# What is upper air divergence?

## What is upper air divergence?

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. First, strong wind is moving into weaker wind.

### At which two quadrants would you expect upper level divergence to occur?

The regions of upper level divergence (rising air) are in the Right Rear quadrant and the Left Front quadrant while the regions of upper level convergence (sinking air) are in the Left Rear and Right Front quadrant. This writing goes over two interpretations for why lifting or sinking occurs in particular quadrants.

#### Is high pressure convergent or divergent?

Air moving in toward a center of low pressure or a trough is forced to rise, exhibiting a motion called convergence. Similarly, air moving outward from a ridge or center of high pressure descends, exhibiting divergence.

What happens when air converges at the surface?

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 does upper-level convergence cause?

While air swirls inward and converges into the center of surface low pressure, an “upper-level disturbance” causes divergence aloft that allows air columns to shed weight. Meanwhile, air swirls outward away from the center of surface high pressure, while upper-level convergence allows air columns to gain weight.

## Does air diverge or converge at the surface?

This causes air to diverge, or move away, from the center of the high near the ground. Air has to come from above to fill in the void left by the diverging air at the surface. This leads to sinking motion in the center of a high pressure system and generally clear air.

### What causes jet streaks?

Jet streaks are caused by a large low-level temperature gradient, thus they are more intense in the cool season when the differential in temperature between the polar regions and tropical regions is largest. Jet streaks are analyzed near the 300-mb level.

#### What kind of vertical motion is surface divergence usually associated with?

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.

Is high pressure convergent?

CONVERGENCE: always associated with increasing surface pressure, since the mass per unit area (i.e., weight) of the air column is increasing with time. DIVERGENCE: always associated with decreasing surface pressure, since the mass per unit area (i.e., weight) of the air column is decreasing with time.

Does air converge at high pressure?

 Air flows outward from a high pressure center at the surface, leading to sinking motion above the high pressure center. This sinking motion is typically associated with clear skies. At upper levels air often converges above a high pressure center.

## What determines the slope of an upper level pressure surface?

the north-south temperature contrast means that upper-level pressure surfaces slope strongly downward (i.e., the height contours are closely packed). this contrast is fundamentally unstable, in that the colder, denser air wants to slide southward under the warmer air.

### Does convergence lift air?

Convergence is an atmospheric condition that exists when there is a horizontal net inflow of air into a region. When air converges along the earth’s surface, it is forced to rise since it cannot go downward. Large scale convergence can lift a layer of air hundreds of kilometers across.

#### When does divergence occur in the upper levels of the atmosphere?

When divergence occurs in the upper levels of the atmosphere it leads to rising air. The rate the air rises depends on the magnitude of the divergence and other lifting or sinking mechanisms in the atmosphere. The 1st diagram below shows two examples of divergence. Diffluence is the spreading of wind vectors.

How are the zones of convergence and divergence similar?

Convection in Earth’s mantle drives the two motions. Convergence occurs above descending limbs of convective cells, whereas divergence takes place above cells’ rising limbs. The two zones’ geologies are similar in many ways—they both have mountain building, earthquakes , and volcanic eruptions—but their geologies also differ in important ways.

Where does the level of nondivergence take place?

The halfway point—around 500 mb or roughly FL180—is known by meteorologists as the level of nondivergence. The level of nondivergence (LND) is so called because it rests beneath the upper levels of the troposphere, where a great deal of convergence or divergence of air flow takes place.

## Where does divergence occur in the jet stream?

This is called diffluence and it is very characteristis of trough/ridge systems in the jet stream that diffluence occurs east of troughs and confluence east of ridges. That would suggest to the eye, at least, that divergence is occuring in the green region.