fbpx
Wikipedia

Trewartha climate classification

The Trewartha climate classification (TCC) or the Köppen–Trewartha climate classification (KTC) is a climate classification system first published by American geographer Glenn Thomas Trewartha in 1966. It is a modified version of the Köppen–Geiger system, created to answer some of its deficiencies.[1] The Trewartha system attempts to redefine the middle latitudes to be closer to vegetation zoning and genetic climate systems.[2]

Trewartha climate types for the world (1967)
  •   Ac: Tropical Wet
  •   Aw: Tropical Wet-And-Dry
  •   Bw: Desert or Arid
  •   Bs: Steppe or Semiarid
  •   Cs: Subtropical Dry Summer
  •   Cf: Subtropical Humid
  •   Do: Temperate Oceanic
  •   Dc: Temperate Continental
  •   E: Boreal
  •   Ft: Tundra
  •   Fi: Ice Cap
  •   H: Highland
Trewartha climate types for the contiguous United States

Scheme edit

Trewartha's modifications to the 1884 Köppen climate system sought to reclass the middle latitudes into three groups: C (subtropical)—8 or more months have a mean temperature of 10 °C (50 °F) or higher; D temperate—4 to 7 months have a mean temperature of 10 °C or higher; and E boreal climate—1 to 3 months have a mean temperature of 10 °C or higher. Otherwise, the tropical climates and polar climates remained the same as the original Köppen climate classification.

The "highland" climate is ambiguously defined. Newer users of KTC generally omit this option.[3]

Group A: Tropical climates edit

This is the tropical climate realm, defined the same as in Köppen's scheme (i.e., all 12 months average 18 °C, 64.4 °F, or above). The "A" climates are the realm of the winterless frost-free zone.

Climates with no more than two dry months (defined as having less than 60 mm, 2.4 inches, average precipitation, same as per Köppen) are classified Ar, while others are classified Aw if the dry season is at the time of low sun/short days or As if the dry season is at the time of high sun/long days. There was no specific monsoon climate identifier in the original scheme, but Am was added later, with the same parameters as Köppen's (except that at least three months, rather than one, must have less than 60 mm average precipitation).

Group B: Dry (arid and semi-arid) climates edit

BW and BS mean the same as in the Köppen scheme. However, a different formula is used to quantify the aridity threshold: 10(T − 10) + 3P, with T equaling the mean annual temperature in degrees Celsius and P denoting the percentage of total precipitation received in the six high-sun months (April through September in the Northern Hemisphere and October through March in the Southern).[4]

If the precipitation for a given location is less than the above formula, its climate is said to be that of a desert (BW); if it is equal to or greater than the above formula but less than twice that amount, the climate is classified as steppe (BS); and if the precipitation is more than double the value of the formula the climate is not in Group B. Unlike in Köppen's scheme, no thermal subsets exist within this group in Trewartha's, unless the Universal Thermal Scale (see below) is used.

Group C: Subtropical climates edit

In the Trewartha scheme the "C" climate group encompasses Subtropical climates that have 8 or more months with a mean temperature of 10 °C (50 °F) or higher.

There are only two types within the "C" or subtropical climate group, Cs which is a dry -summer or Mediterranean climate, and a Cf or humid Subtropical climate. Cw types occur within the Cf group and mean subtropical Monsoon climates (like much of east Asia).

Group D: Temperate and continental climates edit

In the Trewartha scheme the "D" climate group encompasses Temperate climates that have 4 to 7 months with a mean temperature of 10 °C (50 °F) or higher.

"D" climate groups have two types – an Oceanic type (Do), where the coldest month has a mean temperature 0 °C (32 °F) or higher, and a Continental type (Dc), where the coldest monthly mean temperature reaches below 0 °C in some interior landmasses like North America and Asia.

For the continental climates (Dc), sometimes the third letter (a or b) is used to denote a hot or cold summer. "Dca" is where the warmest month has a mean temperature of 22.2 °C (72.0 °F) or higher, and "Dcb" is used for cool summer temperate climates, where the warmest month has a mean temperature below 22.2 °C.

Most of Europe north of the 44th parallel exhibits Do or Dc climate types.

Group E: Boreal climates edit

This represents subarctic and subpolar oceanic climate realms, defined the same as in Köppen's scheme, where 1 to 3 months have an average temperature of 10 °C (50 °F) or above. In this climate zone there is only a short period (normally 50 to 90 days) that is frost free. In the original scheme, this group was not further divided; later, the designations Eo and Ec were created, with Eo (maritime subarctic) signifying that the coldest month averages above −10 °C (14 °F), while Ec (continental subarctic or "boreal") means that at least one month has an average temperature of −10 °C or below. As in Group D, a third letter can be added to indicate seasonality of precipitation. There is no separate counterpart to the Köppen Dfd, Dwd, and Dsd climate types in Trewartha's scheme, but a letter can optionally be added to the end of the symbol to indicate the temperature of the coldest month (see below).

Group F: Polar climates edit

This is the polar climate group, where all months must have a monthly mean air temperature of below 10 °C (50 °F). Polar climates have two subtypes Ft (tundra) and Fi (ice cap):

In the "Ft" climate type, at least one month has an average temperature above 0 °C or 32 °F (but not above 10 °C (50 °F)), so that there is a brief time when the surface might be free of snow or ice and a scrub or Tundra vegetation cover is possible.

In the "Fi" climate type, all months have an average temperature below 0 °C (32 °F). This is the region of the vast deserts of perpetually frozen ocean in the North Pole, and the permanent ice plateaus of Antarctica and Greenland.

Group H: Highland climates edit

Highland climates are those in which altitude plays a role in determining climate classification.[5] Specifically, this would apply if[citation needed] correcting the average temperature of each month to a sea-level value using the formula of adding 5.6 °C (10.1 °F)[citation needed] for each 1,000 meters (3,300 ft) of elevation would result in the climate fitting into a different thermal group than that into which the actual monthly temperatures place it.

Sometimes G is used instead of H if the above is true and the altitude is between 500 and 2,500 meters (1,600 and 8,200 ft), but the G or H is placed in front of the applicable thermal letter rather than replacing it. The second letter used reflects the corrected monthly temperatures, not the actual monthly temperatures.

Universal Thermal Scale edit

An option exists to include information on both the warmest and coldest months for every climate by adding a third and fourth letter respectively. The letters used conform to the following scale:[6]

  • i — severely hot: Mean monthly temperature ≥35 °C (95 °F) or higher
  • h — very hot: 28 to 34.9 °C (82.4 to 94.8 °F)
  • a — hot: 22.2 to 27.9 °C (72.0 to 82.2 °F)
  • b — warm: 18 to 22.1 °C (64.4 to 71.8 °F)
  • l — mild: 10 to 17.9 °C (50.0 to 64.2 °F)
  • k — cool: 0.1 to 9.9 °C (32.2 to 49.8 °F)
  • o — cold: −9.9 to 0 °C (14.2 to 32.0 °F)
  • c — very cold: −24.9 to −10 °C (−12.8 to 14.0 °F)
  • d — severely cold: −39.9 to −25 °C (−39.8 to −13.0 °F)
  • e — excessively cold: −40 °C (−40 °F) or below.

Examples edit

A
B
C
D
E
F

See also edit

References edit

  1. ^ Peel MC, Finlayson BL, McMahon TA (2007) Updated world map of the Köppen-Geiger climate classification. Hydrol Earth Syst Sci 11: 1633–1644
  2. ^ Bailey RG (2009) Ecosystem geography:from ecoregions to sites, 2nd edn. Springer, New York, NY
  3. ^ Belda, M; Holtanová, E; Halenka, T; Kalvová, J (4 February 2014). "Climate classification revisited: from Köppen to Trewartha" (PDF). Climate Research. 59 (1): 1–13. Bibcode:2014ClRes..59....1B. doi:10.3354/cr01204. (additional material, including more recent KTC maps)
  4. ^ Patton CP (1962) A note on the classification of dry climate in the Köppen system. California Geographer 3: 105–112
  5. ^ McKnight, 237–40
  6. ^ Ikonen, Ari T.K. "Working Report 2007-86 Meteorological Data and Update of Climate Statistics of Olkiluoto 2005 – 2006" (PDF). Posiva Oy iaea.org. p. 72.

External links edit

  • Use of the Köppen–Trewartha climate classification for the People’s Republic of China

trewartha, climate, classification, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article, needs, additional, citations, verification, please, help, improve, th. This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Trewartha climate classification news newspapers books scholar JSTOR January 2016 Learn how and when to remove this template message This article has an unclear citation style The reason given is Unclear author year references The references used may be made clearer with a different or consistent style of citation and footnoting March 2022 Learn how and when to remove this template message Learn how and when to remove this template message The Trewartha climate classification TCC or the Koppen Trewartha climate classification KTC is a climate classification system first published by American geographer Glenn Thomas Trewartha in 1966 It is a modified version of the Koppen Geiger system created to answer some of its deficiencies 1 The Trewartha system attempts to redefine the middle latitudes to be closer to vegetation zoning and genetic climate systems 2 Trewartha climate types for the world 1967 Ac Tropical Wet Aw Tropical Wet And Dry Bw Desert or Arid Bs Steppe or Semiarid Cs Subtropical Dry Summer Cf Subtropical Humid Do Temperate Oceanic Dc Temperate Continental E Boreal Ft Tundra Fi Ice Cap H HighlandTrewartha climate types for the contiguous United States Contents 1 Scheme 1 1 Group A Tropical climates 1 2 Group B Dry arid and semi arid climates 1 3 Group C Subtropical climates 1 4 Group D Temperate and continental climates 1 5 Group E Boreal climates 1 6 Group F Polar climates 1 7 Group H Highland climates 2 Universal Thermal Scale 2 1 Examples 3 See also 4 References 5 External linksScheme editTrewartha s modifications to the 1884 Koppen climate system sought to reclass the middle latitudes into three groups C subtropical 8 or more months have a mean temperature of 10 C 50 F or higher D temperate 4 to 7 months have a mean temperature of 10 C or higher and E boreal climate 1 to 3 months have a mean temperature of 10 C or higher Otherwise the tropical climates and polar climates remained the same as the original Koppen climate classification The highland climate is ambiguously defined Newer users of KTC generally omit this option 3 Group A Tropical climates edit This is the tropical climate realm defined the same as in Koppen s scheme i e all 12 months average 18 C 64 4 F or above The A climates are the realm of the winterless frost free zone Climates with no more than two dry months defined as having less than 60 mm 2 4 inches average precipitation same as per Koppen are classified Ar while others are classified Aw if the dry season is at the time of low sun short days or As if the dry season is at the time of high sun long days There was no specific monsoon climate identifier in the original scheme but Am was added later with the same parameters as Koppen s except that at least three months rather than one must have less than 60 mm average precipitation Group B Dry arid and semi arid climates edit BW and BS mean the same as in the Koppen scheme However a different formula is used to quantify the aridity threshold 10 T 10 3P with T equaling the mean annual temperature in degrees Celsius and P denoting the percentage of total precipitation received in the six high sun months April through September in the Northern Hemisphere and October through March in the Southern 4 If the precipitation for a given location is less than the above formula its climate is said to be that of a desert BW if it is equal to or greater than the above formula but less than twice that amount the climate is classified as steppe BS and if the precipitation is more than double the value of the formula the climate is not in Group B Unlike in Koppen s scheme no thermal subsets exist within this group in Trewartha s unless the Universal Thermal Scale see below is used Group C Subtropical climates edit In the Trewartha scheme the C climate group encompasses Subtropical climates that have 8 or more months with a mean temperature of 10 C 50 F or higher There are only two types within the C or subtropical climate group Cs which is a dry summer or Mediterranean climate and a Cf or humid Subtropical climate Cw types occur within the Cf group and mean subtropical Monsoon climates like much of east Asia Group D Temperate and continental climates edit In the Trewartha scheme the D climate group encompasses Temperate climates that have 4 to 7 months with a mean temperature of 10 C 50 F or higher D climate groups have two types an Oceanic type Do where the coldest month has a mean temperature 0 C 32 F or higher and a Continental type Dc where the coldest monthly mean temperature reaches below 0 C in some interior landmasses like North America and Asia For the continental climates Dc sometimes the third letter a or b is used to denote a hot or cold summer Dca is where the warmest month has a mean temperature of 22 2 C 72 0 F or higher and Dcb is used for cool summer temperate climates where the warmest month has a mean temperature below 22 2 C Most of Europe north of the 44th parallel exhibits Do or Dc climate types Group E Boreal climates edit This represents subarctic and subpolar oceanic climate realms defined the same as in Koppen s scheme where 1 to 3 months have an average temperature of 10 C 50 F or above In this climate zone there is only a short period normally 50 to 90 days that is frost free In the original scheme this group was not further divided later the designations Eo and Ec were created with Eo maritime subarctic signifying that the coldest month averages above 10 C 14 F while Ec continental subarctic or boreal means that at least one month has an average temperature of 10 C or below As in Group D a third letter can be added to indicate seasonality of precipitation There is no separate counterpart to the Koppen Dfd Dwd and Dsd climate types in Trewartha s scheme but a letter can optionally be added to the end of the symbol to indicate the temperature of the coldest month see below Group F Polar climates edit This is the polar climate group where all months must have a monthly mean air temperature of below 10 C 50 F Polar climates have two subtypes Ft tundra and Fi ice cap In the Ft climate type at least one month has an average temperature above 0 C or 32 F but not above 10 C 50 F so that there is a brief time when the surface might be free of snow or ice and a scrub or Tundra vegetation cover is possible In the Fi climate type all months have an average temperature below 0 C 32 F This is the region of the vast deserts of perpetually frozen ocean in the North Pole and the permanent ice plateaus of Antarctica and Greenland Group H Highland climates edit Highland climates are those in which altitude plays a role in determining climate classification 5 Specifically this would apply if citation needed correcting the average temperature of each month to a sea level value using the formula of adding 5 6 C 10 1 F citation needed for each 1 000 meters 3 300 ft of elevation would result in the climate fitting into a different thermal group than that into which the actual monthly temperatures place it Sometimes G is used instead of H if the above is true and the altitude is between 500 and 2 500 meters 1 600 and 8 200 ft but the G or H is placed in front of the applicable thermal letter rather than replacing it The second letter used reflects the corrected monthly temperatures not the actual monthly temperatures Universal Thermal Scale editAn option exists to include information on both the warmest and coldest months for every climate by adding a third and fourth letter respectively The letters used conform to the following scale 6 i severely hot Mean monthly temperature 35 C 95 F or higher h very hot 28 to 34 9 C 82 4 to 94 8 F a hot 22 2 to 27 9 C 72 0 to 82 2 F b warm 18 to 22 1 C 64 4 to 71 8 F l mild 10 to 17 9 C 50 0 to 64 2 F k cool 0 1 to 9 9 C 32 2 to 49 8 F o cold 9 9 to 0 C 14 2 to 32 0 F c very cold 24 9 to 10 C 12 8 to 14 0 F d severely cold 39 9 to 25 C 39 8 to 13 0 F e excessively cold 40 C 40 F or below Examples edit AAwha for Surabaya Indonesia Ambb for Merida Merida Venezuela Amhb for Miami United States Araa for Suva FijiBBWil for Riyadh Saudi Arabia BWhl for Aswan Egypt BSbc for Ulaanbaatar Mongolia BSaa for Patos Brazil BWho for Turpan China BWih for Dallol Ethiopia BSlk for Rio Gallegos ArgentinaCCfak for Tokyo Japan Cwak for Changwon South Korea Csll for San Francisco California Cfhk for Dallas U S Cwhl for Hanoi Vietnam Cfbl for Melbourne Australia Cfbk for Vigo Spain Cflk for Nelson New Zealand Cfal for Buenos Aires Argentina Csal for Faro PortugalDDobk for London U K Dcao for Seoul South Korea Dcac for Harbin China Dcbo for Klagenfurt Austria Doak for New York City United States Dclo for Cortina d Ampezzo Italy Dcbc for Quebec City CanadaEEcle for Oymyakon Russia Ecbd for Yakutsk Russia Eolo for Tromso Norway Ecld for Norilsk Russia Eclc for Karasjok Norway Eolk for Punta Arenas ChileFFtkd for Utqiagvik Alaska U S Ftkk for Ushuaia Argentina Fide for Vostok Station in Antarctica See also editHoldridge life zones climate classification by three dimensions precipitation humidity and potential evapotranspiration ratio Koppen climate classificationReferences edit Peel MC Finlayson BL McMahon TA 2007 Updated world map of the Koppen Geiger climate classification Hydrol Earth Syst Sci 11 1633 1644 Bailey RG 2009 Ecosystem geography from ecoregions to sites 2nd edn Springer New York NY Belda M Holtanova E Halenka T Kalvova J 4 February 2014 Climate classification revisited from Koppen to Trewartha PDF Climate Research 59 1 1 13 Bibcode 2014ClRes 59 1B doi 10 3354 cr01204 additional material including more recent KTC maps Patton CP 1962 A note on the classification of dry climate in the Koppen system California Geographer 3 105 112 McKnight 237 40 Ikonen Ari T K Working Report 2007 86 Meteorological Data and Update of Climate Statistics of Olkiluoto 2005 2006 PDF Posiva Oy iaea org p 72 External links editUse of the Koppen Trewartha climate classification for the People s Republic of China Retrieved from https en wikipedia org w index php title Trewartha climate classification amp oldid 1193891429, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.