Schematic diagram of cold current in the Northern Hemisphere

The schematic diagram of the cold current in the Northern Hemisphere is as follows:

Warm current and cold current: large-scale seawater movement in a certain direction is called ocean current. According to the nature of ocean currents (cold, warm), ocean currents can be divided into two types: warm current and cold current.

Warm currents: flowing from sea areas with high water temperatures to sea areas with low water temperatures, bringing a large amount of ocean warm and humid air currents, which "warm and humidify" the coastal climate, bringing sufficient water vapor and precipitation. Cold current: flows from sea areas with low water temperature to sea areas with high water temperature, "cooling and dehumidifying" the coastal climate, making the atmosphere stable and the weather clear.

Judgment of warm and cold currents: Judgment of warm and cold currents can be based on latitude and temperature (when the two judgment results conflict, the temperature shall prevail): Latitude. The flow from low latitudes to high latitudes, that is, the flow from warm sea areas to cold sea areas, is a warm current; the flow from high latitudes to low latitudes is a cold current;

Temperature. The flow from high water temperature to low water temperature, or the isotherm protruding toward low water temperature, is a warm current; the flow from low water temperature to high water temperature, or the isotherm protruding toward high water temperature, is a cold current.

Assume that the earth is a smooth sphere, and there are "seven pressures and six zones" on the earth. At the vernal and autumnal equinoxes, the air pressure belts and wind belts in the northern and southern hemispheres are exactly symmetrical. Their latitude positions and wind directions are: Equatorial low pressure belt: distributed at 0°±5°, with prevailing updrafts; trade wind belt: distributed at 5° ~25°, northeasterly wind in the northern hemisphere, southeasterly wind in the southern hemisphere;

Subtropical high pressure zone: 30°±5°, prevailing downdraft; prevailing westerly zone: 35°~55°, southwesterly wind in the northern hemisphere Wind, northwest wind in the southern hemisphere; subpolar low pressure zone: 60°±5°, warm air climbs; polar easterly wind zone: 65°~85°, northeasterly wind in the northern hemisphere, southeasterly wind in the southern hemisphere; polar high pressure zone: 85° ~90°, downdraft prevails.

Judging the wind direction can be based on three steps: perpendicular to the pressure band; pointing from high pressure to low pressure; deflecting to the right in the northern hemisphere and deflecting to the left in the southern hemisphere. In different seasons, the position of the direct sun point is different, and the positions of the air pressure belt and wind belt are also different. The positions of the vernal and autumnal equinoxes are shown in the figure below. The positions of the air pressure belt and wind belt move 5° northward in summer and 5° southward in winter.