Why does Toronto have better outdoor ice than Ottawa?

Toronto is, on average, warmer than Ottawa. So why does it have better outdoor ice?

Some might argue that it doesn't. Every winter, Ottawa's Rideau Canal freezes to form the world's largest skating rink. Just about every city park sports an outdoor ice surface. But almost all of the city's ice is natural. On warm days, the rinks become puddles, as shown here.

This year, Ottawa is unlikely to have skate-able outdoor ice until January. In Toronto, the outdoor rinks have been open since the end of November.

It might seem odd that Toronto, which is three to five degrees (Celsius) warmer than Ottawa, has an outdoor skating season that lasts a month or two longer. Yet the very fact that Toronto is warmer than Ottawa may be the reason why it has better outdoor ice.

There are two basic ways of making outdoor ice: natural freezing and artificial refrigeration. The marginal cost of creating ice with each of these technologies is shown on the diagram below. Natural freezing is cheap when the weather is cold - all it requires is a bed of packed snow, a good hose and lots of water (or a pond). Yet as soon as night-time temperatures rise above zero, it's impossible to make natural ice - the marginal cost of doing so rises to infinity.

Artificial freezing is more expensive, both in terms of the fixed costs of installing the refrigeration equipment and, possibly, the marginal costs of operating it. But it can be used to create ice at temperatures as high as 5 degrees Celsius, so the skating season lasts from November to March.

The decision to invest in artificial refrigeration equipment is a simple cost-benefit calculus: do the benefits of a longer outdoor skating season outweigh the fixed costs of installing equipment and any increase in costs associated with operating refrigeration equipment?

The first diagram shows a situation where there are substantial potential benefits from installing refrigeration equipment.  This is, essentially, the Toronto situation - refrigeration increases the number of skating days considerably so, as long as the equipment is not too expensive, it is worth buying:

 The second diagram shows a situation where refrigeration is not necessarily a smart investment. When a long, cold winter changes abruptly into spring, there are relatively few skating days gained by using artificial refrigeration, and in the meantime one has to bear the higher costs of maintaining an artificial surface.

This is basically an example of the  "houses are kept warmer in cold climates" phenomenon. This is familiar to anyone who has ever visited England in winter - the difference between England and Canada is that, in Canada, it's only cold outside. In a cold climate, it's worth insulating a house well, which reduces the marginal cost of heating, which allows one to heat the house to a higher temperature.  

In recent years, Ottawa has begun to invest in refrigerated ice surfaces - the latest one just opened at Lansdowne Park.  Cheaper and more effective refrigeration technology? Changing voter preferences/shifting political equilibrium? Climate change? I don't know.

 

Comments

[Jacques René Giguère]

Which begs the question: why isn't the St-Charles river in Québec City no longer used as its own longest skating rink?

[Stephen Gordon]

Too costly to maintain, and not enough people using it?

[Nick Rowe]

Yep.

I've found an ungated version of David Friedman's paper. Lovely mix of physics and economics.

[Frances Woolley]

Nick, thanks for the link.

Jacques Rene - this tourist info page http://www.quebecregion.com/en/what-to-do/activities-attractions/ideas/skating-in-quebec-city/ still lists the St Charles river - but apparently it's only 1.5 k long. The Rideau Canal is much longer - I'll take you if you're ever in Ottawa when it's open. Was the St Charles ever open more?

I could have titled this "Why does Toronto have better outdoor ice than Montreal or Quebec City" also because, looking at the tourist info for both those places, it looks like most of the outdoor ice is natural there too - though both have some truly stunning skating spots.

[Jacques René Giguère]

Frances: For some years, the St-Charles was longer. However never as long as the Rideau (here insert "skating envy" for my native city).
Stephen: why would the maintenance be costlier in Québec than Ottawa? And since both cities are almost the same size and have both strong winter tourism (probably stronger in Québec, too busy enjoying coffee with the dear olds to check...), the customer base should be about the same?

[Frances Woolley]

Jacques Rene -

I don't know anything about the St-Charles, but I do know that rivers are, generally speaking, much harder to maintain than canals, because of currents, storm sewers, water depth, etc. I do go skating and skiing on the Rideau River (as opposed to the Rideau Canal), but I know where the swift water is, I know where the water runs deep, and I'm a strong swimmer.

Another factor: the Rideau Canal is maintained by the National Capital Commission, i.e. it's federal $$. And maintenance is contracted out. If the maintenance of the St Charles can't be contracted out, that would tend to increase costs, also whoever pays for it might not have as deep pockets as the NCC.

Also Quebec City has that awesome looking ice surface on the plains of Abraham - that alone would merit a visit!

[Jacques René Giguère]

The St-Charles is dammed at the mouth and regulated as much as the Rideau Canal. The maintenance is done by the City, a very efficient organisation compared to let's say Montréal (at least as good as Ottawa, a very good one according to my eyes.)
But then , if you have the rink on the Plains of Abraham (a few meters from my dear olds condo where I am still sipping coffee) (for those who never went to QCity, imagine a rink in the middle of Central Park if Central Park was on top of Fort Tryon...)

https://www.ville.quebec.qc.ca/citoyens/loisirs_sports/patinoires_exterieures_fiche.aspx?entID=698

and the one in Place d'Youville

http://www.ville.quebec.qc.ca/citoyens/loisirs_sports/patinoires_exterieures_fiche.aspx?entID=161

(once again imagine Rink at the Rockefeller Center in front of the medieval walls of maybe Carcassonne), then who needs a river like Ottawa or a lake like Regina? Not that there is anything wrong with that.

[Chris J]

I think the plots aren't quite right. You want on the x axis the number of consecutive days with sub zero temperatures. For example here in Sudbury we had a freakishly cold November and warm December. I think including this is the quantitative analysis strengthens your point.

[Chris J]

I have lived in LA and I can state that the fixed-cost insulation etc etc in LA houses just is not there. (Ie my anecdotal observations of LA architecture jive with the Chicago LA paper cited above.)

It *is* there in water use. LA people have beautiful automated sprinklers that turn on at 4am and don't spray any water on pavement. They also grow anlarger-bladed waxy grass.

I bet the same analysis with water use and evapouration would produce the same result.

[Jacques René Giguère]

In Tucson AZ, xeroscaping is now the norm and bathtub stoppers are no longer available in hotels.

[Frances Woolley]

Chris J - yes, temperature fluctuations do complicate the analysis, and it is definitely the case that natural ice takes much longer to recover from a thaw than refrigerated ice. Increased variability in temperature would tend to increase the demand for refrigeration, even without any change in the mean temperature. But the graphs are basically illustrative - they also abstract from any relationship between outside temperature and marginal benefits of skating, issues of ice quality, fixed costs of zambonis, the possibility of using natural ice surfaces as soccer fields in the summer, etc. But I think the basic logic works - just as your analysis of LA works, even though not everyone in that city has a beautiful automated sprinkler system.

[Determinant]

Peterborough, ON is another city that has a canal skating rink. The Trent Canal is the other recreational canal in Ontario. Each year the artificial cut between Lock 21 and the Lift Lock is turned into a skating rink. Except right now it's 5 degrees Celsius out.

[Jacques René Giguère]

Today, in QCity, only three rinks are still functionning; Place d'Youville, the Plains and Gaétan-Boucher in a western suburb. Plus a lot of scary sidewalks.