Notes on the main factors affecting climate

1. Main factors affecting climate

(1) Latitude is the basic factor affecting climate. Because the earth is a large sphere, the angle of the sun's irradiation is different in places with different latitudes. Some places are directly irradiated, some are slanted, and some places are not exposed to sunlight all day or for several months. Therefore, the altitude angle of the sun is different in different places, the amount of solar heat received is different, and the temperature is also very different. Generally, the lower the latitude, the higher the temperature; the higher the latitude, the lower the temperature. The different latitudes of various regions are the main reason for the different temperatures around the world.

(2) Atmospheric circulation is the main factor in forming various climate types and weather changes. The air in the atmosphere moves on different scales, collectively called atmospheric circulation. It is an important way of transporting and exchanging heat, water vapor, etc. in the atmosphere. The manifestations of atmospheric circulation include planetary wind system, monsoon circulation, sea and land breeze, valley wind, etc. The atmospheric circulation that people usually talk about mainly refers to planetary wind system. Atmospheric circulation has a very significant impact on climate. In the equatorial low pressure zone, the rising airflow is strong, water vapor is easy to condense, and precipitation is abundant; in the subtropical high pressure zone, sinking air vapor is prevalent, water vapor is not easy to condense, and rain is scarce; in the trade wind zone, the airflow starts from higher latitudes. The areas flow to lower latitudes, where water vapor is less likely to condense and generally has less rain. But on the east coast of the continent, the trade winds blow from the sea, and there are more chances of precipitation; on the west coast of the continent, the trade winds blow from the inland, and there is less precipitation. In areas controlled by the westerly belt, winds blow from the sea on the west coast of the continent, with abundant water vapor and abundant precipitation. The further inland, the less water vapor and precipitation decrease; on the east coast of the continent, westerly winds blow from the inland, resulting in less precipitation. Generally speaking, updrafts and airflows from low latitudes to high latitudes change from high to low temperatures, water vapor condenses easily, and there are more opportunities for precipitation; downdrafts and airflows from high latitudes to low latitudes change from low to high temperatures. Water vapor is not easy to condense, so there is less chance of precipitation. Therefore, under the control of different pressure zones and wind zones, there are significant differences in climate characteristics, especially changes in precipitation. In addition, the wind belt and pressure belt move with the seasons, resulting in various different climate types.

(3) The distribution of sea and land changes the zonal distribution of temperature and precipitation. Due to the different physical properties of the ocean and land, under strong sunlight, the ocean heats up slowly and the land heats up quickly; after the sunlight weakens, the ocean cools down slowly and the land cools down quickly. The amount of water vapor contained in the air on the ocean and land surfaces is also different. Generally speaking, in ocean or offshore areas, the daily and annual changes in temperature are smaller, precipitation is more abundant, and the seasonal distribution of precipitation is relatively even. Most oceans are formed. sexual climate. Therefore, at the same latitude, areas under the control of the same pressure zone or wind zone have different climate characteristics due to their different sea and land locations.

(4) Ocean currents also have a certain impact on the climate along the continental coasts they pass through. Ocean currents flowing from low latitudes to high latitudes contain a large amount of heat energy, which plays a role in warming and humidifying the coastal areas they pass through; ocean currents flowing from high latitudes to low latitudes have lower water temperatures than the surrounding sea surface, which has a negative impact on the coastal areas they pass through. Coastal areas have cooling and dehumidifying effects. Therefore, in terms of temperature, ocean currents can adjust the temperature difference between high and low latitudes. Under the influence of prevailing air currents, the temperatures on the east and west coasts of the continent at the same latitude are significantly different, destroying the latitudinal distribution of temperature.

(5) The undulations of terrain can destroy the zonal nature of climate distribution. Terrain is a non-zonal factor, and different terrains have different effects on climate. In the same latitude zone, the higher the terrain, the lower the temperature. Within a certain height range, precipitation increases with height. Therefore, in the high mountains in the tropics, from the foothills to the top of the mountain, climate changes from the equator to the poles occur successively. In addition, tall mountains can block the movement of airflow, and there are obvious differences in temperature and precipitation between the windward and leeward slopes of mountains.

2. Basic elements of climate

The basic elements of climate are temperature and precipitation. There are also other non-essential elements that have less impact.

Temperature

Daily average temperature is the sum of the temperatures measured several times in a day, divided by the number of measurements

Diurnal temperature change

The temperature varies from day to day, with the highest temperature minus the lowest temperature in a day.

The monthly average temperature is calculated by adding the daily average temperature of each day in the whole month and dividing it by the number of days.

Monthly changes in temperature

The monthly differences in temperature are The highest daily average temperature in the month minus the lowest daily average temperature

The annual average temperature is the sum of the monthly average temperatures for each month in the whole year, divided by the number of months

Annual change in temperature

The annual temperature range is calculated by subtracting the highest monthly average temperature from the lowest monthly average temperature in a year

Precipitation

Monthly precipitation, intermonthly precipitation changes rate, annual precipitation, interannual precipitation variability, evapotranspiration, air humidity, etc. (The world's rain poles: one is in Cherrapunji in northeastern India; the other is in the northeastern foothills of Mount Kavikini in the Hawaiian Islands)

Air pressure

Air pressure, air flow direction changes, wind frequency and its time direction distribution, air pressure difference, etc.

Wind

Wind strength, wind direction, wind speed, etc.