What is the distribution pattern of the world's annual average temperature?

Refers to the arithmetic mean of the temperature values ??observed during a certain period of time. Depending on the calculation time, there can be average temperature of a certain day, average temperature of a certain month, average temperature of a certain year, etc. The temperature conditions of a day are usually expressed by the average temperature, which is the average temperature.

Since different weather stations have different number of observations per day, the Chinese Meteorological Department uniformly stipulates that the daily average temperature is the average of the temperatures measured four times at 02:00, 08:00, 14:00, and 20:00 every day. Be accurate to 1/10 degree.

In addition to the daily average temperature, there are also climatic (5 days), ten days (10 days), monthly, and annual average temperatures. To express the changing characteristics of temperature in different periods. The meteorological department conducts observations every 6 hours at 02:00, 08:00, 14:00, and 20:00 (Beijing time) or every 02:00, 05:00, 08:00, 11:00, 14:00, 17:00, 20:00, and 23:00 Temperature observations were made every 3 hours.

For special needs (such as aviation), meteorological observations are even conducted at intervals of one hour and half an hour.

1. The average temperature of a certain day: refers to the average temperature of 24 hours a day. In meteorology, the average temperature at 2:00, 8:00, 14:00, and 20:00 is usually used as the average temperature of the day (that is, the four temperatures are added and divided by 4).

2. Average temperature of a certain month: the average temperature of multiple days in a certain month.

3. The average temperature of a certain year: the average of the multi-day average temperature (or multi-month average temperature) of a certain year.

Extended information:

Natural factors

In addition to periodic changes caused by changes in solar radiation, the temperature in a certain place also changes due to atmospheric movement. caused by non-periodic changes. The change in actual temperature is the result of the simultaneous effects of these two aspects. If the former has a large effect, the temperature will show periodic changes; on the contrary, it will show non-periodic changes.

However, judging from the general trend and most situations, the periodicity of diurnal and annual changes in temperature is still dominant. Each component of the heat balance, such as radiation difference, latent heat and sensible heat exchange, is affected by different control factors. These factors such as latitude, season and other astronomical factors have obvious zonal and periodic characteristics.

The nature of the underlying surface, the height of the terrain, and weather conditions, such as cloud cover, atmospheric dryness and humidity, etc., all have non-zonal characteristics. At the same time, the influence of these factors is also different in different locations, so the temperature distribution caused by changes in the heat budget is also uneven.

Human influence

(1) Influence of the characteristics of the urban underlying surface (the contact surface between the bottom of the atmosphere and the ground surface)

A large number of artificial structures in the city such as pavements The ground, various building walls, etc., change the thermal properties of the underlying surface. The urban surface contains less water, and more heat enters the air in the form of sensible heat, causing the air to heat up. At the same time, the urban surface has a higher absorption rate of sunlight than the natural surface and can absorb more solar radiation, which in turn causes the air to gain more heat and increase the temperature.

(2) Urban air pollution

Motor vehicles, industrial production and a large number of crowd activities in cities produce large amounts of nitrogen oxides, carbon dioxide, dust, etc. These substances can It absorbs a large amount of thermal radiation energy in the environment, producing the well-known greenhouse effect, causing further warming of the atmosphere.

(3) Impact of artificial heat sources

Factories, motor vehicles, residents’ lives, etc. burn various fuels and consume a lot of energy. Countless stoves are burning and emitting heat.

(4) The natural underlying surface in the city has decreased

The number of buildings, squares, roads, etc. in the city has increased significantly, and natural factors such as green spaces and water bodies have decreased accordingly, and more heat is released. , there is less heat absorption, and the ability to alleviate the heat island effect is weakened.

Baidu Encyclopedia - Temperature Distribution

Baidu Encyclopedia - Average Temperature

Baidu Encyclopedia - Temperature