The second chapter of geography in senior one.

1 Uneven heat and cold leads to atmospheric movement.

A, the heating process of the atmosphere:

1. Main and direct heat sources of the atmosphere:

The atmosphere absorbs less solar short-wave radiation.

The atmosphere absorbs more ground long-wave radiation.

The main and direct heat source of the atmosphere is the ground.

2. Weakening effect of atmosphere on solar radiation;

Absorption (selective absorption): ozone absorbs ultraviolet rays;

Carbon dioxide, water vapor, methane and chlorofluorocarbons absorb infrared rays.

Reflection: It is related to the amount of clouds in the sky. The more and thicker the clouds, the stronger the reflection.

Scattering: Blue light scatters easily.

The weakening effect of the atmosphere on solar radiation can avoid the "excessive" temperature on the earth, and its intensity can be

Affected by many factors, such as sunny days, solar altitude angle (latitude) and so on.

3. The isolation effect of the atmosphere on the ground:

Carbon dioxide, water vapor, methane, chlorofluorocarbons, etc. In the atmosphere, it absorbs the long-wave radiation from the ground, and then increases it greatly.

It is released in the form of gas radiation, and most of it returns to the ground in the form of atmospheric reverse radiation.

The heat preservation function of the ground atmosphere can avoid the "too low" temperature on the earth, and its intensity can be affected.

To the carbon dioxide content, sunny weather and other factors.

The thermal insulation effect of the ground atmosphere is positively correlated with the intensity of atmospheric inverse radiation.

Second, the simplest form of atmospheric motion-thermal cycle:

Uneven hot and cold

↓

Vertical movement of air

↓

Horizontal pressure difference

↓

Horizontal air movement (wind)

The uneven heat and cold is the fundamental reason for the formation of atmospheric motion.

The air pressure difference is the direct cause of the horizontal motion (wind) of the atmosphere.

Case study:

Sea-land breeze and sea-land temperature difference

Urban wind and heat island effect

1. Vertical motion of air:

The ground is heated → the hot air rises → a low pressure is formed near the ground.

↓

It's cloudy and rainy

The ground cools down → cold air sinks → high pressure forms near the ground.

↓

It's sunny.

2. The horizontal movement of air (wind):

Horizontal pressure gradient force: high pressure points to low pressure and is perpendicular to isobar.

Geostrophic deflection: north, right, south and left

Friction force: (negligible at high altitude, resulting in the wind direction parallel to the isobar)

3. Judgment of wind direction and wind force:

Wind direction judgment: mainly depends on horizontal pressure gradient force and geostrophic deflection force.

Judgment of wind: mainly depends on the pressure difference, that is, the density of isobar.

2 pressure belt and wind belt

I. Atmospheric circulation:

General circulation: global general atmospheric movement. (pressure belt, wind belt; Monsoon)

Second, the pressure belt and wind belt:

1. Distribution of pressure zone and wind zone:

2. The causes of pressure zone and wind zone:

Pressure zone causes: thermal causes: equatorial low pressure zone and polar high pressure zone.

Dynamic reasons: subtropical high pressure zone and subtropical low pressure zone.

Cause of wind belt: it is caused by horizontal pressure gradient force and geostrophic deflection force.

3. Seasonal movement of pressure belt and wind belt: 5438+ 10. Both the northern hemisphere and the southern hemisphere move northward in July and southward in June.

Third, the monsoon:

1. Temperature difference between land and sea:

2. The influence of the thermal difference between land and sea on the pressure area and wind area;

3. Distribution of pressure centers in the northern hemisphere in winter and summer:

Eurasia

Pacific Ocean

the Atlantic

65438+ October

Asian high

(Mongolia, Siberian high)

the aleutian low

Iceland low pressure

July

Asian low pressure

(Indian low pressure)

Western Pacific subtropical high

Hawaii high school

Azores high school

4. Formation of monsoon: The summer monsoon blows from the ocean to the land; Winter winds blow from land to sea.

65438+ October

July

cause

East Asia

Northwest monsoon

Southeast monsoon

Sea and land temperature difference

South Asia

the northeast monsoon

Southwest monsoon

Sea and land temperature difference

Seasonal movement of pressure zone and wind zone

5. The influence of monsoon on China:

Climatic characteristics

Monsoon factor

summer

High temperature and rainy

Western Pacific subtropical high; Southeast monsoon

winter

Cold and little rain

Asia is high; Northwest monsoon

Fourth, the influence of pressure zone and wind zone on climate:

1. Factors affecting climate:

Solar radiation (latitude) is the fundamental factor affecting climate,

There are also atmospheric circulation, underlying surface and human activities.

2. The nature of pressure zone and wind zone and the formation of climate:

(1) Influence of pressure zone and wind zone on climate;

Pressure zone: high pressure zone → less rain; Low pressure area → rainy

Wind area: near sea breeze → less rain; Shore wind → rainy

(2) The climate affected by pressure belt and wind belt:

Keywords tropical rain forest climate, tropical desert climate, temperate marine climate, tropical grassland climate,

Mediterranean climate, tropical monsoon climate

3 Common weather systems

The first is the front and the weather:

1. Air masses and fronts:

Air mass: a large range of air with uniform distribution of physical properties such as temperature and humidity in the horizontal direction. Like ice.

Marine continental air mass, glacier marine air mass, polar marine air mass, polar continental air mass, tropical ocean.

Ocean air mass, tropical continental air mass, equatorial air mass, etc.

When a place is affected by a single air mass, its weather is relatively stable, which is consistent with the nature of the air mass.

Front: when cold and warm air meet, the interface between them is called front, and the front is inclined to one side of cold air mass; Positive sum

The line where the ground intersects is called

Frontline; Front and front are collectively referred to as front.

When a place is affected by the front, there are often weather changes such as clouds, strong winds and precipitation.

2. Types of fronts and weather:

Cold front and weather:

V the cold air mass moves to the warm air mass actively, and the front surface moves to one side of the warm air mass.

V generally moves faster.

V Before crossing the border, affected by the heating air mass, the temperature was high, the air pressure was low, and the weather was fine.

V cloudy rain (snow) wind is easy to appear when crossing the border, and precipitation often appears behind the cold front.

V After crossing the border, affected by the cold air mass, the weather turned fine, the temperature dropped and the air pressure increased.

China has a cold front all year round, especially in winter.

Five, China's winter cold wave, summer northern rainstorm and spring sandstorm are all caused by the influence of cold front.

(2) Warm front and weather:

V the warm air mass moves to the cold air mass actively, and the front moves to one side of the cold air mass.

V moves slowly.

V Before crossing the border, affected by the cold air mass, the temperature was low, the air pressure was high and the weather was fine.

V When crossing the border, it is prone to continuous precipitation or fog, and precipitation often occurs before the warm front.

V After crossing the border, affected by the warm air mass, the weather turned fine, the temperature rose and the air pressure dropped.

The frequency of V in China is lower than that of cold front, mainly in the northeast and the middle and lower reaches of the Yangtze River.

(3) quasi-static front and weather:

V The cold and warm air masses are evenly matched, or the terrain blocks them from swinging in an area for a long time.

V is easy to cause rainy weather.

The V-shaped plum rain in the middle and lower reaches of the Yangtze River in early summer and the Huaxi autumn rain in Yunnan-Guizhou area in winter are all caused by the influence of quasi-static fronts.

3. The front icon:

Two, low pressure (cyclone), high pressure (anticyclone) and its weather:

1. Some basic concepts:

Low pressure and high pressure: refers to the distribution of air pressure;

Low pressure: the central air pressure is lower than the surrounding area; High pressure: central air pressure and surrounding high pressure.

Cyclone and anticyclone: refer to the airflow conditions in low pressure area and high pressure area.

The movement form of airflow in low pressure area is called cyclone; The form of airflow movement in the high pressure area is called anticyclone.

Low pressure trough: a long and narrow area extending from low pressure. High pressure ridge: a long and narrow area extending from high pressure.

2. Low pressure and cyclone:

Horizontal direction: north to south; Vertical direction: the central airflow rises;

Low-level convergence-high-level divergence weather: rainy weather example: typhoon

3. High pressure and anticyclone:

Horizontal: the north is suitable for the south; Vertical direction: the central airflow sinks;

Low level divergence-high level convergence weather: sunny and rainy weather.

For example, our country is dry in summer, crisp in autumn and cold in winter.

Three. Reading of isobar distribution map: (reading of frontal cyclone)

The trough of low pressure in low pressure area (cyclone) is prone to front, which will move with the rotation of cyclone.

4 Global climate change

1. The global climate is constantly changing:

1. Global climate change mainly includes "cold, warm, dry and wet" changes.

(temperature, precipitation)

2. Time scale of global climate change:

Climate change in geological historical period: the whole geological historical period

Climate change in historical period: from 10 thousand years ago

Modern climate change: the period of meteorological observation records in recent 1200 years

Large-scale climate change is the background and analytical basis of small-scale climate change;

Small-scale climate change reflects the details of large-scale climate change.

(Focus on modern climate change)

Second, the main trend of global climate change: global warming

1. Complexity of global warming:

Global warming is aimed at the whole world; For local areas, different areas are different.

Difference. For example, in terms of space, the temperature rise in northern China is very obvious, while the Yangtze River basin is weak;

In terms of time, the temperature increase is obvious in winter and relatively weak in summer.

2. Global warming is increasingly affected by human activities:

Carbon dioxide emissions (fossil fuels); Emissions of hydrochlorofluorocarbons (refrigerants); Destroy forests;

population growth

Three. Possible effects of global warming:

1. Impact on sea level:

Melting of polar glaciers

Global warming and sea level rise → islands and coastal lowlands are submerged.

Volume expansion of seawater

2. Impact on water cycle and water resources:

3. Impact on agricultural production:

Fourth, the countermeasures of human beings to deal with global warming: how can human beings delay global warming and reduce its harm?