What is convergence and divergence in weather

convergence and divergence, in meteorology, the accumulation or drawing apart of air, as well as the rate at which each takes place. … The convergence of horizontal winds causes air to rise, whereas the divergence of horizontal winds causes downward motion of the air (subsidence).

What does divergence mean in weather?

METEOROLOGIST JEFF HABY. Divergence occurs when a stronger wind moves away from a weaker wind or when air streams move in opposite directions. When divergence occurs in the upper levels of the atmosphere it leads to rising air.

What causes air convergence?

At the surface, low pressure systems have a counterclockwise rotation in the Northern Hemisphere, with the wind turning slightly inward towards the lowest pressure. This causes air to converge, or come together, at the center of the low near the ground. Since the converging air has nowhere else to go, it rises.

What is a convergence in weather?

A convergence line is a band of cloud that remains fairly stationary and can produce large amounts of rain across a relatively small area. This forces the air upwards, and if there is enough moisture, clouds form and give rain. …

What is Convergent precipitation?

[kən′vər·jənt prə‚sip·ə′tā·shən] (meteorology) A synoptic type of precipitation caused by local updrafts of moist air.

What is convergence in physics?

Convergence is the physical joining together of light rays. Light rays tend to come together at a point (called point of convergence) from different directions.

What is Convergent winds?

The terms are usually used to refer specifically to the horizontal inflow (convergence) or outflow (divergence) of air. The convergence of horizontal winds causes air to rise, whereas the divergence of horizontal winds causes downward motion of the air (subsidence).

Where are convergence zones?

The location of the Inter-Tropical Convergence Zone is usually readily seen as a line of cumulus clouds in the tropics. This is the location where northeast winds in the Northern Hemisphere converge with the southeast winds from the Southern Hemisphere.

How does convergence form clouds?

Large scale convergence lifts a layer of air (sometimes hundreds of kilometers across), the air cooling as it rises. If the rising air cools to its saturation point, the water vapor will condense out to form cloud droplets. … Cirrostratus clouds is one cloud type that develops from convergence lifting.

What is horizontal divergence?

A measure of the local spreading or divergence of a vector field in a horizontal plane, commonly written ∇H · V. The horizontal divergence of the velocity field is related to the vertical motion and local pressure variations through the equation of continuity and equations of motion. …

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What causes divergence aloft?

Divergence aloft is associated with rising air throughout the troposphere, which is associated with low pressure and convergence at the surface. Convergence aloft is associated with sinking air throughout the troposphere, which is associated with high pressure at the surface and thus divergence at the surface.

What is speed divergence?

speed divergence occurs when winds are speeding up along the direction of flow. Directional divergence occurs when air streams are flowing apart. divergence in the upper atmosphere should indicate areas of rising air.

What is Convectional rain?

Convectional rainfall is a type of rainfall that involves the formation of convection currents. … This rainfall occurs when the temperature gets high and the warmer air rises up in the atmosphere. On expansion, this air cools down and clouds are formed, which are generally cumulus clouds.

What is a lift in weather?

Frontal lifting is when air is lifted along fronts, which is where two different air masses meet. Like jumping into a cold lake and shocking your system, a cold front shocks warm air upward very quickly.

What is relief rainfall?

Relief rainfall occurs when warm moist air from the Atlantic Ocean rises up over mountains. When the warm air rises, it cools and condenses to form clouds, which bring rain. Once the air has passed over the mountains, it descends and warms.

Where is wind convergence common?

The Intertropical Convergence Zone (ITCZ, pronounced “itch”), known by sailors as the doldrums or the calms because of its monotonous windless weather, is the area where the northeast and the southeast trade winds converge. It encircles Earth near the thermal equator though its specific position varies seasonally.

What is low level convergence?

Convergence is air streams flowing into one another or stronger wind moving into weaker wind. When air piles together in the low levels of the atmosphere it has no place to go but up (it obviously can not go through the earth’s surface).

What is the meaning of divergence in physics?

Divergence measures the change in density of a fluid flowing according to a given vector field.

What is divergence and convergence of light?

Post In physics, when a light rays starting from a point diverge themselves or spread themselves, such a ray is called divergent ray. On the other hand when light from a large source converge or focuses itself,such a ray is called convergent ray. In lenses convex lenses converge rays and concave lenses diverge it.

What is divergence and convergence mirror?

Convergence and divergence of mirrors If reflected rays converge to a single point after reflection, then this is called as converging behaviour of the mirror . … If reflected rays appear to diverge from a single point, then this is called as diverging behaviour of the mirror .

What are divergent boundaries?

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries.

Is convergent boundary?

A convergent boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. … Convergent boundaries occur between oceanic-oceanic lithosphere, oceanic-continental lithosphere, and continental-continental lithosphere.

Why is Itcz north of equator?

The ITCZ has a mean position north of the equator because there is much more landmass in the Northern Hemisphere as compared to the Southern Hemisphere. Look at a globe and notice how much more land there is in the tropics in the Northern Hemisphere. … This produces a convergence of air over the land.

What is mass convergence?

Mass convergence is found in areas where winds come together. … As winds come together, mass builds up and therefore causes air to rise, creating an updraft. Convergence may occur due to topography or daytime heating, and can be especially strong along fronts and dry lines.

What happens when the upper level divergence of air is greater than the lower level convergence of air in a storm?

When upper-level divergence is stronger than lower- level convergence, more air is taken out at the top than is brought in at the bottom. Surface pressure drops, and the low intensifies, or “deepens.”

Where do geostrophic winds occur?

The geostrophic wind is the wind flow that occurs in the middle latitudes aloft in the troposphere. The winds have a more difficult time obtaining geostrophic balance in the equatorial latitudes since the Coriolis force is weak.

What causes high pressure aloft?

difference in temperature of air aloft creates a horizontal pressure gradient force which pushes air from warm to cold column. This adds air to cold column, increases surface pressure and generates a pressure difference at the surface between the cold column and warm column of air.

What type of front causes fast moving thunderstorms and severe weather?

Cold fronts occur when warm air is pushed up into the atmosphere by colder air at the ground. These fronts tend to move faster than the other types of fronts and are associated with the most violent types of weather such as severe and super cell thunderstorms, although any type of front can produce these same storms.

What is Convectional rainfall 10th?

Convectional rainfall takes place when the sun’s energy heats the surface and so that water evaporates changing to water vapor. This moist and warm air then rises upwards and as it rises, it starts to cool. The air reaches a point known as condensation level where the water vapor condenses and turns back to liquid.

How is convergence rainfall formed?

A convergence zone in meteorology is a region in the atmosphere where two prevailing flows meet and interact, usually resulting in distinctive weather conditions. This causes a mass accumulation that eventually leads to a vertical movement and to the formation of clouds and precipitation.

What are 3 types of rainfall?

• relief.
• convectional.
• frontal.