Final Study Guide for Questionnaire on Moisture in the Atmosphere

Know how to estimate the elevation of the base of a cumulus cloud.

((air temperature at surface - dew point at surface)/0.8) x 100m

cirrus cloud

(In Latin, "curly," like a lock of hair). High, thin, feathery, white clouds made of ice crystals only due to their high elevation. They can occur as patches or as delicate veil-like sheets or extended wispy fibers that often have a feathery appearance. Their shape is the result of ice particles falling and moving slower than the parent cloud.

cumulus cloud

(In Latin, "heap", or "pile") Thick, puffy clouds made from warm air that is rising vertically (unstable air) because of relatively lower density than surrounding air. Cumulus clouds exhibit a flat base and have the billowy appearance of rising domes or towers. Often taller than they were wide.

Bergeron Process

(more common than the collision-coalescence method). Involves clouds with microscopic ice particles and supercooled water. In a colder cloud with a temperature below freezing, evaporation of H2O molecules from supercooled water droplets produces water vapor which crystallizes onto growing ice/snow. Eventually, the snowflakes become too massive to stay in the cloud and fall to the ground. (To form rain, they melt on the way down and hit the surface as rain). During the winter, 4 different types of precipitation can fall. It is so cold high in the atmosphere during the winter that all four types of precipitation begin as snow produced by the Bergeron Process.

stratus cloud

(stratum = a layer). Clouds that grow in sheets or layers horizontal to the ground and are flat on top and bottom and relatively thin. Cover large portions of the sky. No distinct cloud units. Fog is a special case of stratus clouds

Know the names of various changes of state of water in the atmosphere.

1. gas - water vapor 2. liquid - liquid water 3. solid - ice, snow, hail condensation: the change from as (water vapor) to liquid (liquid water) evaporation: the change from liquid water to water vapor freezing: the change from liquid water to ice melting: the change from ice to liquid water sublimation: the change from solid to gas crystallization: the change from gas to solid

relative humidity

A comparison of the amount of water vapor in the air (specific humidity) with the maximum about of water vapor that the air can hold at a given temperature (capacity). It is a measure of how close the air is to saturation. %Relative humidity = (specific humidity/capacity) x 100.

The Electromagnetic Spectrum

A continuum of all electromagnetic waves arranged according to frequency and wavelength. The sun, earth, and other bodies radiate electromagnetic energy of varying wavelengths. Electromagnetic energy passes through space at the speed of light in the form of sinusoidal waves. Generally, electromagnetic radiation is classified by wavelength into radio wave, microwave, terahertz (or sub-millimeter) radiation, infrared, the visible region that is perceived as light, ultraviolet, X-rays and gamma rays. The behavior of EM radiation depends on its wavelength. All wavelengths travel at the speed of light in a vacuum.

clouds

A form of condensation best described as visible aggregates of minute droplets of water or tiny crystals of ice. Clouds are classified based on form and height. Three basic forms are recognized: cumulus, cirrus, and stratus.

How do you determine the relative humidity with a psychrometer?

A psychrometer consists of two thermometers: the "dry bulb thermometer" records the temperature of the air while the "wet bulb" thermometer records the temperature of the gauze wrapped around the bulb of the thermometer. As the liquid around the gauze evaporates, the temperature of the wet bulb thermometer will fall below the air temperature because evaporation is a cooling process. The lower the relative humidity is, the lower the wet bulb will read because evaporation is taking place with ease. The higher the relative humidity, the closer the air is to saturation and the less the wet bulb thermometer will fall. (If the relative humidity is 100%, the air is saturated, and no evaporation would take place, and the dry bulb and wet bulb temperatures will be the same).

contrail

A special variety of cirrus clouds, exhaust of planes (a lot of H2O in exhaust) If contrails stay for a while, it means that the air is very close to saturation (harder for cloud to dissipate) If cloud disappears quickly, means the relative humidity is low enough (far enough away from saturation) for cloud to sublimate

radiation fog

After cold, clear night, air in contact with the ground is chilled to its dew point temperature (ground has lost its heat in the form of infrared radiation throughout the night)

Thermometer

An instrument for measuring and indicating temperature, typically one consisting of a narrow, hermetically sealed glass tube marked with graduations and having at one end a bulb containing mercury or alcohol that expands and contracts in the tube with heating and cooling.

virga

Any precipitation falling from a cloud that does not reach the ground.

Know how specific humidity, relative humidity, and dew point temperature change as temperature decreases (for example, as air rises)

As temperature falls, the capacity falls the specific humidity does not change the relative humidity rises. As a parcel of air rises, it cools.

dry adiabatic rate

As you travel from Earth's surface upward through the atmosphere, the atmospheric pressure rapidly diminishes, because there are fewer and fewer gas molecules. Thus, any time a parcel of air moves upward, it passes through regions of successively lower pressure. As a result, the ascending air expands. As it expands. it cools adiabatically. Unsaturated air cools at a constant rate of 10 degrees Celcius for every 1000 meters of ascent. Conversely, descending air comes under increasingly higher pressures, compresses, and is heated 10 degrees C for every 1000 meters of descent. This rate of cooling or heating applies only to unsaturated air and is known as the dry adiabatic rate.

condensation

Change of state from gas to liquid (water vapor to liquid water). Condensation may form dew, fog, or clouds.

cumulonimbus cloud

Characterized by a flat base, flat top (usually the boundary of the trophosphere), billowy in the middle. forms like regular clouds. the harder edges of cumulonimbus clouds are made of liquid water, while the hazy, fuzzier edges are made of icy particles. Produces precipitation that reaches the ground. Although cumulus clouds are associated with fair weather, they may grow dramatically under the proper circumstances. Once upward movement is triggered, acceleration is powerful, and clouds with great vertical extent form. The end result is often a cumulonimbus.

hybrid types of clouds

Cirrocumulus clouds ("mackerel sky"), Kelvin-Helmholtz wave clouds, altocumulus, nimbostratus, stratocumulus, cirrostratus

urban heat-island profile

Cities tend to be a few degrees warmer than surroundings because of the high concentration of heat energy due to being largely made of materials that absorb and store heat energy (ex. stone). Lack of wet areas, green spaces, bodies of water also contributes because evaporation is a cooling process. Heat waves can cause many deaths. To prevent risk, use high albedo materials, buildings spaced apart, and green spaces on roofs, and spaces between buildings.

Of what are clouds composed?

Clouds are made of tiny droplets of liquid water that have condensed from the air (or tiny bits of ice that have crystallized from the air.) They are NOT made of water vapor (water vapor is invisible). 1) if temperature is above 0, clouds are made of microscopic particles of liquid water 2) if temperature is below -40 degrees Celcius, clouds are made of microscopic particles of ice. 3) if temperature is between 0--40 degrees Celcius, clouds are made of ice and supercooled water.

fog

Clouds that form at the surface of Earth. It generally forms during a clear night. During a clear night, the ground's heat is radiated away to the upper atmosphere and eventually to space. The coldness of the ground chills the air directly above it to is dew point temperature, creating condensation in the form of fog.

convergence

Collision of contrasting air masses forces air to rise. Whenever air in the lower atmosphere flows together, lifting results. When air flows in from more than one direction, it must go somewhere. As it cannot go down, it goes up. This leads to adiabatic cooling and possibly cloud formation.

How do dew and frost form?

Condensation may form dew. Frost forms when the air is humid but cold enough for water vapor to crystallize.

Farenheit

Created by Daniel Fahrenheit (German physicist). F = 1.8C +32

What does unstable air have to do with the formation of cumulus clouds?

Cumulus clouds form as the result of rising (unstable) air.

convection

Energy transfer by way of moving currents that are moving because of differences in density. Requires a gravitational field. Requires matter.

conduction

Energy transfer by way of physical contact. Requires matter.

evaporation

Evaporation is the change from liquid to gas. Evaporation is a cooling process. Only the most energetic (that is, the warmest) water molecules in liquid water will evaporate (takes an immense amount of energy to change state and make juge jump from liquid to gas). They leave behind liquid water molecules that are, on average, cooler than the water was before the evaporation begun (because evaporated molecules drew energy from other molecules to make change in state).

Why don't cloud particles crash down on us even though they are denser than the surround air?

Even though water vapor that make up clouds is in liquid/solid form and has a higher density than air, it doesn't come crashing down on us because they have so little mass (as tiny microscopic droplets/grains) that the littlest movement of air is enough to keep them aloft.

infrared

Everything emits some kind of light. Different energys (blue has higher energy, shorter wave length than red, which has lower energy and longer wavelength). Kind of energy that is given off is determined by the color of the light. Temperature is also a factor. Infrared can pass through things that blocks visible light. However, infrared can't get through (ex. glass) or get stuc k by things visible light can pass through. Planets give of infrared. Higher temperatures, more infrared is released/emitted. (Temperature is related to infrared); anything that has a temperature above absolute 0 emits infrared and absorbs radation.

How does fog form? What are the three types of fog?

Fog is a special case of stratus clouds, forming as a result of water being chilled to its dew point when in contact with a cool surface. Near the Earth's surface, heat is readily exchnaged between the air above. During the evening hours, the surface radiates heat away, causing the surface and the adjacent air to cool rapidly. Thus radiation accounts for the formation of dew and some types of fog. Thus, surface cooling that occurs after sunset accounts for some condensation. Three types: evaporation fog, advection fog, radiation fog

rain

Forms by two different methods: the collision-coalescence method and the Bergeron Process (snow melts on its way down and falls as droplets of liquid water).

hail

Frozen precipitation, but it is a warm weather phenomenon. To form hail, you need a very tall cumulus or cumulonimbus cloud that has grown vertically to a very great height in the atmosphere driven by powerful currents of rising warm air. The temperature is so cold at the height that water droplets freeze. They are kept in the cloud, however, by strong updrafts and wings in the cloud. They only fall when they are too heavy to be kept aloft by winds.

sleet

Frozen rain. Snow falls toward the surface but melts on its way down (when it meets warmer air) but refreezes as it gets closer to the surface. Can happen at a warm front, or because of a temperature inversion of some sort.

If hail is frozen precipitation, why does it usually form in warm weather?

Hail forms as the result of major league RCC (Radiation, conduction, convection) on hot, humid days (surface hot, heating air, air rising). Cumulonimbus clouds form as a result of RCC. Ice pellets form in the cloud, but as they fall toward the surface, very powerful, vertical convection currents bring the pellets up to the cloud again, where the pellet is "coated" with another layer of ice. Eventually, the pellet becomes way too heavy for the vertical currents to carry up again and falls but hits the ground before it can melt. The hotter the day, the bigger hail because the vertical convection currents are more powerful. If a pellet were to be cracked open, there would be visible layers in the hail for each time it went through the cycle.

radiation

Heat/energy transfer by the way of electromagnetic waves moving at the speed of light. Can occur in vacuums.

snowflakes

Hexagonal core (oxygen and hydrogen lock together in hexagonal structure). Growth occurs from the points (the vertices) of the hexagon and is influenced by the conditions in which the snowflake formed/passed through. All six edges experience the same growth at the same time, resulting in symmetry. supercooled water droplets that collide with snowflakes can freeze on the snowflake and be incorporated into the snowflake's structure.

solar and infrared radiation over the course of a day

Hottest time of day is mid-afternoon (around 3 pm) because the amount of incoming solar radiation is still greater than the amount of outgoing infrared radiation until mid-afternoon.

wet adiabatic rate

If a parcel of air rises high enough, it will eventually cool to its dew point. Here, the process of condensation begins. From this point on along its ascent, latent heat of condensation stored in the water vapor will be liberated. Although the air will continue to cool after condensation begins, the released latent heat works against the adiabatic process, thereby reducing the rate at which the air cools (condensation is a warming process). The slower rate of cooling caused by the addition of latent heat is called the wet adiabatic rate. Because the amount of latent heat released depends on the quantity of moisture present in the air, the wet adiabatic rate varies from 5 degrees to 9 degrees Celcius per 1000 meters.

temperature inversion

In meteorology, an inversion is a deviation from the normal change of an atmospheric property with altitude. It almost always refers to a "temperature inversion", i.e. an increase in temperature with height, or to the layer ("inversion layer") within which such an increase occurs.[1] An inversion can lead to pollution such as smog being trapped close to the ground, with possible adverse effects on health. An inversion can also suppress convection by acting as a "cap". If this cap is broken for any of several reasons, convection of any moisture present can then erupt into violent thunderstorms. Temperature inversion can notoriously result in freezing rain in cold climates. Usually, within the lower atmosphere (the troposphere) the air near the surface of the Earth is warmer than the air above it, largely because the atmosphere is heated from below as solar radiation warms the Earth's surface, which in turn then warms the layer of the atmosphere directly above it, e.g., by thermals (convective heat transfer) Given the right conditions, the normal vertical temperature gradient is inverted such that the air is colder near the surface of the Earth. This can occur when, for example, a warmer, less-dense air mass moves over a cooler, denser air mass. This type of inversion occurs in the vicinity of warm fronts, and also in areas of oceanic upwelling. With sufficient humidity in the cooler layer, fog is typically present below the inversion cap. The fog cab concentrate pollution (smog, smoke) on the surface and prevent it from convecting away. An inversion is also produced whenever radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is very low in the sky. This effect is virtually confined to land regions as the ocean retains heat far longer. In the polar regions during winter, inversions are nearly always present over land. A warmer air mass moving over a cooler one can "shut off" any convection which may be present in the cooler air mass. This is known as a capping inversion. However, if this cap is broken, either by extreme convection overcoming the cap, or by the lifting effect of a front or a mountain range, the sudden release of bottled-up convective energy - like the bursting of a balloon - can result in severe thunderstorms. Such capping inversions typically precede the development of tornadoes in the Midwestern United States. In this instance, the "cooler" layer is actually quite warm, but is still denser and usually cooler than the lower part of the inversion layer capping it.

heating of the land versus heating of the water

Land heats faster because water has a higher specific heat (takes more energy to raise a gram of water by 1 degrees Celcius than it takes to raise land by 1 degrees Celcius).

supercooled water

Liquid water that is colder than the freezing temperature of water. This water needs a "template" on which to freeze. Needs a solid object on which supercooled water freeze (to form rigid, geometric shapes). if temperature is below -40 Celcius, the super cooled water will freeze on its own (without template). Would readily freeze upon impact (usually ice pellets in clouds).

Luke Howard

Lived around the 1800s, from England. Howard was a professional pharmacist that was fascinated by clouds (sketched clouds, made drawings, paintings, etc.) and noticed that they tended to fall into categories and gave names for them:

frontal wedging

Masses of warm and cold air collide, producing a front. Here, the warmer, less dense air rises. The larger the difference in temperature between two air masses at a front, the more violent the weather produced at the front.

condensation nuclei

Microscopic solid particles onto which water can condense or freeze to form cloud particles. Vitally important to cloud formation. 1) dust is by far the most important of these. source of dust (as condensation nuclei) mainly from deserts (dust is blown around the world). 2) smoke (microscopic particles of soot) 3) sea salt 4) pollen, spores, bacteria, insect parts, debris from space.

Why are cloudy nights warmer than clear nights?

On clear nights, heat is radiated out to space while on cloudy nights, the infrared radiation that is emitted by the surface is intercepted by the clouds and is radiated back to earth.

localized convective lifting (basically RCC)

On warm summer days, unequal heating of the Earth's surface may cause pockets of air to be warmed more than the surrounding air. Consequently, the parcel of air in contact with a heated surface (warmer and less dense than the surrounding air) will be buoyed upward. These rising parcels of air are called thermals. The phenomenon that produces rising thermals is called localized convective lifting. When these warm parcels of air rise above the lifting condensation level, clouds form.

orographic lifting

Orographic lifting occurs when elevated terrains, such as mountains, act as barriers to the flow of air. When the air ascends a mountain slope, adiabatic cooling often generates clouds and copious precipitation. By the time the air reaches the leeward side of the mountain, much of its moisture has been lost. If the air descends, it warms adiabatically, inhibiting cloud formation. This can result in a rain shadow desert.

absolute stability

Prevails when the environmental lapse rate is less than the wet adiabatic rate (parcel will sink to its original position because

Know how to use the vocabulary of atmospheric moisture to relate to everyday examples of condensation/evaporation that we have discussed in class (shower steaming up a bathroom, seeing your breath on a cold morning, why indoors is so dry during the winter, glasses fogging over upon entering a warm kitchen from the cold outdoors).

Showering: Bathroom mirrors starting to fog up when the specific humidity reaches capacity (becomes saturated). The air touching the cool surface of a mirror therefore has a lower capacity. Water vapor is chilled, and water vapor condenses on the mirror. When you finish the shower and open the door, the fog disappears because 1) you have stopped adding water vapor and 2)very low specific humidity air flows in, mixes with the air next to mirror and windows. When specific humidity finally lower than the capacity, condensed water vapor evaporates. Breath: On a cold day, you exhale, and you get a "cloud." (you can "see your breath"). Specific humidity in you and and the air that you exhaled is equal. Temperature inside of you is high compared to the the temperature outside of you so when you exhale specific humidity becomes greater than the capacity and your breath condenses. Breath then mixes with the air outside which is relatively dry (low specific humidity) and evaporates. Dryness indoors (in comparison to outside): On a winter day, the air is dry inside because the air inside came from outside (which means it has the same specific humidity) and because it is warmer inside than outside, the relative humidity is less inside than outside and air inside is therefore dryer. Sweating more at Night than in the daytime even though it is hotter midday? Capacity is higher in the daytime. You're actually sweating more, but because the relative humidity is lower, most of your perspiration evaporates. "sea smoke" - ocean warms air right above it

evaporation fog

Steam fog: during the autumn or winter, lake water is warmer than the surrounding. The air in contact with the water will be warmed and will rise until it reaches its dew point temperature. Frontal fog: When frontal wedging occurs, warm air is lifted over colder air. If the resulting clouds yield rain, and the cold air below is near dew point, enough rain will evaporate to produce fog.

Why have we evolved to only see a certain part of the electromagnetic spectrum?

Sun puts out energy and the wavelengths/radiation that reaches the earth's surface is mostly the wavelengths of the light we see. Visible light is largely transparent.

Radiation, Conduction, Convection (RCC)

Sun shines down on surface, warm surface warms the air in contact with it, and warm air rises and cools to its dew point.

grauple ("soft hail")

Supercooled water droplets that collide with snowflakes can freeze on the snowflake and be incorporated into the snowflake's structure. Grauple is essentially snowflakes that are hit with thousands of supercooled water droplets. They are very dense because of the droplets that freezed on them. The difference between grauple and hail is density. Grauple is less dense and tends to fall apart easily.

Celsius scale

Swedish physicist came up with a scale that was perceived to be much more rational than Fahrenheit scale, where 0 degrees was the melting/freezing point of water. C = (5/9)(F - 32)

specific humidity

The amount of water vapor in the atmosphere (grams of water per kilogram of air). Concentration of water vapor. When the specific humidity of the air is high, the temperature of the air does not have to fall very far before its dew point temperature is reached. That is, the air is already close to saturation. When the specific humidity of the air is low, (that is, when the air is dry and the relative humidity is low), the temperature will have to decrease substantially before before saturation is reached. In other words, the capacity of the air will have to be substantially lower to be equal to the specific humidity.

stability of air

The answer is closely related to the stability of the air. By comparing a parcel of air's temperature to that of the surrounding air, we can determine its stability. If the parcel of air were cooler than the surrounding environment, it would be more dense and would therefore sink to its original position if allowed to do so. Air of this type, called stable air, resists vertical movement. If the rising parcel of air is warmer and therefore less dense than its surroundings, it would continue to rise until it reached an altitude where its temperature equalled that of its surroundings. This type of air is classified as unstable air. Stability is the property of air that describes its tendency to remain in its original position (stable) or to rise (unstable).

conditional instability

The environmental lapse rate is between the dry and wet adiabatic rates. It is stable for the unsaturated parcel of air, but unstable for the saturated parcel of air.

incoming solar radiation (annual) and infrared radiation (annual)

The hottest time of year is around late July and early August despite the fact that the maximum point of incoming solar radiation is in June because incoming radiation is still greater than the amount of outgoing infrared radiation until late July/August. Coolest time of year is January for the same reason (outgoing is greater than incoming until January).

capacity

The maximum amount of water vapor that the air can hold at a given temperature (grams per kilogram of air). Function of temperature. When temperature goes up, capacity goes up. This means that as the temperature goes up, the air can cold more water vapor.

albedo

The reflectivity of a material, ((amount of light reflected / amount of light striking object) x 100). The proportion of the incident light or radiation that is reflected by a surface.\ On average, about 30% from the sun is reflected away (albedo of the Earth) and plays no role in warming the Earth. Of the 70% left over, 20% absorbed by the atmosphere and remitted as infrared. 50% is absorbed by the surface of the earth. Of that 50%, 20% is radiated back as infrared, 30% is conducted to lower most atmosphere, and convected to the trophosphere. Generally speaking, water has an amazingly low albedo (however, if light comes in at a low angle, water actually has a high reflectivity). High albedos on the planet: Clouds: 75-95% Snow/ice: 75-95% Deserts: 30% Grasslands: 20% Bare rock: 4-35% Rainforests: 10% Ocean water: 2-4% Gas giants have high albedos because they have many clouds. Mercury: 6% Venus: 72% Earth: 30% Mars: 16% Jupiter: 70% Saturn: 75% Uranus: 90% Neptune: 82% Moon: about 7% (low albedo because its so close)

Why are clouds white?

The size of the nitrogen and oxygen molecules are the perfect size to scatter short wavelength (violets and blues, making the sky appear the color it is). Similarly, cloud particles are the perfect size to scatter all wavelengths of light equally.

dew point temperature

The temperature at which water vapor condenses to liquid water. At the dew point temperature: a) the relative humidity is 100% b) specific humidity = capacity c) the air is saturated with respect to water vapor (this means the air can hold no more water vapor).

environmental lapse rate

The temperature of the atmosphere as determined from observations made by radiosondes and aircraft. (Unlike adiabatic temperature changes which give you a rate at which the PARCEL of air cools, this is the rate at which the temperature of the (surrounding) AIR cools.)

change in the atmosphere

The ultimate source of energy that creates change (winds, storms, precipitation) in the atmosphere is THE SUN.

snow

This forms when tiny water droplets freeze and continue to grow into a 6-sided crystal by the addition of more frozen water.

What are the 3 general methods of cloud formation that we discussed in class?

To form clouds, you need 1) low temperature 2) moist air 3) condensation nuclei The temperature of moist air goes down until it reaches its dew point. At this point, condensation begins to occur. The tiny droplets of condensed water form around condensation nuclei (tiny particles of dust smoke, pollution, other things) During the day, the sun shines down on the ground and it warms it (radiation). The ground warms the air immediately above it (conduction). This newly warmed air rises due to its relatively low density (convection) to an elevation in the atmosphere where the temperature is low enough for condensation to occur (the dew point). This is why there are often more clouds in teh afternoon than in the morning. Clouds form high in the sky because it is colder up there. Generic, typical ways of cloud formation: What they all have in common: an air mass is brought to its dew point temperature (by rising) 1)Radiation, Conduction, Convection (RCC)* 2)Orographic Lifting* 3)Frontal wedging: cloud formation at a front (warm or cold)* 4) Convergence 5)Localized convective lifting

collision-coalescence method

Typically occurs in humid, tropical areas. Water in droplets in the turbulent environment of clouds grow in size by collision with other droplets (this is similar to the way planets grew in the nebula when the solar system began). When the drop becomes too heavy to remain in the cloud, it falls to earth as a raindrop. Each raindrop consists of tens of thousands to condensation nuclei.

freezing rain

Very dangerous, and can be very destructive. Freezing rain starts out as snow formed by the Bergeron process. Snow melts on its way down and forms rain (when it meets warmer air that is above freezing), hits the surface as a liquid, and freezes on contact. 2 ways this can happen: 1) air may be above freezing, but the surface is below freezing 2) snow melts, then enters below freezing air but doesn't freeze (becomes supercooled water) and then freezes on contact with the surface.

advection fog

Warm, moist air moves horizontally over a cool surface which lowers it to its dew point temperature.

water vapor

Water vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible.

adiabatic temperature changes

When energy is used to compress air, the motion of the gas molecules increases and therefore the temperature of the air rises. Conversely, air that is allowed to decompress expands and cools. This results because the expanding air pushes (does work on) the surrounding air and must cool by an amount equivalent to the energy expended. Variations in temperature that occur even though heat is neither added or subtracted are known as adiabatic temperature changes. In summary, when air is allowed to expand, it cools, and when it is compressed, it warms.

absolute instability

When the environmental lapse rate is greater than the dry adiabatic rate. (The ascending particle of air is always warmer than its environment and will continue to rise because of its own buoyancy).

nimbus

cloud capable of producing precipitation that reaches the ground

Know how to use the Capacity Table and your knowledge to solve numerical examples as we have done in class and on worksheets.

relative humidity = (specific humidity/capacity)