Geosystems: Chapter 10

Empirical classification

A classification based on statistics or other data determined by measurement of observed effects.

Microthermal Climates

A climate category with four subregions that occurs in mid to high latitudes and is notable for its cold winters. 21% of the Earth's land surface is influenced by these climates though 7% of Earth actually consists of it. There are great temperature ranges given continentality and air mass conflicts. This climate cannot be found in the Southern hemisphere.

The principal elements of climate

Insolation, temperature, pressure, air masses, and precipitation.

Climatic regions

Climatic analysis that locates areas of similar weather statistics and groups them.

Tropical climate zones

Contains three subcategories of climate regions. It is located around tropical latitudes and covers about 36% of the Earth's surface. The straddle the equator from about 20˚N and 20˚S. They have consistent day length and insolation which leads to consistently warm temps. Also, the ITCZ brings rains as it shifts seasonally with the high sun. Warm ocean temperatures cause unstable maritime air masses.

Subarctic Climate

Farther poleward, this climate experiences greater seasonal change. The short growing season is more intense during long summer days. Mineral and oil reserves have increased interest in these regions. Precipitation and POTET are both low, so soils are generally moist and either partially or totally frozen, a phenomenon called permafrost.

Mesothermal Climates

A climate category with four subregions, meaning middle temperature. Located midlatitudes possesses mild winters. Here, true seasonality begins and seasonal contrasts in vegetation, soil, and human adaptation begins. More than half of the world's population resides in these climates, about 27% of the Earth. Latitudes of greatest air mass interaction. Migration of cyclonic (low-pressure) and anticyclonic (high-pressure) systems bring changeable weather. Effected by sea-surface temperatures.

Tropical monsoon climate

A climate that features a dry season that lasts one or more months when the convergence zone is not overhead. Rainfall brought by ITCZ occurs 6-12 months of the year. Lies principally along coastal areas. Vegetation involves evergreen trees and thorn forests as it phases into a different climate zone.

Tropical rainforest climate

A climate that is constantly moist and warm, as well as rainy all year. Convectional thunderstorms, triggered by local heating and trade wind convergence occur almost daily. Precipitation follows the migrating ITCZ, northward and southward with the Summer sun. Water surplus is enormous. Vegetation is dense and heavy precipitation washes away minerals, resulting in sterile soil.

Midlatitude Cold Desert Climates

A very small area constitutes this climate region. Because of lower temperatures and lower moisture-demand values, rainfall must be low for a station to qualify. There is a precipitation increase from summer convectional showers.

Genetic classification

Causative factors, such as the interaction of air masses.

Ice-Cap and Ice-Sheet Climate

Most of Antarctica, central Greenland, and the North Pole all have this climate. All months average below freezing.

Humid Continental Mild-Summer Climate

Soils in this climate are thinner and less fertile, yet agricultural activity is important. Precipitation is less than in the hot-summer regions to the south, but heavy snowfall is important to soil-moisture recharge when it melts. Thus, tall stubble is created for snowdrifts.

Classification

The process of ordering or grouping data or phenomena into related classes.

Climatology

The study of climate and its variability.

Climate

The weather over many years, including its variability and extremes.

Humid Continental Hot-Summer/Winter-Dry Climate

These two sub-sub-regions are differentiated by their annual precipitation distribution. Maritime tropical air masses influence both regions. Tropical and continental polar air masses contain frequent weather activity between them. In the US, these regions are commonly used to grow soy, wheat, barley...etc.

Dry Climates

This climate category is characterized by permanent moisture deficits. They dry regions occupy more than 35% of Earth's land area. Sparse vegetation leaves the landscape bare; water demands exceeds the precipitation water supply throughout, creating permanent water deficits. Dry, subsiding air in subtropical high-pressure systems in dominant. Some are located in the rain shadow (leeward side) of mountains and they are often located in continental interiors which are far from moisture-bearing air masses. Shifting subtropical high-pressure systems produce semiarid steppes around arid deserts.

Tropical, Subtropical Hot Steppe CLimates

This climate exists around the periphery of hot deserts, where shifting subtropical high-pressure cells create a distinct summer-dry and winter-wet pattern.

Tropical savannah climate

This climate exists poleward of the tropical rain forest climates. The ITCZ reaches these regions for about 6 months or less. Summer are wetter than winters because convectional rains accompany the shifting ITCZ. When ITCZ is not present, there are notable dry conditions, causing POTET to exceed PRECIP in winter. Temperatures vary here and there can be two temperature maximums given that the Sun's direct rays are overhead twice. Vegetation consists of grasslands with scattered trees and drought resistance.

Marine West Coast Climate

This climate features mild winters and cool summers and are common in Europe and other middle-to-high latitude west coasts. Maritime polar air masses - cool, moist, unstable - dominate marine west coast climates. Coastal fog and frost can shorten growing season.

Tropical, Subtropical Hot Desert Climates

This climate features temperatures above 18˚C. They generally are found on the western sides of continents though Egypt, Somalia, and Saudi Arabia also fall within this classification. Rainfall is from summer convectional showers though there is often no more than 35cm per year.

Mediterranean Dry-Summer Climates

This climate involves 70% of annual precipitation occurring during the winter months. Shifting cells of subtropical high pressure block moisture bearing winds from adjacent regions. This shifting of stable, warm to hot, dry air over an area in summer and away from that area in winter creates a pronounced dry-summer climate. There are summer water-balance deficits which are recharged during the winter. Vegetation consists of chaparral, which is drought resistant.

Humid Subtropical Winter-Dry Climate

This climate is characterized by dry winters and is affected by the seasonal pulse of the monsoons. They extend poleward from tropical savannah climates and have a summer month that receives 10 times more precipitation than their driest winter month.

Humid Subtropical Hot-Summer Climate

This climate is characterized by hot summers and moist conditions all year. Warm, moist, unstable air produces convectional showers over land. In fall, winter, and spring, maritime tropical and continental polar air masses interact, generating frontal activity and frequent midlatitude cyclonic storms.

Midlatitude Cold Steppe Climates

This climate occurs poleward of about 30˚ latitude and the midlatitude cold desert climates. These are not found in the Southern Hemisphere. Rainfall is widely variable and undependable, ranging from 20-40 cm. Not all rainfall is convectional, for cyclonic storm tracks penetrate the continents. Most storms produce little precipitation.

Tundra Climate

This climate region is under continuous snow cover for 8-10 months, with the warmest month above 0˚C, but never above 10˚C. In spring, when snow melts, numerous plants persist through the short summer. This area experiences permafrost and ground ice conditions - a periglacial region. They are strictly in the Northern Hemisphere, except in elevated mountain locations and some elevated mountain locations in the Southern Hemisphere.

Polar Marine Climate

This climate zone is more moderate than other polar climates yet they are not as warm as tundra climates. Because of marine influences, annual temperature ranges are low.

Polar and Highland Climates

This is a climate category that has no true summer. The low sun altitude even during the long summer days is the principal climatic factor. Extremes of daylight between winter and summer, extremely low humidity, surface albedo impacts all exacerbate the frozen desert quality of these regions.