Atmosphere Articles from GINASRECIPES.COM Free Article Directory

Search our Site:

An atmosphere (from Greek atµ?? - atmos, "vapor" + sfa??a - sphaira, "sphere") is a layer of gases that may surround a material body of sufficient mass,^[1] by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, and therefore have very deep atmospheres (see gas giants).

The term stellar atmosphere is used for the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Relatively low-temperature stars may form compound molecules in their outer atmosphere. Earth's atmosphere, which contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis, also protects living organisms from genetic damage by solar ultraviolet radiation. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

The pressure of an atmosphere decreases with altitude due to the diminishing mass of gas above each location. The height at which the pressure from an atmosphere declines by a factor of e (an irrational number with a value of 2.71828..) is called the scale height and is denoted by H. For an atmosphere with a uniform temperature, the scale height is proportional to the temperature and inversely proportional to the mean molecular mass of dry air times the planet's gravitational acceleration. For such a model atmosphere, the pressure declines exponentially with increasing altitude. However, atmospheres are not uniform in temperature, so the exact determination of the atmospheric pressure at any particular altitude is more complex.

Since a gas at any particular temperature will have molecules moving at a wide range of velocities, there will almost always be some slow leakage of gas into space. Lighter molecules move faster than heavier ones with the same thermal kinetic energy, and so gases of low molecular weight are lost more rapidly than those of high molecular weight. It is thought that Venus and Mars may have both lost much of their water when, after being photodissociated into hydrogen and oxygen by solar ultraviolet, the hydrogen escaped. Earth's magnetic field helps to prevent this, as, normally, the solar wind would greatly enhance the escape of hydrogen. However, over the past 3 billion years the Earth may have lost gases through the magnetic polar regions due to auroral activity, including a net 2% of its atmospheric oxygen.^[2]

Atmosphere Subcategories Atmosphere Articles Creating An Appealing Atmosphere By Using Custom Fountains by Apurva . Sep 02, 2008 Custom fountains are being used widely in commercial establishments to promote brand value by making their fountains unique and one-of-a-kind. Fountains are visually extremely appealing and their musical sounds can calm and sooth us. This is one of t... How Mimosa Tree Makes A Rich Garden Atmosphere by Muna wa Wanjiru Jan 23, 2008 The beautiful mimosa tree comes from Africa and Asia, but it has now extended to lots of other places all over the world thanks to its great decorative looks. It grows at a maximum height of thirty feet, and being a deciduous tree, it a... I Love Wine Tasting in NYC Cosmopolitan Atmosphere, Do You? by Muna wa Wanjiru Feb 26, 2007 New York City is known as one of the most sophisticated cities on Earth. Here you will find many opportunities to see some interesting ways of wine tasting NYC style. These different wine tasting events will not take place in any vineyards. As ... Tips to Improve the Functionality and Atmosphere of Your Patio with Plants by Nicole Martins Feb 23, 2006 When I began to create planting plans for clients in the mid 1990’s one of my main concerns was, how will this collection of plants; the greenery, the flowering, the size and the shape grow together to create an aesthetically pleasing arrangement tha... The Secret of Unstable Atmosphere Training for Strength, Speed and Power by Joe Driscoll Jan 10, 2006 Luckily I learned a long time ago that if you train the same way that average people are training, you can expect the same average results. This couldn’t be truer when it comes to traditional bodyweight exercises and weightlifting routines. So many f...