Cool oceans. Westerly winds. Storm-driven rains.
Half-way between equator and pole, the lands on the westerly fringes of the continents
are dominated by their neighbouring seas. Mild winters. Mild summers. If you excuse
the constant ocean storms, cloudy skies and rain, then these are not lands of extremes.
Having some of the most dramatic coastlines on earth, these lands also carry idyllic green
countryside that has been the inspiration of poets and authors down the ages.
These are the lands that birthed not one, but three global empires.
Defined by the cool ocean winds, this is the Marine W est Coast, the lands of the Oceanic Climate.
As we continue our journey in this series
from equator to poles, it’s now time to look at the last, and most northerly of the
three climates in the temperate band – the Oceanic Climate.
In some ways, this climate is a combination of the Humid Subtropical and Mediterranean
climates that it shares the temperate band with. It has the year round rain and occasional
humid summer heat of the Humid Subtropical, but with winters similar to the cool Mediterranean,
with whom it shares its westerly winds. Like the Mediterranean climate, it also has a very
mild temperature range between summer and winter, but is a good 10 degrees cooler than
its sunnier and hotter counterparts in summer due to its more polar latitude. Averaged across
the day-night cycle the temperature is above freezing in winter, but below 22 degrees Celsius
in summer. This does not prevent deep night frosts in
winter cold snaps, or peak day temperatures from reaching 30 degrees or more during a
summer heat wave. But these events occur infrequently in this land of mild oceanic influence.
In comparison to its southerly neighbour, the Mediterranean, the people that live in
these lands love to complain about the most distinctive feature of this climate when compared
to others, the lack of sun. While other lands, especially in the tropics are wetter, the
Oceanic lands are dogged by frequent cloud cover, with at least half the days throughout
the year seeing cloudy or rainy days. The Marine West Coast yet has a more favourable
superlative, in that it exhibits much milder winters compared to all other regions at the
same latitude. While it is 20 below freezing in Siberia, it is 5 degrees above in London.
This “anomaly” is at its most extreme in the north of Norway, where in Lofoten,
it is above the Arctic Circle, and yet stays above freezing in winter, due to the presence
of warm currents of the Gulf Stream and North Atlantic Drift bringing warm waters from the
tropics. This climate is dominated by westerly winds
blowing in from the adjoining oceans. Most pronounced in autumn and winter, these winds
bring in storm after storm, battering the coasts of these areas with heavy rain and
gales, while more inland areas, spared the worst, nonetheless experience wind and rain
on a regular basis. Spring and especially summer see less of the westerly wind conditions,
but weather can remain unpredictable even during these seasons, as any Brit or Kiwi
will tell you when anxiously planning a weekend barbeque.
At the heart of these westerlies is a meteorological phenomenon known as the Polar Jet Stream.
This is a narrow band of high altitude winds that frequently exceed 100 miles per hour,
and circles the north and south poles at a latitude of between 50 and 60 degrees, travelling
from west to east. It occurs at these latitudes, since it is in this region that winds from
the tropics and poles converge. Due to a complex mechanism known as the Coriolis effect, air
moving between high and low pressure is forced to spin. In the case of the more equatorial
high pressures, the poleward sides of these travel west, in the same direction as the
equatorial sides of the more polar low pressure areas, providing a constant momentum to this
jet of air. In winter, the jet stream travels south toward the equator with the retreating
high pressures, impacting both the Oceanic and Mediterranean west coasts. In summer it
retreats back toward the pole, leaving alone the Mediterranean climates but still brushing
the Oceanic zones. This explains why the Mediterranean zones only get rain in winter, while Oceanics
get rain all year round. There are two subdivisions of the Oceanic
climate, separated only by summer temperatures. The most significant in terms of land area
and population is designated with the Koppen climate code Cfb, which sees maximum summer
day temperatures above 17 degrees Celsius. This is known as the Marine West Coast, or
Marine Mild Winter, or simply the standard Oceanic climate. The other, Cfc, known as
the Subpolar Oceanic climate does not see summer maxima above 17 degrees Celsius. Since
both have similar winter temperatures, the Cfc variant therefore has a significantly
narrower variation in seasonal temperature. The Oceanic climate is, like the Humid Subtropical,
a true four seasons climate, with the usual pattern of blossom in spring, green leaves
in the growth season of summer, yellow and falling leaves in the autumn and bare branches
in winter. Snowfalls usually occur at least once per winter, but usually melts within
a few days. Cold snaps of below freezing conditions lasting a week or more are rare but not unknown.
The influence of the ocean can be seen in this sample of graphs stretching across Northwest
Europe, which is the most significant part of the world under the Cfb Oceanic climate
in terms of population. The west coast of Ireland has the narrowest summer/winter temperature
range. while moving east into England, and then into Germany, the temperature range increases
as we head to the border of the Continental climate zone further east.
So, where in the world do we find the Oceanic climate areas? Well, they mostly lie on the
western coasts of continents where they extend beyond 45 degrees of latitude. Starting in
North America, the extreme north-west of the American State of Washington, the west coast
of Canadian British Columbia and the southern half of the Alaskan panhandle come under its
influence. Due to the closeness of the Rocky Mountains, this influence does not extend
far inland, but nonetheless, covers the key regional city of Vancouver, which experiences
the mildest winter temperatures in Canada. A mirror image of this pattern occurs in South
America, where the southern third of Chile is covered by first Cfb and then Cfc variants
of this climate as one heads toward the southern tip of the continent and Antarctica. Again,
an extensive mountain range, the Andes, is immediately adjacent to the coast, thus limiting
the influence within the narrow margin of this longest of countries.
Skipping all the way, now, across to Australia, and we find the south-eastern margin of this
island continent containing among the warmest of the Oceanic climates with all of Tasmania,
most of Victoria and the southern coastal fringe of New South Wales under its influence,
including the state capitals of Melbourne and Hobart. At first this might seem a contradiction
to the “westerly coasts” model of this climate, but in actual fact, this is the only
part of Australia that extends far enough south to have year-round westerly winds.
Travelling further east still, and we reach the most isolated country in the developed
world and the two islands of New Zealand. Both islands are dominated by westerly winds
year round since they are firmly in the latitude of the “Roaring Forties” and so all but
the most mountainous parts of this country lie firmly within the Oceanic climate zone.
Like all such zones, temperatures are mild in winter, but summer temperatures are significantly
warmer in the north compared to the south. Lastly, we come to Europe, where this climate
zone most strongly leaves its mark, both in terms of land area, and population. In the
far north and west, we have the island of Iceland, land of the midnight sun, so far
north is it that it touches the Arctic Circle. The lower lying western parts of this island,
including the capital Reykjavik are under the Polar Cfc variant of the Oceanic climate,
experiencing cool summers, but also mild winters due to being firmly within the warm Gulf Stream
ocean current. At a similar latitude, we have the long and broken coastline of Norway, where
in the north the Cfc Polar Oceanic variant keeps winters mild and summers cool, but as
we travel further south along this coast, this turns to the standard Cfb Oceanic variant.
Hopping across the North Sea, and we arrive in the British Isles, where both islands of
Great Britain and Ireland are firmly within the Cfb Oceanic zone. The Western coasts of
Ireland and Scotland have the most rain, and mildest temperature ranges, being directly
washed by the warm Gulf Stream ocean current. Further east, on the leeward side of the mountain
ranges of Wales and Scotland and throughout England, winters are cooler and summers warmer.
Heading south across the English channel and Bay of Biscay and we arrive on the main continent
of Europe, where the north coast of Spain is visited by Atlantic storms year round.
Heading north and east, and we find that most of France is under the Oceanic influence,
and like Victoria in Australia, has some of the warmest summers that this climate has
to offer. As we continue to move north and east along the North European plain, we find
few obstructions in the form of mountains to block westerly winds and so this climate
extends far east into north and west Switzerland, then north into the low countries of Belgium
and the Netherlands, and further east into Germany, where it covers the bulk of that
country, from Bavaria in the south to North Sea coasts in the north. Parts of Denmark
are also under the Oceanic influence, but, like Eastern Germany, this country lies on
the border of the continental climate of more seasonal extremes, which we’ll take up two
episodes from now. The Oceanic climate has some of the most enviable
landscapes in the world. An upside to the year round rain, and not subject to intense,
burning sun of less temperate climes, the lands of the Oceanic climate are green in
a way that no others are. Broken, mountainous coasts with deep valleys, known as Fjordlands
are a hallmark of this climate. From British Columbia, to Southern Chile, South Island
New Zealand, and the country that gave its name to such landscapes, Norway, no other
climate zone possesses these particular natural gems in such quantity. At the other extreme,
we have the plains and rolling country of South Eastern Australia and Europe, that under
human hands over centuries have produced the archetypal form of what we would call “countryside”.
In its natural state the Oceanic climate is covered in thick woodland, either of a deciduous
or coniferous nature, depending upon the region. In some small surviving enclaves we can find
areas of temperate rainforest, where so much rain falls that these lush woodlands are thick
with trees, moss and ferns, producing a very rich green bioscape.
Most of the natural forest in Europe, however, has given way to farmland, where a vast array
of crops are grown, from apples and strawberries to wheat and grapes, including world famous
French wine growing regions such as Champagne, to a host of different vegetables and even
flowers. The Netherlands, at the heart of the Oceanic climate zone has some of the richest
farmland in the world and is one of the few countries which exports more food than it
eats, so much so that it has been called the Market Garden of the World. Some of the finest
cattle breeds have emerged in this area, including the Frisians or Holsteins of Holland and North
Germany, the world’s most productive dairy breed, plus the Aberdeen Angus of Scotland,
considered the world’s finest beef cattle by many. Northwest Europe, with its rich soil
suited to the cultivation of barley, also produces the widest array of beers in the
world including most of the world’s famous brands, with Ireland, England, France, Belgium,
Holland, Germany and Denmark all contributing significantly.
The region’s finest breeds and seeds have been exported all around the world, and there
is perhaps no other area more influential in terms of agricultural diversity in the developed world.
And that’s the Oceanic climate zone – one
particularly close to my heart, since I have spent most of my life in it. And yes, I grumble
about it as much as any other Brit, but then I see the green fields and the nature in summer,
and I remind myself of what climate is responsible for such beauty, and then I stop complaining.
Well, at least for a short while, anyway. I hope you enjoyed the video – and if you
did, then please click the Subscribe button so you don’t miss future episodes – you’ll
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click the like button, and share your thoughts in the comments section, particularly if you
have experienced life one of the Oceanic climate zones around the world.
Thanks again for watching, and I’ll see you in the next episode, where we’ll be
headed into the interior of the continents and the cool deserts that lie within. Until
then, stay dry… and no complaining!