2 Test Geography 2050 Geog 2-08-08 Solar Radiation is the primary heat source for the Atmosphere, it's the primary fuel for it and our weather We must balance between... Insolation is incoming solar radiation Absorption of terrestrial radiation by atmospheric gases And how much of it goes into space from the earth All of which will describe the global energy budget There are regional and global differences in radiation and temperature and how they effect the atmosphere Atmospheric influences on Insolation Solar energy interacts with atmospheric gases and/or Earth's surface, some makes it to the ground after it goes through all of this Some energy might get absorbed directly by a gas particle, some might hit and reflected, some might be scattered and some making it all the way to the ground Absorbed, reflected/scattered, or transmitted Only absorbed energy leads to direct heating, it's the only way, everything else is indirect and secondary process Processes of the Solar Energy in the Atmosphere: Absorption which is particular gases/liquids/solids in atmosphere absorb the solar energy Some are better than others at doing this, the molecule absorbs it, heats up the molecule and so less of it gets down to the ground For weather, the more energy absorbed at this level, the less that gets down and drives the thunderstorms Heat increase in the absorber -less energy at surface 55 degrees F temperature average in the world Overall atmosphere gases are relatively poor absorbers, they are not very efficient, it meant most energy coming is not being absorbed and being thrown out another way And with most actually making its way to the ground surface Reflection/Scattering, is a way Energy is redirected in the atmosphere
In this the energy is basically being bounced, and NO heat increase in the object Usually only a portion of energy is reflected, maybe a portion of it gets absorbed but a percentage is reflected Ice sheets of Greenland, tops of white clouds are great reflectors Albedo is percentage of reflected energy, like a white cloud has a 90 percent albedo, its how much reflected light there was If it gets warmer means more energy and more clouds which could count act the warming by reflecting more radiation away Energy can be reflected, in an equally intense beam it is Specular Reflection, like looking in a mirror seeing a perfect one to one reflection and is common Diffuse Reflection is when it goes into many weaker wavelengths or Scattering Most gases are very good at scattering so they make up the absorption factor Scattering with most gases are very good at doing this to radiation Most of what we get is the radiation having been bounced around like crazy so it is diffuse usually when it hits the surface Not all particles scatter equally, it depends on the size of the scattering agents Like a hail stone will be better at it than a small oxygen molecule 3 types of Scattering 1.Rayliegh is responsible for the sky being blue, involves gases smaller than energy wavelengths, visible light is about a micrometer, so they are smaller than that Scatters both forward and backwards, it goes everywhere almost like an explosion and occurs more readily with shorter wavelength energy Blues and Purples have shorter wavelengths, so when they hit they scatter easily, where Reds and Yellows scatter with less intensity and what we see are the ones scattered easily All of these are in the upper atmosphere, we see blue because it gives out less purple light so it gets scattered out more than the Blue wavelengths At sunrise and sunset, longer visible wavelengths which are the Yellow and Red which are longer wavelengths dominate because solar energy must pass through greater atmospheric distance and the Blue is being scattered completely
2.Mie are Medium particles the same size as the Wavelengths, such as Aerosols will produce Hazy or Greyish skies, they reflect all the wavelengths, same size as radiation wavelengths in other words They tend to only scatter things FORWARD only Different visible wavelengths coming through and then being washed out as they go through the particle These tend to be closer to the ground, in the Troposphere 3.Nonselective are Larger than the Wavelengths such as Rain drops, all visable wavelengths scatter equally, these focus just in an area of the scattering, its not everywhere so no haze or wash out It just produce white or gray appearance in clouds Transmission is whatever percentage of Solar energy left over after all this that reach the surface This varies Diurnally(Day/Nights Variation) and from place to place, such as the equator to the Arctic How much Insolation is left for Transmission to surface do we get from all of this A Global Energy Budget Start with Insolation 100% Absobortion Reflection Scattering Ref. Ground Amount Absor. Gr. END CLASS Geog 2-11-08 Surface Radiation Earth has relatively low temperature compared to the Sun, Earth Radiation peaks in the longer wavelengths in the Infrared area of the spectrum So it emits a Longwave wavelength Solar Radiation (insolation) peaks in the visible spectrum 25 19 6 5 45(which drives our atmosphere workable)
Earth Heats up from some of the radiation getting through so it will emit some which helps heat up the area of the Earth and we get some more radiation The energy coming out of the Earth is initially from the Sun, so it is Secondary Radiation Longwave goes back into the Atmosphere and get absorbed, back into aerosols, clouds, crystals just like from the incoming Insolation So all of this means the Heating comes from the two sources, initially from the Sun, then the Secondary from Earth giving off the energy it has absorbed Atmosphere then radiates energy in all directions, including downward Not all atmosphere particles and such are effective at absorbing the radiation from the Earth and some are very good Greenhouse Gases, they absorb longwave radiation very well Water Vapor and Carbon Dioxide are the primary ones Clouds act like a blanket almost, they absorb nearly all Longwave Radiation Cloudy nights are usually warmer than clearn nights How do the atmosphere and Earth's surface maintain a Net Radiation Balance(so we do not freeze or burn)? Insolation+Greenhouse Effect is what gives us the net radiation balance and comfortable temperatures Natural Greenhouse Effect is what sustains life on the plant It is termed this because of the secondary process is a lot like what happens in a Greenhouse You have a glass structure where the glass lets the Solar Radiation to pass through, it heats up the inside of it or the earth, it gives off the Longwave radiation, the glass actually traps the Infrared Energy Without this, the average Earth Temperature would be -18 Celcius or 0 F With the gases our average temperature is +15C or the 50's F Recent increases in Greenhouse Gases are due to human activities, basically energizing the effect more If we just had Solar and Longwave, Earth's surface would get hot while atmosphere would be cold, so there is something else that is spreading it around This does not happen because energy also transferred by Conduction and Convection, they offset atmosphere-surface energy imbalance
Conduction is as surface warms, Temperature Gradient develops, as the ground surface heats up, the Gradient happens where the air around it heats up, but as you go away from it its cooler from the air and ground Maybe just a few centimeters above and below the surface, helps to spread the heat energy basically, it starts to take a life of its own Energy transferred down beneath the surface to compensate Surface warming also creates a gradient with a thin layer of air above This thin layer is called Laminar Boundary Layer(LBL) Convection are the LBL gradients cause energy transfer up thru the atmosphere, starts a reaction that continues on itself, this happens anytime the surface temperature exceeds above air temperature This is strongest in the middle of the heat with most of the heat hitting the earths surface or its peak Free Convection is basically rising air is what starts the weather, it's the free moving air that cycles through, warm air becomes buoyant and rises since it is less dense Forced Convection is like a gust of wind pushing against an obstacle on the surface, creating rising air motions Sensible Heat is heat energy that is readily detected Objects with greater mass require more energy to heat up, Specific Heat is energy needed to change temperature of an object some given amount Some object heat rather quickly, where some do not such as certain metals have a higher specific heat than others Even a long time to cool off after it has been heated Latent Heat is energy required to induce change of state of something, the physical aspect of it such as Water going to gas or freezing it to ice Latent Heat of Evaporation is where energy is stored Latent Heat of Condensation is energy being released END CLASS Geog 2-15-08 Net Radiation and Temperature Earth's radiation balance function of incoming and outgoing energy
Balances occur daily(Diurnally) at local scale, annually at global scale Basically we have a constant change on the local level, in the day we have a surplus of energy and at night we have a deficit The coolest par to the day is just before sunrise, then accumulates around noon and the warmest part of the day is around 2pm then starts to decline and starts the cycle all over again The course of a year has a similar curve, just take a location and map out the seasons and you get the same curve of radiation Latitudinal Variations in Energy Annually, areas between 38degreesN-38degreesS, it will run energy surplus, even on the solstices Areas poleward of 38degrees experience energy deficits Boundary between net gains and deficits migrates seasonally, it basically changes over the times, we have ocean currents and wind patterns, pressure differences, circulation and transport which all effect the energy into being moved around The energy will be transported away from the Equator and distributed Global Temperature distributions-Latitude General decrease in temperatures with higher latitudes, so basically the higher Latitude the colder the temperatures Stronger latitudinal contrast in winter hemisphere, so if you took the temp. in low latitude in Jan. and compared it to Alaska you would see a big change, but in the summer the change is not as big, so it is more pronounced in the Winter Hemisphere Northern Hemisphere temperature gradients more pronounced It is because of the land surfaces, more land is in the Northern Hemisphere, land heats and cools more quickly than ocean Isotherms are lines on a map that connect locations with equal temperatures It's a way to visualize broad temperatures You can see through these maps by comparing them you can tell that the Northern Hemisphere gets a greater change Other influences on Temperature--Altitude/Elevation Longwave energy enters atmosphere from Earth's Surface The energy from the ground being released is warming the Troposhere mainly
At high Altitudes the temperatures remain pretty constant since it is further up, more warming from the surface and closer to the ground with minimal from the higher ups When the density of the atmosphere decreases the energy isn't as compressed and is lessened Air at high elevations undergoes more rapid diurnal temperature change than air at lower elevations Other influences on Temperature--Circulation Latidunial differences cause large-scale horizontal energy transport Advection it's the movement of energy for this, several things like currents Influences moisture/cloud cover, which then impact temperature, such as cloudy days will make the temperatures warmer, or snow storms, hurricanes to clear days Other influences on Temperature--Land/Water contrasts Water bodies heat slower than land because of: Oceans have a Higher specific heat Transparency, they are partially transparent, the land gets absorbed quicker, where the ocean some of that energy will spread deeper into the water It spreads more in the oceans so the surface change is small Evaporative cooling, the water evaporates and takes energy out and it cools Horizontal and Vertical Mixing, none on land where the Ocean moves and mixes with itself, like the currents moving it around, which can effect the weather Continentality is you get more extremes on land surfaces than the Oceans Other Influences on Temperature--Local Impacts South-facing slopes heat more quickly than North-Facing slopes, since they get more direct radiation during the day If the land is covered with trees that makes a difference, it reduces insolation during the day since they reflect the energy more, where at Night they retain some of it END CLASS
Geog 2-18-08 Measurement of Temperature Mercury was used in the early days but it was found unhealthy so now they use Alcohol based ones As the temperature warms the liquid will expand so as it expands it will be gauged Thermistors is used to measure Temperature via electrical current resistance, the current is taken to the receiving station to be looked at Radiosondes and automated stations use this especially if up in a weather balloon Instrument Shelter called a Stevenson Screen that is vented with being elevated a few feet off the ground and around since the 1800's The thermometers are inside the box, away from the shade and direct sunlight to not inflate the temp., it is ventilated so the air passes through and off the ground because it can heat up faster than the air around it With these you could supposedly take temperature accurately and compare them Global Extremes Due to Continentality, most extreme temperatures are in land interiors, so basically when your further in land you will have extremes of both ends Hottest place on earth is in Africa and Middle East World Record High was 57degrees C(137F) in Libya, 1913 World Record Low was -89Degrees C(-129F) in Antarctica, 1960 Temperature and Human Comfort Wind Chill Index: wind causes body to lose heat more quickly It takes little of this to make it feel colder Heat Index: High humidity reduces body's evaporative cooling ability You feel hotter because of this, and again it doesn't take much to make it feel uncomfortable to cause certain problems with the body too END CLASS
Geog 2-20-08 Atmospheric Pressure and Winds Atmospheric Pressure is Force of the atmosphere per unit of area The average air pressure at 0 feet of elevation is about 1013mb You have molecules all in the atmosphere and all of these are going to exert a pressure in all directions by gases Function of density and temperature work together in to show what the pressure is like in the area Most of the material is near the ground levels, and as you go up it starts to space out or disperse Vertical and Horizontal changes in pressure Pressure decreases with height exponentially and dramatically with it being non-linear due to compressibility Say your in a valley, you have all this atmospheric mass pushing down on you to have a high pressure then as you go up the mountain the pressure decreases as you get above it Pressure will be less at the mountain top than in the valley Need to take in account of where you are in relation to sea level and elevation effects Calibrate measurements to sea level pressure, convert them what they would be if you went down to sea level So when you see a pressure map it has already been calibrated or converted The Equation of State Relationship between pressure, temperature, and density, it shows how these three things work together Sometimes called the Ideal Gas Law P=Ro or density pRT Pressure=Density*Constant*Temperature One change in the variables may cause another change in another, the key is that as the air warms or cools down, the pressure is going to respond Measurement of Pressure A Barometer is what is used to measure it
Mercury Barometer is a inverted tube filled with Mercury developed first by Torachili, he would take a dish fill it with mercury with a glass tube calibrated with different pressure readings, as the pressure went up there would be more pushing down on the dish and force more into the tube Aneroid Barometer is now being used since it is safer and is a collapsible chamber that compresses, vacuumed chamber that goes up and down based on pressure Corrections to Barometer Readings Three corrections need to consistency: ensure Elevation has to be checked in the area Air Temperature with Mercury only since it is affected by the temperature on its density Latitude with Mercury again and is affected by the gravity since we spin The Distribution of Pressure Horizontal pressure differences help generate weather, knowing what they are doing will help us to determine the weather Just like Isotherms, the lines on the map are the same or equal to the same number of pressure Pressure maps depict Isobars which are lines of equal pressure across the map or on it Certain times of the year the pressure actually changes through the globe Pressure Gradients or the changes in pressure across space, knowing this will tell us the wind speed, direction, potential for storms and ect. Which by how when the lines are close it's a sharp gradient where spaced out the pressure changes gradually Pressure Gradients Pressure Gradient Force initiates movement of atmospheric mass, it wants to move air from high pressure areas to low pressure areas When this happens you get Wind A strong pressure gradient will create a stronger wind, if there is more dramatic change you will get a more pronounce response It only takes a slight difference to have weather patterns to change or be driven further Horizontal Pressure Gradients Typically only small gradients exist across large spatial scales, still important to the weather though
It is possible to get a rather large one, the pressure say in a tornado will be really low where outside would be very high, across the small distance you could get a large gradient Small-scale weather feature can have large gradients like a tornado Vertical Pressure Gradients usually greater than horizontal pressure gradients Updrafts and downdrafts can be huge in the weather Wind shear affecting aircraft Hydrostatic Equilibrium Downward force of gravity balances strong vertical pressure gradients Higher pressure near the surface, and lower pressure aloft thanks to gravity pushing on average Local temporary imbalances called Edies initiate updrafts and downdrafts All sorts of things can cause these, cooling and warming of air, surface changes, fronts ect. END CLASS Geog 2-22-08 Gravity is pulling down the air and pressure to form a balance The magnitude of these forces might be different depending on the density up in the atmosphere The role of density in Hydrostatic Equilibrium A dense atmosphere experiences greater gravitational force, so the vertical pressure gradient must increase to compensate Denser atmosphere would have a great down and upward force Warm Air is less dense, smaller vertical pressure gradients, takes up more air space with bigger volume, as it expands it becomes less dense Cold Air is more dense, greater vertical pressure gradients , takes up less air space with less volume, doesn't expand and stays more compact basically Two columns of air, same Temp. same mass same volume, the pressure both at 1kmb, top of the column its 500mb Make once change where on box of air you like a fire, the #molecules stays the same, what changes is the volume and density, the column expands and takes up more space while the cool one stays the same
You have to go to a higher altitude now on the warm one to find 500mb so its become a smaller gradient change of pressure Horizontal Pressure Gradients un the Upper Troposphere Examined with Heights of Constant Pressure aloft Lower Heights over cooler than over warmer air Lower heights correspond with cooler air, and higher heights with warmer air On average the air near the Equator the pressure heights are higher than as you go up to the Pole its decreases Heights decrease with Latitude "Surfaces" of constant pressure show height differences Because of the Pressure Gradient Forces, the warm air will basically want to move to areas of the Warm air because of Density Forces affecting the speed and direction of wind PGF: a parcel of air will want to move from high pressure to low pressure Things like high pressure at the ground will expand away from it as where in Low things will go into it This seems simple but with the Earth spinning, it messes with the Force We move with different angular momentums Free moving objects in atmosphere are influenced by Earth's Rotation If your in the middle of the earth, your going faster with greater distance in a rotation, but if you go north you ill be flying into areas with angular rotation is less so you kind of move fast Coriolis Force resulting in Apparent Deflection of these objects because of the change of angular speed In Northern Hemisphere things appear to deflect to the Right such as if you take off from the middle of Africa and go Due North, you will appear to go off course and head to the right In Southern Hemisphere it is the Opposite and you go Left, such as taking off from Middle of Africa and go Due South you will go left It is not a true force, no physical mechanism doing this, more of a mathematical response to the PGF, or opposite of it totally, it's the counter balance of PGF Zero at equator and maximum at the Poles
Increases with speed of a moving object, such as a plane moves faster than a baseball Overall though this Force is weak, need to have a big object of air mass to see this work like a Hurricane or tropical storm Winds in the Upper Troposphere Air moving from high to low pressure undergoes Coriolis Deflection The Coriolis effects starts to happen and effects the wind to deflect it to the right in NH, they will balance exactly and end up going Right PGF=COR so the wind will go parallel to height constricts called Geostrophic Flow Supergeostrophic and Subgeostrophic Flow Height contours and pressure distributions frequently are curved Supergeo is where the wind accelerates around high pressure areas, so it has a bigger Coriolis force to keep it around the curve to dominate the PGF Subgeo is when you have Low pressure areas, the air will slow down around it and the PGF dominates a weaker Coriolis Result from both is airflow parallel to curved height contours, also called Gradient Flow If this was all we had, we would not have any wind moving through the pressure systems and no storms would happen so something else must be fueling this or pushing the system to work and its at the ground surface END CLASS Geog 2-27-08 Forces affecting the speed and direction of wind Friction Force is force of opposition which slows air in motion and only operates near the ground Initiated by surface features or the ground itself, and then extends upwards The ground starts to resist the movement of air, as if it is dragging along it Important within 1 mile of surface, this is called Planetary Boundary Layer Above 1 mile the effect is Negligible and is called Free Atmosphere Because friction reduces wind speed, it also reduces the Coriolis strength
You apply this to the layer close to land, the balance goes off, where the Coriolis will go down no longer get the parallel wind flow and goes across the isobars No more balance with PGF Instead, air crosses isobars rather than flowing parallel basically in a nutshell Airflow moves toward low pressure centers, and away from high pressure centers Its this circulation of the low pressure that will drive the weather such as hurricanes, blizzards, and such, this is the key for it to work Cyclones, Anticyclones, Troughs, and Ridges Global air pressure can be divided into many high and low pressure areas Highs, or Anticyclones are clockwise airflow in the Northern Hemisphere, because it is not a storm system since the air is going away from it Air diverges away from a High Center(at the surface) Anticyclones are characterized by: Sinking and warming as it does, it limits weather formation Clear skies and fair weather Lows, or Cyclones are Counter clockwise airflow in Northern Hemisphere The air is Converging into itself or the center of the Low(at the surface) The direction has changed to counter clockwise They are characterized by: Rising air that cools off as it goes up Formation of clouds, and precipitation, where we find rain, snow, and such In the upper atmosphere the air is parallel to each High and Low thanks to the friction at the bottom that drives the storm systems In the upper troposphere if your looking at a cross section of it, Ridges in constant pressure heights correspond to surface anticyclones Troughs in pressure heights correspond to surface cyclones Measuring Wind Wind direction indicates where wind is blowing FROM
Wind Vanes indicate wind direction, the wind will blow and it will pivit on its pedestal and you can measure it where it goes Anemometer records the speed of the wind Aerovane that measures both speed and direction END CLASS Geog 2-29-08 Atmospheric Moisture Over 70% of the planet is covered by water, more than 2/3rds If you take all of the earth's water almost all of it is in the Oceans so they drive a lot of our weather Water exists as Solid, Liquid, and Gas in the Atmosphere, it can shift between these states very easily Water is the only substance to be in all of these states on earth Hydrologic Cycle is what the cycle of water through the atmosphere and the ecosystem Evaporation is how water gets into the atmosphere, it is triggered by input of energy The change of liquid to gas, you do not have to boil water to have this, you can go swimming get out the water beads would just be gone Water vapor increases as surface temperature evaporates More and more water vapor would build up until it reaches a threshold, and at that point it becomes liquid again to let it go which is called Condensation Saturation is the equilibrium between evaporation and condensation, you have the same amount of both Vapor Pressure is the amount of pressure exerted by water vapor molecules, Maximum possible is Saturation Vapor Pressure, a maximum amount of water vapor you can have in a certain area SVP increases exponentially with Temperature, so as the temp goes up the vapor pressure possible goes up So warmer air can have more vapor than cool air, more water in warmer air than cool air basically Measuring Water Vapor Content
Humidity indicates amount of water in the air, it's the gaseous water in the atmosphere or air around you Expressed in several forms, each with advantages and disadvantages, more complicated than what you see on the news though Absolute Humidity is the density of water vapor (g/m3) not very useful Changes as the air volume changes, so it throws off the calculations at times Specific Humidity uses a ratio instead, mass of water vapor per mass of air (g/kg) Comparing the mass of water vapor to the total mass of air, if you mess with the volume or temp, the ratio does not change at all, so you could compare them better Saturation Specific Humidity is the highest amount of specific humidity possible for some given Temp and Pressure Relative Humidity is what everyone knows, most common and is given as a Percentage Amount of water vapor relative to maximum possible, basically when they say a percentage its versus how much could possibly be in it This is dependant on Temperature, if the temp goes up or down, the relative humidity will go down even if the water vapor stays the same This is great for single point reporting When air is Saturated, RH=100% Warm air has more evaporation, so greater possible max vapor content, as the temp goes up you get more evaporation rate so the maximum amount of water vapor does as well In other words, the vapor cap goes up as the temperature does too RH= H2O(now)/H2O(max poss), the fraction will get smaller and RH will go down during the day The temp and amount of RH are in opposite through the day Lowest RH values are mid-to-late afternoon Cannot compare RH values at locations with different temperatures Measuring Humidity Sling Psychrometer has two thermometers, regular one on side and another with something on the end with a cloth wick on it, attached to a handle, dip it in water and whip it around in the air and the water evaporates which will give you the measurement of the air temperature if it were Saturated
Hydrometers which are automated, piece of human or horse hair that responds to humidity with it being tension filled to copy it onto paper Dew Point Temperature(Td) is the temperature at which saturation occurs, it is much easier to measure this and use it as a substitute for humidity, good indicator to how much vapor is in the air If the Dew Point is high, that's an indicator that the Humidity is high The Dew Point can never be higher than the actual air Temperature For saturated air the dew and air temp will equal but never go higher than Air The closer they are, the wetter the air could be Frost point is the same as Dew Point and is below freezing you get frost instead of dew END CLASS Geog 3-03-08 Atmospheric Moisture Continued... How do you get the air to become saturated and have cloud activity Methods of Achieving Saturation 1.Addition of water vapor to the air, with the Temperature being constant(stable), eventually you will have added enough to get 100% relative humidity Fog forms beneath clouds as vapor added from raindrops, some of them evaporate and adds It in that small location with the constant temp 2.Mixing cold air with warm, moist air, you mix them together, so the humid warm mass and add some cold air brings the temp down of the mixture, to where it gets to the dewpoint Fog forms as cold air passes over warm water 3.Cooling air to the dew point is the most common Air Temperature changes occur from either: Direct energy exchange which is Diabatic processes, literally adding or taking heat away from the air mass and interacting it with the masses directly, only important to fog Air cooling over in a valley to where you get valley fog Processes with no net energy exchange which are called Abiabatic processes which are indirect, clouds coming from this more Forms of Condensation(gas>Liquid is Condensation, Gas>Solid is Deposition)
Dew Liquid condensation onto surface objects called Condensation Nuclei Diabatic process, cooling of the air via energy loss on calm, cool, clear nights, very effectively on the clear nights Surface air becomes saturated, then the condensation forms on objects Frost Similar to Dew, but it happens when temperatures are below Freezing, so the condensation that forms is Ice Deposition is what happens instead of condensation(Ice) Frozen Dew Normal dew formation followed by a temperature drop of below freezing Its normal dew temp and all but just after it forms the temperature falls below freezing or Black Ice Fog Is just a cloud really, simply a surface cloud, its just hugging the ground surface so just about elevation on what defines it You can get fog by either Diabatic(common) or Adiabatic 1.Radiation Fog is Diabatic is very common and causes most fog Cooling of warm air to saturation via energy loss, the valley basically cools off from the warm air, which requires a light breeze of about 1-3mph to mix the air near the ground surface Combination of the two forms this blanket of fog over an area, which last just after Sunrise, and it will evaporate due to the surface heating 2.Advection Fog is Diabatic is very common and causes most fog Cooling of the warm air to saturation as it passes over a cool surface, the transfer from the cool ground, your taking heat energy out of it so it cools Frequently develop near boundaries of opposing ocean temperatures so it happens a lot near the coastal waters Like the West Coast with warm pacific air moving over a cold current 3.Upslope Fog is Abiabatic
Warm air is advected over land surfaces that increase in elevation, has a high humidity level already, such as running into a mountain and as it goes up it does this, cooling itself off so it becomes saturated to form the fog No energy exchange, just taking the air mass and lifting it 4.Precipitation Fog is Abiabatic Is evaporation from falling raindrops and it increases water vapor content, no heat exchange , just the rain evaporating and adding more moisture in the air
5.Steam Fog is Abiabatic Is when Mixing of the warm, moist air with the cold air, such as a lake or pond , where cool air passes over a warm body of water so more evaporation of water as it passes with no direct heating change since its moving across basically Midwest is more protected from the fog making triggers