Climate and Weather

Rain

Question:

I was wondering anytime it rains is the water always clean?

Answer:

That is a great question! How clean the rain is depends mostly on how clean the air is that the water drops (and snow flakes) fall through. As rain (and snow) falls through the atmosphere, it picks up or scavenges tiny specks of dirt or particles that may be suspended in the air. If it did not rain, much of these particles would remain in the air and possibly be transported around the world building up and creating more and more air pollution. This is one of the reasons we find some pollution in the polar ice of the Canadian Arctic. Particles in the atmosphere of the far north are brought down to the surface by rain and snow.

- Ian Droppo

 


 

Words for Snow

Question:

I recently moved to Ontario from New York City. In the eastern United States, we have only three words for snow: slush, ice, and “that stuff we used to get every winter.” Is it true that in Canada we have many more words for snow than in the US? Thanks!

Answer:

There are many terms to describe snow that are commonly used in the Canadian vernacular. Examples include ‘powder’: light fluffy fresh snow that is ideal for alpine skiing; and ‘packing snow’: heavy wet snow ideal for snowball fights. There are many other terms that describe snow but are much less commonly used or known, such ‘firn spiegel’ (an ice crust on top of the snow) and ‘depth hoar’ (large coarse grains found at the base of the snowpack). It’s difficult to say if there are more terms used in Canada than in the United States – those regions of the States that get a lot of snow are likely familiar with the same terms we tend to use in Canada.

What’s definitely true is that the scientific community has a vast terminology to describe snow that the general public does not use. There is a classification system for snowflakes, developed in the 1960′s by two Japanese scientists (Makono and Lee) which includes names for 80 specific types of snow crystals. These can be grouped into general classes such as dendrites, needles, plates, and graupel. The formation of these different types of snow crystals depends on factors such as temperature, humidity, and collisions with other falling snow flakes.

Once snow hits the ground, it slowly undergoes metamorphosis, changing through the winter due to temperature gradients in the snowpack (snow at the bottom is generally warmer than snow at the top). There is a separate classification system (“The International Classification for Seasonal Snow on the Ground”) which defines the terminology for describing snow on the ground covering characteristics such as grain size, density, hardness, and wetness. The appendix of definitions in this snow classification provides an exhaustive list of English, French, Swedish, and Russian terms for describing snow.

So snow can be described in general terms (slushy, icy, powdery), or within an exhaustive scientific classification system. Depending on your perspective, perhaps by the end of winter, it may simply be a nuisance!

- Chris Derksen

 


 

Environmental Issues

Question:

We often hear it said that the environment is the crucial issue of the 21st century. Some examples of environmental issues that spring to mind are the melting of the ice sheets in Greenland and the Antarctic, the hole in the ozone layer and the disappearance of numerous marine species. In your opinion, what chances do we really have of stopping all this? Can you give me a percentage?

Answer:

Hello, and thank you for your question. The environment certainly is a crucial issue on a number of fronts, as you pointed out. Because of the many impacts that human beings are having on our planet, this problem is increasingly measurable and visible. It is a scientific fact that the earth has been getting warmer since the industrial age began and, according to scientists around the world, this is in large part because of the actions of human beings. Also, this warming has been happening more quickly than ever before in the last 850,000 years at least, and probably the last 2 to 20 million years. This rapid warming is one of the problems because, the faster the changes occur, the more difficult it is for species to adapt. However, it is difficult to put percentages on the possibilities of a given event occurring. The situation we find ourselves in now is unprecedented. We can only look at the past for clues to the future. The earth’s balances are at once delicate and robust. We know that, in the history of our planet, species have disappeared and others have taken their place. For the first time, though, human beings are the reason for the big changes. However, we know that we can have positive impacts too. For example, in the 1970s and 1980s, scientists realized that the ozone layer was thinner because of manufactured aerosols. In 1987, the countries of the world got together to sign the Montreal Protocol for eliminating production of CFCs. As a result, the ozone layer will have regenerated by 2050. We are truly in an era in which our actions will make a big, positive difference for centuries to come.

- René Brunet

 


 

Wind Patterns

Question:

I am a realtor in Victoria and wondering how I can learn more about wind patterns in the area ie. for a particular property how do I find out in which direction the wind blows what proportion of the time. I’ve had the question asked of me in regards to waterfront property but also wonder if in general there are differences in the direction, speed and temperature of the wind depending on the exact position of the property in question.

Answer:

For specific information concerning local weather data, you should contact your local British Colombia (Vancouver) Environment Canada office. Specifically, you should contact the Meteorological Service of Canada office and ask for the climatological data office. They may charge a fee for this information.

- René Brunet

 


 

Microclimates

Question:

Hi there-a question about microclimates: I get Seasonal Affective Disorder in the winter here in Vancouver, B.C. People often say Surrey, B.C. gets more sunshine hours than Vancouver. As I am thinking of moving, I’m wondering if this is true, and if so, how many more sunny days do they get on average? (Substantial enough to move there?) By contrast, would North Vancouver get more cloudy days than Vancouver? I’m asking because that was my first choice for areas to live. Thanks so much for any info!!

Answer:

Thank you for your question. Indeed many in the Pacific NorthWest Coast experience Seasonal Affective Disorder and is a medical condition concerning lack of Vitamin D coming from sunlight. The many climates in Southern British Columbia have a lot to do with your proximity to the ocean and where you are in relation to mountains. As a general rule in B.C., if you are on the west side of a mountain, you will likely have more clouds and precipitation and less sunshine, while on the east side of a mountain, there is usually less clouds and precipitation and a bit more sunshine. But these ‘microclimates’ can vary greatly in a short distance, depending on mountains, valleys, altitude and wind direction. The bottom line concerning Vancouver, North Vancouver and Surrey is that they are relatively close to one another and have minor topographical differences. So the amount of difference in sunshine in the winter months would hardly be noticeable! To give you an example, Vancouver’s average daily sunshine in December is 1.4 hours, while Victoria’s is 1.8 hours. The difference between Vancouver, North Vancouver and Surrey would be even less. If you would like specific numbers for each of these areas, I’d suggest contacting your local Vancouver Environment Canada Weather Office. I hope this helps, and keep smiling!

- René Brunet

 


 

Robotics in Polar Research

Question:

Hi, I am a member a robotics team that is participating in an international robotics competition called Robofest. For our competition, we are allowed to make our robot accomplish anything that we desire. We plan on designing and building a full-scale functional robot that can collect various types of data in cold and icy climates for climate research. Robots that other groups have built for Robofest have been very useful in solving other world issues. Recently a team filed a patent for their robot that can defuse land mines. ( link) My question is what kinds of data are useful to climatologists that study cold or icy climates like in the Arctic? For example, are scientists interested in the pH level o the snow, the chemicals contained in the ice, the time and intensity of sunlight that the land is exposed to, wind levels? Would scientist like robots to collect samples of the ice? With the input of climatologists, we can help climatologists in their research by gathering useful data. Thank you

Answer:

This is an excellent question.

Major obstacles to gathering field observations in polar regions are the vast areas to cover, inhospitable conditions, high costs, and complicated logistics. Robotics provide an alternative approach to placing people in the field, with the benefits of reduced human risk, continuous operations, and access to remote areas. Because of these benefits, robotics have been explored by some groups, including a robot developed for deployment in Antarctica (http://www.sciencedaily.com/releases/2005/03/050329130622.htm) and unmanned aerial vehicles (http://www.wired.com/wiredscience/2009/12/scientific-uavs/).

Even with these developments, the use of robotics for polar research is extremely limited and the potential remains largely untapped. There are various measurements that could be made from a robotic platform that would address some of our current observational gaps. Example applications include:

Robotically acquired snow samples from remote regions could return south for laboratory analysis for elements such as mercury and black carbon. Mercury in snow is an important component of the chemical reactions in the atmosphere that result in ozone depletion events. Black carbon from industrial emissions is deposited in snow across the Arctic and affects the amount of absorbed and reflected solar energy, and contributes to global warming. We know mercury and black carbon are important, but have a very poor understanding of their distribution across the Arctic.

Weather stations in the Canadian Arctic are very sparse and located almost exclusively in coastal locations. Robotic vehicles could be equipped with sensors to make meteorological measurements such as air temperature and humidity across vast inland areas for which we have no observations. We often to go to great effort and expense to put instruments in one place in the Arctic. Robotics provide a mobile measurement platform.

Of course for scientists like myself who love working in the field in polar regions, I’ll always argue that some human participation is required! Best of luck in Robofest, and I’d very interested to see your design.

- Chris Derksen

 


 

Ozone Layer

Question:

Hi, I work in Cancer Prevention – ultraviolet exposure prevention. I would like to know by what percentage has the ozone layer decreased in Canada. I am revising some fact sheets about myths and sun safety, and one question is on the state of the ozone layer in Canada. Would you have recent data. What I have now is this statement: Today the ozone layer over Southern Canada is about 6% thinner than it was before 1980 and the amount of UV radiation reaching the surface has increased by about 7%. I believe this references dates back to over 10 years ago. Any change? Thank you, Diane Desjardins Public Health Nurse Ottawa Public Health

Answer:

An excellent document for information on ozone measurements, processes, and trends in Canada is a special issue of the journal Atmosphere-Ocean published in 2007 (Ozone Science in 2007: A Canadian Perspective on Ozone in the Changing Atmosphere / La science de l’ozone en 2007 : une perspective canadienne sur l’ozone dans l’atmosphère en changement, Atmosphere-Ocean Volume 46 No. 1).

The observed decline in ozone is due to chemical reactions with bromine- and chlorine- based ozone depleting substances (ODS’s). The Montreal Protocol (which entered into force in 1989) sought to regulate the production of these gases. Observations published by Fioletev (2007) show a decline in the major ODS’s as a result of these regulations. While ozone reached a minimum over Canada in the early 1990′s, a recovery is now evident (although not yet to pre-1980′s levels) because of the successful reduction in ODS’s. A recent estimate is that annual mean total ozone over Canada is now about 3% lower than the pre-1980′s level (Fioletev, 2007) so this slight recovery in ozone should be associated with a small reduction in UV radiation reaching the surface. The success of the Montreal (and subsequent) protocols to reduce OSD’s is a story of the international community successfully addressing an environmental issue with global implications.

Source: Fioletev, V. 2007. Ozone Climatology, Trends, and Substances that Control Ozone. Atmosphere-Ocean. 46(1): 39-67.

 


 

Cottage

Question:

I have bought a cottage near Barry’s Bay. I am making it a year round residence and as self supportive as possible. I currently live in Woodstock. I feel this alternate residence could help with escaping heat & drought. Do you agree? Is this far enough north to make any difference from where I live now? Is there any suggestions for other additional improvements that might help my family with stand this climate change?

Answer:

Considering that Barry’s Bay is some 400 kilometres farther north of Woodstock, the climate is generally not exposed to the extreme heatwaves that are more common farther south. However, this does not mean that you are immune to the heat and humidity in Barry’s Bay. If you are in a more rural setting (trees/forest) and in a high elevation in Barry’s Bay, then the climate should be a bit less hot than in more urban settings to the south. I would suggest contact the MSC for specific climatological data for the past 30 years for both Woodstock and Barry’s Bay to make a more precise comparison.

As for your home in Barry’s Bay, or any house for that matter, I would suggest having tall deciduous trees on the south end of your house to block the summer sun, and evergreens on the north end of your house to block the cold northerly winds in winter. If you are located near a lake, this will also help to moderate the summer heat near your house. I hope this helps you to stay cool!

- René Brunet

 


 

Bathurst Weather

Question:

Hi, I live in Bathurst in northern New Brunswick. People have been telling me for some time that Bathurst is located at a rare confluence of three currents, making it the most difficult place on Earth for which to forecast the weather. Is this a myth or is it actually true? I know that weather forecasting is far from an exact science, but I have noticed that the forecasts are more and more accurate.

Answer:

Ocean currents have a major influence on global climate. For example, the relatively temperate climate of northern Europe (even at relatively high latitudes) is due to the import of heat by the Gulf Stream in the North Atlantic. Helsinki Finland is located at approximately 60 degrees North – about the same as Churchill, Manitoba, yet the maritime influenced climate of southern Finland means Helsinki has an average January temperature of -4 Celsius. The cold continental climate of Churchill has a comparatively frigid January mean of nearly -27 Celsius!

When considering ocean circulation, the climate of the east coast of Canada is influenced primarily by the Labrador current. This is a southerly flowing cold current (which, incidentally, is responsible for transporting icebergs down the Atlantic coast). During summer, easterly onshore winds induce cooler weather along the coast because the cold current has a cooling effect on air masses that pass over it. During winter, the ocean is relatively warmer than the land surface, so easterly winds can bring in more moderate temperatures (but also precipitation and fog) than air masses that move over the snow-covered land. Influence from the Gulf Stream is modest along the Canadian Atlantic coast because the air masses that control our weather typically move from west to east, so any warming influence is minimal.

I’m glad that you are receiving helpful forecasts! The Meteorological Service of Canada (MSC) is constantly striving to improve weather forecasts. Research on land surface and atmospheric modeling performed within Environment Canada contribute to improving the numerical weather prediction models used for operational forecasting at MSC. In addition, information from satellites, including variables such as snow cover and soil moisture, are used to improve our forecasting capabilities.

- Chris Derksen

 


 

Tree Line

Question:

I read an article recently that said certain animal species are moving northward at a measurable rate, a km or so a year if I remember. This leads me to ask if the tree line is moving north in Canada or higher up mountains where this exists. And are species changing in the forests?

Answer:

Thank you for your question. Many scientists at the Government of Canada work towards exploring this very question, particularly within the Canadian Forest Service (CFS). A number of studies outside of the CFS have recorded modest shifts northwards in distribution of tree and forest animal species.  The CFS has worked on projecting future shifts based on climate scenarios, as well as examining adaptation options to reduce the impact of climate change on Canada’s forests.

Dan McKenney (Chief, Landscape Analysis and Applications) and his team have created an interactive map which displays current distributions of habitat for plant species (http://planthardiness.gc.ca/), and have been working towards projecting future range limits of tree species across Canada (http://planthardiness.gc.ca/index.pl?m=16&lang=en).

A group of scientists, led by Catherine Ste-Marie (CFS Climate Change Research Coordinator), recently published a special issue on Assisted Migration (Forestry Chronicle, Nov/Dec 2011 – http://pubs.cif-ifc.org/toc/tfc/87/06#d131019e134), examining the possibility of moving tree species north in order to help them adapt to climate change. Although all of the articles address current tree species movement to some degree, Richard Winder’s article on “Ecological implications for assisted migration in Canadian forests” covers the scientific evidence in the most detail.

I hope this has been helpful and please do not hesitate to follow-up on these answers.

-Catherine Ste-Marie, Ph.D.

 


 

Seasonal Temperature Changes

Question:

In Ottawa, Canada we see a huge change in temperature between Summer and winter and as I understand it this is largely due to the ’tilt’ of the earth toward or away from the sun as we orbit it. Question: What is the difference in distance during Summer and Winter from Ottawa to the sun and is this the sole reason for this massive temperature change? It just seems to me, that in the totality of distances in space that this differential is quite insignificant and that there must be other factors at work?

Answer:

As we all observe, much of Canada, especially in the mid part of the continent (including Ottawa) experiences its hottest weather in the summer and coldest in the winter. However, this does not have to do with the change in distance of the earth from the sun. Ironically, the earth is actually a little bit closer to the sun in winter and slightly farther in the summer. Around January 4th the earth is 147,098,074 km from the sun, while around July 4th, the earth is 152,097,701 km from the sun. So the earth is about 5 million kilometres closer to the sun in winter.

But the real difference is indeed the angle of the earth on its axis. During the summer, the Northern Hemisphere (Ottawa, Canada) is tilted toward the sun. This means the sun’s rays approach Ottawa at a more direct angle as opposed to winter. These more direct rays from the sun are much more efficient at warming the air near the earth’s surface, thus giving us warmer weather in the summer.

However the scientific explanation of large temperature swings in Ottawa doesn’t stop there. In fact, because of the earth’s tilt away from the sun in the winter, little sunlight hits the Arctic Circle during the 3 months of winter. As a result, the temperature falls and the cold air accumulates in the north until it slides down into Canada and Ottawa. Because of Canada’s relative proximity to the Arctic Circle, we have direct access to this very cold air. As a result, Ottawa experiences extreme temperatures swings between winter and summer.

- René Brunet

 


 

Rain clouds

Question:

Why do clouds turn grey when it’s about to rain and darker when there are tornadoes?

Answer:

How we perceive the colour of the sky and clouds is due to the scatter of visible light by different particles in the atmosphere. Large water droplets in clouds scatter all colours equally (‘non-selective’ scatter) causing clouds to appear white because a mixture of all colors of light in approximately equal quantities produces white. Rain clouds appear dark on the bottom because little light makes it through the cloud layer, but if you viewed these same clouds from above (like from an airplane) they would appear white.

- Chris Derksen

 


 

Greenhouse Gases

Question:

I have always wondered why greenhouse gases from natural sources like rotting vegetation and ruminant animals are seen as contributing to global warming when they are just cycling carbon that is already in the system. It seems to me that the carbon in petroleum is more of a problem because it is being brought back into the ecosystem after being locked away for millions of years and that is where the excess carbon comes from. Is this so or not?

Answer:

This is an excellent question, and is best answered by looking at the sources of increased greenhouse gases in the atmosphere over the past two and a half centuries.

Analysis of ice cores shows that current atmospheric concentrations of greenhouse gases (carbon dioxide - CO2; methane – CH4; nitrous oxide – N2O) are at their highest level in at least 800 000 years. The two primary human influences on increases in these greenhouse gases over the past 250 years are fossil fuel consumption, and land use changes. Land use changes include the impacts of human activities on land cover, including animal grazing and related activities. The impacts of fossil fuel consumption and land use changes are not equal. The Intergovernmental Panel on Climate Change (IPCC) recently estimated that 8.3 gigatonnes of CO2 per year (over 2002–2011) were released to the atmosphere from fossil fuel consumption while net CO2 emissions over the same time period from anthropogenic land use were only 0.9 gigatonnes per year.

Like the energy cycle and the water cycle, carbon also cycles through the atmosphere, oceans, and terrestrial ecosystems. Human activities influence this cycle. The impact of fossil fuels on the carbon cycle is quite intuitive: carbon is released from long term storage into the atmosphere, hence the observed increases in gases like CO2. The impact of land use changes on the carbon cycle are harder to identify and link together. Some examples are the clearing of forested land for animal grazing – this reduces the terrestrial ecosystem sink for carbon. The clearing of land by slash and burn techniques, and large disturbances like forest fires also contribute carbon to the atmosphere. While strictly not a land use change, warming at higher latitudes impacts the land surface through changes to permafrost, which alters the storage of methane.

While fossil fuel consumption is the primary source of human induced greenhouse gas increases in the atmosphere, the role of the land surface and changes to it play a measurable role in the carbon cycle.

- Chris Derksen

 


 

The effect of global warming on hurricanes

Question:

Does global warming affect a hurricane's intensity and size? If yes, does CO2 emission play a big part in this?

Answer:

The power of Atlantic Hurricanes is characterized by their duration, intensity, size, and amount of rainfall. One of the leading influences on these storm characteristics is the sea surface temperature (SST). A conceptually straightforward mechanism is that warmer SSTs due to global warming will increase the power of Atlantic Hurricanes because warmer surface waters provide more energy for storm development and intensification. It's overly simplistic, however, to project future storm characteristics simply based on SST trends because of a number of complicating factors including the role of the atmospheric in influencing storm initiation and development.

Additional uncertainties in our understanding of the links between SSTs and hurricanes is due to changes in the nature of our observations. Determining trends in hurricane characteristics is difficult because historical (pre-satellite era) ship-based observations likely failed to capture smaller and shorter duration storms which are now readily identifiable from satellite imagery.

So while there is strong scientific consensus that global temperatures are rising due to greenhouse gas emissions, and this warming is increasing Atlantic Ocean SSTs, the potential impact on hurricane characteristics remains an open issue.

A detailed discussion of potential linkages between global warming and Atlantic Ocean hurricane activity is available from the NOAA Geophysical Fluid Dynamics Laboratory: http://www.gfdl.noaa.gov/global-warming-and-hurricanes.

-Chris Derksen

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