Oceanic climate

From Wikipedia, the free encyclopedia

An oceanic climate (also called marine west coast climate, maritime climate, subtropical highland and British climate) is the climate typically found along the west coasts at the middle latitudes of all the world's continents, and in southeastern Australia. Oceanic climates are characterized by a narrower annual range of temperatures than are encountered in other places at a comparable latitude, and do not have the extremely dry summers of Mediterranean climates.^[1]

Similar climates, at least in thermal range, are also found in tropical highlands even at considerable distance from any coastline. Generally, they fall into Köppen climate classification Cfb or Cwb. The narrow range of temperatures results not from proximity to a coastline but instead to the slight thermal range of temperatures between seasons characteristic of tropical lowlands; altitudes are high enough that such places have at least one month cooler than 18 °C and do not qualify for grouping in the true tropical climates. Unlike the norm in true oceanic climates, these moist highland tropical climates may have a marked winter drought, as in Mexico City. As with oceanic climates, winters are relatively warm and summers are comparatively cool, so the agricultural potential in both oceanic climates and moist tropical highland climates is practically identical. These climates are most dominant in Europe, where it spreads much farther inland than in other continents.

Contents 1 Precipitation 2 Temperature 3 Additional information 4 Countries/Regions with mild maritime climate 5 Countries/Regions with subpolar oceanic climate 6 Some notable cities with the subpolar Cfc climate are 7 Examples 7.1 Northern hemisphere 7.2 Southern hemisphere 8 See also 9 References 10 External links

[edit] Precipitation

Precipitation is both adequate and reliable at all times of the year in oceanic climates, except in certain tropical highland areas, which would have tropical savanna or steppe climates (with a dry season in winter) if not for the high altitude making them cooler (Koppen Cwb). Under some variations of the Koeppen classification system, parts of the Pacific Northwest and south-central Chile are sometimes considered as having a Mediterranean climate (Koppen "Csb") due to a drying trend in the summer.

[edit] Temperature

Overall temperature characteristics vary among oceanic climates; those at the lowest latitudes are nearly subtropical from a thermal standpoint, but more commonly a mesothermal regime prevails, with cool, but not cold, winters and warm, but not hot, summers. Summers are also cooler (often much cooler) than in areas with a humid subtropical climate. Average temperature of warmest month must be less than 22 °C (72 °F) and that of the coldest month warmer than -3 °C (27 °F) (Although American scientists prefer 0 °C in the coldest month). Poleward of the latter is a zone of subpolar oceanic climate (Köppen Cfc), with long but relatively mild winters (coldest month warmer than -3 or 0) and cool summers and a short summer season (average temperature at least 10 °C or 50 °F) of less than four months; examples of this climate include parts of coastal Iceland in the Northern Hemisphere and extreme southern Chile in the Southern Hemisphere (the fact that this form of climate exists in both hemispheres rules out the use of such terms as subarctic or boreal to denote it; even though these terms are used to refer to climates characterized by short summers, they are also synonyms for "northern" and therefore inappropriate).

[edit] Additional information

The UK experiences a typically maritime climate, with prevailing south-westerly winds from the Atlantic Ocean. The annual average temperature range in the UK is only about 24 °C. Although the west coast of Alaska experiences a maritime climate, the absence of an equally significant warm Pacific current in the upper-mid latitudes means that these regions are generally colder in winter, with more precipitation falling as snow.

All mid-latitude oceanic climates are classified as humid. Some rainshadow climates with thermal régimes similar to those of oceanic climates but steppe-like (BSk) or even desert-like (BWk) scarcity of precipitation include lowland valleys of Washington and Oregon to the east of the Cascade Range, Patagonia in southern Argentina, and the Atacama Desert in northern Chile. Another example are coastal areas in southeast Western Australia.

[edit] Countries/Regions with mild maritime climate

• Northern and western France
• The Netherlands
• Belgium
• Western and Northwestern Germany
• Western Switzerland (lowland areas)
• Northern Spain (so-called "Green Spain")
• Northern extreme of Portugal
• Southwest Norway
• Parts of Denmark
• Ireland
• United Kingdom
• Northern Turkey
• New Zealand
• Tasmania, Australia
• Southern parts of Victoria and New South Wales, Australia
• Western areas of the south coast of Western Australia
• Central Argentina
• Southern Chile
• Western parts of Oregon, Washington and the mildest coastal areas of the Alaskan panhandle (U.S.A.)
• Extreme Northwest California (U.S.A.)
• Western parts of British Columbia (Canada)
• Mountainous locations in some tropical countries (e.g. Indian subcontinent, Latin America, southern and central Africa; often as Cwb)^{[citation needed]}
• Parts of south and south-eastern South Africa
• Some mountainous areas across southern Europe
• Parts of Himalayas

The 0 °C (32 °F) isotherm (freeze line) or the -3 °C (26.6 °F) isotherms (persistent snow line) are the possible lines dividing the oceanic and the warm summer humid continental (Dfb) climates, in between which are the following regions:

• Eastern Germany
• Luxembourg
• Liechtenstein
• Western Poland
• Eastern Switzerland and parts of Austria
• Western Alps between 700 and 1000 meters.
• Central and Eastern Alps between 500 and 800 meters.
• Southern Sweden
• Fjord areas inland from the coast of southwest Norway and parts of the southeast coast of Norway
• Much of Denmark
• Southern coastal areas of the Alaskan Panhandle
• Most of the Czech Republic
• Parts of western Slovakia
• Northwest Romania
• Most of Hungary
• Most of Slovenia
• Parts of Bosnia-Herzegovina
• Mountainous areas across southern Europe
• Himalayas
• Some southern coastal areas of New England
• Parts of the southern Appalachians at the higher elevations

[edit] Countries/Regions with subpolar oceanic climate

• Parts of coastal Iceland
• Faroe Islands
• Northwestern coastal areas of Norway reaching to 70°N on some islands
• Southern islands of Alaska and parts of the Alaskan Panhandle
• Far south of Chile and Argentina
• Parts of the Andes and Himalaya (as cwc)
• Mountainous areas of Europe, including the Scottish Highlands and uplands near the coast of southwestern Norway

[edit] Some notable cities with the subpolar Cfc climate are

• Harstad, Norway
• Punta Arenas, Chile
• Thorshavn, Faroe Islands
• Unalaska, Alaska (also known as Dutch Harbor)
• Ushuaia, Tierra del Fuego, Argentina
• Vestmannaeyjar, Iceland
• La Paz, Bolivia

[edit] Examples

[edit] Northern hemisphere

Climate chart for Seattle, USA
J	F	M	A	M	J	J	A	S	O	N	D
130   8 2	107   10 3	97   12 4	66   14 6	46   18 8	38   21 11	20   24 13	25   24 13	41   21 11	81   16 8	150   11 4	142   8 2
average max. and min. temperatures in °C precipitation totals in mm source: [1]
Imperial conversion J F M A M J J A S O N D     5.1   46 36     4.2   50 37     3.8   54 39     2.6   57 43     1.8   64 46     1.5   70 52     0.8   75 55     1   75 55     1.6   70 52     3.2   61 46     5.9   52 39     5.6   46 36 average max. and min. temperatures in °F precipitation totals in inches

Climate chart for London, United Kingdom
J	F	M	A	M	J	J	A	S	O	N	D
52   8 2	34   8 2	42   11 4	45   13 5	47   17 8	53   20 11	38   23 14	47   23 13	56   19 11	62   15 8	52   11 5	54   9 3
average max. and min. temperatures in °C precipitation totals in mm source: [2]
Imperial conversion J F M A M J J A S O N D     2   46 36     1.3   47 36     1.7   52 39     1.8   56 41     1.9   63 46     2.1   68 52     1.5   73 56     1.9   73 56     2.2   67 52     2.4   59 46     2   52 41     2.1   48 38 average max. and min. temperatures in °F precipitation totals in inches

Climate chart for Cork, Ireland
J	F	M	A	M	J	J	A	S	O	N	D
119   9 2	79   9 3	94   11 4	57   13 5	71   16 7	57   19 10	70   20 12	71   20 12	94   18 10	99   14 7	116   11 4	122   9 3
average max. and min. temperatures in °C precipitation totals in mm source: [2]
Imperial conversion J F M A M J J A S O N D     4.7   48 36     3.1   48 37     3.7   52 39     2.2   55 41     2.8   61 45     2.2   66 50     2.8   68 54     2.8   68 54     3.7   64 50     3.9   57 45     4.6   52 39     4.8   48 37 average max. and min. temperatures in °F precipitation totals in inches

Climate chart for Copenhagen, Denmark
J	F	M	A	M	J	J	A	S	O	N	D
49   2 -2	39   2 -3	32   5 -1	38   10 3	43   16 8	47   19 11	71   22 14	66   21 14	62   18 11	59   12 7	48   7 3	49   4 1
average max. and min. temperatures in °C precipitation totals in mm source: BBC Weather[3]
Imperial conversion J F M A M J J A S O N D     1.9   36 28     1.5   36 27     1.3   41 30     1.5   50 37     1.7   61 46     1.9   66 52     2.8   72 57     2.6   70 57     2.4   64 52     2.3   54 45     1.9   45 37     1.9   39 34 average max. and min. temperatures in °F precipitation totals in inches

[edit] Southern hemisphere

Climate chart for Valdivia, Chile
J	F	M	A	M	J	J	A	S	O	N	D
66   23 11	74   23 11	132   21 9	234   17 8	361   13 6	550   11 6	394   11 5	328   12 4	208   14 5	127   17 7	125   18 8	104   21 10
average max. and min. temperatures in °C precipitation totals in mm source: [3]
Imperial conversion J F M A M J J A S O N D     2.6   73 52     2.9   73 52     5.2   70 48     9.2   63 46     14   55 43     22   52 43     16   52 41     13   54 39     8.2   57 41     5   63 45     4.9   64 46     4.1   70 50 average max. and min. temperatures in °F precipitation totals in inches

Climate chart for Tsitsikamma, South Africa
J	F	M	A	M	J	J	A	S	O	N	D
77   23 17	70   22 17	81   21 16	80   20 14	86   19 12	75   18 10	78   17 10	111   17 10	66   17 11	83   19 13	78   20 14	60   22 16
average max. and min. temperatures in °C precipitation totals in mm source: [4]
Imperial conversion J F M A M J J A S O N D     3   73 63     2.8   72 63     3.2   70 61     3.1   68 57     3.4   66 54     3   64 50     3.1   63 50     4.4   63 50     2.6   63 52     3.3   66 55     3.1   68 57     2.4   72 61 average max. and min. temperatures in °F precipitation totals in inches

Climate chart for Auckland, New Zealand
J	F	M	A	M	J	J	A	S	O	N	D
75   23 15	65   24 16	94   22 15	105   20 12	103   17 10	139   15 8	146   15 7	121   15 8	116   16 9	91   18 11	93   20 12	91   22 14
average max. and min. temperatures in °C precipitation totals in mm source: [5]
Imperial conversion J F M A M J J A S O N D     3   73 59     2.6   75 61     3.7   72 59     4.1   68 54     4.1   63 50     5.5   59 46     5.7   59 45     4.8   59 46     4.6   61 48     3.6   64 52     3.7   68 54     3.6   72 57 average max. and min. temperatures in °F precipitation totals in inches

[edit] See also

• Continental climate
• Mediterranean climate
• Polar climate

[edit] References

[edit] External links

• University of Wisconsin Stevens Point: Marine (Humid) West Coast Climate
• EPIC Data Collection On-line ocean observational data collection
• NOAA In-situ Ocean Data Viewer Plot and download ocean observations
• http://www.ace.mmu.ac.uk/eae/Climate/Older/Maritime_Climate.html

v • d • e Climate types under the Köppen climate classification Class A Equatorial (Af) · Monsoon (Am) · Savanna (Aw, As) Class B Desert (BWh, BWk) · Semi-arid (BSh, BSk) Class C Humid subtropical (Cfa, Cwa) · Oceanic (Cfb, Cwb, Cfc) · Mediterranean (Csa, Csb) Class D Humid continental (Dfa, Dwa, Dfb, Dwb) · Subarctic (Dfc, Dwc, Dfd, Dwd) · Continental Mediterranean (Dsa, Dsb, Dsc) Class E Polar (ET, EF) · Alpine (ET/H)