Thursday, February 15, 2018

Growing plants with moist air.

http://onlinelibrary.wiley.com/doi/10.1111/nph.12332/full says, "Foliar water uptake has now been identified in at least 70 species representing 34 plant families in seven different ecosystems.." Since leaves can take in water, I am more confident in my system shown.
Also see
https://s3.amazonaws.com/academia.edu.documents/46639964/Foliar_uptake_of_fog_water_and_transport20160620-2196-w9qw2v.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1518800411&Signature=zxQ0xODcmRkJFCEOuO7cAC3q5I8%3D&response-content-disposition=inline%3B%20filename%3DFoliar_uptake_of_fog_water_and_transport.pdf




Wednesday, January 31, 2018

If coastal cities need more rain...

Can also visit https://www.facebook.com/groups/RainSeaVsAirT/
If coastal cities need more rain they could try heating water in greenhouses to add water vapour to the air. Here is a graph (below) using the average of six evaporation equations. You can get 20 or more times the evaporation by increasing water temperatures. 
Studies on evaporation from windy sea conditions show more rain with more evaporation of spray. 
In many cities you can evaporate over 100 000 litres every day with a 100m by 100m greenhouse and add it to the atmosphere, humidifying it and increasing chances of rain. 1kWh can evaporate about 1.5 litres and many cities can easily get about 8 kWh of solar energy on every horizontal square metre in a day.
When the air is hotter than the sea the water cools the air immediately above it and the relative humidity (RH) of this air increases and water can even condense out of the air so that "negative evaporation" occurs. If the seawater is hotter than the air the evaporation increases substantially, because the water heats the air above it, the RH of the air decreases, and the hotter air can take up moisture faster. This principle of high evaporation rate with water being hotter than air can be used to increase the humidity of the air and increase chances of rainfall. Therefore, heating seawater in greenhouses and so on can be very effective. Evaporation equations do not all give the same rate of evaporation and I use an average from six evaporation equations. Example: Wind speed=10 km/h, Air temperature above water is 32 deg C, temperature of water is 20 deg C, pressure = 1 atm. The average of the six equations is -1 mm per day so water condenses out and we could get a mist immediately above the water. Now we keep everything the same except we heat the water in a greenhouse to 37 deg C. The rate of evaporation (given by the average result of the 6 equations) is now 28 mm per day and we can increase the humidity of the air substantially, increasing chances of rain. Calculations show, if the area of greenhouses were one square kilometre, one could evaporate over 10 million litres a day in sunny areas.

Air tends to move back and forth with sea breezes and land breezes, so the humidity could accumulate every day from the greenhouse evaporation.
 BELOW IS A GRAPH SHOWING HOW EVAPORATION FROM THE SEA CAN BE INCREASED BY HEATING SEAWATER. INCREASED EVAPORATION MEANS INCREASED CHANCES OF RAIN:

Here is another graph (below) where air temperature is increased by only 1 deg C. So, as the air heats more relative to the sea, so the evaporation from the sea decreases. Decreased evaporation means decreased chances of rain.




Tuesday, January 9, 2018

Rain by humidification above the ocean.

Above shark nets, about 20 m above the ocean, have thick pipes with thousands of holes in that water streams out. Water can be pumped into the pipes using wind turbines. If the wind is blowing at 10 km per hour and the pipes are 1 km long, then the volume of air humidified in an hour is 1 km x 10 km x 0.02 km = 0.2 cubic kilometres.
In a day this is 4.8 cubic km of air. Nights are warmer with more humid air and I am going to use this as an example: RH=65% and Tair=20 deg C before humidification. RH=80% and Tair=22 deg C after humidification (the air will be blowing back and forth with land and sea breezes). Before humidification the water vapour content of the air is 11.2 grams/cubic metre and after humidification it is 15.5 grams/cubic metre. This is an increase of 38%. This relies on the fact that more humid air will keep in heat from the ocean when air is colder than the ocean. See 
http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf

The heat from the ocean will help humidify. Air is usually colder than the ocean at night. During the day any mist will absorb solar energy and heat up and evaporation will occur. 

Thursday, January 4, 2018

Easy wet bulb temperature determination

People have been searching on the Internet for an easy way to calculate wet bulb temperature (and so have I). Experts give various long calculations and I wanted an accurate value easily calculated. I had a lot of trouble searching on various forums and eventually found a site that uses an equation that can be solved numerically that gives me an accurate answer, but the formula did not work unless I changed the P units from hectopascals to atmospheres. So instead of 1000 hPa I use 1000/1013.25. I solve numerically using a computer program I wrote to get Tw (wet bulb temperature). The formula is at
and I notice that P is included in one equation and left out in the next equation. However if you use atm it should work well with P included in both. The formula gives RH, but you can find Tw numerically. Say you are trying to find the wet bulb temperature for Td=45 deg C and RH=67%. Then let RHS=formula given and start with Tw=45 (represents RH=100%) and decrease Tw iteratively until RHS<=67. Find Tw at that point.

You can use a wet bulb calculator to check how accurate the above formula is (pretty good).
Your inputs into the program will be Td, RH and P. (P in atm). (Td is dry bulb T and Tw is wet bulb T.)

Code in Pascal:
Tw:=Td;
repeat
Tw:=Tw-0.001;
A:=611.2*exp(17.502*Tw/(240.97+Tw))-66.8745*(1+0.00115*Tw)*P*(Td-Tw);
B:=6.112*exp(17.502*Td/(240.97+Td));
RHS:=A/B;
until (RHS<=rh);

{Now print Tw}

Monday, December 25, 2017

Increasing sea surface temperatures and decreasing deeper ocean warming

As I expected there is a correlation between wind and rainfall. More wind then more rainfall. See
http://journals.ametsoc.org/doi/full/10.1175/JCLI3519.1
I propose that my idea of floating spray pumps, to create a spray mist on the sea, will have a similar effect as more wind. The spray mist will keep in heat radiated by the sea when sea is warmer than air and will generally tend to increase sea surface temperatures on clear nights. This will increase humidity and the chances of rain. Fortunately, during sunny days, the mist will prevent solar radiation from entering the sea and warming deeper levels of ocean.
Generally the mist will increase evaporation and enhance chances of rain. It will absorb solar energy during the day and heat up, again increasing chances of rain.
See also https://www.facebook.com/groups/RainSeaVsAirT/

Wednesday, December 13, 2017

Power coastal cities and cool oceans

Here is a way to provide power to cities on the coast and to cool the oceans to combat global warming. Usually the sea is warmer than the air at night. So at night use solar updraft towers, but pump heat, using a heat pump, from the sea to seawater in the solar updraft towers to heat and humidify the air in the solar updraft towers at night. Say the sea temperature was at Tsea=15 deg C and the seawater and air temperature in the solar updraft tower was 18 deg C after warming. Suppose the outside air temperature was 10 deg C. Then the heat pump would be very efficient and the air temperature difference between inside and outside the solar updraft tower would be in a nice range to start with. The heat pump could be powered by wind energy. During the day use the standard greenhouse at the base of the solar updraft tower to heat seawater in the tower to heat and humidify the air. The humid air will increase chances of rain and the clouds will reflect solar energy to space, cooling Earth. Have had a look at Greenland. It seems very suitable for this method. Ocean near the Arctic region could be cooled using this method. See
See
https://en.wikipedia.org/wiki/Solar_updraft_tower
See the the Carnot heat pump formula.at
 http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatpump.html
TH=291.15 kelvins. TL=288.15 kelvins

 COP=291.15/(291.15-288.15)=291.15/3 = 97.1

Saturday, December 9, 2017

Long greenhouse method to bring rain.

One could have a greenhouse to evaporate seawater near the sea and have a long greenhouse (or "greenhouse pipe") running upwards to where the dam areas are. Because the air will be kept warm during the day in the greenhouse pipe and moist air is less dense than drier air, the air will rush up through the greenhouse pipe and heat the dry air region and increase relative humidity there. Now it might seem that this would have little effect, but this system could be kept running day and night throughout the year. From my "stack effect" calculations quite a few cubic kilometres of warm moist air could be delivered every week to higher regions. The slight increase in relative humidity could just tip the balance enough to help it rain significantly more.
 More humid air is less dense than drier air, enabling it to rise when it is at the same temperature as  surrounding drier air: 
Example: 
1) At sea level the air pressure is 101.325 kPa. The air has a temperature of 30 deg C and the relative humidity (RH) is 95%. Then the density of the air is 1147 g per cubic metre.
2)  At sea level the air pressure is 101.325 kPa. The air has a temperature of 32 deg C and the relative humidity (RH) is 50%. Then the density of the air is 1147 g per cubic metre.
So humidifying the 30 deg C air by increasing RH from 50% to 95% has about the same affect on air density as heating the RH=50% and T=30 deg C air to T=32 deg C. 
Note: RH drops slightly on heating from 30 to 32 deg C, but it does not affect calculations much.

Tuesday, November 28, 2017

Rain when sea temperatures are greater than minimum air temperatures

Cape Town is one city where the minimum (night) temperatures are generally colder than the sea temperatures (see photo). This means that if you can create a spray over the sea with floating spray pumps at night you will have this situation: The warmer sea will have a spray "mist cloud" of low elevation over the sea. This cloud will capture radiation from the sea (greenhouse effect, with sea hotter than air above) and warm up, because clouds are good absorbers of infrared radiation. So at night the air will become warm and humidified. During the next day the land will heat up and a sea breeze will develop (at about midday). The warm moist air will blow onto land and the hot land will heat this moist air from below, increasing chances of rain. I am trying to get other countries interested in this concept, so perhaps South Africa will be able to observe what happens in other countries. 
See http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf to gain insight to the radiation effect from the sea.
Many cities have this property.
See photo for Cape Town below.

Note that sea spray is natural and occurs in massive amounts when wind blows over the sea.

Tuesday, November 14, 2017

Water from seawater

Here is a method to make clean water from the sea: Geothermal heat pumps use ground as a heat sink. The air is cooled above and the heat pumped to the ground. 
To make clean water have a huge steel cylinder above the sea. Cool the steel using a heat pump that takes heat from the steel cylinder and puts the heat into the water. The heated water will evaporate into the steel cylinder and so the process will continue with water vapour condensing on the cool steel where it is collected. Solar energy could be also be used to heat the water below the steel cylinder. See https://en.wikipedia.org/wiki/Direct_exchange_geothermal_heat_pump
If a lot of solar energy were used to heat the water below the steel cylinder the heated water could also add more moisture to the surrounding air to slightly increase chances of rain.

Heat pumps are very efficient - you can get about 4 units of cooling with 1 unit of power. Wind, wave energy and batteries could be used to power the heat pump.
 If the air temperature inside the cylinder were 100 deg C and the cylinder walls were at a temperature of 80 deg C, the cylinder would cool by radiating heat and by being in contact with cooler air on the outside. This would enable increased condensation of water vapour on the cylinder walls.
Imagine a small scale system like this. If you use 1 kW of power to cool the cylinder you could get about 4 kW of cooling. So say you run it for an hour. Then you get 4kWh of cooling. It takes roughly 0.7 kWh to condense out a litre of water, so you should get about 4/0.7=5.7 litres an hour using power of 1 kW (assuming a coefficient of performance (COP) of 4). Note that as the water of the water heat sink evaporates it cools, making the system more efficient.

This whole system could be used in reverse to cool the sea and heat air in the cylinder. If the air were heated and seawater were sprayed in at the bottom, one could also create hot humid air and release it to the surroundings to increase chances of rain. One would need a huge cylinder and a lot of power to have a marked effect. With wind, wave and solar power it could work. Fortunately heat pumps do a lot of cooling or heating with a small amount of power (COP=4 or so).

COOLING THE SEA: If you can create cloud to shade the sea you can cool the sea down. Here is a method that will directly cool the sea and will cause convection above the sea by heating air above the sea. This will cause more clouds and rain. Rain cools the sea surface because it comes from cool regions higher up. Method: Use a heat pump to take water from the sea (sea is the fridge) and place it in some air cooled metal heat sink above the sea (fins of the fridge). The fins will warm the air causing upwards convection of warm air causing clouds and rain. Wind power could be used to power this heat pump. Heat pumps are very efficient and you can get about 4 units of cooling for 1 unit of input power - see https://en.wikipedia.org/wiki/Geothermal_heat_pump
Another desalination method I came across: https://atmocean.com

Monday, November 6, 2017

Green parties could play the blues

Green parties could play the blues to solve global warming: In some places daylight persists much longer than at other places and near the Arctic circle one has very long days in summer and phytoplankton must have adjusted to this. Phytoplankton remove huge quantities of carbon dioxide from the atmosphere by using green and blue light to flourish. The phytoplankton is harmed by ultraviolet light and so here I propose a global warming solution:
At night, when there is virtually no ultraviolet light, irradiate the ocean with green and blue light, that penetrates the night, reducing CO2 as revellers delight. The ocean could be irradiated from green and blues lights on tall poles on land while people dance on the sand. This would create an attraction, inviting to the rich tourist faction.
Would flashing green and blue lights harm the phytoplankton though? I am hoping the concept can be implemented on coastlines extensively.
See https://www.whoi.edu/oceanus/feature/shedding-light-on-light-in-the-ocean

Tuesday, October 31, 2017

Rain producing ideas.

1) Use wind energy to heat air at night for rain: When temperature drops at night the relative humidity increases. Just look at Internet weather reports and you will see that this is a regular occurrence. For dry areas, why not have greenhouses with rocks in to absorb solar energy during the day and use electrical energy from wind power (wind turbine, etc) at night to heat the air and rocks in the greenhouse so that high relative humidity air can be heated and rise to form convectional rain? Drought is costing billions and it would be worth spending millions on enhancing chances of rain. One would need some method of letting the hot air out of the greenhouse at night. It does not take much heat energy to heat a lot of air.
2) From the Internet I read that the sea temperatures at Los Angeles in Jan and Feb are about 14.5 deg C. The average minimum air temperature for Los Angeles is about 9.2 deg C. At night, if one had a pipe inlet with a big collection area just above the sea the air temperature of the air coming into the pipe would be about 5 deg C warmer than the air temperature above the city. This means natural upwards convection of relatively warm moist sea air could occur in the pipe. If the pipe were coated with a low emissivity surface (shiny aluminium, etc) it would retain heat. It seems quite possible that convectional rain could occur with enough big pipes leading from the sea to over the city.
This idea might not work all of the time because air pressures over the sea and land might be different, but here are some points:. 1) The air just over the sea will be warmer and therefore less dense 2) The air from just over the sea will be moist and moist air is less dense. 3) For some periods it will work.
This calculation would be suitable for Cape Town: I use the Engineering Toolbox stack formula, with the following: A 20 m radius pipe (huge) Inside T of 14 deg C. Outside T of 8 deg C. This gives a flow rate of more than 1 cubic kilometre of air per 24 hour day, so the amount will be less, but it is a large volume of air.

3) If you look at the pdf called Pilot Exam Notes Meteorology on the internet you will see, on page 10, a discussion of turbulence clouds. Turbulence clouds can form when rough terrain funnels air upwards. As the air rises it cools and clouds can form. My system uses biochar to absorb solar energy and heat air and channels the air upwards. With even light wind and some sun rain could result.
4) The wind speed is low just over the ocean (as it is just above the ground). There is therefore a fairly stagnant layer with very high relative humidity just above the sea. If one used thousands of floating devices as shown below one could increase moisture in the air so that air blowing to land would produce more rain. Water has a very high emissivity (about 0.95), so the greenhouse plastic will keep in a lot of radiation from the sea surface. For high sea surface temperatures of 30 deg C or so, the greenhouse will keep in about 450 W per square metre of infrared radiation from the sea surface.

The light portion of the solar energy passing through the greenhouse plastic will be absorbed by the black sheet instead of it penetrating deep into the ocean. The infrared portion of solar energy entering the greenhouse will be absorbed within the uppermost few centimetres of the sea surface. Any infrared radiation from the sea that is reflected back to the sea by the greenhouse plastic will also be absorbed in the upper few centimetres of the sea. The result will almost certainly be a heating of the sea surface under the greenhouse plastic, enhancing evaporation and high humidity. About 53% of solar energy is light energy, so the black sheet will prevent a lot of energy from escaping down to deeper levels and will concentrate it near the surface.




Wednesday, September 27, 2017

Creating rain using convergence of sea breezes

Some people will know more than me about sea breezes around Cape Town than I do, but Florida and other narrow land masses have sea breezes from both sides and there is an area of convergence where high pressure and rising air result where the two breezes meet. This is associated with high rainfall in areas such as Florida. Could one heat the middle of the Cape Peninsular by using biochar? The dark biochar soil will heat up more than the surrounding land and air above it will rise. Could this result in a situation similar to those they have in other areas of convergence, such as Florida? The sea round Cape Town is not as hot as the sea round Florida, but I bet one could increase rainfall by making land darker in the middle of the land area. Convergence and rain also occurs in New Zealand - see http://blog.metservice.com/SeaBreezes 
See also http://climate.ncsu.edu/edu/k12/.liftingmechanisms 
In summer in Florida rain occurs daily during some periods. A sea breeze is created by hot rising air over the land, wind blows in from both sides (two sea breezes) and the two air masses collide. Pressure is created where they collide and the air has only one place to go and that is upward. This rising air creates the frequent convectional rain mentioned. 

To dry out the air so that less hurricanes are formed in the Gulf of Mexico, put wide strips of solar air heaters in the Gulf to imitate a sort of very narrow Florida and create convectional rain that way to dry the air. The phenomenon of drying out of the air in tropical regions, because of frequent convectional rain, is discussed in "Understanding the sky" by Dennis Pagen - it can be found on the Internet - see https://www.google.co.za/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwi_yt7fm8fWAhWBCMAKHbTnDDsQFggnMAA&url=http%3A%2F%2Fblog.rodbailey.com%2Fuploads%2FDennisPagen-UnderstandingTheSky.pdf&usg=AFQjCNEGUkY7t2VnkKagFH3NKNXtHDys7g

The United Kingdom has various air masses moving onto it. 1) Polar maritime air that has blown over the sea and is cold and moist. 2) Polar continental air that is cold and dry 3) Tropical maritime air that has blown over the ocean and is warm and moist 4) Tropical continental that is warm and dry 
 Question: Which of the above do you think brings both showers and thunderstorms?
 Answer: Although warm moist air holds a lot of moisture, when warm moist air is heated from the ground or ocean (this is the usual way air is heated - it is heated from below), it is not much warmer than the air above it (or the sea may be colder and cool the air from below) and not much upward convection (or no upward convection) occurs. With the cool moist polar maritime air (1 above), the air heated by the ground or ocean is hotter than the air above it and rises, so case 1 is the only option that provides both showers and thunderstorms (Reference: Aviation Law And Meteorology by Air Pilot Publishing Ltd).

Could one create rain using floating spray generators in the sea to humidify the air and floating solar air heaters to heat the moist air and cause convectional rain?
Example: Suppose sea and air temperature above the sea and over land is 20 deg C. Suppose the relative humidity (RH) is 60%. Then the wet bulb temperature is 15.21 deg C. If we assume fine mist evaporative cooling with an efficiency of 80%, then the evaporation of spray will cool the air down to 16.17 deg C. This is 3.83 deg C lower than the 20 deg C. With sea at 20 deg C and air at 16,17 deg C the air can be heated from below by the sea. This would simulate the situation in option 1. I calculate that 1.9 g of water needs to be evaporated into every cubic metre of air to result in a temperature lowering of 3.83 deg C. If the spray generators were permanent, a cooler micro-climate would result, but sea temperatures would stay more constant and convectional rain should occur. Calculating relative humidity (RH) after an 80% efficiency fine mist cooling, I get that RH=90% after evaporation. With such a high RH, if you heated an air parcel 2 deg C to 18.17 deg C, it could rise 606 m by virtue of being 2 deg C warmer, and it would only have to rise 456 m for cloud to start forming (used general sorts of lapse rates).
Previously I mentioned that when the sea was hotter than air temperatures, then from graphs, rain was more likely. This makes sense because then the air is heated from below by the sea, it will rise into the colder air and keep rising until it is at the same temperature as the surrounding air, and convectional rain should occur.

 AIR POLLUTION: I will quote you something from Aviation Law and Meteorology by Air Pilot Publishing LTD. It talks about rising air (which will result when solar air heaters heat air). "In a depression , the rising air will be cooling and so cloud will tend to form. Instability in the rising air may lead to quite large development of cumuliform cloud accompanied by rain showers. Visibility may be good (except in the showers), since the vertical motion will tend to carry away all the particles suspended in the air."

Friday, September 15, 2017

Cool Earth Using Evaporation

https://www.ess.uci.edu/~yu/class/ess55/lecture.2.thermodynamics.all.pdf says,
"�Earth’s surface lost heat to the atmosphere when water is evaporated from oceans to the atmosphere. �The evaporation of the 1m of water causes Earth’s surface to lost 83 watts per square meter, almost half of the sunlight that reaches the surface. �Without the evaporation process, the global surface temperature would be 67°C instead of the actual 15°C."
I am trying to convince scientists to implement the use of floating spray pumps to create evaporative fine mist cooling over the Gulf of Mexico and regions where the tropical storms form. It will prevent solar energy from entering the ocean and cool, preventing hurricanes from forming.To get convection and convectional rain, solar air heaters can be used to heat the moist air - I think it will save insurance companies billions. The whole mechanism of rain (evaporation and condensation) moves energy away from the surface to regions higher up.
https://www.sciencedaily.com/releases/2011/09/110914161729.htm explains that evaporation increases low level clouds which reflect solar energy back to space. In fact low level clouds in low latitudes are comparatively warm and radiate heat back to space better than other clouds. Some scientists used to believe that more evaporation could even warm Earth because water vapour is a greenhouse gas. When they fed extra evaporation into climate models it showed that evaporation cools Earth.

Are warming sea temperatures making hurricanes worse?

One sees constant discussion about whether global warming is making hurricanes worse. There is a lot of rain with hurricanes, which means huge energy comes from the ocean. It takes about 2400 kJ to evaporate a kg (about a litre) of water and rain means there must have been evaporation in the first place. The energy for the evaporation comes almost entirely from the water, because air has such a small heat capacity that if the energy came from the air it would quickly be cooled. Air has a volumetric heat capacity of about 1.2 kJ per cubic metre for every 1 deg C drop in temperature. Water has a volumetric heat capacity of about 4180 kJ per cubic metre for every 1 deg C drop in temperature. 
http://www.aoml.noaa.gov/hrd/tcfaq/D7.html  tells us that a hurricane has about 5.2x10¹⁹ J or 5.2x10¹⁶ kJ of energy per day spread out over about an area with radius 665 km. My calculations give that this is about 37429 kJ per square metre per day or 10.4 kWh per square metre per day. By comparison one may get about 8 kWh per day per square metre from the sun (Weatherspark will tell you how much for you area). If the energy is coming from the water, then one cubic metre of water (1000 kg) would be cooled 37429/(4180)=9 deg C in a day. So if we do not have deep hot water to provide the energy, the hurricane will lose strength. It seems obvious that warming sea temperatures will fuel hurricanes more, or have I missed something?