Atmosphere of Earth The Earth’s atmosphere is a dynamic system that is changing continuously while undergoing chemical and physical change. It is the thin layer of gases that envelopes the earth. Gases in the air support plant and animal life. Some gases even block rays the radiation of the sun. COMPOSITION OF THE EARTH’S ATMOSPHERE Air is a mixture of many gases, each with its own physical properties and varying quantities of both solid and liquid particles. 1. Nitrogen (78%) - the most abundant and important gas in the atmosphere. It dilutes oxygen to lessen the rate at which oxidation or burning occurs. -It is important element in the body of plants and animals 2. Oxygen (21%) - Breath of life, it is the most important gas in the atmosphere. The energy exhibited by animal life is released by using the oxygen to burn the foods, releasing energy and carbon dioxide. - it aids in the purifying water, decaying waste matter and destroying germs. 3. Carbon Dioxide (0.03%) -plays an important role in life. It is used in the plant’s photosynthesis. -in industries, it is used in making soda water, and carbonated drinks. - When in solid form, it known as “dry ice” which is used in refrigiration. -it helps keep the atmosphere warm. 4. Argon (1%) - used in the incandescent light bulb. Other gases are Neon, Helium, and Methane. In addition to gases, the atmosphere also contains particulate matter such as dust, volcanic ash, rain, and snow. They can sometimes remain in the atmosphere for relatively long periods of time. Volcanic ash from the 1991 eruption of Mt. Pinatubo in the Philippines, for example, darkened skies around the globe for over a year. LAYERS OF ATMOSPHERE 1. Troposphere - is the layer closest to Earth's surface. It is 4 to 12 miles (7 to 20 km) thick and contains half of Earth's atmosphere. Air is warmer near the ground and gets colder higher up. Nearly all of the water vapor and dust in the atmosphere are in this layer and that is why clouds are found here. 2. Stratosphere -is the second layer. -Ozone is abundant here and it heats the atmosphere while also absorbing harmful radiation from the sun. -The air here is very dry, and it is about a thousand times thinner here than it is at sea level. Because of that, this is where jet aircraft and weather balloons fly. 3. Mesosphere - the top of the mesosphere, called the mesopause, is the coldest part of Earth's atmosphere, (minus 90 C). -This layer is hard to study. Jets and balloons don't go high enough, and satellites and space shuttles orbit too high. - Scientists do know that meteors burn up in this layer. 4. Thermosphere - Temperatures can get up to 2,700 degrees F (1,500 C) at this altitude. - Air density is so low that most of this layer is what is normally thought of as outer space. In fact, this is where the space shuttles flew and where the International Space Station orbits Earth. 5. Exosphere - the highest layer, is extremely thin and is where the atmosphere merges into outer space. -It is composed of very widely dispersed particles of hydrogen and helium. WEATHER AND CLIMATE Weather & Climate Weather and climate describe the world outside the window - whether it’s hot or cold, humid or dry, sunny or cloudy. Weather is the short term conditions present in the moment that let people know what to wear today and whether or not to bring an umbrella. Climate describes the long term conditions that let people know what clothes to keep in their wardrobe all year long and whether they need to own snow boots, flip flops or both. Elements of Weather and Climate 1. WIND Wind is the movement of air parallel to Earth’s surface. 2. TEMPERATURE Refers to the degree of coldness or hotness of the air, water, soil and living organisms. Temperature changes may also be associated with wind direction. In the Northern Hemisphere winds from the south usually bring rising temperatures, while northerly winds are normally accompanied by falling temperatures 3. HUMIDITY Humidity is the amount of moisture/vapor in the air. Water exists in the air in gaseous form, called water vapor. Warm air can contain more vapor than cold air can. When the air feels damp, the humidity is high. If humidity is low, there is very little moisture in the air. Low humidity can cause lips crack and skin dryness. 4. CLOUD It is an aerosol consisting of a visible mass of minute liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture. 5. PRECIPITATION Precipitation is water released from clouds in the form of rain, freezing rain, sleet, snow, or hail. It is the primary connection in the water cycle that provides for the delivery of atmospheric water to the Earth. Most precipitation falls as rain. Sleet- a form of precipitation consisting of ice pellets, often mixed with rain or snow. Hail- It is distinct from ice pellets, though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone GREENHOUSE EFFECT The "greenhouse effect" is the warming that happens when certain gases in Earth's atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse. First, sunlight shines onto the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped. GLOBAL WARMING The globe is heating up. Both land and oceans are warmer now than record-keeping began in 1880, and temperatures are still ticking upward. This temperature rise, in a nutshell, is global warming. Glaciers are melting, sea levels are rising, cloud forests are dying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years. What are El Niño and La Niña? El Niño El Niño means The Little Boy, or Christ Child in Spanish. El Niño was originally recognized by fishermen off the coast of South America in the 1600s, with the appearance of unusually warm water in the Pacific Ocean. Typical El Niño effects are likely to develop over North America during the upcoming winter season. Those include warmer-than-average temperatures in places which are generally cold. . The presence of El Niño can significantly influence weather patterns, ocean conditions, and marine fisheries across large portions of the globe for an extended period of time. La Niña La Niña means The Little Girl in Spanish. La Niña simply "a cold event." La Niña episodes represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific. Global climate La Niña impacts tend to be opposite those of El Niño impacts. In the tropics, ocean temperature variations in La Niña also tend to be opposite those of El Niño. During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest.. 4 Types of Climate in the Philippines There are four recognized climate types in the Philippines, and they are based on the distribution of rainfall. Type I. Two pronounced season: dry from November to April and wet during the rest of the year. Type II. No dry season with a pronounced rainfall from November to January. Type III. Seasons are not very pronounced, relatively dry from November to April, and wet during the rest of the year. Type IV. Rainfall is more or less evenly distributed throughout the year. There are three recognized seasons: 1. Tag-init or Tag-araw (the hot season or summer from March to May), 2. Tag-ulan (the rainy season from June to November), and Taglamig (the cold season from December to February) 3. The humid southwest monsoon (May-October) is known as "Habagat". The cool and dry winds of the northeast monsoon (November April) are called "Amihan". HABAGAT VS AMIHAN HABAGAT • Summer Monsoon (West or southwest) • characterized by a strong, generally West or southwest breeze that is responsible for bringing significant rainfall to the Asian subcontinent and to South and East Asia. AMIHAN • Winter Monsoon (North or northeast) • features a generally less strong, East or northeast breeze that is cool and dry (compared to the Summer Monsoon weather) with prolonged periods of successive cloudless days Weather Disturbances Weather Disturbances - a term used to describe a change in atmospheric conditions or weather patterns. - The Philippines is located in the North Pacific Ocean where the greatest number of cyclones form. An average of 22 cyclones form in this area every year, about 19 of which enter the Philippine Area of Forecast Responsibility (or Philippine Area of Responsibility, PAR). The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) issues warning bulletins about a typhoon only when it is within the PAR. Tropical Cyclone Tropical cyclones are low pressure areas that forms in the tropics over the seas and ocean. It is called a HURRICANE if the cyclone has sustained winds of 74 mph or more. The terms cyclone, typhoon and hurricane are almost just the same. The name only varies depending to is location. Tropical Cyclone It is called cyclone in the Indian ocean and typhoon in the western Pacific. The Pacific Ocean is located between the Philippines and the Marianas and Caroline Islands and it is where the typhoons are formed, thus affecting greatly our country Hurricanes are the most violent storms on Earth. They form near the equator over warm ocean waters over the Atlantic Ocean or eastern Pacific Ocean. Typhoons Are considered as the most destructive weather disturbance because it is characterized by heavy rains and violent winds. Some places in the Philippines like Bicol region, Quezon province, Nueva Vizcaya, Samar and Leyte are frequently visited by typhoons because they are open to both northwest and southern monsoons. Southern Mindanao, Southern Visayas, Mindoro and Palawan are seldom affected by typhoons because they are protected mountain ranges. How Typhoons are Formed? Eye of the Storm They are found at the center and are between 20-50km in diameter. It is the focus of the hurricane, the point about which the rest of the storm rotates and where the lowest surface pressures are found in the storm Skies are often clear above the eye and winds are relatively light. It is actually the calmest section of any hurricane. Inter Tropical Convergence Zone The Inter Tropical Convergence Zone, or ITCZ, is a belt of low pressure which circles the Earth generally near the equator where the trade winds of the Northern and Southern Hemispheres come together. It is characterised by convective activity which generates often vigorous thunderstorms over large areas.
