Showing posts with label Explanation Text about Science. Show all posts
Showing posts with label Explanation Text about Science. Show all posts

Monday, May 20, 2019

Explanation Text (Explanatory) : The Phenomena of El Nino

Explanation or also knows as explanatory text is a kind of text that explain the processes involved in the formation or workings of natural or sociocultural phenomena.

Explanation Text is a kind of Factual Genre. Explanation Text consist of two structure, they are general statement and explanation.

General Statement provides a general statement to position the reader. It focuses on generic, non human participants.

Explanation gives a sequence explaining of why or how something occurs. It is comprised mainly material and relational process, temporal, causal circumstances and conjunctions.

Here is one of the example of Explanation or Explanatory text. It explains about science. Remember that it is just a simple example. You can develop by your self according your need and your tasks from your teacher. You may use it as a reference.

The Phenomena of El Nino

What Is El Nino (General Statement)
El Nino is a warm water current which moves off the west coast of Chile and Peru. The current is believed to be closely associated with irregular variations in the global weather system and it occurs approximately every 7–11 years. The wider consequences of El Nino can be catastrophic. The current is associated with short–term changes in worldwide climate patterns, and may cause drought in place such as Australia and violent tropical cyclones in the Pacific Ocean. Some scientists fear that global warming may be making El Nino occur more frequently.

How does El Nino Occurs (Explanation)
The combined influence of land, sea and air on weather conditions can create a global climate rhythm. In the Pacific Ocean, for example (A), trade winds normally blow from east to west (1) along the Equator, “dragging” sun–warmed surface waters into a pool of North Australia and there by the thermocline–the boundary between warm surface waters and the cooler layers beneath (2). High cumulus  clouds form above these warm waters, bringing rain in the summer wet season (3). Cooler, nutrient-rich waters rise to surface off Southern America (4), supporting extensive shoals of anchovies on which a vast fishing industry has developed. The weather over this cold water region is dry.

Every 3–5 years a change occurs in the ocean-atmosphere interaction. The climatic pattern is reserved (B)–an event known as El Nino. The trade winds ease, or even reverse direction (5), during El Nino and the warm surface waters which have “pilled up” in the West Pacific flow back to warm the waters off South America by 2–3°C (6). This depresses the east thermocline (7) and dramatically affects the climate. In an El Nino year, drought and bush fires occur over Australia, while flood affect Bolivia and Peru. The warm waters off South America suppress upwelling of the cold nutrient rich waters, bringing disaster to the fishing industry.

Sunday, May 19, 2019

Explanation Text (Explanatory) : What Causes Air to Rise

Explanation or also knows as explanatory text is a kind of text that explain the processes involved in the formation or workings of natural or sociocultural phenomena.

Explanation Text is a kind of Factual Genre. Explanation Text consist of two structure, they are general statement and explanation.

General Statement provides a general statement to position the reader. It focuses on generic, non human participants.

Explanation gives a sequence explaining of why or how something occurs. It is comprised mainly material and relational process, temporal, causal circumstances and conjunctions.

Here is one of the example of Explanation or Explanatory text. It explains about science. It is About The causes air to rise. Remember that it is just a simple example. You can develop by your self according your need and your tasks from your teacher. You may use it as a reference.

What Causes Air to Rise? 

There are several ways in which air can be forced to rise, thus causing the water droplets to condense. We will look at each of these in turn.

1. The air is heated from the ground
This tends to occur mainly in the tropics, where the air in contact with the ground is warmer than the air above. So it will rise. As a result, sometimes huge thunder–clouds (called cumulonimbus clouds) form and the associated rainfall can be very heavy. This type of rainfall is called convection rain.

2. The air is forced to cross a mountain barrier
As an air mass crosses a mountain barrier, it is forced to rise. If the mountains are sufficiently high and the air mass contains enough moisture, clouds will form and rain will fall on the windward side (the side closest to where the air mass is coming form). This rainfall is known as orographic rain, meaning “caused by the shape of the land”. The air mass, now drier and warmer, will continue to flow down the other side of the mountains (the leeward side).

3. Air rises as it enters an area of low pressure
As air rises, other air must replace it which, in turn, also rises. This is a complex process. As the air rises, it moves in a spiral, but if enough air enters an area of flow pressure, clouds will form and rain may fall

Saturday, May 18, 2019

Explanation Text (Explanatory) : Acid Rain

Explanation or also knows as explanatory text is a kind of text that explain the processes involved in the formation or workings of natural or socio-cultural phenomena.

Explanation Text is a kind of Factual Genre. Explanation Text consist of two structure, they are general statement and explanation.

General Statement provides a general statement to position the reader. It focuses on generic, non human participants.

Explanation gives a sequence explaining of why or how something occurs. It is comprised mainly material and relational process, temporal, causal circumstances and conjunctions.

Here is one of the example of Explanation or Explanatory text. Remember that it is just a simple example. You can develop by your self according your need and your tasks from your teacher. You may use it as a reference.

Acid Rain
Acid rain is rain that is highly acidic because of sulphur oxides, nitrogen oxides, and other air pollutants dissolved in it. Normal rain is slightly acidic, with a pH of 6. Acid rain may have a pH value as low as 2.8.

Acid rain can severely damage both plant and animal life. Certain lakes, for example, have lost all fish and plant life because of acid rain.

Acid rain comes from sulphur in coal and oil. When they burn, they make sulphur dioxide (SO2). Most sulphur leaves factory chimneys as the gaseous sulphur dioxide (SO2) and most nitrogen is emitted as nitrogen oxides (NO or NO2), both of which are gases. The gases may be dry deposited–absorbed directly by the land, by lakes or by the surface vegetation. If they are in the atmosphere for any time, the gases will oxidise (gain an oxygen atom) and go into solution as acids. Sulphuric acid (H2SO4) and the nitrogen oxides will become nitric acid (HNO3).

The acids usually dissolve in cloud droplets and may travel great distances before being precipitated as acid rain. Catalysts such as hydrogen peroxide, ozone and ammonium help promote the formation of acids in clouds. More ammonium (NH4) can be formed when some of the acids are partially neutralised by airborne ammonia (NH3). Acidification increases with the number of active hydrogen (H+) ions dissolved in acid. Hydrocarbons emitted by for example, car exhausts will react in sunlight with nitrogen oxides to produce ozone. Although it is invaluable in the atmosphere, low level ozone causes respiratory problems and also hastens the formation of acid rain.

When acid rain falls on the ground it dissolves and liberates heavy metals and aluminium (Al). When it is washed into lakes, aluminium irritates the outer surfaces of many fish. As acid rain falls or drains into the lake the pH of the lake falls. Forests suffer the effect of acid rain through damage to leaves, through the loss of vital nutrients, and through the increased amounts of toxic metals liberated by acid, which damage roots and soil micro organisms.