Precipitation plays a major role in determining the climate of an area. Rainfall is critical, in particular, for it replenishes ground water and supplies both natural watershed systems and irrigation channels. Worldwide rainfall averages vary greatly from region to region. Average rainfall is determined by the depth of water falling on a flat surface and is measured by a rain gauge.

Climate is the long-term effect of the sun's radiation on the rotating earth's varied surface and atmosphere. It can be understood most easily in terms of annual or seasonal average precipitation and average temperature. Precipitation is any kind of water that falls from the sky as part of the weather. This includes snow, rain, sleet, freezing rain, hail, and virga. Precipitation is a major part of the hydrologic cycle, and is responsible for depositing most of the fresh water on the planet.

Vegetation is a general term for the plant life of a region. It refers to the ground cover provided by plants, and is the most abundant biotic element of the biosphere. The term Natural Vegetation characterizes those soils where vegetation grows without active and frequent intervention by people. Vegetation serves several critical functions in the biosphere. It regulates the flow of numerous biogeochemical cycles; affects soil characteristics and is a primary source of oxygen in the atmosphere.

Geographical areas, characterized by distinct plant communities are called vegetation regions. Community composition, determined by climate, may be affected by factors such as geology, soil composition and erosion, water drainage patterns and human interference. The specific traits of tundra vegetation are: one-layer closed vegetation cover; predominance of perennial plants; high importance of dwarf shrubs, mosses and lichens; the lack of shrubs and trees.

Rain is associated with water. During the summer season from time to time we ask God for rain. We need rain not only because it is hot and rain usually refreshes us but also because we know that crops depends much on rain. The more crops we get the better for us and for economy of the country we live in and for other countries as well. Rainfall predictions associated with climate change may be variable across even one country, not speaking about larger areas on a global scale. For example across Australia some areas are getting more and other less rain. Since 1975 to 2005 Perth annual average rainfall is half what is was from 1911 to 1974.

The Canadian Shield is Canada's largest physiographic area, stretching through the territory of at least six provinces (Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Newfoundland and Labrador) and two regions (Northwest and Nunavut). Thick forests cover the southern part of the shield, whereas in the north there is only tundra. Since the Canadian Shield is so large, weather conditions differ considerably from one region to another. In the southern parts of it the climate is seasonal, while in the northern shield the climate is arctic, and lakes are free of ice for only about three months annually.

The Bering Sea is a zone that links the North Pacific Ocean and the Arctic Ocean, and shares characteristics of each and is influenced by both. Its intermediary location results in neither a truly north temperate nor arctic type of this sea. However, such juxtaposition also makes the Bering Sea extraordinarily productive, with a high marine biodiversity and large populations of birds, mammals and fish.

The climate and ecosystem of the Bering Sea has changed drastically over the previous fifty years. The first serious "regime shift" was noted in the late 1970s, the second- around 2000. They both resulted in a significant temperature increase and a reduction in the seasonal ice cover. At the same time, some species of the Bering Sea and adjacent regions have undergone large and sometimes sudden population fluctuations. Obviously, any interaction in this region, climatic/ oceanographic or biological, can have unexpected, complex ecological outcomes.

As a result of a large size, the Australian continent experience a great variety of weather patterns on its vast territory. Seasonal fluctuations of average temperatures range from fifty degrees Celsius above zero to well below zero. The lack of mountains and the influence of surrounding oceans have a paramount effect on typical Australian weather conditions.

Eighty percent of Australia continent annually receives less than six hundred milimeters of precipitation. A low rainfall together with a very high evaporation (predominantly in inland Australia) results in seasonal river systems and low surface water flows. Scientists are likely to consider that irregular and insufficient rainfall patterns in Australia are the consequences of the high pressure belt and the El Nino-Southern Oscillation.

The Canadian Shield is Canada's largest physiographic area, stretching through the territory of at least six provinces (Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Newfoundland and Labrador) and two regions (Northwest and Nunavut). Thick forests cover the southern part of the shield, whereas in the north there is only tundra. Since the Canadian Shield is so large, weather conditions differ considerably from one region to another. In the southern parts of it the climate is seasonal, while in the northern shield the climate is arctic, and lakes are free of ice for only about three months annually.

The Bering Sea is a zone that links the North Pacific Ocean and the Arctic Ocean, and shares characteristics of each and is influenced by both. Its intermediary location results in neither a truly north temperate nor arctic type of this sea. However, such juxtaposition also makes the Bering Sea extraordinarily productive, with a high marine biodiversity and large populations of birds, mammals and fish.

The climate and ecosystem of the Bering Sea has changed drastically over the previous fifty years. The first serious "regime shift" was noted in the late 1970s, the second- around 2000. They both resulted in a significant temperature increase and a reduction in the seasonal ice cover. At the same time, some species of the Bering Sea and adjacent regions have undergone large and sometimes sudden population fluctuations. Obviously, any interaction in this region, climatic/ oceanographic or biological, can have unexpected, complex ecological outcomes.

As a result of a large size, the Australian continent experience a great variety of weather patterns on its vast territory. Seasonal fluctuations of average temperatures range from fifty degrees Celsius above zero to well below zero. The lack of mountains and the influence of surrounding oceans have a paramount effect on typical Australian weather conditions.

Eighty percent of Australia continent annually receives less than six hundred milimeters of precipitation. A low rainfall together with a very high evaporation (predominantly in inland Australia) results in seasonal river systems and low surface water flows. Scientists are likely to consider that irregular and insufficient rainfall patterns in Australia are the consequences of the high pressure belt and the El Nino-Southern Oscillation.

In the light of the current climate changes, the science of nature processes observation - better known as phenology - is extremely essential. All over the word there is a rather great number of acting organizations dealing with the variation in timing of life cycle events. Their goal is to increase the efficiency, added value and use of phenological monitoring and research.

Being an integral part of nature, we are the witnesses of constant changes that have taken place all over the world, not to mention during probably millions years of human existence. Our ancestry provided us with different weather tokens that are rather helpful. Nowadays this usual keenness of observation has become the science that is known as phenology. Plant phenology has evolved into a respected yet still relatively new area of study.

Maritime climate, as its name implies, is greatly influenced by the nearby ocean. For example: the ocean has the ability to retain warmth much longer than land. The ocean currents constantly move warm or cold water, not to mention precipitation that creates heavy cloud cover and results in high level of precipitation - all these are the factors of maritime climate formation. And that in turn impacts your vacation.

The term "arid zone" is ascribed to three types of arid environment: hyper-arid, arid and semi-arid. Climates of these arid zones strongly depend on temperature fluctuations; time of the year, in which the rain falls (that determine dry and wet seasons), and a degree of aridity. There are Mediterranean, tropical and continental climatic patterns in arid areas.

Southeast Alaska, also known simply as "Southeast", is a portion of the state that is from the southeast corner of the state's main land mass. Southeast justifies its name of the "Gateway to Alaska" due to the relative accessibility, and for decades it has been a common destination for tourists. However, visitors often know little about the climate of this area and get discouraged by the weather conditions, when they arrive. Helpful information on the typical weather of Alaska Southeast will reduce surprises.

Alpine biomes are found in mountain regions worldwide, including the Andes, Alps and Rocky Mountains. They usually lie between altitudes of about 10,000 feet at the place, where the snow line of a mountain begins. Although Alpine biomes are typically harsh environments, characterized by extreme weather conditions, they have the plant and animal life.

Almost one-third of the total land area of the world is arid. The arid environment is distinguished by an excessive heat and inadequate, changeable precipitation, which occurs infrequently and irregularly. It is vegetated by drought resistant species, which have developed adaptation strategies to cope with the lack of rainfall. Although there is so much in common between different types of arid zones, arid environments are diverse in many aspects.

Visiting Alaska for the first time, do not forget to find out some information, concerning its climate. A vast forty ninth state is a big one, and weather conditions can vary greatly by region and season. As a rule, tourists flow into Alaska at the end of May or early June, as many attractions open at that time. However, some popular activities and festivals take place during the spring, fall or even winter.

The Alpine vegetation is highly adapted to survive in a particularly harsh setting. It has to withstand low temperatures, frost and snow for more than six month a year. At the same time, solar energy in the atmosphere is only enough to provide a frugal day to day living and a renewal of leaves. There are no natural resources for maintaining large root systems and branches, which normal trees have. The plants in Alpine zones are mostly ground hugging and, as a rule, reach no more than a meter in height.

There's more to the earth's oceanic climate than cool breezes and gentle waves washing up on the beach. Occupying two-thirds of the dry land oceans and seas play an important role in our life. This huge territory represents an enormous amount of scientific information. They determine climates and biomes as well as our life in general. One of the climates that most of all influenced by the ocean is oceanic climate.