than most years. We’ve only fallen behind if you compare this spring to the exceptionally early ones.

Signs of spring: I saw a pair of Mallards today. Also Caroline found a tick on our dog, Ebony*. Yay.

*Ebony is new. Our (mostly) Husky, Piper, succumbed to complications of Lyme Disease earlier this spring. She was only six. It was lonely without a dog in the house, so we have adopted two-year-old Ebony from A Dog’s Life.

April 10, 2021: Satellite Saturday / Multiple Contributors

Okay, this is going to be a long post, because several people sent me stuff.

But first, the week’s big news.

Ontario has gone back into lockdown, and this time it includes a stay-at-home order.

Here’s the wording from the alert that popped up on my phone:

A stay-at-home order is in effect. Only leave home for essential purposes such as food, health care, vaccines, exercise or work. It’s the law. Stay home, save lives.

And here’s a link to some more detailed information.

I have not found any specific wording about visiting summer residences in the new order. I have enquired, but it may take a while to get a response. The old rules from the previous lockdown were that you could: A) visit your camp for up to 24 hours to perform necessary maintenance, in which case you cannot be in contact with anyone, or B) isolate for 14 days, so you’d have to bring gas and food with you to last for for two weeks before you could go shopping.

It gets more complicated if you are visiting from Manitoba, as you might also have to isolate for 14 days upon your return, but I’ve been told this needn’t apply as long as you adhere to the Ontario requirements while here.

Here’s an excerpt from the Manitoba government website that was updated on April 8:

As per the public health order, 14 days of self-isolation is required for people returning or coming to Manitoba from all jurisdictions.

Now back to a more comfortable topic: the weather. The NASA satellites got good images on April 6, and then it turned cloudy until today.

Here’s what things looked like on Tuesday the 6th.

If you click on this image, you’ll see a version with some landmarks tagged.

Aqua satellite’s MODIS image from April 6, 2021, in false colour.

Today’s images haven’t been uploaded yet.

In the meantime, I have a picture from Devon Ostir, whose dock cam on Hare Island looks out on the Manitou.

With the exception of the satellite imagery, you can click on today’s pictures to see a full-screen version that is zoomable.

Next up, a drone shot of Keewatin Channel, courtesy of Paul Leischow.

I chose this specific shot from over Crowe Island because it shows that the water is open all the way to Keewatin. Actually, there’s a whole 360° panorama, and you can view it here if you want to scope out Rat Portage Bay or the Tangle from this vantage point.

Now photos from Josh Broten, and they are very revealing.

Over Buffalo Bay looking east to Garden Island.

Looking east at the big ice patch between Garden, Big, and Oak Island.

Over Windfall Island looking north between Falcon Island and the Western Peninsula.

Looking SW over Bishop Bay with Shoal Lake in the distance.

Over Skeet Island looking NNE.

Over Yellow Girl Point looking SE down Long Bay.

Aside from the huge stretches of open water, the key point is that all over the south end of the lake, the ice has separated from the shore. It’s still in enormous sheets, but it will start to break apart into pans soon.

Further north, where there are more islands and less vast stretches of water, the progress does not look as dramatic, but it’s following a similar path.

In case you missed it, regular commenter Stu Everett pointed out the other day that when current through the lake is slow in  winter, the ice forms to a more even thickness all over the lake, and sets up a situation where the big slow-moving parts of the lake are melting almost as fast as the places that usually have more current.

Before I forget, special thanks to all the people who sent in pictures or messages today.

The first of today’s satellite images is available.

Terra satellite’s MODIS image for April 10, 2021, in false colour.

Pity about the cloud cover [low altitude cumulus clouds at the left, made of water vapour, high level cirrus clouds with more ice at the right] but you can see the same trend photographed by Josh.

UPDATE: Aqua’s image is up.

Aqua satellite’s MODIS image from April 10, 2021, in false colour.

Still some cloud, but it’s moved a little, revealing different parts of the lake.

The big question is: have we reached the tipping point? Once the ice breaks up, the end is very near, because wind action becomes a major factor. I think we’re almost there.

So naturally, the forecast is for some cool temperatures. The Weather Network has revised the fourteen day forecast since I last talked about it, and it now shows Monday as the coolest, with temps hovering around the freezing point all day. After that, daytime highs may run a little below normal for the next two weeks, while overnight lows are kind of 50/50.

Will the ice go? Your guess is as good as mine.

April 6, 2021: Andy Zabloski

Tom Hutton and Andy Zabloski were out in one of the MAG Canada King Airs today, and Andy snapped some aerial photos for us.

You can click on these to see a larger, full screen version.

Downtown Kenora, Rat Portage Bay, Safety Bay.

Yesterday’s sunshine and heat (we topped out at 17°C) did a number on the ice along the Kenora waterfront. Kenora Bay, where the MS Kenora and the Whitecap Pavillion are,  is ice free this afternoon, and Safety Bay, in the middle of the photograph, is almost entirely open. Rat Portage Bay, on the left, is usually slower to melt, but the ice looks really rotten.

Rat Portage Bay, Gun Club Island, Keewatin Channel.

This second shot looks slightly south of west. Treaty Island dominates the foreground, with Rat Portage Bay to the right and Gun Club Island  at the right side. The water near the middle of the picture is Keewatin Channel, and you can see that the open water there extends past Anglican Island to Crowe Island and Forrest Island.

Holmstrom’s Marsh, the Manitou, the Barrier Islands.

Facing south, and looking over Holmstrom’s March across the Manitou to the Barrier Islands. At the left edge of the frame is the western tip of Scotty Island, and at the right side are the Slate Islands, and at the very edge is one of Whiskey Island’s points. The ice on the Manitou is always slow to go, but it’s very vulnerable to wind once it starts to break apart.

The Elbow, Allie Island, Mather Island.

Here’s a closer look at the Barrier Islands, facing south east. This water is in the Elbow, between Allie Island at the left and Mather Island at the right. Each of the narrow gaps in this chain of large islands has significant current.

It’s amazing what one really warm day can do. The waterfront at Norman has been completely transformed since yesterday. Today was nice, too, but it looks as if we’re going to max out at 11°C today, and then we have some interesting weather coming. Wednesday and Thursday will be cooler and rainy, then the weekend will pick up to slightly above normal temperatures.  However, most of next week will be below normal, and flurries are in the forecast. Temperatures bottom out next Wednesday when we’ll barely creep above freezing.  A normal high this time of year is about 7°C, and overnight lows would typically be about -3°C. After that cool spell, it looks like we’ll be heading back to  temperatures close to or slightly better than normal.

Out of that mixed bag, the rain is on our side. Snow would be bad if it persisted as a reflective white layer on the ice, but my guess is it’ll mostly turn to slush right away.

Signs of spring: I saw a water-bomber yesterday. The MNR’s spring training has probably begun, and Kenora offers some of the first big stretches of open water.

Because it’s been such a dry spring, the forest fire hazard is medium to high, and there are actually three active fires in the Northwest Ontario region. None of them are what you’d call headline news, but you can find more info at this MNR website.

April 5, 2021: Seems slow

I’ve been talking a lot about how favourable our conditions are this year. We had a mild winter that formed less ice than usual. We had an early start to the thaw, and we’ve had mostly higher than normal temperatures. Conditions seemed primed for a record-breaking early ice-out, but that’s not developing.

I’m not saying this year’s thaw is getting delayed, but I am pointing out that it’s gradual.  Gentle reminder that neither Sean or I predicted records would fall.

We’ve had years in the past, notably 2010 and 2012, where the thaw started almost as early as this year, and the ice was gone pretty quick. But I think we’ve begun to lag behind the progress of those years.

I’ll pop the pancake graph in here so you can see what I’m talking about.

You can click on it to see an enlarged, easier to read version.

Remember, each year since 2003 (at the bottom) gets a bar that starts on the inflection date* and ends when the lake is 100% ice-free. The first thing you might notice is that 2021’s line begins earlier than any other. And yet, it looks set to be one of the longest, representing a surprisingly drawn-out thaw for a warm spring following a mild winter.

*Inflection point or inflection date means the date when the air temperature started to average out at above freezing. More precisely, when the Mean Daily Temperature rose above zero Celsius on a lasting basis.

The two years that come closest to our starting point are 2010, at March 8, and 2012, at March 10. Both of those years had reasonably quick thaws, at less than 5½ weeks. [38 & 37 days, respectively, but who’s counting?] To match that, we’d want to be looking at a total thaw by April 10. So that’s where I began the pale blue of uncertainty on this year’s bar. But Sean Cockrem’s prediction, based on presumed ice thickness and air temperatures forecast, is April 20. Side note: this is his stated and preferred estimate, but his simplest formula, without intuitive insights, produced a date of April 25, so I ran the uncertainty zone out that far.

There are two things going on here. First, the earlier you start, the longer it can take, simply because March is apt to be cooler than April, even if temperatures are running above average. Second, air temperature is not the whole story when it comes to getting rid of lake ice. Sean’s model uses data from past years, and that data is all over the map. In other words, every thaw is different, which is why Sean has to make some educated guesses as to what kind of year we’re having.

Last year we got schooled. After air temperatures stayed depressingly low, the ice went in a hurry  (17 days!) There are many factors other than air temperature: snow cover, rain, wind, sunshine and so on. But I increasingly suspect that the biggest one is current.

Most years that I can recall, the water seemed to open up through the Keewatin Channel faster than this year. Sometimes the water spreads from Channel Island to Safety Bay quite quickly. This year it seems to be rather lethargic.

So I happened to be talking  with some friends on Zoom, and one who lives on Golf Course Bay remarked that this winter, the end of their dock iced in for the first time ever. Usually, the current swirling past the tip of their dock prevents ice from forming there, and the ice is notoriously thin in the whole area around the Coast Guard docks. This sparked a conversation about how—although the lake ice was generally thin—the low current allowed people to route some ice roads through usually untenable areas.

To talk about current, we need to check in with the Lake of the Woods Control Board, who strive to keep lake levels safe by altering the outflow through the Norman Dam. Spring is the season when that typically gets trickiest. It’s prudent to keep the lake levels on the low side in March, to allow for spring run-off and flooding. They call this the winter drawdown, and it’s part of their regular strategy. It’s usually followed by the spring refill. This year there wasn’t  much spring run-off, so lake levels have not risen as rapidly as some other years. So the outflow is being kept low, to give the lake levels a chance to rebound.

Here’s the latest bulletin from the Board.

The current level of Lake of the Woods is 322.42 m (1057.8 ft), a 40th percentile level for this time of year. The average lake level changed little over the past week and is expected to remain stable or slightly increase (less than 2 cm or 1 in) over the next week.

Lake of the Woods authorized outflow is 150 m³/s with no changes scheduled.

This time last year, when we had that very rapid thaw, the outflow was nearly four times as high. The current was probably eating away at the ice from below long before the air temperature rose above freezing.

From the air, this shows as open water in the narrows and channels, and ever since I started Ice Patrol, I’ve been paying close attention to those areas. It makes perfect sense that progress of that type is slow this year, despite the mild weather.

So while current is a big factor, its role this year will be passive. Which is one less wild card for Sean’s predictive model.

April 4, 2021: Shoal Lake to Kenora

Some new aerial photographs from Josh Broten, and also the first drone picture of the year, taken by George Dyker over Clytie Bay, a popular cottage area on Shoal Lake. All were taken Saturday.

Let’s start with Josh’s overview of Shoal.

You can click on these pictures to see them full screen and full size.

Northwest Angle, Shoal Lake.

Looking north from over the Northwest Angle towards Shoal Lake. Lots of water and only pan ice in the Angle. In the distance, the ice looks poor on Shoal.

Monument Bay, Shoal Lake.

Here’s a slightly closer look at Shoal, with the camera pointing north west over Monument Bay, so that Shoal Lakes large Dominique and Stevens Island appear side by side. Mason Lake and part of Reid Lake are a the right side of the frame.

Now George Dyker’s drone shot of Clytie Bay on Shoal. George operates a DJI drone.

Shoal Lake’s Clytie Bay.

This view looks south west, with the open water at Gateway Point in the foreground. That ice road that heads off onto the main body of the lake looks to be in one piece, but it’s riddled with cracks.

Now, back to our tour with Josh’s Cub, picking things up at the south end of the lake, where Josh is based.

Oak Island, Flag Island, Brush Island.

We’re back by the NW Angle, looking at the area by the international border. The open water is mainly by Flag Island, which has a webcam, by the way. You can find a link to it on the Lake of the Woods Links sidebar.*

*When viewed on a desktop or large tablet, Ice Patrol offers a number of features on a sidebar to the right of the main column. These include Recent Comments, a Search Tool, a Flag Counter, the Archive Tool, and an extensive list of links that may be of interest to lake dwellers and visitors.  However, if you’re in the habit of viewing Ice Patrol on a phone, or via the email subscriber list, you may not see the sidebar.

Also a link to my writing blog. Support me by buying my SF novel, AVIANS. It’s about girl power, alternative aviation, and volcanoes! E-book and trade paperbacks available. Averaging 4.5% stars last time I checked.

Oak Point, Big Narrows.

Looking south. The patch of open water in the foreground is right at Oak Point, and there’s open water almost all the way through Big Narrows. At the left, on the far side of Big Narrows Island and Tranquil Channel, there’s some open water through French Portage Narrows.

Chisholm Island, Cliff Island.

Looking north west, with Chisholm Island at the bottom of the frame, and Cliff Island at the left. The Alneau Peninsula is just off the picture to the left, and the Barrier Islands are near the upper right corner. Prominent pressure ridges show the strain on the ice.

Let’s finish Josh’s tour with a shot of the Kenora area.

Poplar Bay, Keewatin Channel, Rat Portage Bay.

Centered on Keewatin Channel, this picture looks north east towards Rat Portage Bay, Safety Bay and Kenora. Poplar Bay is in the lower left corner.

The ice is weakening, slowly but steadily. Warm temperatures all week, with daily highs in the double digits, should help.

In the meantime, a reminder. Ontario went back into a province-wide lockdown on Saturday, April 3rd, and is expected to stay that way for a four week “emergency brake.” Hairdressers are closed, restaurants are take-out only, and stores are restricted to half or quarter occupancy, depending on how essential they are. More details here.



April 3, 2021: Satellite Saturday

I haven’t received many aerial photographs lately, so Ice Patrol has been a bit quiet. Also, we had a couple of days of cold temperatures, so there wasn’t much to report.

Satellite imagery from the last week was a bit baffling. Changes to the ice made it appear as if the lake was refreezing, and then some fresh snow made things look streaky and weird. But today was sunny and warm, and the NASA satellites got a good look at us.

Let’s start with today. Here’s Terra’s MODIS image from this morning.

If you click on this first image, you’ll see a version with some landmarks tagged.

Terra satellite’s MODIS image from April 3, 2021, in natural colour.

And the false colour version, which incorporates some infrared and gives a better idea of the quality of the ice.

These images are just 640×640 pixels, so you cannot zoom in on them.

Terra satellite’s MODIS image from April 3, 2021, in false colour.

For the last ten days or so, the satellite images have been a bit hard to interpret, so let’s go back almost two weeks to see how things looked on March 22.

Aqua satellite’s MODIS image from March 22, 2021, in false colour.

I have to say, the differences are subtle, and not clearly in this week’s favour.

But if you’ve been following the comments, you might have noticed Eroc’s post that the webcam at Red Wing Lodge, near Morson, Ontario, is showing a lot of candled ice and open water. If you’d like to take a look for yourself, I’ll add a link to the lodge’s homepage on the Lake of the Woods Links sidebar. There’s a link to the Flag Island Webcam, too. I just checked, and the ice looks really rotten there.

So I think most of the paler blue in the latest picture, which normally represents thicker ice, is actually candled or air-filled ice.

The other thing I’ve been wondering is: how does this year—with such an early start to the thaw—compare to other years?

The two years I’d be most interested in checking are 2010 and 2012, because they both had early melts and were ice-free by the middle of April.

2010 was cloudy for the whole first week of April, so there are no satellite pictures suitable for a direct comparison.

But in 2012, Terra got this lovely image on this exact date.

Terra satellite’s MODIS image from April 3, 2012, in false colour.

Okay, there’s no getting around it. 2012’s thaw was way more advanced on April third than we are this year. But don’t feel bad. 2012 was a very early thaw: the lake was clear by April 16.

What does a more typical year look like? Well, the first five days of May is a very common ice-out range, so the best years to check would be 2015 or 2016. Presto! Terra got a good shot on this date in 2015.

Terra satellite’s MODIS image from April 3, 2015, in false colour.

So in a typical year, early April has the lake pretty much frozen solid except for some of the narrows.

We’re doing well, and the forecast is for above normal temperatures for the next two weeks. A normal high this time of year is 6°C, and overnight lows would average out to -4°C.  We’re forecast to be above freezing almost all the time, and we’ll have some lovely warm days in the next little while.

My conclusion: we’re still on track for an ice-free lake in late April.

Signs of Spring: Motorcycles. I’ve seen several, and have made a note to be more alert for them. Please try to do the same.

Also bugs. This is one of the powerline clearways on Tunnel Island. You could click on this picture to see it full screen, but trust me, it doesn’t get any prettier.

Swarm of flying insects.

Blackflies? Sandflies? Gnats? I didn’t stick around to find out. I snapped a quick picture and left. Note to self: either take my Covid mask on hikes, or grow a moustache long enough to breathe through.

March 31, 2021: Myrtle Rapids

There’s no real news, because it’s been cold. If you’re checking in from far away, it was -14°C when I got up this morning, and it hasn’t gone above freezing today. A normal high this time of year is 5°C and with pleasing symmetry, a typical low is -5°C. We’ll be back to above normal temperatures tomorrow, and double digits by the weekend.

So while there hasn’t been much active thawing, Luke Burak sent me two pictures of the Myrtle Rapids area on the Winnipeg River, just west of the Dalles. I’ll just post this one, as they show the same area.

You can click on this picture to see the full screen, zoomable version.

Myrtle Rapids.

Looking south east towards Kris Island in the upper right corner.

Thanks, Luke!

Meanwhile the satellite pictures continue to be perplexing.

Here’s today’s from Aqua.

Aqua satellite’s image from March 31, 2021, in false colour.

Those stripes look pretty wild, so I checked the true colour image.

Aqua satellite’s image from March 31, 2021, in true colour.

That looks a bit more natural. I’m guessing streaks of wind-blown snow.

Terra‘s pictures this morning were a bit glitchy, but the same streaks are visible.

Technical notes. I’ve lost access to Photobucket, the internet home of some of my oldest archives. They’ve revised the service, and I cannot log in because I no longer have the email address I had when I set up the account. So I am gradually uploading my old pictures to a new archive here at WordPress. I won’t be able to recover the captions or any remarks I made, but I do have all the pictures, neatly filed by date. These are pictures from before Ice Patrol was a proper website: the years from 2009 to 2013. I started with 2009, and you can try the Previous Years tool on the sidebar for that year, if you like. The other years probably won’t work until I do a lot more work. Eventually, I’ll put up some of the pictures I took as far back as 2003.

March 27, 2021: Satellite Saturday

First, a high resolution satellite photograph from the European Space Agency’s Sentinel 2 satellite, taken on March 23.

You can click on this image to see it full-screen. You can zoom in enough to make out roads and big buildings.

Lake of the Woods north of the Alneau Peninsula and west of Whitefish Bay.

The south end of the lake was captured, but the full size image is too big to upload whole. You can view it online, here. Sorry, Sioux Narrows, the image cuts off just west of Whitefish Narrows. You got left out.

Okay, so this is a nice picture, but it’s four days old. What’s happening now?

Strange things. But first I have to explain a bit about the different ways satellites can image stuff. The ESA’s Sentinel satellites (there are six in active service) use powerful instruments to take pictures of a small part of the planet with high resolution, sort of like a telephoto lens. But because they’re working with such a tight field of view, they can’t cover everything all the time. So opportunities to photograph our lake only come up once in every several days. Throw in periods of cloud cover and darkness, and it’s actually more like once or twice a month.

This is why I usually rely on the NASA Terra and Aqua satellites. They’re designed to constantly take pictures, using a wide-angle view that lets them sweep over pretty much the whole planet every day or so, but in less detail. The pair of satellites have matching but complementary orbits, and the general situation is that Terra images LotW in the morning, and Aqua in the afternoon. The instruments they use to do this are called MODIS. That’s short for MODerate resolution Imaging Spectroradiometer. If you want to read more about it, you can see a brochure here. The key facts from an Ice Patrol perspective is that they scan the planet in multiple wavelengths, including separate bands of Blue, Green and Red light, two bands of Near Infrared, and two bands of Shortwave Infrared. For the true colour images, the blue, green and red components are blended to create a natural looking view, in a manner somewhat comparable to how your printer uses three ink cartridges to print full colour. For the false colour versions, a computer takes information from several wavelengths and processes it a bit differently. Today I learned that the images I use, which come from the University of Wisconsin at Madison, are processed using the same algorithm every day. That’s relevant, because some of the recent images have shown an unexpected development.

Here’s the image I posted a few days ago, from March 22.

Aqua satellite’s MODIS image from March 22, 2021, in false colour.

The ice is darkening all over.

And here’s the latest image, from March 25.

Aqua satellite’s MODIS image from March 25, 2021, in false colour.

Whoa! When I first saw this, (after I said “What the…?”) I thought maybe I’d accidentally pulled a picture from last year or something. Nope. So what on earth is going on? We can’t have suddenly created a foot of ice, because these pictures are from before our recent  drop to freezing temperatures. This picture was taken by the Aqua satellite on the afternoon of March 25, when the temperature was probably about 5°C. The overnight low the night before was a mild -2.7°C. We’d have been losing ice in the days before this picture was captured, not making it.

Okay, you know that TV show about the pawn shop? The one where they say, “I’m not an expert, but I have a friend…”? Well, I have a few contacts, and this time I reached out to Hilary Dugan, an associate professor at the University of Wisconsin at Madison, the place that publishes these satellite images to the web. She’s a limnologist (a freshwater scientist who studies lakes and rivers), and she knows a lot more about the MODIS images than I do. In fact, much of the information I dumped on you a few paragraphs ago comes from her. She was able to confirm that the image processing has not been altered. So she, and her colleagues who work directly with the public versions of the imagery that I use here, have two possible explanations. The lake looks different because of a change in lighting, or the lake looks different because the ice has transformed in some way.

I don’t really think it’s just the lighting, so there has to be some change in the quality of the ice. I thought that maybe the ice had candled, and Hilary suggested that it could have developed a lot of air bubbles, making it airier and whiter.

We’ll know more when we have a sunny day and get new pictures. In the meantime, I’m going for a little drive. Take a second look at that Sentinel image at the top of this post. You might have noticed that two little lakes just west of Kenora—Muriel Lake and Sandy Lake—are shining bright and conspicuously blue. I want to know why.

Okay, I’m back. Neither of those lakes is covered in blue snow. They’re shiny, and the ice is thin: there’s a prominent warning on the  Pellatt Community Centre sign. I went to the shoreline and photographed the ice. This is how it looked at Sandy Lake:

Shoreline ice at Sandy Lake.

And this is what it was like at Muriel Lake.

In both cases, the ice was granular, and very white from the air in it.

Maybe this is what’s happened to the ice all over Lake of the Woods.

I started work on this post this morning. Since then, today’s Terra image has come in.

Terra Satellite’s MODIS image from March 27, 2021 in false colour.

There are cute little cumulus clouds hugging the ground along the top and left of this picture, and high altitude ice clouds in the lower right. You can definitely see the shadow of the ice clouds altering the look of the lake ice. So I guess the quality of light does affect the colour.

I am reminded of the lyrics of Paul Simon’s song Graceland. “The Mississippi Delta was shining like a National Guitar…”

It’s sunny this afternoon, so I’m interested to see what Aqua‘s image looks like. It’s not ready yet, so I’ll publish this now, and update this post when the new image comes in. Revisit Ice Patrol and hit refresh on your browser sometime this evening if you’re curious too.