Removing fog at airports

You can contact me at millertrader@gmail.com  
My Facebook page: https://www.facebook.com/Swayseeker
Two methods that could be used to heat foggy air at airports. THE MOST IMPORTANT ASPECT OF THESE METHODS IS: To heat air, air must be brought into contact with warm surfaces. When this happens (as in a solar air heater) air can be heated by 10 deg C very quickly. The air should have intimate contact with large surface areas. This can happen when air is moved through gauze, for example.
Method 1: Solar thermal collector with a large surface area that air will come in contact with in passing through the system. The evacuated tube collector supplies significantly more energy under cloudiness than the flat plate collector.  So use evacuated tube collectors to heat water in an apparatus that has a large surface area, for air passing through it to come into contact with. The water will retain heat and air can be heated throughout the night. The wind could blow foggy air through this hot water system and onto the airport. These collectors do not loose much by radiation (as black surfaces will). You can heat a huge volume of air with warm water. Water has a volumetric heat capacity of about 4200 kJ per cubic metre per 1 deg C rise in temperature and air has a volumetric heat capacity of about 1.2 kJ per cubic metre per 1 deg C rise in temperature.

Method 2: What about placing a gauze fence round foggy airports (but not in places that will affect air traffic)? Hopefully fog particles would collect on the gauze as foggy air moves through it. 
Another variation:  It appears that London uses about 35 GWh of electricity every hour (power is 35 GW). Wikipedia says that in fog there is typically 50 000 kg of water per cubic kilometre of fog (liquid water content of fog is typically 0.05 g per cubic metre). 
To vaporize this 50 000 kg of water takes about 50 000x2257 kJ=112 850 000 kJ = 112 850 000/3600 kWh = 31347 kWh. 
Say it would take 35000 kWh to evaporate the fog and this is done in an hour. 
Then this would use (35000000 Wh)/(35000000000 Wh) = 1/1000 of the energy used by the city of London in an hour.
 If one had gauze shaped heaters between gauze fences around Heathrow, one could clear fog like this (air has to come into contact with large surface areas to heat up efficiently and gauze would provide this as air blows through it).
If you are going to have to heat the air as well as vaporise the liquid water content, that will require some more energy. You need roughly 1.2 kJ of energy to heat one cubic metre of air by 1 deg C (1.2 includes water vapour).
The question remains: If the air is saturated at, say, 2 deg C and there is 0.05 g of water content per cubic metre, how much would a cubic metre of air need to be heated before it could absorb the 0.05 g?
Well if the temperature is 2 deg C then the air will hold 5.56 g of water vapour per cubic metre and if the temperature is 2.13 deg C, then the air will hold 5.61 g of water vapour (5.56+0.05=5.61). So it would have to be heated only 0.13 deg C. 
For one cubic kilometre of air with 0.05 g of water per cubic metre the following holds:The energy just for vaporization is approximately 31300 kWh and if you include heating the air 0.13 deg C, the energy required will be about 75000 kWh. 
The graph below shows the number of Megawatt-hours needed to vaporize one cubic kilometre of fog in saturated air for different liquid water contents in the fog. The energy needed is of the form 
(V)(LWC)(2257) + (V)(Tinc)(1.2), where V=volume of air, Tinc=temperature increase of the air needed so that it can take up the extra vapour generated by vaporisation and LWC is the liquid water content. Since, for the small range of temperature increases needed, Tinc is approximately proportional to LWC, the form becomes
V(2257xLWC + 1.2xTinc) = constant volumex(2257xLWC + 1.2xconstantxLWC) = 
constantx(LWC)(2257 + constant) = LWCxconstant. Therefore Energy needed=LWC times constant and so the graph is linear.

Note on calculations

The calculations are made easier if you have a table of saturation pressures for water vapour and perform linear interpolation to get in between values. The partial vapour pressure is given by PsatxRH, where RH is the relative humidity and Psat is the saturation vapour pressure for water vapour. If you heat a parcel of air, the surrounding air remains at more or less the same pressure (unless there are other factors). On heating the parcel the mole ratio of all components in the parcel remains the same, the total pressure P remains the same, so the pressure of all components remains the same (including the partial pressure of the water vapour). Another way to look at is to say that the partial pressure of any component is its mole ratio multiplied by the total pressure.

Cooling Earth Using Clouds

http://www.bostonglobe.com/news/nation/2017/01/18/for-third-straight-time-earth-sets-hottest-year-record/A3TCBHxy4pXgAgBcrSt2uI/story.html#comments says, "For third straight time, Earth sets hottest year record"
One way to get rid of heat is to enhance formation of low level clouds in warm climate zones. To make clouds you need at least these two aspects: 
1) Air with moisture in and the more the better. 
2) A means to make this air rise.
If you just make air moist, but it is cold air relative to the surrounding air, it will not rise and form clouds. To heat air, air must come into contact with warm surfaces. So here is an idea: Put black netting in the sea where there is spray from waves. The black netting will absorb solar energy and when air passes through the netting the hot netting will heat the air and with the right construction you will have hot moist air rising to form low level clouds.

Air Cleaner

You can email me at millertrader@gmail.com
The blog owner T E Miller (Swayseeker), known as Eddie will not accept liability or responsibility for any problems arising from the use of this blog and its calculations. I try to provide good calculations and analysis, but cannot guarantee that there are no mistakes. Here is a site that tells you how to build your own solar air heater:
 http://www.builditsolar.com/Experimental/PopCanVsScreen/PopCanVsScreen.htm
My Facebook page:
https://www.facebook.com/Swayseeker
Have been doing the following calculations: Los Angeles (latitude 34.05 deg N) has a maximum (always facing the sun) 11.2 kWh of solar energy per square metre on a good day on 1 July. On a horizontal surface it has 8.8 kWh of solar energy per sq metre per day (assuming a sunny day). It takes about 1.2 kJ of solar energy to heat 1 cubic metre of air 1 deg C (volumetric heat capacity of air is about 1.2 kJ per cubic metre per 1 deg C temperature rise - depends on pressure, etc). I have done this for the first day of each month and give a graph of how much air could be heated 5 deg C by one sq metre of horizontal surface by solar energy in one day. These are theoretical values and solar air heaters are certainly not 100% efficient, but the volume is enormous. I have been promoting this idea in Africa, China, US, India, via the Internet, etc, and am hoping it will have a good effect on the world.
If people generally knew the following facts about air the world might have been been different: 
Air is very little affected by radiation (sun shining through it, radiation from fires, heaters and so on). But air is heated by coming into contact with hot surfaces (casing of heaters, hot tar and so on) and the hot ground heats air and causes upward movement of this less dense air on a grand scale. The ground only has fairly superficial contact with air. On the other hand a solar air heater (a sort of greenhouse with a solar absorber to heat up in the sun and large hot surfaces to make contact with the air) is a different matter - it will heat air efficiently and a solar air heater on each rooftop could get warm air rising and out of polluted cities and also cause more rain to fall when vapour condenses in the cooler regions. 
People make their own solar air heaters and I believe India and China, with their pollution, could get polluted air moving out of their cities with them. It takes about 1.2 kilojoules of solar energy to heat 1 cubic metre of air by 1 degree C and every second 0.8 kilojoules of solar energy can easily fall on every square metre of some locations at noon.
The graph shows the number of cubic metres of air in a day that can theoretically be heated 5 deg C, using solar energy falling on a square metre of horizontal surface in Los Angeles. The x-axis shows 1 July, 1 Aug, etc.
Wikipedia says that rain dust (alkaline rainfall deposits, caused by particles from Saharan dust, etc) could help combat acid rain. 
An idea of mine: If one had huge solar air heaters and put Saharan dust in them, the hot air could carry the alkaline dust into sulfur dioxide-polluted air and neutralize acidity.
Wikipedia also says," Acid rain does not directly affect human health. The acid in the rainwater is too dilute to have direct adverse effects. However, the particulates responsible for acid rain (sulfur dioxide and nitrogen oxides) do have an adverse effect. Increased amounts of fine particulate matter in the air do contribute to heart and lung problems including asthma and bronchitis." 
Therefore the rain itself is good, because sulfur oxides, etc, are washed out, improving health prospects (reducing asthma, etc). Rain also washes out ozone, so if one could neutralize rain and get more rain, that would generally be good.
Graph below: The number of cubic metres of air in a day that can theoretically be heated 5 deg C, using solar energy falling on a square metre of horizontal surface in Los Angeles. The x-axis shows 1 July, 1 Aug, etc.

Graphs

The first two graphs are for Cape Town, South Africa (lat 33.9 deg S). These two graphs show 
1) the solar energy falling per day on one square metre, maximum (always facing the sun - upper graph) and for a horizontal surface (lower graph). Solar energy in kWh 

2) the theoretical volume of air per day (cubic metres) that could be heated 5 deg C by a solar air heater of dimensions 1m by 1m always facing the sun (upper graph) and on a horizontal surface (lower graph).

The graph below is for Delhi, India. Lat 28.4 deg N. The graph shows the theoretical volume of air per day (cubic metres) that could be heated 5 deg C by a solar air heater of dimensions 1m by 1m on a horizontal surface. The x-axis shows 1 July, 1 Aug, etc. So on 1 July, in a day, the 1m by 1m solar heater on a horizontal surface in Delhi could heat 5241 cubic metres of air by 5 deg C.

Looking at temperatures and relative humidities for Delhi (India) and taking a low rainfall month of November, with an average RH of 55% and daily average temperature of 20.8 deg C, the graph uses figures as follows: The surrounding air temperature is 20.8 deg C and air is heated to the temperature shown on the T-axis (parcel of heated hotter air is at temperature T deg C), using solar air heaters. The line with the steeper slope shows the height to which the parcel will rise, using a dry adiabatic lapse rate of 9.8 deg per 1000 m rise and an environmental lapse rate of 6.5 deg C every 1000 m (fairly standard sort of figures). The line with less steep slope shows how high the heated air parcel must rise before clouds start to form (uses Espy's equation). When the parcel is heated to 28 deg C it will rise further than it needs to before clouds start to form. Before about 28 deg C it will not rise far enough for clouds to form. Actual lapse rates for Delhi would have to be taken into consideration for accurate conclusions. You can also work this out yourselves.I will tell you the near ground dew point for the parcel - it is 11.43 deg C. Espy's equation says, for clouds to form, the air parcel must rise 125(T-Tdew) where T is the near ground level temperature of the parcel and Tdew is the near ground level dew point of the parcel. As for how high it can rise, after it has risen 1 km, starting at T=27 deg C, say, the temperature of the parcel is 27-9.8 deg and the surrounding air is at 20.8-6.5 deg, etc. When the parcel and surrounding air are at the same temperature the parcel will stop rising (this is modified a bit because water vapour is less dense than air)

Rain for deserts near cold seas

Deserts near cold sea, such as the Namib Desert, appear to me to be ideal candidates for rain making. With the Namib there is a good strong sea breeze bringing in air from the sea as land warms up, and this breeze starts fairly early in the morning. Sometimes mists form and when the sun heats these mists up the water droplets evaporate, thus cooling the air. The cool air from the sea and the cooling by evaporation cause a stable situation - that is the air does not rise because of cold air beneath warmer air, or same temperature air. If the air were warmer than the surrounding air, it would rise. Looking at the air around Walvis Bay, one may note that relative humidities are high, but lack of rising air, that would cool on ascent to form rain, causes dry conditions. Because air requires contact with warm surfaces to heat up and only makes fairly superficial contact with hot ground, there is no efficient heating of the air. But if one could use huge solar air heaters in the Namib desert (there is plenty of space) one would have air rising and hopefully causing rain. Using average sorts of figures from Wikipedia for Walvis: Jan T=17.5 deg C, RH= 80%. Now if the air is cooler than surroundings, it will not rise. Say the surrounding air is at 17.5 deg C. Now heat air up to 22.5 deg C, using huge solar air heaters, and we find that the air could rise 1515 m and it only needs to rise 1060 m before clouds form (used general sort of lapse rates and Espy's equation). The high relative humidity makes for very good rain prospects. These are general figures and actual lapse rates would have to be determined, but things look good. It might be interesting to note that whilst air does not significantly heat up with solar radiation (it has to be in contact with a hot surface), clouds do heat up with sunlight. In fact clouds absorb all thermal infrared and at Earth's surface roughly 50% of "sunlight" is infrared radiation. Mist is a sort of low level cloud. So clouds or mist will heat up, water droplets will evaporate, cooling things, and so on.
See also  
 http://www.homepages.ed.ac.uk/v1ewaveg/rain%20making/shs%20rain%20paper%20Feb.pdf on why Saudi Arabia is dry.
I must point out that when temperatures are low the air cannot hold much water vapour. The graph below shows the maximum number of metric tons 1 cubic kilometre of air can hold at different temperatures (number of metric tons when the air is saturated).

Cooling Earth using solar air heaters.

Ice reflects solar energy fairly well, keeping Earth cool. When ice melts, dark solar energy-absorbing surfaces sometime take the place of the ice surfaces. 

https://nsidc.org/cryosphere/seaice/processes/albedo.html says: Sea ice has a much higher albedo compared to other earth surfaces, such as the surrounding ocean. A typical ocean albedo is approximately 0.06, while bare sea ice varies from approximately 0.5 to 0.7. This means that the ocean reflects only 6 percent of the incoming solar radiation and absorbs the rest, while sea ice reflects 50 to 70 percent of the incoming energy. The sea ice absorbs less solar energy and keeps the surface cooler.
The whole process of rain formation takes heat from the lower levels where evaporation cools things and takes it higher up where clouds form from condensation. This condensation releases heat again, so that the heat has been transferred from lower to higher regions. The clouds then generally reflect solar energy, cooling Earth, but high level cold clouds might actually warm Earth.. Low level clouds are especially associated with cooling of Earth (for one reason, they are warmer and emit more energy by radiation than high level clouds). We could create something similar in the following manner. When ice melts, shade the area with huge solar air heaters. The solar air heaters prevent ground from heating up, because of the shading and absorbing of the solar energy, and they are cooled to some extent by the air passing through them. This hot air rises, allowing for the possible formation of low level clouds, which could cool Earth by reflection and radiating to space. So this process again takes energy from lower regions to higher regions as with rain formation. But generally, one could put solar air heaters on the roofs of buildings in hot climate regions. This would cool buildings and enhance cloud and rain formation. Low level clouds in warm climate zones are especially associated with cooling of Earth.

Pieces of art to bring rain

See how to build a solar air heater at
http://www.builditsolar.com/Experimental/PopCanVsScreen/PopCanVsScreen.htm
Your piece of art can be built in the shape of a solar air heater and the dark painting inside can absorb solar energy.
To heat up air well requires hot surfaces for the air to come into contact with. Black objects absorb solar energy well and so if you have black gauze or a black wire mesh that has a large surface area that air can come into contact with and the surface is hot, you will heat the air well. When a black object heats up it radiates heat and this heat will generally be lost to the surroundings. The glass (or other glazing) on the solar air heater keeps heat in, but even without it you can heat up the air with a piece of art made of black material, such as a wire mesh, that stands in the sun.
For those interested: The book Heat Transfer by JP Holman tells us that ordinary window glass transmits radiation up to about 2.5 microns (the energy goes through the glass if its wavelength is less than about 2.5 microns).
Now the question is: How much solar energy has wavelength of less than 2.5 microns?
The answer is 'about 97% of solar energy.' So about 97% of the solar energy passes through the glass and is absorbed by the black surface of the solar air heater (assuming a perfect absorber).
Now how much of this energy escapes? Well if the absorber heats up to 50 deg C, then radiation from it that is above 2.5 microns will not escape. The answer is that far less than 1% of this radiation can escape through the glass. The reason is that the energy of wavelengths greater than 2.5 microns radiated from a black body at 50 deg C is more than 99% of the total.
If there is no glass and your piece of art is at 20 deg C, it will radiate 419 W per square metre. If your piece of art is at 60 deg C it will radiate nearly 700 W per square metre. You do not want heat loss by radiation. Instead you want the heat to heat the air so there can be convection - so it is better to have your dark piece of art in the solar air heater. "Cool roofs" can reduce rainfall and "dark art in greenhouses" can increase rain - see https://www.scientificamerican.com/article/cool-roofs-may-have-side-effects-on-regional-rainfall/

Air land temperatures and sea temperatures and rain

Looking at sea temperatures near Jeddah, I see they are very high (about 30 deg C). So why is there not rain? Literature says that it is because the expanse of the Red Sea is too small for moisture to have been picked up by air, but it also could partly be because the waves are fairly low and generally calm conditions prevail, so there is not much evaporation from spray. I have noticed that when the sea temperature is higher than the land temperature there is sometimes a dramatic increase in rainfall - see graph. The graph shows the sea and land temperatures and (although it in the wrong units of mm) shows the rainfall in mm (bottom curve).The graph starts out with sea temperature being greater than land temperature (and rainfall is relatively high). Later the land temperature is higher than the sea temperature (and rainfall is close to zero). Later the sea temperature becomes higher than the land temperature and the rainfall increases dramatically. Of course if sea temperatures are lower than land temperatures, the air heats up on going to land areas and relative humidity decreases, making rain less likely. 
For Los Angeles, etc, it would be good to investigate this: If one had shallow pools of seawater with dark bottoms to absorb solar radiation one could increase water temperatures to more than land temperatures. The second graph is for Cape Town. The upper two curves show sea and land temperatures. The lowest curve (generally) shows the rainfall in mm. The land temperature starts out being higher than the sea temperature and rainfall is low. Then the land temperature is less than the sea temperature and rainfall is high, etc. Third graph is for Los Angeles Basin. Usually high land air temperatures bring in air from the sea. But if land is hotter than sea air then the relative humidity of the sea air will decrease on being heated by the land. Here is a graph for Los Angeles basin. It uses mean sea temperatures and land air temperatures. The rainfall is in inches and the temps are in deg C (not really right to do T and rainfall on one axis, but still), The sea is hotter than land air T up to month 4. Then sea temp is cooler than land air temp up to month 9, then sea is warmer for 10, 11 and 12. Do not know why it works so dramatically in some cases, but it seems generally higher sea temps than land air temps mean much more rain.
GRAPHS:
Jeddah graph below: The graph shows the sea and land temperatures and (although it in the wrong units of mm) shows the rainfall in mm (bottom curve).The graph starts out with sea temperature being greater than land temperature (and rainfall is relatively high). Later the land temperature is higher than the sea temperature (and rainfall is close to zero). Later the sea temperature becomes higher than the land temperature and the rainfall increases dramatically. 

The second graph (below) is for Cape Town. The upper two curves show sea and land temperatures. The lowest curve (generally) shows the rainfall in mm. The land temperature starts out being higher than the sea temperature and rainfall is low. Then the land temperature is less than the sea temperature and rainfall is high, etc. 

Here is a graph for Los Angeles basin (below). It uses mean sea temperatures and land air temperatures. The rainfall is in inches and the temps are in deg C (not really right to do T and rainfall on one axis, but still), The sea is hotter than land air T up to month 4. Then sea temp is cooler than land air temp up to month 10, then sea is warmer after 10, 11 and 12. I have an idea of how it might work - hotter humid air blowing onto land would enhance rain chances.

Graphs by me (blog owner)

Melting snow faster

There may be snow in cold months. The Japanese use biochar on the snow to melt it. The biochar makes the snow darker and it can therefore absorb solar energy and melt days sooner than without the biochar. This could help animals trapped in the snow. One could also use ordinary dark earth dust to decrease albedo and get snow to melt earlier. Snow reflects sunlight during the day and keeps cool during the day in this manner. Snow has a high emissivity (a measure of its closeness to a blackbody in thermal properties) and gets very cold at night (releases its heat to surroundings and space).
By my calculations, roughly 1/3 of the energy emitted on a clear night by snow can radiate out to space through the 8 to 14 micron "atmospheric window" (the fraction of the total energy radiated by the snow that has wavelength of between 8 and 14 microns is about 1/3 - I used Planck's law and integrated). If one plowed the snow the albedo would decrease (more solar energy would be absorbed).
Even by making furrows in the snow one decreases the albedo of the snow (increases absorptivity for solar energy). This is because sunlight entering into a furrow can get reflected back and forth and eventually be absorbed by the sides. This is well known in agriculture where plowing decreases albedo.
http://costsnow.fmi.fi/workshops/24%20-%2025.08.2016,%20Helsinki/presentations/COST_2016_Manninen.pdf
says, " Surface roughness reduces the albedo of the surface due to
multiple reflection and in some cases by trapping the incoming
radiation completely. "

Bringing rain with seawater spray pumps

My guess is that with global warming there are going to be more droughts. The land heats up faster than the sea and if the land is warmer than the sea then air coming from the sea heats up and its relative humidity falls. Example: Air comes off the sea with relative humidity of 70% and temperature at 20 deg C and heats up to 25 deg C over land. The relative humidity drops to 52% and low relative humidity is associated with low rainfall. One needs to get air from the sea flowing over land as it brings moisture. Cold air tends to be denser and so cold air from the sea has more of a chance of flowing onto land. So here is the idea: 1) Make air over the sea fairly cold and very moist so it will tend to move in over land and bring moisture. 2) Over land, heat this air up so it will rise and vapour will condense, making rain.
You can do all this as follows: Use spray pumps operated by waves in the sea to form a mist that is evaporated in sunlight, causing air to be very moist and also cool (because of evaporation). Now use a solar air heater on every rooftop to heat this air when it comes onto land, so it will rise causing rain. Every two seconds one can have 1.2 kJ of solar energy falling on every square metre in many locations and this 1.2 kJ can heat one cubic metre of air 1 deg C. You could move massive volumes of moist air up like this. Another advantage is that low level clouds (and I would think mist) is associated with cooling of Earth. So you should have cooler Earth and more rain.
EXAMPLE: Say you have a 2km stretch of coast with the spray pumps (operated with wave motion). Let the air temperature over this stretch be 18 deg C with a relative humidity of 95%. Suppose the 2 km wide air parcel from the sea blows onto land. If you heat this 18 deg parcel up to 26 deg C with solar air heaters the relative humidity of the parcel falls to 58.3%. Suppose the surrounding air over the rest of the land area (surrounding the 2 km wide parcel) is at 22 deg C. Then the parcel can rise 1212 m (using a fairly standard dry adiabatic lapse rate). Using Espy's equation it only has to rise 1102 m for clouds to form, so it could rain.