Meteorology is a sub-discipline of the broader field of knowledge known as atmospheric sciences. The purpose of the science of meteorology is to understand the processes and phenomena that make up our planet’s weather. From this understanding, meteorologists are able to generate short-term weather forecasts using current climate information, software and powerful computers. Weather forecasts are very important as they help us plan the various social and economic aspects of our lives. Modification of the software used in weather forecasting has allowed scientists to build models for understanding the climate of the Earth’s past. These models can also be used to make predictions about the future of our planet’s weather and climate under the scenario of global warming.
NOAA 2011 Atlantic Hurricane
The 2011 Atlantic hurricane season outlook is an official product of the National Oceanic and Atmospheric Administration...
CloudsLast Updated on 2014-09-30 10:52:27A could is a visible aggregate of minute water droplets or ice particles in the atmosphere above the Earth's surface. Clouds are classified according to their height above and appearance (texture) from the ground.
Clouds form when air is cooled to its dewpoint—or the temperature at which, if the air is cooled, it reaches saturation with water. Air can reach saturation in a number of ways. The most common way is through lifting.
As a bubble or parcel of air rises it moves into an area of lower pressure (pressure decreases with height). As this occurs the parcel expands. This requires energy, or work, which takes heat away from the parcel. So as air rises it cools. This is called an adiabatic process.
The rate at which the parcel cools with increasing elevation is called the "lapse rate". The lapse rate of unsaturated air (air with relative humidity <100%)... More »
Von Humboldt, AlexanderLast Updated on 2014-06-26 16:40:53
Baron Alexander von Humboldt (1769-1859) was one of the last true generalists in science. While generally considered a geographer, he contributed to most of the sciences of the natural environment found today. Born in Berlin, von Humboldt’s father was Chamberlain to the King, a royal advisor, who died when Alexander was nine years old. As a child, he received a private education and was a slow learner and sickly much of the time. On his own, though, he loved collecting local plants and animals and reading books on foreign travel and adventure. He also loved to draw, mostly landscapes. Typical of the time, science was not part of his schooling; Humboldt was generally self taught in that area. At sixteen, he attended some lectures on physics and philosophy by a local doctor and then he decided to pursue a career in science.
Humboldt... More »
Seed dispersal of desert plantsLast Updated on 2014-06-24 19:28:08
Seeds generally need to be transported some distance from the parent plant in order to find a suitable site for establishment.
Some plants have wind-dispersed seeds, which are occasionally blown many miles from their origins. This means of dispersal is common among pioneer plants (plants that are adapted to colonizing disturbed habitats). Because of their superior ability to invade newly-disturbed ground, pioneer plants comprise many of our agricultural and garden weeds. Moreover, most annual crops are domesticated pioneer plants. That’s why we need to plow (disturb) fields in order to grow them.
Many plants use animals to disperse their seeds in another complex coevolutionary process. Small, brightly-colored fruits such as hackberry and boxthorn are offered as food for birds that swallow them whole. Other fruits such as those of hedgehog cacti are large and... More »
Earth's atmospheric airLast Updated on 2014-04-02 14:56:48The Earth's atmospheric air is a colorless, odorless and tasteless mixture of gases consisting mostly of nitrogen (N2) and oxygen (O2). It is the part of Earth's atmosphere that humans and all other animals breathe in order to obtain the oxygen needed to sustain life.
The Earth's atmosphere not only contains the air we breathe, it also holds clouds of moisture (water vapor) that become the water we drink. Furthermore, it protects us from meteors and harmful solar radiation and warms the Earth's surface by heat retention. In effect, the atmosphere is an envelope that protects all life on Earth.
The air may contain pollutants that originate from a variety of sources such as our industries and our vehicles, and can directly or indirectly affect our health and the natural environment. These effects may be experienced near the sources of air pollution and some air... More »
RespirationLast Updated on 2014-01-31 16:43:42Respiration is the gas exchange effected by living organisms for the purpose of sustaining vital metabolic processes. In the case of most animals, oxygen is taken into the organism, and carbon dioxide is expelled. In the case of plants, the inverse process occurs of consuming carbon dioxide and expelling oxygen as a waste gas.
Respiration may also be viewed at a cellular level, examining gas exchange at the cell wall; for very simple organisms, such as unicellular lifeforms, the process of gas exchange with the environment is simplified, so that cellular wall gas exchange is the totality of respiration for such an organism.
In the case of some bacteria and archaea, respiration sometimes occurs without any oxygen, and alternative molecular gases such as hydrogen sulfide or methane may participate in respiration and subsequent cellular metabolic reactions. Often such organisms are... More »
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