EVAPORATION AND THE PLANET
Comments on “Climate forcing and response to idealized changes in surface latent and sensible heat”, by Ban-Weiss et al, Environmental Research Letters 6, 2011.
Comments on “Climate forcing and response to idealized changes in surface latent and sensible heat”, by Ban-Weiss et al, Environmental Research Letters 6, 2011.
The paper by Ban-Weiss et al (2011) concludes that the evaporation from trees and waters cools the global climate because evaporation creates more clouds and these ones increase the reflection of the Sun's rays, thus cooling the planet in 0.54 ºC. This conclusion also generates the message that evaporation cools the low atmosphere where humans live. In synthesis, the work corresponds to the authors’ empirical decision of adding 1 W/m2 of latent heat and decreasing 1 W/m2 of sensible heat to/from the atmosphere and concluding that this zero energy balance creates more clouds. The authors also state that the evaporation does not affect the global energy balance of the planet and that the water vapor is not a factor forcing changes in climate. Another conclusion of the paper is that the precipitation decreases 0.41%.
I do not see the evaporation influence on the atmospheric behavior by the way and as simple as obtained by the empirical assumptions and their imaginary calculations (for example, calculations are not shown in the paper, even the main ones – exact science requires that at least the main calculations be explicit and clear for verification of the validation and correctness of the physics employed, as well as to show clearly the authors’ particular choices) and by the well-known incomplete and not as improved as desired models (e.g., Stott et al 2013). Analyzing the issue through the physical principles I think that I have contributions for a broaden understanding of the subject.
Besides mass, evaporation carries heat together and thus cools the surfaces and some portions around of its original environments, but this heat and mass must go to other parts of the atmosphere where cause influences, suffer interactions and many things happen, and then I do not associate evaporation with an atmospheric or planetary cooling. There are several factors, conditions and effects to take into account different than the ingenuous assumptions and conclusions (many incorrect) of the empirical methods adopted by Ban-Weiss et al. The comments below are supported mainly by Sartori (1996; 2012).
1. Since more evaporation creates more clouds and these ones change the solar radiation that reaches the surface of the planet, how then the authors state that evaporation does not affect directly the energy balance of the planet? The atmospheric physical processes do not work isolately and thus everything in the atmosphere is interrelated and one action causes reactions or consequences. Moreover, more water vapor changes the mass balance, which on its turn changes the heat balance of anything and of the atmosphere, too.
2. There is not real physical relationship between the supposed “zero energy balance” and the formation of clouds/cooling effect, that is, zero energy balance does not create clouds, and then, doesn’t matter whether such a procedure was adopted or not for such purpose. On the contrary, not only more mass creates more clouds but also more heat generates more clouds (Sartori 2012), and then the (authors supposed) zero energy balance does not explain or affect the process of creation of clouds. We can depict that the authors’ conclusion on such creation of clouds and cooling effect corresponds to their previous or pre-determined understanding (not a physical result of the work or a physical principle) on the possibility that clouds cool the planet.
3. The reflectance is a property of surfaces (not of volumes) and depends on the surface color, and because of this the cloud reflectance may decrease instead of increase. Also, the literature on global warming and climatic changes normally associate the clouds as producing a definitive or final cooling effect, but does not consider and does not calculate them as being a cover that also causes less heat loss (by radiation and convection) and traps more heat below. Before stating that more clouds increase a cooling effect only, calculations must be performed to verify which situation is valid for each case.
4. The clouds do not increase only in area, but also in thickness, which condition affects the absorption of radiation and the higher/lower loss of heat and thus the cooling/warming consequences, and because of this clouds cannot be associated immediately and only with a cooling effect.
5. Even with a relatively less energy received, any greenhouse where there is water can increase its inner temperatures and humidity much more than the ones got by a corresponding open system, which situation also happens with the greenhouse formed by the cloud cover due to evaporation, to less heat loss and to other sources of heat and humidity (Sartori 1996; 2012).
6. The closing of any system eliminates the wind and consequently the higher and more rapid removal of heat and humidity, and then this cover generates an airless and uncomfortable environment below it. If such system is transparent, contains water and is submitted to a heat source, the inside temperatures and humidity increase, being these ones properties of greenhouses. In the last decades, the clouds have increased, the solar radiation and the wind under the cloud covers have decreased and the temperatures and humidity increased in some places of the world. This is well explained in Sartori (2012).
7. Since the atmosphere works according to heat and mass balances, everything in it is interrelated and then if the solar energy reaching the Earth’s surface changes due to more clouds, this must correspond to changes in the energy lost by this surface, that is, the latent and sensible heats cannot be kept constant. Since the authors’ empirical assumptions produced lots of “exact” values such as 0.49 W/m2 and 0.54 ºC, let’s then see whether these ones are based on exact and correct considerations and can really generate such accurate results. The atmosphere does not work in steady state, but for simplicity let’s consider the energy balance in steady state for the Earth’s surface
G = qe + qr + qc + qk
1. Since more evaporation creates more clouds and these ones change the solar radiation that reaches the surface of the planet, how then the authors state that evaporation does not affect directly the energy balance of the planet? The atmospheric physical processes do not work isolately and thus everything in the atmosphere is interrelated and one action causes reactions or consequences. Moreover, more water vapor changes the mass balance, which on its turn changes the heat balance of anything and of the atmosphere, too.
2. There is not real physical relationship between the supposed “zero energy balance” and the formation of clouds/cooling effect, that is, zero energy balance does not create clouds, and then, doesn’t matter whether such a procedure was adopted or not for such purpose. On the contrary, not only more mass creates more clouds but also more heat generates more clouds (Sartori 2012), and then the (authors supposed) zero energy balance does not explain or affect the process of creation of clouds. We can depict that the authors’ conclusion on such creation of clouds and cooling effect corresponds to their previous or pre-determined understanding (not a physical result of the work or a physical principle) on the possibility that clouds cool the planet.
3. The reflectance is a property of surfaces (not of volumes) and depends on the surface color, and because of this the cloud reflectance may decrease instead of increase. Also, the literature on global warming and climatic changes normally associate the clouds as producing a definitive or final cooling effect, but does not consider and does not calculate them as being a cover that also causes less heat loss (by radiation and convection) and traps more heat below. Before stating that more clouds increase a cooling effect only, calculations must be performed to verify which situation is valid for each case.
4. The clouds do not increase only in area, but also in thickness, which condition affects the absorption of radiation and the higher/lower loss of heat and thus the cooling/warming consequences, and because of this clouds cannot be associated immediately and only with a cooling effect.
5. Even with a relatively less energy received, any greenhouse where there is water can increase its inner temperatures and humidity much more than the ones got by a corresponding open system, which situation also happens with the greenhouse formed by the cloud cover due to evaporation, to less heat loss and to other sources of heat and humidity (Sartori 1996; 2012).
6. The closing of any system eliminates the wind and consequently the higher and more rapid removal of heat and humidity, and then this cover generates an airless and uncomfortable environment below it. If such system is transparent, contains water and is submitted to a heat source, the inside temperatures and humidity increase, being these ones properties of greenhouses. In the last decades, the clouds have increased, the solar radiation and the wind under the cloud covers have decreased and the temperatures and humidity increased in some places of the world. This is well explained in Sartori (2012).
7. Since the atmosphere works according to heat and mass balances, everything in it is interrelated and then if the solar energy reaching the Earth’s surface changes due to more clouds, this must correspond to changes in the energy lost by this surface, that is, the latent and sensible heats cannot be kept constant. Since the authors’ empirical assumptions produced lots of “exact” values such as 0.49 W/m2 and 0.54 ºC, let’s then see whether these ones are based on exact and correct considerations and can really generate such accurate results. The atmosphere does not work in steady state, but for simplicity let’s consider the energy balance in steady state for the Earth’s surface
G = qe + qr + qc + qk
that is, the energy received from the Sun must equal the heat lost by the Earth’s surface through its different modes, and where G = solar radiation at the Earth’s surface, W/m2; qe = latent heat loss by evaporation, W/m2; qr = sensible heat loss by radiation, W/m2; qc = sensible heat loss by convection, W/m2; qk = sensible heat loss by conduction through the soil, W/m2. The general literature on global warming considers only changes in the radiation to explain a greenhouse effect and the planet’s average temperature, but as can be seen from the equation above, this is an incomplete, incorrect and inaccurate understanding, because other heat transfer modes, such as by evaporation and by convection also affect the atmospheric warming/cooling processes. And all of these heat transfer modes are submitted to cyclic warming/cooling processes of the atmosphere, not only the evaporation or the water vapor. So, if we take any value for the solar radiation, let’s say, G = 600 W/m2, then the sum of the energy released by the surface to the atmosphere must be equal to 600 W/m2. Therefore, if we have, for example,
600 = 300 + 200 + 99 + 1
then
600 = 600
We can easily see if only the radiation heat transfer was considered, this energy balance would not match.
According to the authors’ assumptions we have, for example
600 = 301 + 200 + 98 + 1
then
600 = 600
but the authors state that the solar radiation decreases 0.5 W/m2 keeping constant the mentioned addition and subtraction of heats. Thus, let’s see if the energy balance matches:
599.5 = 301 + 200 + 98 + 1
or
599.5 ¹ 600
that is, the energy balance using the authors’ assumptions does not match, which means that something in their assumptions and work is invalid. This also means that for any new situation the values must change and cause new conditions, and thus the constant “zero energy balance” is not valid. If the referred assumptions were used for obtaining approximate values, then this had to be left clear and the results could not be given with precisions on the hundredths to make the readers to think that the calculations are perfect and the results highly accurate. As seen, the results are based on approximate (and, in my opinion, incorrect) empirical methods and considerations. These same verifications are valid when we make the heat balance in transient mode.
8. The authors also concluded that for every 1 W/m2 that is transferred from sensible to latent heating, there is approximately a 0.5 W/m2 decrease in the top-of-atmosphere energy. Let’s see if this is correct by applying the energy balance example above:
600 = 300 + 200 + 99 + 1
Now, let’s replace 50 W/m2 of sensible heat by 50 W/m2 of latent heat and decrease 25 W/m2 from the solar radiation reaching the surface to verify whether the authors’ conclusion is correct or not:
575 = 350 + 200 + 49 + 1
then
575 ¹ 600
Again, the authors’ energy balance and conclusions do not match and the result above also violates the first law of thermodynamics and of the nature, because there is creation or generation of energy from the nothing and then the surface loses more heat than receives, an impossible condition.
9. In a normal day in Brazil with a solar radiation of about 700 W/m2 the temperatures vary from ~ 23 ºC to 30 ºC, let’s say, a linear average of 100 Wm-2/1 ºC. With a reduction of 0.54 W/m2 in the solar radiation due to clouds the authors obtained a decrease of 0.54 ºC for the entire planet, that is, a linear average of 1 Wm-2/1 ºC. So, would go a decrease of 700 W/m2 in the solar radiation (at night, for example) generate a decrease of 700 ºC? What a power has the authors’ solar radiation?
9. In a normal day in Brazil with a solar radiation of about 700 W/m2 the temperatures vary from ~ 23 ºC to 30 ºC, let’s say, a linear average of 100 Wm-2/1 ºC. With a reduction of 0.54 W/m2 in the solar radiation due to clouds the authors obtained a decrease of 0.54 ºC for the entire planet, that is, a linear average of 1 Wm-2/1 ºC. So, would go a decrease of 700 W/m2 in the solar radiation (at night, for example) generate a decrease of 700 ºC? What a power has the authors’ solar radiation?
10. If for every 0.5 W/m2 decrease in the solar radiation there is a reduction of 0.54 ºC due to clouds, then for a decrease of 500 W/m2 is there a decrease of 270 ºC in the air temperature?
11. The authors say that “forests have a greater latent heat flux relative to sensible heat flux”, which also means that forests obviously have a greater evaporation relative to a dry place. More latent heat also means more mass. This also means that more mass (not only heat) of water is sent upward from forests than from dry places. Therefore, since more mass rises, how is it possible that the precipitation decreases? Since more mass rises, how is it possible that less mass comes back? The authors’ evaporation creates more clouds, then how these same clouds generate less precipitation? Do we need fewer clouds to have more precipitation? Is the law of conservation of mass invalid? Artificial inputs in models and empirical analyses may produce results that violate fundamental laws and that are not checked according to the physical principles.
12. What would occur if 300 W/m2 of latent heat was added and 50 W/m2 of sensible heat was withdrawn? Would the atmosphere warm or cool? Would be this 300 W/m2 also eliminated by considering the entire cycle again only for the evaporation? In this case, doesn’t matter how much heat is released into the atmosphere? In this case, doesn’t matter how greater latent heat flux forests have relative to dry places? Furthermore, the role of water vapor is not only for creating clouds.
13. The study and the literature on global warming and climatic changes normally consider the sensible heat as a whole without differentiations and thus consider that it has a unique value and goes only to one direction or sense at each time, but the sensible heat is formed by the convection heat transfer, by the radiation heat transfer and by the conduction heat transfer, that have different values and can go in different senses at each time. The authors also adopted: “all energy fluxes are positive upward such that the L (with arrow upward) simulation has positive changes in upward energy flux and the S (with arrow downward) has negative changes in upward energy flux”. This is the same as saying that the latent heat warms the atmosphere while the sensible heats cool the atmosphere, all at the same time. The sign convention must be according to the 2nd law of thermodynamics and coherent with the physics of the atmosphere. The direction of all real heat fluxes is determined by the real temperatures, not by personal choices. When the water or surface temperature is higher than the air temperature, both the latent and sensible heats are positive upward, that is, they warm the atmosphere. When a forest, a water surface and a dry place all have the same temperature difference, same sense and same emissivities, the corresponding sensible heats have the same value, and thus there isn’t a decrease from a dry place to a forested one, in contrast to supposed by the authors. When the air temperature is higher than the water temperature the heat by convection goes from the air to the water surface and is thus positive downward (cools the air while heats the surface) but the radiation exchanges heat with the sky temperature, which is much lower (in clear sky) than the air temperature, and then even when the air temperature is higher than the water temperature the radiation goes from the water to the sky, thus it is positive upward. The conduction heat transfer from the water body to the soil is normally negligible, but it also depends on the corresponding temperatures, which soil temperature also depends on the humidity. Therefore, to consider a same value and a same heat direction for all of the sensible heats at the same time are invalid procedures, and the authors’ consideration makes the heat balances to be incorrect and not match. Furthermore, in the paper, the influence of the latent heat was eliminated by considering its return path due to the rain while for the sensible heat this return path was not considered. If we heat an iron bar we say that the bar is heated after this process and the heated bar warms the atmosphere around, and we don’t care if the bar is cooled by the atmosphere completing the warming/cooling cycle, but this return path also exists for the sensible heats. Artificial inputs in models not always correspond to the real physical processes.
14. Only due to its cover, an igloo converts outside temperatures of about – 50 ºC to inside temperatures of about + 16 ºC because it eliminates the high and rapid heat loss caused by the wind as well as the latent heat from sweat and lungs increase the inside warming and humidity. The higher humidity also increases the thermal inertia which helps to keep the warming conditions for a longer time and avoids quick swings of temperatures. While there is the supply of heat and mass together with the reduction of heat losses, the inner warming is kept. The same effects happen with the heat, humidity and cloud cover of the Earth’s atmosphere (Sartori 2012). In Prague, Czech Republic, there is a forest which inside temperatures reach about 30 ºC while the outside temperature is about 4 ºC. The elevation of inside temperatures also happens with other closed forests, such as the Amazon.
15. In places or greenhouses where there is water, the heat by evaporation per m2 corresponds to most of the heat released into the atmosphere in comparison to the corresponding radiation and convection heat transfers. The same happens in relation to the total heat transfer from the entire planet’s surface. Such large amount of heat and mass changes the atmospheric heat and mass balances and then the corresponding warming. The 20th century and almost the entire world became cloudier and more humid (Alexander et al 2006; Groisman et al 2005; Sartori 2012).
16. “Increased latent heat flux to the atmosphere has a local cooling influence, but this energy will be released back to the atmosphere wherever the water condenses”. The local cooling of a water surface does not happen only due to the latent heat, because the surfaces also lose sensible heats that cool the water bodies and consequently warm the atmosphere.
17. The Amazon is certainly the place where there is more evaporation from trees and waters than any other in the world, but that region is not an example of a cooled place. The average annual temperature of Manaus is > 30 ºC, with variations from 23 ºC to 39 ºC and average annual humidity of 85%, and where the sky is normally cloudy and rains everyday (these are common conditions for the Amazon region). The constant high humidity with cloudy conditions and consequently with less loss of heat makes the evaporation from the skin to be difficult and slow, and then the people normally feel uncomfortable there. So, the rain increases the humidity and depending on the temperatures and humidity within the greenhouse formed by the cloud cover, the rain does not decrease the warming, but keep it. The temperature of the rain depends on the temperatures of the atmosphere, and thus, if more heat is directly sent upward, warmer will be the atmosphere and the rain. The condensation does not need only very low temperatures to happen. The temperature that starts the condensation can vary from much below 0 ºC to much above 30 ºC, depending on the air humidity and atmospheric warming. For example, if for the Amazon the air temperature at the clouds altitude is 30 ºC and RH = 90%, the temperature that starts the condensation is 28 ºC. In its path, the rain also exchanges heat with the atmospheric layers and if these are warmer (because received heat from evaporation, radiation, convection, nuclear and fossil fuel power plants, industries, etc), the rain becomes warmer, too, and the atmosphere almost does not cool due to the rain.
18. In the Sahara desert it is estimated that a person can live about 4 hours without water (WWF, 2013), due to the high and fast loss of water from the body. We can also make other comparisons between the Sahara and the Amazon. Although the temperatures in that desert can reach 50 ºC during the daylight, the night temperatures can reach – 5 ºC, and then the average annual temperature in summer is about 30 ºC (WWF 2013). Those very low temperatures at night are due to the absence of sufficient humidity, clouds and solar radiation. Thus, if the Sahara desert was converted into an Amazon region, the daylight temperatures would decrease about 20 ºC but the night temperatures would increase about 30 ºC, that is, the water vapor cannot be associated simply with a cooling effect. More mass with the same energy causes a cooling effect (in open conditions, i.e., without cloud cover), but in closed conditions (with cloud cover) there is less heat loss and thus even more mass with the same energy increases the warming and the thermal inertia that make the cooling/warming processes lower and slower. The higher the humidity the higher is the sensation of warming, not necessarily with higher temperatures – a comparatively lower temperature and higher humidity produce higher warming. The temperature is not sufficient to determine warming/cooling or comfort/discomfort conditions. Two places with the same air temperature, but where one is humid and the other dry, the humidity causes more discomfort because the evaporation of sweat is less and slower and then the corresponding latent heat and mass remain onto the skin, avoiding the heat transfer and making the person feel uncomfortable mainly when there isn’t wind, and also because the humid air applies a higher air pressure onto the skin. When the relative humidity is high we feel much hotter (3-4 ºC) than the warming produced by the actual temperature because humans perceive the rate of heat transfer from the body rather than the temperature itself. When there is abundant wind, this flow quickly removes the heat and mass from the skin and the sensation becomes comfortable. Therefore, the Sahara region plenty of trees and waters would be a warm and uncomfortable place. The difference is that in the Sahara it is not possible to survive for a long time without water due to the lack of sufficient water vapor in the air, while in very warm and humid places this is possible, but the comfort is affected. Thus, in contrast to the authors’ statement, changes in atmospheric water vapor and the vertical temperature profiles caused by this gas are factors forcing changes in climate.
19. The authors say that “This study focuses on climate effects of replacing sensible heating by latent heating, as might occur when a grassland is converted to forest”. The substitution of a desertic or grassland place by a forested one does not eliminate the sensible heat, on the contrary, only more heat (latent) is added to the atmosphere while the convection and radiation heat transfers are kept. Without human specific actions, the radiation and convection heat transfers cannot be eliminated! Also, according to basic physical principles, the sensible heats do not depend on the types of surfaces such as grassland, forest, dry place, water surface, etc, but essentially on their temperatures. Thus, if the temperatures of the systems, say, a desert and a water surface are the same, the sensible heat will be essentially the same (the convection depends also on turbulences and the radiation on the emissivities, but are not eliminated or replaced). The following calculations compare the Sahara with the Amazon and give an insight on the relative influences of the heats from both systems on the atmospheric warming.
All equations below (Sartori 1996; 2000; 2003; 2006; 2012) are based on the boundary layer theory, which is mandatory for any fluid flow over surfaces and show close agreement with experimental data. In these equations V = wind velocity, m/s; L = length of surface in the wind direction, m; ts = surface temperature, ºC; ta = air temperature, ºC; td = air dew point temperature, ºC; tw = water temperature, ºC; Ts = surface temperature, K; Tsky = sky temperature, K; Tw = water temperature, K; e = emissivity; s = Stefan-Boltzman constant, W/m2K4; m = evaporation, kg/m2s; hw = latent heat of vaporization, kJ/kg; Pw = partial pressure of air at the water temperature, Pascal; Pa = partial pressure of air at the air temperature, Pascal; P = atmospheric pressure, Pascal; f = relative humidity, fraction.
All equations below (Sartori 1996; 2000; 2003; 2006; 2012) are based on the boundary layer theory, which is mandatory for any fluid flow over surfaces and show close agreement with experimental data. In these equations V = wind velocity, m/s; L = length of surface in the wind direction, m; ts = surface temperature, ºC; ta = air temperature, ºC; td = air dew point temperature, ºC; tw = water temperature, ºC; Ts = surface temperature, K; Tsky = sky temperature, K; Tw = water temperature, K; e = emissivity; s = Stefan-Boltzman constant, W/m2K4; m = evaporation, kg/m2s; hw = latent heat of vaporization, kJ/kg; Pw = partial pressure of air at the water temperature, Pascal; Pa = partial pressure of air at the air temperature, Pascal; P = atmospheric pressure, Pascal; f = relative humidity, fraction.
SAHARA – daylight:
qc = 5.74V0.8L-0.2(ts – ta) = 5.74x50.81000-0.2(50 – 40) = 52.3 W/m2
qr = es[(Ts)4 – (Tsky)4] = 0.9x5.6697x10-8[(323.15)4 – (300.72)4] = 139.1 W/m2
Tsky = [ta +273.15][(td/250) + 0.8]0.25. With ta = 40 ºC and RH = 20% => td = 12.6 ºC =>
Tsky = 300.72 K.
Tsky = 300.72 K.
SAHARA – night:
qc = 5.74V0.8L-0.2(ts – ta) = 5.74x3081000-0.2(15 – 5) = 34.7 W/m2
qr = es[(Ts)4 – (Tsky)4] = 0.9x5.6697x10-8[(288.15)4 – (259)4] = 122.2 W/m2
With ta = 5 ºC and RH = 20% => td = – 10 ºC => Tsky = 259.0 K.
AMAZON – daylight:
For the Amazon it is considered evaporation from free water surfaces (rivers, lakes, etc). Since any cover homogenizes the temperatures below, the cloud cover also does this and then the temperature differences here are considered smaller than for the Sahara and are also according with the local average temperatures.
qc = 5.98V0.8L-0.2(tw – ta) = 5.98x50.8x1000-0.2(35 – 30) = 27.2 W/m2
qr = es[(Tw)4 – (Tsky)4] = 0.95 x 5.6697x10-8[(308.15)4 – (295.9)4] = 72.7 W/m2
With ta = 30 ºC and RH = 85% => td = 27.04 ºC => Tsky = 295.9 K
qe = m x hw = [0.0041V0.8L-0.2(Pw - fPa)/P] = [0.0041x50.8x1000-0.2(5618.20 – 0.85X4239.65)/101325] x hw = 0.00007420 x 2417.8 = 0.1794 kJ/m2s = 179.4 W/m2
hw = 3160.7 – 2.411(tw + 273.15) (Sartori )
= 3160.7 – 2.411(35 + 273.15) = 2417.8 kJ/kg
= 3160.7 – 2.411(35 + 273.15) = 2417.8 kJ/kg
AMAZON – night:
qc = 5.98V0.8L-0.2(tw – ta) = 5.98x30.8x1000-0.2(30 – 25) = 18.1 W/m2
qr = es((Tw)4 – (Tsky)4) = 0.95x5.6697x10-8[(303.15)4 – (289.5)4] = 76.6 W/m2
With ta = 25 ºC and RH = 85% => td = 22.14 ºC => Tsky = 289.5 K.
qe = m x hw = [0.0041x30.8x1000-0.2(4239.65 – 0.85x3165.07)/101325] x hw =
0.00003792 x hw = 0.00003792 x 2429.8 = 0.092138 kJ/m2s = 92.1 W/m2
hw = 3160.7 – 2.411(30 + 273.15) = 2429.8 kJ/kg
Total Sahara: 348.3 W/m2 Total Amazon: 466.1 W/m2
As can be seen, with the referred conditions, the Sahara warms 348.3 W/m2 its atmosphere while the Amazon warms 466.1 W/m2 its atmosphere, also remembering that to the Amazon total it must be added the evaporation heat released from trees, not calculated here. This confirms that a forested and humid area (even with smaller temperature differences) releases more heat than a dry one and doesn’t matter whether this heat is latent or sensible, because the warming effect of the atmosphere becomes the same until the latent and sensible heats complete their own cycles. Also, although the released sensible heat reduced for the Amazon, it is not eliminated and continues warming the atmosphere. Inversely, if the latent heat from the Amazon could be blocked, its atmosphere would present a cooling in relation to the Sahara, because there would have less heat (sensible) for warming it. A reduction in the sensible heat applied to the period of Sahara’s highest temperatures reduces these temperatures, while an addition of heat (latent or sensible) applied to the period of Sahara’s lowest temperatures increases these temperatures. The same is valid for the Amazon and for any other place of the world. Before these heats complete their cycles, they remain in the atmosphere and depending on the rates and amounts of these heats and masses they can cause longer effects. All atmospheric processes are cyclic, including the sensible heat gains and losses, but the authors applied the entire cycle of warming/cooling for the latent heat but not for the sensible heat. Furthermore, for the sensible heat they applied only the cooling path of the cycle. In reality, the authors applied a negative energy balance to the atmosphere in favor of its cooling, not a zero energy balance. Let’s see: they added 1 W/m2 (evaporation), they withdraw 1 W/m2 (sensible) and removed 1 W/m2 (rain), or, 1 – 1 – 1 = – 1 W/m2. Again, their energy balances do not match.
20. The atmosphere does not work in steady state where the same amount of water vapor by evaporation comes back as precipitation in the same time and place. Much before the cycles are completed many things happen in the atmosphere, including the changes caused by the amounts, types and rates of the supplies. There is storage, variations of storage and various combinations of heat and mass in air, since various and different conditions determine how much water evaporates and how much water precipitates in different times and places, as well as the water vapor does not exist or remain only in clouds. The evaporation carries heat and mass together and these remain and affect the atmosphere until the same amounts of heat and mass are exchanged with other parts of it, but these processes are not immediate, instantaneous, localized and identical. Also, the evaporation changes the mass balance which on its turn affects the atmospheric heat balance. The same is valid for the precipitation, that is, one effect does not cancel the other directly, immediately and simply without causing effects, in contrast to supposed by the authors. Moreover, high humidity increases the air thermal inertia, which avoids extreme variations and swings of temperatures and makes the differences and consequences between a desert and a humid place. The higher the level of water vapor in the air the higher is the storage and thermal inertia and the higher is the warming. The 20th century and almost the entire world became more humid (Alexander et al 2006; Groisman et al 2005). Therefore, yes, the evaporation and the humidity affect directly the global heat and mass balances of our planet.
21. If a student once said that he/she would go to measure a certain atmospheric parameter at his/her own location and after the measurements he/she would state for the entire world that the results are valid for every place of the planet, then he/she would be ridiculed. Thus, besides the well-known questionable influence of the CO2 on the atmospheric warming, how can be this gas measured at only one place of the planet and the results adopted for the entire world? Additionally, how these values are obtained in Hawaii, a place plenty of volcanoes in activity that release various gases constantly and even so such a place is considered representative for the entire planet? Why equivalent measurements at only one place of the world are not accepted for the temperatures? The temperatures are always related to the amount of CO2, but both parameters are not obtained at the same places! Since the temperatures suffer influence from local conditions, the same must be considered for the CO2, and then each temperature record can be related with each CO2 record at the same place (or as more approximate as possible) and average values obtained according to local conditions, as is normal. Also, since the rain removes CO2 from the atmosphere, how then the CO2 value at the Sahara desert is considered the same as that at the Amazon region? Furthermore, as demonstrated in Sartori (2012), the participation of the CO2 on the average air temperature is of the order of only one percent!
22. The adiabatic gradient (adiabatic lapse rate) tells us that Gdry air = - 0.98 ºC/100m, Ghumid air = - 0.6 ºC/100m, Gsaturated air = - 0.4 ºC/100m (Sentelhas and Angelocci 2009), which numbers mean that the cooling effect for every 100 m of elevation in the atmosphere is about half for humid air than for dry air. That is, the elevations where humans live have half the capacity of cooling in humid air than in dry air. We can see again the strong power that the humidity (caused by evaporation, precipitation and certain human activities) has to increase the atmospheric warming and the thermal inertia. More water vapor creates more clouds and the greater cloud cover reduces the removal of heat and mass below (also by reducing the wind below the cloud cover, as demonstrated in Sartori 2012), thus increases the warming and the uniformity of temperatures and humidity where humans live.
When the humidity and closed conditions between the cloud cover and the surface are high due to evaporation and rain such as in the Amazon, the cooling effect due to the rain and wind is small and the space remains warm, humid and uncomfortable. Furthermore, if one drop of water is thrown upward by humans, one drop must come back, and certain human activities have released much more than one drop of water upward. For example, the power plants (nuclear and fossil fuels) that heat water and convert it into steam account for 40% of the US freshwater usage, while in Europe these plants account for about 50% of the freshwater usage (van Vliet et al 2012). Much of this water is “recycled”, but a great part of these enormous volumes and heats are sent upward and humidifies and warms the atmosphere, influencing the atmospheric processes, its behaviors and its heat and mass balances.
The increasing greenhouse effect due to the increasing cloud cover and water vapor in air with their consequences must be the concern relative to direct and indirect climatic changes caused by certain human activities (Sartori 2012). In Sartori (2012) the New Hydrological Cycle is also demonstrated physically and mathematically, which demonstrations have never been done before, even for the conventional hydrological cycle.
When the humidity and closed conditions between the cloud cover and the surface are high due to evaporation and rain such as in the Amazon, the cooling effect due to the rain and wind is small and the space remains warm, humid and uncomfortable. Furthermore, if one drop of water is thrown upward by humans, one drop must come back, and certain human activities have released much more than one drop of water upward. For example, the power plants (nuclear and fossil fuels) that heat water and convert it into steam account for 40% of the US freshwater usage, while in Europe these plants account for about 50% of the freshwater usage (van Vliet et al 2012). Much of this water is “recycled”, but a great part of these enormous volumes and heats are sent upward and humidifies and warms the atmosphere, influencing the atmospheric processes, its behaviors and its heat and mass balances.
The increasing greenhouse effect due to the increasing cloud cover and water vapor in air with their consequences must be the concern relative to direct and indirect climatic changes caused by certain human activities (Sartori 2012). In Sartori (2012) the New Hydrological Cycle is also demonstrated physically and mathematically, which demonstrations have never been done before, even for the conventional hydrological cycle.
Ernani Sartori
Email:e.solar@hotmail.com
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