The Mediterranean climate climate regime resembles the climate of the lands in the Mediterranean Basin, which includes over half of the area with this climate type worldwide. Elsewhere, this climate type prevails in parts of western North America, in parts of Western and South Australia, in southwestern South Africa and in parts of central Chile. The climate is characterized by hot, dry summers and cool, wet winters.[21] For example, the city of Perth, Australia, in the southern hemisphere winter months of June-August, experiences 450 millimetres (18 in) of rainfall and an average daily minimum of 8 °C (46 °F). Meanwhile, during the summer months of December to February, the city only averages 32 millimetres (1.3 in).[22]
[edit] Continental steppe
Steppe in MongoliaA steppe is a dry grassland, but not dry enough to be a desert. The term steppe originally comes from the Russian word /stɛp/ which means a flat and arid land. The climates of all steppes are summarized by a continental climate. Peaks can be recorded in the summer of up to 40 °C (104 °F) and in winter down to −40 °C (−40.0 °F).[23] Besides this huge temperature variation, the diurnal temperature differences are also very great. In the highlands of Mongolia, 30 °C (86 °F) can be reached during the day with temperatures below 0 °C (32 °F) at night. The mid-latitude steppes average 250 millimetres (9.8 in) to 500 millimetres (20 in) of precipitation per year. In tropical locations, necessary rainfall to separate steppes from true deserts may be double this criteria due to greater evapotranspiration.
[edit] Subarctic
A subarctic climate has monthly temperatures which are above 10 °C (50 °F) for one to three months of the year, and experiences some of the largest annual temperature ranges on the planet.[24] Except for those areas adjacent to warm ocean currents, there is usually continuous permafrost due to the very cold winters. This means that building in most subarctic regions is very difficult and expensive: cities are very few (Murmansk being the largest) and generally small, whilst roads are few and railways non-existent. An important consequence is that transportation tends to be restricted to "bush" planes, helicopters and, in summer, river boats.
Precipitation tends to be low due to the low moisture content of the cold air, with no more than 15 inches (380 mm) to 20 inches (510 mm) of precipitation per year, on average.[24] Typically, there is a summer maximum in precipitation ranging from moderate in North America to extreme in the Russian Far East.[16] In drier areas, glaciers are largely absent because of the lack of winter precipitation. In the wettest areas, glaciers tend to be abundant and Pleistocene glaciation covers even the lowest elevations. Soils of the subarctic are generally very acidic largely because of the influence of the vegetation both in the taiga and in peaty bogs, which tends to acidify the soil, as well as the extreme ease with which leaching of nutrients takes place even in the most heavily glaciated regions. The dominant orders are Spodosols and further north Gelisols. Agriculture is mainly limited to animal husbandry, though in some areas barley can be grown.
Tuesday, May 20, 2008
Mediterranean Climate
The Mediterranean climate climate regime resembles the climate of the lands in the Mediterranean Basin, which includes over half of the area with this climate type worldwide. Elsewhere, this climate type prevails in parts of western North America, in parts of Western and South Australia, in southwestern South Africa and in parts of central Chile. The climate is characterized by hot, dry summers and cool, wet winters.[21] For example, the city of Perth, Australia, in the southern hemisphere winter months of June-August, experiences 450 millimetres (18 in) of rainfall and an average daily minimum of 8 °C (46 °F). Meanwhile, during the summer months of December to February, the city only averages 32 millimetres (1.3 in).[22]
[edit] Continental steppe
Steppe in MongoliaA steppe is a dry grassland, but not dry enough to be a desert. The term steppe originally comes from the Russian word /stɛp/ which means a flat and arid land. The climates of all steppes are summarized by a continental climate. Peaks can be recorded in the summer of up to 40 °C (104 °F) and in winter down to −40 °C (−40.0 °F).[23] Besides this huge temperature variation, the diurnal temperature differences are also very great. In the highlands of Mongolia, 30 °C (86 °F) can be reached during the day with temperatures below 0 °C (32 °F) at night. The mid-latitude steppes average 250 millimetres (9.8 in) to 500 millimetres (20 in) of precipitation per year. In tropical locations, necessary rainfall to separate steppes from true deserts may be double this criteria due to greater evapotranspiration.
[edit] Subarctic
A subarctic climate has monthly temperatures which are above 10 °C (50 °F) for one to three months of the year, and experiences some of the largest annual temperature ranges on the planet.[24] Except for those areas adjacent to warm ocean currents, there is usually continuous permafrost due to the very cold winters. This means that building in most subarctic regions is very difficult and expensive: cities are very few (Murmansk being the largest) and generally small, whilst roads are few and railways non-existent. An important consequence is that transportation tends to be restricted to "bush" planes, helicopters and, in summer, river boats.
Precipitation tends to be low due to the low moisture content of the cold air, with no more than 15 inches (380 mm) to 20 inches (510 mm) of precipitation per year, on average.[24] Typically, there is a summer maximum in precipitation ranging from moderate in North America to extreme in the Russian Far East.[16] In drier areas, glaciers are largely absent because of the lack of winter precipitation. In the wettest areas, glaciers tend to be abundant and Pleistocene glaciation covers even the lowest elevations. Soils of the subarctic are generally very acidic largely because of the influence of the vegetation both in the taiga and in peaty bogs, which tends to acidify the soil, as well as the extreme ease with which leaching of nutrients takes place even in the most heavily glaciated regions. The dominant orders are Spodosols and further north Gelisols. Agriculture is mainly limited to animal husbandry, though in some areas barley can be grown.
[edit] Continental steppe
Steppe in MongoliaA steppe is a dry grassland, but not dry enough to be a desert. The term steppe originally comes from the Russian word /stɛp/ which means a flat and arid land. The climates of all steppes are summarized by a continental climate. Peaks can be recorded in the summer of up to 40 °C (104 °F) and in winter down to −40 °C (−40.0 °F).[23] Besides this huge temperature variation, the diurnal temperature differences are also very great. In the highlands of Mongolia, 30 °C (86 °F) can be reached during the day with temperatures below 0 °C (32 °F) at night. The mid-latitude steppes average 250 millimetres (9.8 in) to 500 millimetres (20 in) of precipitation per year. In tropical locations, necessary rainfall to separate steppes from true deserts may be double this criteria due to greater evapotranspiration.
[edit] Subarctic
A subarctic climate has monthly temperatures which are above 10 °C (50 °F) for one to three months of the year, and experiences some of the largest annual temperature ranges on the planet.[24] Except for those areas adjacent to warm ocean currents, there is usually continuous permafrost due to the very cold winters. This means that building in most subarctic regions is very difficult and expensive: cities are very few (Murmansk being the largest) and generally small, whilst roads are few and railways non-existent. An important consequence is that transportation tends to be restricted to "bush" planes, helicopters and, in summer, river boats.
Precipitation tends to be low due to the low moisture content of the cold air, with no more than 15 inches (380 mm) to 20 inches (510 mm) of precipitation per year, on average.[24] Typically, there is a summer maximum in precipitation ranging from moderate in North America to extreme in the Russian Far East.[16] In drier areas, glaciers are largely absent because of the lack of winter precipitation. In the wettest areas, glaciers tend to be abundant and Pleistocene glaciation covers even the lowest elevations. Soils of the subarctic are generally very acidic largely because of the influence of the vegetation both in the taiga and in peaty bogs, which tends to acidify the soil, as well as the extreme ease with which leaching of nutrients takes place even in the most heavily glaciated regions. The dominant orders are Spodosols and further north Gelisols. Agriculture is mainly limited to animal husbandry, though in some areas barley can be grown.
Humid Continential
Humid continental climate is found over large areas of land masses in the temperate regions of the mid-latitudes where there is a zone of conflict between polar and tropical air masses. The humid continental climate is marked by variable weather patterns and a large seasonal temperature variance. The seasonal temperature variance can be as great as 33°C (59°F), but is typically 15-25°C (27-46°F). The temperature difference between the warmest and coldest months increases as one moves further inland and away from the moderating influence of the ocean. Places with a hottest monthly temperature above 10 °C (50 °F) and a coldest month temperature below −3 °C (26.6 °F) and which do not meet the criteria for an arid climate, are classified as continental.[16]
[edit] Oceanic climate
World map showing the oceanic climate zones.An oceanic climate (also called marine west coast climate and maritime climate) is 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. Precipitation is plentiful throughout the year in this climate regime.[20]
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 14 °C (57 °F) 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.
[edit] Oceanic climate
World map showing the oceanic climate zones.An oceanic climate (also called marine west coast climate and maritime climate) is 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. Precipitation is plentiful throughout the year in this climate regime.[20]
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 14 °C (57 °F) 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.
Trophical savanna
Tropical rain forest
Rain forests are characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1,750 millimetres (69 in) and 2,000 millimetres (79 in). Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year.[9] Rainforests are home to half of all the living animal and plant species on the planet.[10] Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[11] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[12] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[13]
Onset dates and prevailing wind currents of the southwest summer monsoon.
[edit] Tropical monsoon
A monsoon is a seasonal prevailing wind which lasts for several months, ushering in a region's rainy season. The term was first used in English in India, Bangladesh, Pakistan and neighboring countries to refer to the big seasonal winds blowing from the Indian Ocean and Arabian Sea in the southwest bringing heavy rainfall to the region.[14] In hydrology, monsoon rainfall is considered to be that which occurs in any region that receives the majority of its rain during a particular season. This allows other regions of world such as within North America, South America. Sub-Saharan Africa, Australia and East Asia to qualify as monsoon regimes.[15] In terms of total precipitation and total area covered, the monsoons affecting the Indian subcontinent dwarf the North American monsoon. The South Asian monsoon affects larger number of people due to the high density of population within that part of the world.
Rain forests are characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1,750 millimetres (69 in) and 2,000 millimetres (79 in). Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year.[9] Rainforests are home to half of all the living animal and plant species on the planet.[10] Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[11] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[12] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[13]
Onset dates and prevailing wind currents of the southwest summer monsoon.
[edit] Tropical monsoon
A monsoon is a seasonal prevailing wind which lasts for several months, ushering in a region's rainy season. The term was first used in English in India, Bangladesh, Pakistan and neighboring countries to refer to the big seasonal winds blowing from the Indian Ocean and Arabian Sea in the southwest bringing heavy rainfall to the region.[14] In hydrology, monsoon rainfall is considered to be that which occurs in any region that receives the majority of its rain during a particular season. This allows other regions of world such as within North America, South America. Sub-Saharan Africa, Australia and East Asia to qualify as monsoon regimes.[15] In terms of total precipitation and total area covered, the monsoons affecting the Indian subcontinent dwarf the North American monsoon. The South Asian monsoon affects larger number of people due to the high density of population within that part of the world.
Koppean Classification
Tropical rain forest
Rain forests are characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1,750 millimetres (69 in) and 2,000 millimetres (79 in). Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year.[9] Rainforests are home to half of all the living animal and plant species on the planet.[10] Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[11] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[12] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[13]
Onset dates and prevailing wind currents of the southwest summer monsoon.
[edit] Tropical monsoon
A monsoon is a seasonal prevailing wind which lasts for several months, ushering in a region's rainy season. The term was first used in English in India, Bangladesh, Pakistan and neighboring countries to refer to the big seasonal winds blowing from the Indian Ocean and Arabian Sea in the southwest bringing heavy rainfall to the region.[14] In hydrology, monsoon rainfall is considered to be that which occurs in any region that receives the majority of its rain during a particular season. This allows other regions of world such as within North America, South America. Sub-Saharan Africa, Australia and East Asia to qualify as monsoon regimes.[15] In terms of total precipitation and total area covered, the monsoons affecting the Indian subcontinent dwarf the North American monsoon. The South Asian monsoon affects larger number of people due to the high density of population within that part of the world.
Rain forests are characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1,750 millimetres (69 in) and 2,000 millimetres (79 in). Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year.[9] Rainforests are home to half of all the living animal and plant species on the planet.[10] Tropical rain forests are called the "world's largest pharmacy" because over one-quarter of modern medicines originate from its plants.[11] The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level.[12] This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called a jungle.[13]
Onset dates and prevailing wind currents of the southwest summer monsoon.
[edit] Tropical monsoon
A monsoon is a seasonal prevailing wind which lasts for several months, ushering in a region's rainy season. The term was first used in English in India, Bangladesh, Pakistan and neighboring countries to refer to the big seasonal winds blowing from the Indian Ocean and Arabian Sea in the southwest bringing heavy rainfall to the region.[14] In hydrology, monsoon rainfall is considered to be that which occurs in any region that receives the majority of its rain during a particular season. This allows other regions of world such as within North America, South America. Sub-Saharan Africa, Australia and East Asia to qualify as monsoon regimes.[15] In terms of total precipitation and total area covered, the monsoons affecting the Indian subcontinent dwarf the North American monsoon. The South Asian monsoon affects larger number of people due to the high density of population within that part of the world.
Climate Classification
There are several ways to classify climates into similar regimes. Originally, climes were defined in Ancient Greece to describe the weather depending upon a location's latitude. Modern climate classification methods can be broadly divided into genetic methods, which focus on the causes of climate, and empiric methods, which focus on the effects of climate. Examples of genetic classification include methods based on the relative frequency of different air mass types or locations within synoptic weather disturbances. Examples of empiric classifications include climate zones defined by plant hardiness,[8] or more generally the Köppen climate classification which was originally designed to identify the climates associated with certain biomes. A common shortcoming of these classification schemes is that they produce distinct boundaries between the zones they define, rather than the gradual transition of climate properties more common in nature.
Definition
Climate (from Ancient Greek klima) is commonly defined as the weather averaged over a long period of time.[1] The standard averaging period is 30 years,[2] but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations. The Intergovernmental Panel on Climate Change (IPCC) glossary definition is:
Climate in a narrow sense is usually defined as the “average weather”, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.[3]
The difference between climate and weather is usefully summarized by the popular phrase "Climate is what you expect, weather is what you get."[4] Over historical time spans there are a number of static variables that determine climate, including latitude, altitude, proportion of land to water, and proximity to oceans and mountains. Other climate determinants are more dynamic: for example, the thermohaline circulation of the ocean leads to a 5 °C (9 °F) warming of the northern Atlantic ocean compared to other ocean basins.[5] Other ocean currents redistribute heat between land and water on a more regional scale. The density and type of vegetation coverage affects solar heat absorption,[6] water retention, and rainfall on a regional level. Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling. The variables which determine climate are numerous and the interactions complex, but there is general agreement that the broad outlines are understood, at least insofar as the determinants of historical climate change are concerned
Climate in a narrow sense is usually defined as the “average weather”, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.[3]
The difference between climate and weather is usefully summarized by the popular phrase "Climate is what you expect, weather is what you get."[4] Over historical time spans there are a number of static variables that determine climate, including latitude, altitude, proportion of land to water, and proximity to oceans and mountains. Other climate determinants are more dynamic: for example, the thermohaline circulation of the ocean leads to a 5 °C (9 °F) warming of the northern Atlantic ocean compared to other ocean basins.[5] Other ocean currents redistribute heat between land and water on a more regional scale. The density and type of vegetation coverage affects solar heat absorption,[6] water retention, and rainfall on a regional level. Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling. The variables which determine climate are numerous and the interactions complex, but there is general agreement that the broad outlines are understood, at least insofar as the determinants of historical climate change are concerned
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