Related Research Articles
Autumn, also known as fall in North American English, is one of the four temperate seasons. Outside the tropics, autumn marks the transition from summer to winter, in September or March, when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December and June. One of its main features in temperate climates is the shedding of leaves from deciduous trees.
The Northern Hemisphere is the half of the Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's North Pole.
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by reference to the solstices and the equinoxes.
Winter is the coldest season of the year in polar and temperate zones; it does not occur in most of the tropical zone. It occurs after autumn and before spring in each year. Winter is caused by the axis of the Earth in that hemisphere being oriented away from the Sun. Different cultures define different dates as the start of winter, and some use a definition based on weather. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere, and vice versa. In many regions, winter is associated with snow and freezing temperatures. The moment of winter solstice is when the Sun's elevation with respect to the North or South Pole is at its most negative value. The day on which this occurs has the shortest day and the longest night, with day length increasing and night length decreasing as the season progresses after the solstice. The earliest sunset and latest sunrise dates outside the polar regions differ from the date of the winter solstice, however, and these depend on latitude, due to the variation in the solar day throughout the year caused by the Earth's elliptical orbit.
In geography, the temperate climates of Earth occur in the middle latitudes, which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small.
The tropics are the region of Earth surrounding the Equator. They are delimited in latitude by the Tropic of Cancer in the Northern Hemisphere at 23°26′11.4″ (or 23.4365°) N and the Tropic of Capricorn in the Southern Hemisphere at 23°26′11.4″ (or 23.4365°) S; these latitudes correspond to the axial tilt of the Earth. The tropics are also referred to as the tropical zone and the torrid zone. The tropics include everywhere on Earth which is a subsolar point at least once during the solar year. Thus the maximum latitudes of the tropics have the same value positive and negative. Likewise, they approximate, due to the earth not being a perfect sphere, the "angle" of the Earth's axial tilt. The "angle" itself is not perfectly fixed due chiefly to the influence of the moon, but the limits of tropics are a geographic convention, being an averaged form, and the variance is very small.
Continental climates often have a significant annual variation in temperature. They tend to occur in the middle latitudes, where prevailing winds blow overland, and temperatures are not moderated by bodies of water such as oceans or seas. Continental climates occur mostly in the Northern Hemisphere, which has the kind of large landmasses on temperate latitudes required for this type of climate to develop. Most of northern and northeastern China, eastern and southeastern Europe, Western and north western Iran, central and southeastern Canada, and the central and northeastern United States have this type of climate.
The Southern Hemisphere is the half (hemisphere) of Earth that is south of the Equator. It contains all or parts of five continents, four oceans, New Zealand and most of the Pacific Islands in Oceania. Its surface is 80.9% water, compared with 60.7% water in the case of the Northern Hemisphere, and it contains 32.7% of Earth's land.
The midnight sun is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the Sun remains visible at the local midnight. When the midnight sun is seen in the Arctic, the Sun appears to move from left to right, but in Antarctica the equivalent apparent motion is from right to left. This occurs at latitudes from 65°44' to 90° north or south, and does not stop exactly at the Arctic Circle or the Antarctic Circle, due to refraction.
Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses.
The subtropical zones or subtropics are geographic and climate zones located to the north and south of the tropical zone. Geographically part of the north and south temperate zones, they cover the latitudes between 23°26′11.6″ and approximately 35° in the northern hemisphere and in the southern hemisphere.
The North American Central Time Zone (CT) is a time zone in parts of Canada, the United States, Mexico, Central America, some Caribbean Islands, and part of the Eastern Pacific Ocean.
The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936. Later, the climatologist Rudolf Geiger (1894-1981) introduced some changes to the classification system, which is thus sometimes called the Köppen–Geiger climate classification system.
The Eastern Time Zone (ET) is a time zone encompassing part or all of 23 states in the eastern part of the United States, parts of eastern Canada, the state of Quintana Roo in Mexico, Panama and Colombia, mainland Ecuador, Peru, and a small portion of westernmost Brazil in South America, along with certain Caribbean and Atlantic islands.
A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot summers and cold winters. Precipitation is usually distributed throughout the year. The definition of this climate regarding temperature is as follows: the mean temperature of the coldest month must be below 0 °C (32.0 °F) or −3 °C (26.6 °F) and there must be at least four months whose mean temperatures are at or above 10 °C (50 °F). In addition, the location in question must not be semi-arid or arid. The Dfb, Dwb, and Dsb subtypes are also known as hemiboreal.
Climate of Peru describes the diverse climates of this large South American country with an area of 1,285,216 km2 (496,225 sq mi). Peru is located entirely in the tropics but features desert and mountain climates as well as tropical rainforests. Elevations above sea level in the country range from −37 to 6,778 m and precipitation ranges from less than 20 mm (0.79 in) annually to more than 8,000 mm (310 in). There are three main climatic regions: the Pacific Ocean coast is one of the driest deserts in the world but with some unique features; the high Andes mountains have a variety of microclimates depending on elevation and exposure and with temperatures and precipitation from temperate to polar and wet to dry; and the Amazon basin has tropical climates, mostly with abundant precipitation, along with sub-tropical climates in elevations above 1,550 m (5,090 ft).
The summer solstice, also known as estival solstice or midsummer, occurs when one of the Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere. For that hemisphere, the summer solstice is when the Sun reaches its highest position in the sky and is the day with the longest period of daylight. Within the Arctic circle or Antarctic circle, there is continuous daylight around the summer solstice. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°. Likewise, the Sun's declination from the celestial equator is 23.44°.
A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of Earth's orbit around the Sun and Earth's axial tilt relative to the ecliptic plane. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical cultures whose number of seasons vary.
Antarctica sits on every line of longitude, due to the South Pole being situated on the continent. Theoretically, Antarctica would be located in all time zones; however, areas south of the Antarctic Circle experience extreme day-night cycles near the times of the June and December solstices, making it difficult to determine which time zone would be appropriate. For practical purposes time zones are usually based on territorial claims; however, many stations use the time of the country they are owned by or the time zone of their supply base. Nearby stations can have different time zones, due to their belonging to different countries. Many areas have no time zone since nothing is decided and there are not even any temporary settlements that have any clocks. They are simply labeled with UTC time.
Centers of action are extensive and almost stationary low or high pressure areas which control the movement of atmospheric disturbances over a large area. This does not mean that the position of the center is constant over a specific area but that the monthly atmospheric pressure corresponds to a high or a low pressure.
References
- ↑ Worldtimezone.com Time zone names - Peru Time, Retrieved December 28, 2007
