Vancouver case study - Atmosphere and weather Flashcards
(13 cards)
Where is Vancouver?
Provence of British Columbia. Borders Seattle to the South. On the coast of the Pacific.
Where is Vancouver island and how does it affect the city’s weather?
Vancouver Island is to the West which blocks the winds coming across from the Pacific. This places it in a partial rain shadow, since the precipitation travels over the mountains to the West and North and is deposited on the other side, which is where Vancouver is.
How much rainfall does Vancouver receive every year on average?
It receives around 1,189mm of rainfall per year on average.
How does the structure and material in the city affect weather processes?
The streets are arranged in a grid pattern. They are long and straight. There is lots of impermeable surfaces which contribute to surface runoff.
What air masses mainly influence Vancouver?
The coastal zone around Vancouver is influenced by Polar Maritime air, causing cool and relatively dry summers and mild, wet winters. It is also influenced by the Continental Polar air mass, which causes fairly dry weather.
What is the pattern of climate in Vancouver over the year?
The climate of Vancouver varies greatly over the year. Generally, the pattern of climate is that the precipitation decreases from the start of the year to around August, and the temperature increases during that time.
Similarly, after August the climate tends to get cooler, with the temperature dropping and precipitation increasing after August until the end of the year.
Compare Vancouver’s precipitation to London’s.
In comparison to London, Vancouvers precipitation tends to fluctuate a lot more during the year (around 230mm - 50mm), whereas London’s precipitation stays more steady at around 50-75mm.
What is the urban heat island effect?
- The way in which cities experience higher temperatures than surrounding rural areas.
Explain the 3 reasons why the urban heat island effect occurs.
Urban areas have a lower albedo.
More cars = more emissions of N2O and CO2
More heat trapped = hotter cities
Why is the sea around Vancouver colder, and how does this contribute to the urban heat island effect?
The Pacific has a hugher albedo. This means the sea does not heat up as much as other materials would.
Because the sea surrounds Vancouver, it means the surrounding area has a lower average surface temperature, making Vancouver very warm in relativity.
How can anticyclonic conditions enhance the urban heat island effect?
Anticyclonic conditions (cloudless weather) leads to higher surface temperatures in urban areas due to more longwave radiation reaching the ground, combined with the lower albedo of the surfaces in the area and the little wind available to remove the heat.
What are the two most dominant types of rainfall in Vancouver and what is the most?
The two most dominant types of rainfall are orographic and frontal.
The most important is orographic, as it is caused by moist air being lifted over the coastal mountains, leading to frequent precipitation especially in the winter.
