Geographic structure chart for senior high school students

Picture Analysis of the Compulsory Course in Geography for the First Year of Senior High School

Figure 1.1 The Universe Is Composed of Matter

This is a schematic diagram showing that the universe is composed of matter. It consists of four pictures. Small picture composition. From top to bottom are the Crab Nebula, Saturn, the Leonid meteor shower and Comet Harbin. The images are intuitive, adding to the reality and credibility that the universe is composed of matter.

When reading the schematic diagram "The universe is composed of matter", you should pay attention to its rich connotations and extensions, and reveal to students one by one based on the actual situation of your own teaching, such as what is the universe and celestial bodies , planets, meteoroids, nebulae, comets, etc., making the "universe is composed of matter" schematic diagram full and interesting from a single understanding of the several materials that make up the universe, stimulating students' enthusiasm for learning and spirit of exploration.

The steps for reading the diagram "The universe is composed of matter" are as follows:

①Explain the purpose of reading the diagram

The purpose of reading the diagram is to understand that the universe is composed of matter of. What is shown in the picture is part of the matter that makes up the universe. This part of matter is commonly called celestial bodies. The figure only shows the shape of each celestial body, and does not involve their height and mutual position in space. It is a schematic diagram of the shape of each independent celestial body.

②Explain the relevant concepts involved in the picture

Universe: Ancient Chinese scholars said that "the four directions above and below are called the universe, and the past and present are called the universe, to metaphor the heaven and the earth." It means that Yu refers to infinite space, and Universe refers to infinite time. The universe is the material world that is boundless in space, has no beginning and no end in time, and is constantly moving according to objective laws. It is also the general name of all things in the world. The universe is diverse yet unified. Diversity refers to the diversity of material manifestations in the universe, such as the diversity of various celestial bodies. Unity refers to the fact that the universe is composed of matter. The various substances that make up the universe have their own processes of emergence, development, evolution and destruction, and are limited; while the universe as a whole is infinite in space and time, and in the transformation of material movement and form. Therefore, the universe is composed of matter, and matter is in motion.

Celestial bodies: the general name for various stars in the universe. Divided into two categories: natural celestial bodies and artificial celestial bodies. Stars, planets, satellites, meteoroids, comets and nebulae are natural celestial bodies. Artificial satellites are artificial celestial bodies.

The Crab Nebula: It is a famous gas nebula in the Milky Way. It has quite strong radio sources, infrared sources, X-ray sources and γ-ray sources. It is located 1° northwest of the star Zeta Taurus (called "Tianguan" star in our country). Orion, Sagittarius, Lyra and Vulpecula are some of the brighter nebulae in the sky, among which the diffuse nebula in Orion can be seen with the naked eye.

Saturn: One of the nine planets in the solar system, it is the sixth planet in order from nearest to far from the sun and has 23 natural satellites. Its atmosphere is very thick, consisting mainly of methane and a small amount of ammonia. The cloud belts on its surface are more regular than Jupiter's, but not as dramatic as Jupiter's. Surrounding its equatorial plane is a beautiful, flat and wide halo. The halo is composed of countless particles, all of which revolve around Saturn. The diameter of the halo is more than 270,000 kilometers, the width is about 94,000 kilometers, and the thickness is very thin. Less than 20 kilometers. The halo is not complete. It is separated by several dark cracks and becomes several rings. Saturn's sixth satellite is larger than Mercury and has an atmosphere on its surface. It is the only satellite among the nine planets in the solar system. In ancient my country, Saturn was called the "filling star" and the "zhen star".

Meteoroid: Small, dark dust particles and solid matter in interplanetary space. When it breaks into the Earth's atmosphere, it rubs violently with the atmosphere and emits light, producing a short and bright light trail, which is called a meteor. Meteors are divided into two categories: occasional meteors and meteor groups. Occasional meteors are single, sporadic, and unrelated to each other. Their appearance time and direction are irregular. Generally, there are more meteors in the second half of the night than in the first half of the night, and they are brighter. Meteor swarms refer to characteristic groups of meteors that gather in the same orbit around the sun. They may be the fragments of comets that disintegrate and are unevenly distributed in the orbit. When the earth meets a dense part of these meteor groups, the meteors radiate out from a certain point in the sky in all directions, as if it is raining. People call this phenomenon a "meteor shower." Compared with other constellations, Perseus and Leo have more "meteor showers" and are famous meteor constellations. Meteors are a phenomenon that occur in the atmosphere 80 kilometers to 120 kilometers above the ground. The meteor phenomenon is related to both the meteor itself and the conditions of the atmosphere. By observing meteors, we can understand the physical conditions of the atmosphere.

Halley's Comet: A comet is a small cloud-like celestial body with a small mass that moves towards the sun in an elongated orbit. To commemorate the British astronomer Halley, who for the first time used the law of gravity to calculate the orbit of a comet and predicted that it would orbit the sun in a 76-year cycle, the comet was named Halley's Comet. A comet consists of a head and a tail, as shown in the figure. The comet head includes the comet nucleus, coma and coma cloud. The comet nucleus is composed of relatively dense solid blocks and particles. The cloud-like light around it is called the coma. The hydrogen atom cloud is distributed on the periphery of the comet head. The material in the comet's tail, affected by the radiation pressure of the solar wind, extends in the direction away from the sun and is shaped like a broom. Therefore, the comet is commonly known as a broom star, and ancient my country called it a "demon star". There are three types of comet orbits: ellipse, parabola and hyperbola. Comets with parabolic and hyperbolic orbits are non-periodic comets. They make a single turn around the sun and never return, and can only be seen once.

Comets with elliptical orbits, which always orbit the sun periodically, are called periodic comets and can be seen multiple times, such as Halley's Comet. Most comets orbit the sun in the same direction as the planets, which is direct motion. But there are exceptions. For example, Halley's Comet orbits the sun in a different direction than the planets, and is called a retrograde comet. Our country is the first country in the world to record Halley's Comet and has the most abundant records. It first recorded Halley's Comet in 613 BC, while Europe only had records of observing Halley's Comet in 11 BC.

■Figure 1.2 Celestial systems at different levels in the universe

This picture not only illustrates that the universe is composed of matter, but also further reveals the subordinate relationship between each matter. This The existence of this subordination relationship is determined by the fact that matter is in motion. Moving matter attracts each other and forms its own group. Small groups are subordinate to large groups, and large groups are subordinate to larger groups. They are composed of many, many larger groups. Groups of people form a vast universe.

The arrows in the figure indicate the affiliations of celestial systems at different levels in the universe. The lower part of the picture is a celestial system composed of the earth and its natural satellite, the moon, with the earth as its central celestial body. Since the mass of the Earth is very different from the mass of the Moon, the ratio is 81:1. According to the law of universal gravitation, there is a mutual attraction between two objects due to the mass of the matter. An object with a large mass has a greater attraction to an object with a smaller mass. The moon and artificial satellites orbit the earth for this reason. Due to the huge difference in mass between the Earth and the Moon, the center of mass of the Earth-Moon system is only 4,728 kilometers away from the center of the Earth, which is about 1,650 kilometers below the ground. The moon's revolution around the earth is usually said to be the revolution of the earth and the moon equivalent to their respective centers of mass.

The arrow in the Earth-Moon system diagram in the picture points directly to the solar system, staying at the position of the earth and the affiliation between the two. The solar system is a celestial system with the sun as the central celestial body. Gravity connects all the celestial bodies in the system. The solar system is roughly a sphere with a radius of more than 100,000 astronomical units (one astronomical unit = the average distance between the sun and the earth = 1.4960 × 108 kilometers). The sun is the main body of this system, accounting for 99.86% of the total mass of the solar system. The solar system includes the sun and nine planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto), 2958 officially numbered asteroids, 48 ​​satellites, many comets and meteoroids, etc. Geochemical dating shows that the Earth and the entire solar system separated from a certain part of the Milky Way 4.7 billion years ago.

The arrow of the solar system in the picture points directly to the Milky Way, staying at the position of the solar system in the Milky Way. It clearly tells us the position of the solar system in the Milky Way and the affiliation between the two. The Milky Way is the celestial system in which the Earth and the Sun are located. The projection of this celestial system on the celestial sphere is the Milky Way we see at night. The Milky Way is a spiral galaxy consisting of two spiral arms that are 4,500 light-years apart. The Milky Way contains more than 200 billion stars and a large number of nebulae, interstellar gas and interstellar dust. The total mass is 140 billion times the mass of the sun, of which 5% to 10% is gas and dust. Most stars are concentrated in an oblate spherical space, which is shaped like a discus; some stars are sparsely distributed in a spherical space, which is called the "galactic halo". The center of the Milky Way is about 12,000 light-years thick and lies in the direction of the constellation Sagittarius. The Sun is approximately 33,000 light-years from the center. The entire Milky Way is rotating, and the rotation speed and period of each part vary depending on the distance from the center of the Galaxy. The rotation speed at the sun is 250 kilometers/second. It takes the Sun approximately 250 million years to complete one revolution around the center of the Milky Way.

The arrow in the Milky Way diagram in the picture points directly to the general galaxy, staying at the position of the Milky Way in the general galaxy. It clearly tells us the position of the Milky Way in the universe and the affiliation between the Milky Way and the general galaxy. A celestial system composed of billions to hundreds of billions of stars, interstellar gas, dust and other materials is called a galaxy. The Milky Way is an ordinary galaxy. Galaxies outside the Milky Way are called extragalactic galaxies. At present, there are about 1 billion extragalactic galaxies that can be observed. According to their shapes, they can be divided into five major galaxies: elliptical galaxies, lenticular galaxies, spiral galaxies, barred spiral galaxies and irregular galaxies. The Andromeda Galaxy and the Small Magellanic Cloud can be seen with the naked eye. galaxy. The Andromeda Galaxy is the nearest giant spiral galaxy to us. The Large and Small Magellanic Clouds can be seen above our country's Nansha Islands. They are two cloud-like objects. In astronomy, the Milky Way and the currently observable extragalactic galaxies are collectively called the total galaxy. The total galaxy is the scope of the universe that we can observe.

■Figure 1.3 The Earth’s position in the solar system

This is a close-up picture of the solar system. It is the most common and frequently used image in geography books; It is an image that appears more frequently in the exam and gives higher scores; it is also a key image in geography teaching for the first grade of high school, describing the earth’s cosmic environment; it is also a key image in this section of the textbook, together with Figures 1.1 and 1.2, from far to near It accurately expresses the accurate position of the earth in the universe and completes the level requirements of knowledge education. Among the three images, this image is where the key knowledge is located, and it is very important to connect the upper and lower parts.

When reading this picture, you should closely follow the text description in the book and the data description in Table 1.1. The levels are as follows: ① The correctness of the "heliocentric theory".

In the third century BC, the ancient Greek astronomer Aristarchus proposed the "heliocentric theory". He believed that the sun was at the center of the universe and that the earth and other planets revolved around the sun. Later, the ancient Greek astronomer, mathematician, geographer and cartographer Ptolemy proposed a geocentric system in his main work "The Grand Synthesis". He advocated that the earth was in the center, and the sun, moon, and Planets and stars all orbit the earth, which is the "geocentric theory". This theory was used by Christian theology and held a dominant position for a long time. It was not until the publication of Copernicus' "heliocentric theory" that the "geocentric theory" was overturned. It dealt a heavy blow to the divine power and caused a revolution in the cosmology. Copernicus was a Polish astronomer. His greatest achievement was to deny the "geocentric theory" with the scientific "heliocentric theory" and liberate natural science from theology. The picture on the previous page vividly reflects Copernicus's "heliocentric" universe system. Copernicus believed that the sun was the center of the universe and that the other planets and stars orbited the sun in "perfect" circular orbits. In fact, the sun is the center of the solar system, not the center of the universe. With the progress of the times and the development of science, after Kepler summarized the three laws of planetary motion and Newton discovered the law of universal gravitation, the heliocentric theory was established on a more solid scientific basis. ②The Earth is an ordinary planet in the solar system. First, guide students to find the earth in the picture, name the earth's neighbors, and determine the earth's position in the solar system. Secondly, refer to Table 1.1 to compare the mass, volume, average density, rotation and revolution characteristics of the Earth with other planets one by one, and draw the conclusion that the Earth is an ordinary planet in the solar system, highlighting its ordinaryness. ③The Earth is a special planet in the solar system. First, students are guided to analyze the shape of the orbits of the planets in the figure and conclude that their orbits are quite close to the same circle (near circularity). Secondly, read the arrows in the revolution directions of the nine planets, and get the characteristics of the same direction of their revolutions around the sun. On this basis, the teacher said that the orbital planes of the nine planets revolving around the sun are almost on the same plane, that is, the orbital plane. Since the nine planets orbiting the sun have the characteristics of planeness, homogeneity and near-circularity, the earth is in a relatively safe cosmic environment. Finally, the reasons why the earth has life are explained from several aspects such as the distance between the sun and the earth, the volume and mass of the earth, and the internal changes of the earth. Highlight its specialness.

■Figure 1.4 Solar radiation and solar constant

This picture starts with several concepts such as solar radiation, solar constant and distance between the sun and the earth to illustrate that solar radiation is the source of energy on the earth. . The steps for reading the "Solar Radiation and Solar Constant" diagram are as follows:

①Explain the structure of the diagram.

②Explain the relevant concepts in the picture.

Sun: The sun is the most eye-catching celestial body in the sky. It is the star located in the center of the solar system. Its apparent magnitude is - 26.78 (magnitude is divided based on the amount of stellar light received on the earth). It is called "visual magnitude", and the brightness decreases as the magnitude number increases. Zero-magnitude stars are brighter than first-magnitude stars, and negative-magnitude stars are brighter than zero-magnitude stars.) It is 500,000 times brighter than the moon (the apparent magnitude of the moon is - 12.8) . The diameter of the sun is 1.39 million kilometers, which is 109 times that of the earth and 400 times that of the moon. The volume of the sun is 1.3 million times that of the earth, its mass is 330,000 times that of the earth, and its average density is 1.4 g/cm3. The weight of the sun is 270 times that of the moon. Compared with the moon, the sun is like an elephant compared with an ant. . The distance between the sun and the earth is 150 million kilometers, which is 400 times the distance from the moon to the earth. The sun is a hot gas ball. The temperature gets higher and higher from the surface to the center. The central area is about 16 million degrees Celsius and has a pressure of 300 billion atmospheres. A huge nuclear reaction zone is formed in the center of high temperature and pressure. Its components are hydrogen and helium. When hydrogen is converted into helium, a huge amount of energy can be released. This is the nuclear fusion reaction. The energy released in the nuclear fusion reaction is radiated around in the form of electromagnetic waves. This is what people often call solar radiation. Five billion years ago, since the sun was formed, it has continuously released huge amounts of energy. It is estimated that this state will continue for another five billion years. The surface layer of the sun seen with the naked eye is the "photosphere", the periphery of the "photosphere" is the "chromatic sphere", and the outermost layer is the "corona". These layers make up the atmosphere of the sun. The sun also rotates and revolves. The rotation period is about 25 days in the solar equatorial zone and about 35 days in the two-plane zone; the revolution period (the period of orbiting the center of the galaxy) is about 250 million years (assuming that the orbital eccentricity is zero) .

The solar constant in the picture is a physical quantity that represents the solar radiation energy. The meaning of this physical quantity is that when the solar radiation reaches the upper limit of the earth's atmosphere and is one astronomical unit away from the sun (the distance between the sun and the earth), without atmospheric weakening, for every 1 square centimeter of area perpendicular to the sun's rays, the radiation within 1 minute will The commonly used units for the radiation energy obtained are cal/cm2·min or Joules/cm2·min. The solar constant is not an absolute constant. It can vary by ±3.5% due to changes in the distance between the sun and the earth, or by ±1.5% due to diurnal changes in the physical conditions of the sun and cyclical activities of the sun. When solar radiation passes through the earth's atmosphere, due to the weakening effects of absorption, scattering and reflection, the direct solar radiation reaching the earth's surface is greatly weakened. For most areas on the earth, it will not exceed 1.5 kcal/cm 2·points. The solar radiation energy reaching the earth is only equivalent to 1/22 billion of the solar radiation energy.

The energy that the earth obtains from the sun in one year is equivalent to tens of thousands of times the energy provided by various existing energy sources of mankind in the same period. Some natural energy sources on the earth may one day be exhausted, but solar energy is an inexhaustible and clean energy source. The earth also obtains energy from the moon and other celestial bodies, but the amount is insignificant. For example, the energy the earth obtains from the moon and other celestial bodies is only one billionth of the solar radiation energy; the radiant energy from the universe is also only one millionth of the solar radiation. One part in 2 billion; the energy transmitted from the interior of the earth to the ground is only one ten thousandth of the solar radiation energy. Therefore, solar radiation is the earth's main energy source, the most fundamental driving force causing various phenomena and evolution processes in the atmosphere, and an extremely important factor in the formation and change of the geographical environment. Solar radiation is the most important influence of the sun on the earth. , is the source of life on earth.

■Figure 1.5 Distribution of total annual solar radiation in China

Solar energy utilization has huge potential. In order to facilitate the development and utilization of solar energy resources, the utilization of solar energy resources in my country is divided according to the following indicators: first, the total annual solar radiation, and secondly, the number of days with ≥6 hours of sunshine during the period when the monthly average temperature is ≥10°C. According to this standard, my country is divided into solar resource-rich areas, relatively abundant areas, usable areas and poor areas (see figure).

① Resource-rich areas: The total annual solar radiation is more than 1,700 kilowatt hours per square meter, and the number of sunshine hours is more than 300 days when the monthly average temperature is ≥10℃. Mainly distributed in southern Xinjiang, Longxi, most of the Qinghai-Tibet Plateau and the western part of the Inner Mongolia Plateau. Among them, the Qinghai-Tibet Plateau is the center of high values.

②Resource-rich areas: The total annual solar radiation is between 1500 and 1700 kilowatt hours per square meter, and the number of days with ≥6 hours of sunshine during the period when the monthly average temperature is ≥10°C is between 200 and 300 days. Mainly distributed in northern Xinjiang, eastern Inner Mongolia Plateau, most of the North China Plain, most of the Loess Plateau, southern Gansu, western Sichuan and part of southern Sichuan and northern Yunnan.

③ Resource utilization area: The total annual solar radiation is between 1200 and 1500 kilowatt hours per square meter, and the number of days with ≥6 hours of sunshine during the period when the monthly average temperature is ≥10°C is between 125 and 200 days. Mainly distributed in most of the northeast, hilly areas of the southeast, Han River Basin, most of Guangxi, part of western Sichuan and western Guizhou, southeastern Yunnan, and eastern Hunan.

④ Resource-poor areas: The total annual solar radiation is less than 1,200 kilowatt hours per square meter, and the number of days with ≥6 hours of sunshine during the period when the monthly average temperature is ≥10°C is less than 125 days. Mainly distributed in most areas of Sichuan, Chongqing, and Guizhou, with the least in the Chengdu Plain.

In picture reading teaching, students can be guided to complete: A. Find the four distribution areas of solar energy in my country. B Analyze the reasons for the abundant resources in solar energy-rich areas (high terrain, small thickness of solar radiation passing through the atmosphere, more sunny days, less precipitation, and less solar radiation weakened by the atmosphere). C. Find out which distribution area your hometown is in and analyze the prospects of using solar energy in your hometown.

■1.6 The structure of the solar atmosphere

In the vast universe, the sun is just an ordinary star in the Milky Way, but to the earth, it is different from ordinary stars. Its light and heat are the source of human survival and activities. Many natural phenomena on the earth are closely related to the sun. Due to its close proximity to Earth, the Sun is the only star on Earth whose surface details can be seen. The outside of the sun, that is, the solar atmosphere, can be divided into three layers from the inside out: the photosphere, the chromosphere and the corona. The photosphere is the innermost layer of the solar atmosphere. The bright and dazzling circular surface that can be observed with the naked eye is the photosphere. The sunlight reaching the earth comes from this layer, which is about 500 kilometers thick and has a temperature of about 6000K. The chromosphere is the middle layer of the solar atmosphere, located above the photosphere. It is a rose-colored circle on the sun's disk. It is only visible to the naked eye at all times of the day. It is about 2,000 kilometers thick. The temperature ranges from 5,000 degrees Celsius at the bottom to about a few degrees at the top. Ten thousand degrees. The corona is the outermost layer of the solar atmosphere, located above the chromosphere. The particle density it contains is extremely thin. It is the transition zone between the solar atmosphere and interplanetary space. It is only visible to the naked eye during a total solar eclipse. Its thickness is about several suns. diameter, and the temperature is about 1 million to 2 million degrees Celsius.

■Figure 1.7 Sunspots, Figure 1.8 The change process of a large flare, Figure 1.9 Correlation between sunspots and annual precipitation

These three pictures illustrate the impact of solar activity on the earth influence. The reading steps are as follows:

① Explain the relevant knowledge in the picture.

② Summarize the three pictures to get the impact of solar activity on the earth.

Solar activity is the general term for all activities in the solar atmosphere, which is manifested in changes in sunspots, spots, flares, spectral spots, prominences, radio waves, etc. Solar activity is strong or weak, and changes periodically. Abnormal changes in weather and climate on the earth are related to the intensity and periodic changes of solar activity. Aurora, magnetosphere and ionospheric disturbances on the earth are also related to solar activity.

Sunspots are dark spots that often appear on the solar photosphere. The number of sunspots reflects the intensity of solar activity. It is a basic symbol of solar activity. Due to the contrast of the bright photosphere, sunspots appear dark, but are actually still glowing. A large sunspot can emit light as bright as the full moon. There are large and small sunspots. The diameter of small sunspots is about 1,000 kilometers, and the diameter of large sunspots can reach 200,000 kilometers.

The sunspot is shaped like a shallow dish with a depression of about 500 kilometers in the middle. Fully developed sunspots are divided into umbra and penumbra, as shown in Figure 1.7. The distribution of sunspots on the sun's surface has certain rules. For example, if you observe sunspots at any time, there are always more in the east half than in the west. Another example is that sunspots are basically distributed within the range of ±8 degrees to ±40 degrees in latitude on the sun's surface. Most sunspots appear in groups, and each sunspot group consists of several to dozens of sunspots, up to more than 100. The activity cycle of sunspots is 11 years. When large sunspot groups appear, they can produce magnetic storms, auroras, and ionospheric disturbances on Earth.

A flare is a sudden brightening of an area of ​​the sun's chromosphere. Flares mostly appear in the sky near sunspots, and their lifespan lasts from a few minutes to a few hours. The "Change Process of a Flare" in Figure 1.8 is only about 2 hours. When there are many sunspots, there are more opportunities for flares to occur. When a flare occurs, a large number of high-energy electrons and protons are ejected, strong ultraviolet rays and X-rays are emitted, and a series of radio phenomena occur. The ultraviolet rays and X-rays reach the upper atmosphere of the earth, destroying the normal state of the ionosphere and affecting short-wave radio communications. When particle radiation reaches the earth, it will cause geomagnetic disturbances, aurora and other phenomena. The high-energy particles and short-wave radiation produced by flares are very harmful to manned spacecraft. Therefore, observatories around the world often issue forecasts of flares, which are the main signs of solar activity.

After understanding the impact of solar activity on the earth’s ionosphere, magnetic field, aurora, etc., students should be guided to read Figure 1.9, which is the correlation between sunspots and annual precipitation, so that students can further understand that solar activity There are also impacts on climate.

The measuring station locations represented by the three small pictures in Figure 1.9 are all in the northern hemisphere, ranging from mid-latitudes to high latitudes. The ordinate on the left side of the figure is the average annual precipitation, the ordinate on the right side is the relative number of sunspots, and the abscissa on the bottom is the time span of the observed point, up to 80 years. The red curve in the figure is the change curve of sunspots in 80 years, and the blue curve is the change curve of average annual precipitation during the same period.

The correlation of the two color curves in the figure can be described as follows: ① Among the 36 measuring stations in the mid-latitudes, in the 30 years from the end of the last century to the beginning of this century, whenever the number of sunspots is relatively high, , that is, in years when solar activity increases, the annual precipitation on the earth is at its lowest value, that is, 30% to 40% less than usual. The weather is drier and the climate is dry. The number of sunspots is inversely proportional to the annual precipitation. Starting from 1910, when the number of sunspots is relatively high, the annual precipitation at this measuring point is also high, and there is a direct proportional relationship between the two. ②The correlation between the two curves of the 22 measuring stations in the figure shows that in years when the number of sunspots is relatively high, the precipitation at the measuring point will increase and the climate will be humid. The correlation between the two curves is inversely proportional. ③For the 12 measuring stations in the high latitudes in the figure, since the observation data were available, the changes in the valleys and peaks of the two color curves are basically consistent, that is, in years when the number of sunspots is relatively large, the precipitation at the measuring points will also increase accordingly; sunspots In years where the number is relatively small, the precipitation at the measuring points is also small. The correlation between the two curves is directly proportional. ④ From the analysis of the three pictures, we can draw the conclusion that the period of changes in the number of sunspots is basically consistent with the period of changes in the average annual precipitation, which is about 11 years. This shows that there is a certain correlation between changes in sunspot numbers and average annual precipitation, that is, solar activity does affect the weather and climate on the earth. Why there are different correlations at different latitudes requires further demonstration by scientists. As a student, you only need to know these correlations qualitatively.

■Figure 1.10 Schematic diagram of the causes of the moon phases, Figure 1.11 Changes of the moon phases

These two pictures illustrate the relationship between the sun, the moon, and the earth and the rules of the moon phase changes. . The steps when guiding students to read pictures are as follows: ① Explain the structure of the picture; ② Explain relevant knowledge; ③ Guide students to observe the moon phases on the spot. Figure 1.10 shows the sunlight coming from the right. The inner circle shows the eight different positions of the moon in its orbit (one side is always bright and the other side is dark. When viewed from space, the moon has no round or missing parts. Changes in profit and loss). The outer circle represents the phases of the moon as viewed from the Earth at various locations.

In Figure 1.10, the moon travels from A through B, C, D, and back to A, completing one revolution around the earth. With the different positions of the moon in its orbit, the sun, earth, and moon The positional relationship between the three has also changed accordingly. On average, one moon phase appears every 3.7 days on the chart. In one month of the lunar calendar, eight moon phases appear. When the moon is at point A, the moon is between the sun and the earth, and its dark side is facing the earth, so the moon cannot be seen from the earth. This is the first day of the lunar calendar, also known as the new moon. When the moon is at point B, the moon is located 90° east of the sun and on one side of the earth. At this time, half of its dark side and half of its bright side face the earth. We see half of the moon with the bright side facing west. This is the first quarter. The month usually appears on the seventh or eighth day of the lunar calendar. When the moon is at point C, the earth is between the sun and the moon, and the moon is opposite the sun. At this time, the side of the moon illuminated by the sun is all facing the earth. We see a round full moon. The moon phase at this time is called Wang, equivalent to the fifteenth or sixteenth day of the lunar calendar. When the moon is at point D, the moon is located 90° west of the sun and on one side of the earth. At this time, we see half of the moon with the bright side facing east. This is the last quarter moon, which is exactly the opposite of the first quarter moon. It usually appears on the twentieth day of the lunar calendar. Two or twenty-three.

Then the moon continues to move eastward, getting closer and closer to the sun, and returns to point A. The moon phase gradually changes from waning quarter to full moon. The moon travels from point A through points B, C, and D, and back to point A, and revolves around the earth. Due to the changes in the positions of the sun, the earth, and the moon, the time interval the moon takes from one new moon to the next is called a synodic month. , the synodic month is the cycle of moon phase changes.

Figure 1.11 illustrates the correspondence between the shape of the moon phase and its position in the sky at different times. In the first half of the lunar calendar, the moon goes from new to full (that is, from waning to waxing, from waning to full), and is located to the east of the sun. It has risen from the horizon before sunset, and appears in the sky. Therefore, there is a saying that "the sun has not set, but the moon has risen." ” argument. The new crescent moon often rises shortly after the sun rises. It appears in the western sky after dusk. The crescent moon's arc faces west, but soon disappears in the western sky. During the first quarter moon, the moon rises at noon, appears in the southern sky around 18:00, sets at midnight, arcs toward the west, and is visible in the first half of the night. At a full moon, when the sun sets on the western horizon, the moon rises on the eastern horizon and is visible all night long.

In the second half of the lunar calendar, the moon phase from waxing to waning is called the waning moon. The waning moon is located to the west of the sun. The moon does not set from the horizon until after sunrise, so there is a saying "the sun is gone". out, the moon has not yet set." During the last quarter of the moon, the moon appears on the eastern horizon at 24:00 midnight, sets at noon, and arcs toward the east. The crescent moon (waning moon) appears in the eastern sky before dawn. The crescent moon arcs toward the east and soon disappears in the eastern sky. It can be seen from the "moonrise" column in the table below that the moon rises later and later every day, with an average of about 50 minutes later than the previous day every day.

The table on P.10 "Activities" in the textbook is used to observe the moon phases. Teachers should ask students to observe the moon phases for a month continuously from the beginning of the lunar calendar to the end of the month, and check their observations. Record. From the beginning of the month to the full moon, you can observe the moon phase when the sun has just set, and record the moon phase and position every day. From the full moon to the end of the month, you can observe the moon phase before the sun rises, and also record the moon phase and position. Then organize observers to hold a special class meeting on the moon to achieve the purpose of applying geographical knowledge to practical teaching.