1w051 A Set Volume 1 Edit Code 05

The prevailing visibility at US stations is reported in statute miles, while at overseas stations it is reported in meters. This is because the US uses the imperial system of measurement, which includes statute miles, while many other countries use the metric system, which includes meters. Therefore, the visibility measurements are reported in the appropriate units for each location.

The driving mechanism for the Earth's large-scale atmospheric circulations is the unequal heating of the Earth. This is because different parts of the Earth receive different amounts of solar radiation, causing variations in temperature. As a result, warm air rises at the equator and cold air sinks at the poles, creating a pressure gradient that drives the movement of air. This movement, combined with the rotation of the Earth, leads to the formation of distinct circulation cells such as the Hadley cell and polar cell. However, it is the unequal heating of the Earth that ultimately sets this process in motion.

The distinguishing feature of any tornadic activity is the funnel-shaped appendage that hangs from the base of the cloud. This funnel-shaped appendage, also known as the tornado, is a rapidly rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud. It is this characteristic funnel shape that sets tornadic activity apart from other weather phenomena such as intense thunderstorm activity, wind gusts over 35 knots in speed, or cumulonimbus mammatus clouds.

The air mass that forms over land only during the summer is cT. This is because cT refers to a continental tropical air mass, which is characterized by warm and dry air. During the summer, the land heats up more quickly than the ocean, leading to the formation of this air mass. It is typically found in regions with hot and arid climates, such as deserts.

A heat low is a warm barotropic low that forms during the summer. This means that it is a low-pressure system that is characterized by warm air and uniform temperature distribution throughout its vertical extent. Heat lows typically form over land areas during the summer months when intense heating from the sun causes the air to expand and rise, creating a region of low pressure.

The Coriolis force is a result of the rotation of the Earth and causes moving objects to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. In this scenario, as the ball is thrown from a speeding vehicle, it has both the forward velocity of the vehicle and the rotational velocity of the Earth. The Coriolis force acts perpendicular to the direction of motion, causing the ball to deviate to the right of its intended target. Therefore, the ball will miss the target to the right.

The greatest velocities are located in the region of confluence of the subtropical jet (STJ) and polar front jet (PFJ). This means that the highest speeds are found where the STJ and PFJ merge together. The confluence of these two jets leads to a strengthening of the winds and an increase in velocity. Therefore, the region of confluence is where the greatest velocities are found in relation to the STJ.

A thunderstorm officially ends fifteen minutes after the last occurrence of thunder, hail, or lightning. This means that even if there is no more thunder, hail, or lightning, the storm is still considered to be ongoing for an additional fifteen minutes. This allows for any lingering effects or potential dangers associated with the storm to dissipate before it is officially declared over.

The statement "Jet fingers often develop more than 400 miles apart" suggests that the jet stream is beginning to dissipate. When the jet stream weakens and starts to break apart, it can form separate "fingers" that are spaced far apart. This indicates a loss of the strong, continuous flow that characterizes a well-organized jet stream. Therefore, the occurrence of jet fingers at a significant distance from each other implies the dissipation of the jet stream.

When the radiation from the sun reaches above 13 miles in the atmosphere, it has enough energy to break down the oxygen molecules (O2) into individual oxygen atoms (O). These oxygen atoms then combine with other oxygen molecules to form ozone (O3) gas. Therefore, the correct answer is ozone gas.

An increase in mass in a column of air will cause the surface pressure to increase. This is because an increase in mass leads to a greater number of air molecules in the column, resulting in more collisions between the molecules and the surface. These collisions exert a force on the surface, which in turn increases the pressure. Therefore, as the mass of the column of air increases, so does the surface pressure.

When a low-pressure system undergoes cyclogenesis, it means that it is forming or deepening. Cyclogenesis refers to the process of a low-pressure system intensifying and developing into a stronger storm. This can occur when there is an increase in convergence of air at the surface, leading to the formation of a low-pressure center. As the system deepens, it becomes stronger and can potentially develop into a more severe weather event, such as a tropical storm or hurricane.

When the central pressure of an anticyclone is rising, it indicates that the air within the anticyclone is becoming denser and sinking. This sinking air leads to the compression and building up of the anticyclone. Therefore, the correct answer is building.

Unstable waves are classified as baroclinic lows. Baroclinic refers to the condition where there is a gradient of temperature or density in the atmosphere or ocean. Unstable waves in this context are characterized by the presence of such gradients, which can lead to the development of storms and other turbulent weather conditions. Barotropic highs and lows, on the other hand, do not have such gradients and are associated with more stable atmospheric conditions. Therefore, the correct answer is baroclinic lows.

The air mass classification cPws signifies a stable, continental polar air mass that is warmer than the surface it is moving over. Continental polar air masses are formed over land and are characterized by their cool and dry nature. The "w" in cPws indicates that this air mass is warmer than the surface it is moving over, which creates a stable condition. This classification is commonly associated with clear and dry weather conditions.

The correct answer is freezing fog, and blowing spray. These two weather conditions, freezing fog and blowing spray, can obstruct vision and make it difficult to see clearly. Freezing fog occurs when fog forms and the temperature drops below freezing, causing the fog to freeze and create icy conditions. Blowing spray refers to water droplets that are blown by strong winds, such as those near bodies of water or during storms. Both freezing fog and blowing spray can significantly reduce visibility and pose hazards to drivers and pilots.

In winter, when a cPk air mass moves over the Great Lakes, it brings cold air and moisture from the lakes, causing heavy snowfall. The cold air mass interacts with the warmer lake waters, creating an unstable atmosphere that promotes the formation of snow clouds. As the air rises and cools, the moisture condenses and falls as snow. Therefore, the southern shores of the Great Lakes will experience heavy snow during this situation.

During the self-development process, the surface low deepens due to divergence aloft. Divergence aloft refers to the movement of air away from a certain point in the upper atmosphere. As air diverges, it creates a vacuum effect, causing air from lower levels to rise and fill the void. This vertical motion leads to the intensification of the surface low, as the rising air allows for the transport of more moisture and energy, further fueling the development of the low-pressure system.

Centripetal force is described as any center-seeking force. This force acts towards the center of rotation and keeps an object moving in a circular path. Inertia is the tendency of an object to resist changes in its motion. Coriolis force is an apparent force that acts on moving objects in a rotating system. Centrifugal force is a perceived force that appears to push objects away from the center of rotation. Therefore, the correct answer is centripetal force, as it is the force that acts towards the center.

To properly report the visibility for more than one sector, it is important to list the sectors in a clockwise direction starting with the northernmost sector. This ensures consistency and clarity in reporting the visibility for each sector. By following a clockwise direction, it becomes easier to identify and track the visibility for each sector in a systematic manner. Starting with the northernmost sector helps to establish a reference point and provides a logical order for reporting the visibility in subsequent sectors.

The RVR report of R22/1000V1600FT indicates that the visual range down the runway can vary between 1,000 and 1,600 feet. This means that the pilot can expect to see anywhere between 1,000 and 1,600 feet ahead while looking down the runway. The "R22" indicates the lowest value of 1,000 feet, and the "V1600FT" indicates that the visibility can vary up to 1,600 feet.

Ice crystals can be observed with clear skies because they are formed when water vapor in the air freezes directly into ice without passing through a liquid phase. This process can occur even when the sky is clear and there are no visible clouds. Ice crystals can take the form of snowflakes, which are intricate and symmetrical structures, or they can appear as smaller ice particles suspended in the air. Therefore, observing ice crystals is possible even when there are clear skies.

Divergence aloft is the primary cause of surface pressure changes for a dynamic low. Divergence refers to the movement of air away from a certain area. When there is divergence aloft, it means that air is moving away from the upper levels of the atmosphere. This leads to a decrease in air mass and lower atmospheric pressure at the surface. As a result, a dynamic low pressure system is formed. Adiabatic cooling and warming aloft do not directly cause surface pressure changes, while surface divergence is a result of the pressure changes rather than the cause.

As altitude increases in the troposphere, the temperature decreases at a rate of 6.5 degrees centigrade per 1,000 meters. This is known as the lapse rate. The decrease in temperature with increasing altitude is due to the decrease in air pressure and the expansion of air molecules, which causes cooling. This lapse rate is an important factor in understanding weather patterns and atmospheric conditions in the troposphere.

The air mass classification mTku signifies an unstable, maritime tropical air mass that is colder than the surface it is moving over. This means that the air mass is warm and moist, originating over tropical waters, but it is colder than the surface it is moving over. This can lead to instability in the atmosphere, potentially causing the formation of thunderstorms or other severe weather conditions.

Lenticular clouds are formed when moist air flows over a mountain or hill and creates a series of stationary lens-shaped clouds. These clouds often have a smooth, rounded appearance and can resemble the shape of an almond or a fish. They are commonly seen near mountain ranges and are known for their unique and distinctive shape.

A change in wind direction of 45° or more that takes place in less than 15 minutes is called a wind shift. This term is used to describe a sudden change in the direction of the wind, which can occur due to various factors such as the movement of weather systems or the influence of local topography. Wind shifts can have significant impacts on weather conditions and can affect activities such as sailing, aviation, and forecasting.

During the self-development process, a surface high builds due to convergence aloft. Convergence aloft refers to the horizontal movement of air towards a central point in the upper levels of the atmosphere. This convergence leads to the sinking of air and the development of high pressure at the surface. As the air sinks, it warms and becomes denser, creating a stable environment and inhibiting cloud formation. This results in clear skies and calm weather conditions associated with a surface high.

The Coriolis force (CoF) is created by the cyclonic rotation of the earth. This force is a result of the earth's rotation and causes moving objects, such as air or water, to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere. It is an important factor in the formation of weather patterns and ocean currents.

The correct answer is convergence and surface high pressure. In the context of the damper effect, convergence refers to the coming together of air masses at the surface, which leads to the formation of high pressure. High pressure systems are associated with clear skies and calm weather conditions. This explanation aligns with the given answer choice.

Advection refers to the horizontal movement of a property, such as temperature, by the wind. In this context, it means that temperature is transferred horizontally through the atmosphere by the movement of air masses. This is different from vertical transfer, which occurs through convection, and molecular motion, which refers to the random movement of molecules. The correct answer states that advection transfers temperature horizontally by the wind, indicating that the wind plays a crucial role in moving and distributing heat in the atmosphere.

A region must possess a uniform surface, stagnant air, and large-scale difluent flow in order to facilitate air mass formation. A uniform surface ensures that there are no significant variations in temperature or moisture content, which allows for the development of a stable air mass. Stagnant air means that there is little or no vertical movement of the air, which allows the air mass to remain intact and not mix with surrounding air. Large-scale difluent flow refers to the divergence of air at the upper levels of the atmosphere, which helps to maintain the stability and integrity of the air mass.

In the polar region, the slow formation of air masses is primarily due to the loss of heat by radiation. This process involves the transfer of heat energy from the Earth's surface to the atmosphere through the emission of infrared radiation. The polar region receives less sunlight and has colder temperatures, resulting in a slower rate of heat transfer. This gradual loss of heat leads to the formation of stable, cold air masses characteristic of polar regions.

The correct answer is Cumulonimbus-L9. Cumulonimbus clouds are known for their anvil-shaped tops, which are formed when the cloud reaches the tropopause and spreads out in the shape of an anvil. The cirriform anvil refers to the thin, wispy appearance of the cloud top, which is characteristic of cirrus clouds. Therefore, the presence of a cirriform anvil indicates a Cumulonimbus cloud with a high classification of L9.

The best way to distinguish stratocumulus from altocumulus clouds is by observing the size of the elements. Stratocumulus clouds have larger elements compared to altocumulus clouds. By examining the size of the cloud elements, one can differentiate between these two types of clouds. Movement, appearance, and color of the elements may vary but are not the most reliable factors for distinguishing between stratocumulus and altocumulus clouds.

The term "a layer" refers to clouds or obscuring phenomena that have bases at the same approximate level. This means that these clouds or phenomena are situated at a similar height in the atmosphere, creating a uniform layer of cloud cover. It is different from other options like sky condition, sky cover, and a ceiling, which may refer to different aspects of the sky or cloud cover.

Wind observing equipment is oriented to magnetic north because the wind direction is measured relative to the Earth's magnetic field. Magnetic north is the direction towards the Earth's magnetic north pole, which is different from true north (the direction towards the Earth's geographic north pole). By aligning the equipment with magnetic north, accurate measurements of wind direction can be obtained.

Oxygen and ozone are the two atmospheric gases most responsible for the absorption of incoming solar radiation. Oxygen absorbs ultraviolet (UV) radiation in the upper atmosphere, preventing it from reaching the Earth's surface. Ozone, which is a form of oxygen molecule (O3), absorbs UV radiation in the stratosphere, forming a protective layer that shields the Earth's surface from harmful UV rays. This absorption process helps to regulate the amount of solar radiation that reaches the Earth, playing a crucial role in maintaining the planet's temperature and supporting life.

In the life cycle of a low, the system goes through different stages. The dissipation stage occurs when the low weakens and eventually dissipates. During this stage, the low loses its organized structure and the associated weather conditions gradually diminish. This stage is characterized by the dissipation of the low's energy and the gradual disappearance of its circulation. Therefore, the correct answer is the dissipation stage.

When warm air with an unstable wave is pushed aloft and cuts off from a cyclone, the cyclone will become barotropic and begin to fill. In meteorology, a barotropic system refers to a weather system in which the density surfaces are parallel to the surfaces of constant pressure. When a cyclone becomes barotropic, it means that the temperature and wind fields are aligned and there is no significant temperature gradient. As a result, the cyclone starts to fill, meaning that it weakens and loses its intensity.

The correct answer is a temperature that remains isothermal to about 100,000 feet, the strongest concentration of ozone, and excellent flying conditions. This answer accurately describes the characteristics of the stratosphere. The stratosphere is known for having a temperature that remains relatively constant, or isothermal, up to a certain altitude. It also contains the highest concentration of ozone, which acts as a protective layer against harmful UV radiation. Additionally, the stratosphere is known for providing excellent flying conditions due to its stable atmosphere and lack of weather disturbances.

The correct answer is Centrifugal. In physics, the "equal and opposite reaction" to the center-seeking force, also known as the centripetal force, is the centrifugal force. When an object moves in a circular path, the centripetal force acts towards the center of the circle, while the centrifugal force acts outward, away from the center. These two forces are equal in magnitude and opposite in direction, allowing the object to maintain its circular motion. Inertia, Coriolis, and Centripetal forces are not the equal and opposite reaction to the center-seeking force.

The 3-cell circulation model explains the general atmospheric circulation patterns on Earth. At around 60°N, there is a belt of low pressure caused by the convergence of air masses from the Ferrel and Polar cells. This belt is associated with two major low-pressure systems: the Icelandic low, located near Iceland, and the Aleutian low, located near the Aleutian Islands in Alaska. These low-pressure systems are characterized by stormy weather and play a significant role in shaping the weather patterns in their respective regions. Therefore, the correct answer is Icelandic and Aleutian lows.

In an unstable wave cyclone, the amplitude of the wave increases with time and the wave deepens. This means that the wave becomes stronger and more pronounced as time passes, and the depth of the wave also increases. This can lead to more intense weather conditions and potentially severe storms.

In a cold occlusion, the coldest air is found behind the cold front. Cold occlusions occur when a cold front overtakes a warm front, lifting the warm air and creating a mix of cold and warm air masses. The coldest air is located behind the cold front because it is being pushed forward by the advancing cold air mass, causing it to undercut and displace the warmer air. This results in the coldest air being found behind the cold front in a cold occlusion.

Sea-level pressure is the reference level for all pressure values because it is the pressure that would be measured at a specific location if it were at sea level. This reference level is used to compare and standardize pressure readings taken at different elevations. By using sea-level pressure as the reference, meteorologists and scientists can accurately compare and analyze pressure data from various locations, regardless of their altitude.

Red is the correct answer because red light has the longest wavelength among the given options. This longer wavelength allows red light to scatter less when it passes through the thin clouds, making it easier to determine the ceiling heights. Blue, black, and yellow balloons would not be as effective because their shorter wavelengths would scatter more in the clouds, making it difficult to accurately measure the ceiling heights.

Continental tropical air masses are formed over warm land areas, typically in the tropics or subtropics. These air masses are characterized by high temperatures and low humidity. Due to their warm and dry nature, they tend to create areas of low atmospheric pressure, known as thermal lows. This is because the warm air rises, creating a region of relatively lower pressure compared to the surrounding areas. Therefore, the correct answer is thermal lows.

Horizontal divergence within an air mass refers to the spreading out of air horizontally. This causes the air column to vertically contract, meaning it becomes thinner and shorter. As the air column contracts vertically, it also expands horizontally, leading to a wider distribution of air. Therefore, the correct answer is that horizontal divergence will vertically contract the original column of air and then expand it horizontally.

As air converges at the surface and toward the center of a layer, it will experience contraction horizontally, meaning it will become more compact. This is because the air is being forced to come together and occupy a smaller area. At the same time, there will be vertical expansion, as the air is pushed upwards due to the convergence. This vertical expansion occurs because the air needs to rise to fill the void left by the converging air at the surface. Therefore, the correct answer is contraction and vertical expansion.