the process is not so simple. For the atmosphere "winds" (driven, as their most fundamental level by pressure (temperature) gradients) move the matter and one cannot single out any single source of the pressure gradients which drive winds. Local phenomena, like heat rising off the surface and up through lower layers, carrying water and other compounds vertically mixes on its way up and is transported horizontally as well as vertically by pressure gradients, which are associated with temperature gradients. the surface topography affects the local temperature/pressure profiles, which similarly contribute to the driving forces for convection, and, as you note, the absorption of solar energy by the local content of the atmosphere (mostly by water, which makes up the vast majority of material in our atmosphere), and water changes its state to as solid as it rises into very cold upper layers, further changing the local pressures. Moreover, the vast majority of Earth's surface is water, and temperatures and vapor content of the lower levels of the atmosphere above water are driven by what is happening in the bodies of water - so the processes are extremely intertwined. The computation involves understanding all source of energy being generated and moved. Within our vast oceans there are local sources of energy, such as undersea volcanoes which generate huge localized plumes of heated gases (containing particulate as well as gases). I hope this gives you a beginning of how you might address the problem.

Regards

Dr Paul Abramson thank you for your contribution to the discussion

The Sun also provides the energy that drives convection in the ocean and produces ocean currents. Earth's weather and climate are mostly driven by energy from the Sun. As, unequal warming of Earth's surface and atmosphere by the Sun drives convection within the atmosphere, producing winds, and influencing ocean currents. The primary source of energy that drives convection within the atmosphere and oceans is the Sun. Solar radiation, which includes visible light, ultraviolet (UV) radiation, and infrared (IR) radiation, provides the energy that heats the Earth's surface. The heat source for these currents is heat from Earth's core and from the mantle itself. Hot columns of mantle material rise slowly through the asthenosphere. At the top of the asthenosphere, the hot material spreads out and pushes the cooler material out of the way. Ocean thermal energy conversion produces energy from temperature differences in ocean waters. Ocean thermal energy conversion (OTEC) is a process or technology for producing energy by harnessing the temperature differences (thermal gradients) between ocean surface waters and deep ocean waters. The Sun imparts a tidal force on Earth's atmosphere through radiative heating of the atmosphere and surface and latent heat release via global scale convection. The ocean can produce two types of energy: thermal energy from the sun's heat, and mechanical energy from the tides and waves. Oceans cover more than 70% of Earth's surface, making them the world's largest solar collectors. Volcanoes spewed gases into the air. Comets carried in ices from outer space. These ices warmed and became gases. Nitrogen, carbon dioxide, hydrogen, and water vapor, or water in gas form, were in the first atmosphere. The energy of the sun is the original source of most of the energy found on earth. We get solar heat energy from the sun, and sunlight can also be used to produce electricity from solar (photovoltaic) cells. The sun heats the earth's surface and the Earth heats the air above it, causing wind. Natural sources of carbon dioxide include most animals, which exhale carbon dioxide as a waste product. Human activities that lead to carbon dioxide emissions come primarily from energy production, including burning coal, oil, or natural gas.

RK Naresh: you seem to be firing a string of questions that can be answered by a short web-search or, even better, by consulting standards texts. What is your reason for this?

RK Naresh: interesting question. The answer lays in the derivative of the heat transfer equations since, if you heat something uniformly, you will not have convection. When energy from the sun is applied to the air and water at a non uniform heat flux (e.g. higher energy flux at the equator and lower at the poles) convection will occur as the fluid density changes and becomes lower. lower density fluids will rise, being replaced by colder denser fluid from the north and south pole. As the earth rotates, the fluid that is moving to the equator is affected by the earth's rotation, causing the air to rotate faster as it moves farther from the poles. Thus, the earth's rotation contributes to the movement of the fluid. Again, remember that this rotation would not occur if the fluid were uniformly heated and not moving. rotation of fluids is driven by the change in tangential velocity as the air moves away from the center of rotation. "Coriolis effect".

This drives the convection that Paul is discribing above.

In addition, there is a thermodynamic cycle that is enabled by the convection. Water at higher temperatures will evaporate at a logarithmically faster rate (the pressure / temperature curve of water is very strong), resulting in a strong evaporation at the equator and condensation at the colder temperatures. This drives a partial pressure gradient that drives mass transfer (convection). The colder temperatures are located in two directions. Higher elevations in the atmosphere are colder due to the lower pressure (perfect gas law), resulting in freezing particles (clouds). Colder temperatures are also located at the poles. This temperature is driven by radiative cooling to space. Outer space has a temperature of 2.7 Kelvin, minus 453.8 degrees Fahrenheit or minus 270.45 degrees Celsius and heat transfer to space is proportional to the 4th power of the temperature difference. In the absense of heating, the north and south poles would become very frozen (like the south pole of the moon). The rate of cooling increases when the air is heated due to global warming. (stabalizing negative feedback loop)

In addition, the existance of counter clockwise rotation (in the northern hemisphere) results in a reduced pressure at the center of rotation (coriolis forces). When this pressure occurs over water, the evaporation rate increases drastically, resulting in high moisture low density air that rises and pulls air in from the outer bands of a hurricane. Conservation of rotational energy results in an increase in velocity at the center (vortex).

Thank you for the question. Very few people understand the Physics behind this complicated world. Even the weather modelers have not included all of the physics in their models, only recently adding there thermal capacity of the oceans to the models, moderating the atmospheric temperatures.

Also interesting to note there earth is in a balance between the heating from the sun and the radiative cooling to space. The sun is only heatign for 12 hours a day and primarily at the equator due to the angle of incidence. Space on the other hand is cooling the earth 24 hours a day and with a 99 percent solid angle to space (adjustments for the sun and moon). Both heating and cooling transfer the same amount of energy.

Rick

I appreciate the approaches taken and note that they are all "Big Picture" views, My involvement with modeling this sort of phenomena has always been in the trenches - building computer models and codes to do the computations. SO when I hear the sort of questions posed by RK Naresh, my analysis always focuses on how one can model and compute what goes on. With respect to ANY such analysis, a few principles dominate the direction:

second - how big can the physical dimensions of the spatial cells used to numerically model the phenomena being tracked - for example - if we are attempting to model the entire thermohydrodynamics of the Earth, can we get away with 1000 cells o ro do we need to use 10,000,000 cells. In the former case, physical changes will be smeared and washed out, but we can take larger timesteps without creating numerical error which cumulatively wipes out the accuracy of the long term projection. This approach, however, loses the effects of local properties and fails to predict effects from things like volcanoes, severe storms, forest fires and the like. Moreover, it will, of necessity, be based upon very broad physical approximations of reality.

If, on the other hand we take very small timesteps, we can get much more accuracy in the computation, but computer time becomes exhorbitant, and eventually numerical error will rise its head anyway.

third - is there data (from experiments or real-life measurements) of the parameters which must be used for physical effects in the equations - i.e heat transfer between water droplets in the strstosphere and the surrounding other matter (gaseous, particulate, etc). Generally speaking, there is no such data available for modeling the Earth's atmosphere or it's seas.

SO, while we may well be able to write equations which describe all the physical phenomena we need to model , and we have (at least in theory) a numerical methodology which can provide reasonable results - the absolute lack of data for building the models which must go into the equations renders the venture fruitless. Many researchers in fields other than Climate Science have encountered this issue. For example when we attempted to model what happens in a nuclear reactor core which undergoes a transient which takes it well beyond its design basis - for example such as we encountered in the accident at Three Mile Island, or at Fukushima, or at Chernoble, the physical configuration changes as material melted and relocated, changing the geometry of the system causing flow paths and heat transfer paths to be entirely modified and equations designed to represent the physics of an intact geometry to require time-dependent modification. However, the entire evolution of such a situation is intertwined among all the physical phenomena involved, so evolution is simply not predictable. While certain global results were computable, the detailed evolution could not be computed. For such accidents in Light water reactors, the scientific community developed a method to use the detailed original equations to predict a huge array of possible results, engaged expert consortia to ""guestimate" how parameters might vary, and then used stochastic (often monte-carlo, methodologies to run the code for thousands of possible scenarios and then estimate which parameters were of fundamental importance for certain types of accidents and thus guide future research, NOTABLY - these computations were of no use to predict what will happen in reality - and the same is true at present for the modeling of Climate evolution for the Earth.

apologies - the "first"point was lost during drafting.

"first" relates to how to approximate the continuous physical equations which govern the time dependent behavior of the phenomena of interst. Invariably, creating a numerical digital representation of continuous equations (such as the Navier-Stokes equations) involves making an approximation which can be relied upon under expressed conditions to represent the continuous equations, and linearized digital representation is always accurate for numerical methods, so long as timesteps are chosen so small that the changes in parameters do not materially affect the properties of the phenomena being tracked, The computation performs a single time step at a and then recreates the physical properties at the new "time" and repeates. Since this is a linear approximation of the actual equations, over many timesteps the computation eventually has accumulative error which voids the accuracy of the representation of the continuous equations, and there fore voide the accuracy of the computation. At what point in the computation this happens depends on how small the timesteps are compared to the changes,but eventually EVERY such approximation will fail. SO every numerical computation must be carefully examined to see whether the overall time dependent result has passed (or neared) this threshold.

Excellent points. I would add that structural inaccuracies are built into numerical models based on the selection of the coordinate system that must be orthoginal to provide independance in the differential equations and secondly, all models suffer from extrapolation error when they cannot be pinned to actual data along the dimension (including time). e.g. rotating instability in thermonuclear reactor systems or the need for general orthogonal curvilinear coordinates in modeling fan systems

Dr Richars DeVos and Paul Abramson thank you for your contribution to the discussion

In fact, Earth's weather and climate are mostly driven by energy from the Sun. As, unequal warming of Earth's surface and atmosphere by the Sun drives convection within the atmosphere, producing winds, and influencing ocean currents. The source of energy that drives mantle convection is heat whereas the source of energy that drives all other is solar energy. Mantle convection is how the Earth's mantle moves due to currents of convection. While winds are responsible for ocean currents, the sun is the initial energy source of the currents. Since the sun heats the Earth more in some places than in others, convection currents are formed, which cause winds to blow. Earth's rotation produces a force on winds and currents. Convection currents are heat-driven cycles that occur in the air, ocean, and mantle. They are caused by a difference in temperature, often due to a differing proximity to a heat source. The difference in temperature relates directly to the density of the material, causing this effect. Surface currents in the ocean are driven by global wind systems that are fueled by energy from the Sun. Large-scale surface ocean currents are driven by global wind systems that are fueled by energy from the sun. These currents transfer heat from the tropics to the Polar Regions, influencing local and global climate. The sun heats the air, and the warm air rises. This rising warm air makes the cooler air from the surrounding areas come in to replace it. This then creates the wind. Ocean currents operate similarly. In the atmosphere, air currents are caused by the uneven heating of Earth's surface. In the ocean, water currents are caused by winds or differences in density. Solar radiation is the fundamental energy driving our climate system, and nearly all climatic and biologic processes on Earth are dependent on solar input. Energy from the sun is essential for many processes on Earth including warming of the surface, evaporation, photosynthesis and atmospheric circulation.As air is heated by surfaces or solar radiation, it triggers convection currents, sometimes called thermals. Other absorbed solar radiation is emitted from surfaces as longwave (or infrared) radiation and then eventually moves back out into space via the atmosphere. As the rock's temperature rises due to conduction, heat energy is released into the atmosphere, forming a bubble of air which is warmer than the surrounding air. This bubble of air rises into the atmosphere. As it rises, the bubble cools with the heat contained in the bubble moving into the atmosphere.

The primary source of energy that drives convection within the atmosphere and oceans is thermal energy from the Sun. Solar radiation heats the Earth's surface unevenly, with the equator receiving more heat than the poles. This uneven heating creates temperature differences, which drive convection.

In the atmosphere, convection is responsible for the formation of clouds, precipitation, and wind patterns. In the oceans, convection drives ocean currents, which have a significant impact on climate and marine ecosystems.

Here is a more detailed explanation of how convection works:

• Atmospheric convection: When the Earth's surface is heated by the Sun, the air above it warms up. Warm air is less dense than cold air, so it rises. As the warm air rises, it cools and condenses, forming clouds. When the water droplets in the clouds become too large, they fall as precipitation. The cycle then repeats itself.
• Oceanic convection: When the ocean's surface is heated by the Sun, the water above it warms up. Warm water is less dense than cold water, so it rises. As the warm water rises, it cools and sinks. The cycle then repeats itself.

Ocean currents are driven by convection on a global scale. Warm ocean currents flow from the equator to the poles, while cold ocean currents flow from the poles to the equator. These currents transport heat around the globe, which helps to regulate the Earth's climate.

Overall, the energy from the Sun is the primary driver of convection within the Earth's atmosphere and oceans. Convection plays a vital role in regulating the Earth's climate and supporting life on Earth.

Dr Murtadha Shukur thank you for your contribution to the discussion

Yes, the sun is the external source of energy that causes convection currents, which drive the winds, ocean currents, and the water cycle. The flow of heat from Earth's interior to the surface is estimated at 47±2 terawatts (TW) and comes from two main sources in roughly equal amounts: the radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat left over from the formation of Earth. The primary source of energy that drives convection within the atmosphere and oceans is the Sun. Solar radiation, which includes visible light, ultraviolet (UV) radiation, and infrared (IR) radiation, provides the energy that heats the Earth's surface. The Sun also provides the energy that drives convection in the ocean and produces ocean currents. The Sun is Earth's primary source of energy. In this paper, we compare the magnitude of the Sun to all other external (to the atmosphere) energy sources. The heat source for these currents is heat from Earth's core and from the mantle itself. Hot columns of mantle. material rise slowly through the asthenosphere. At the top of the asthenosphere, the hot material spreads out and pushes the cooler material out of the way. Magma is the molten rock below the crust, in the mantle. Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth's crust. The sun is the main source of energy on Earth.Geothermal energy is the heat energy derived from the earth's interior and hot rocks. Geothermal energy is heat energy from the earth Geo (earth) + thermal (heat). Geothermal resources are reservoirs of hot water that exist or are human made at varying temperatures and depths below the Earth's surface. Ocean thermal energy is derived from the solar energy that is absorbed by the oceans. Given that almost two-thirds of the planet's surface is covered by the oceans, the majority of solar radiation hitting Earth is absorbed and stored here. The water at the surface of the sea or ocean is heated by the Sun while the water in deeper sections is relatively cold. This difference in temperature is exploited to obtain energy in ocean-thermal-energy conversion plants. The ocean is storing an estimated 91 percent of the excess heat energy trapped int he Earth's climate system by excess greenhouse gases. Averaged over the full depth of the ocean, the 1993–2022 heat-gain rates are approximately 0.64 to 0.83 Watts per square meter averaged over the surface of the Earth. Thermal energy also moves within the ocean and within the atmosphere through the process of convection. During convection, cooler water or air sinks, and warmer water or air rises. This movement causes currents. The sun's heat warms the surface water a lot more than the deep ocean water, which creates the ocean's naturally available temperature gradient, or thermal energy.

All accurate RK, but now imagine trying to build a model which incorporates the details of the processes you describe - for example the incorporating details of heat tranfer among, as well as physical interaction details among, the distributed sizes of water vapor droplets, (not even considering phase transfer among them) - we need a distribution function for the droplets, a dispersion model etc. We have virtually NO data on such parameters, and so actual calculation of the heat transfer is, in reality, impossible. And this is only one of the many details which cannot be properly modeled because of lack of data!

Regards

Paul

please remember for perspective that the sun provides 173000 terawatts while the core of the earth provides 47. The sun dominates the driving forces with the exception of the poles during their winter

Dr Richard DeVos thank you for your contribution to the discussion

Ocean thermal energy is derived from the solar energy that is absorbed by the oceans. Given that almost two-thirds of the planet's surface is covered by the oceans, the majority of solar radiation hitting Earth is absorbed and stored here. Ocean thermal energy is generated due to the difference in temperature of water at the surface of the ocean and temperature at deeper levels of the ocean. The ocean is storing an estimated 91 percent of the excess heat energy trapped into he Earth's climate system by excess greenhouse gases. Averaged over the full depth of the ocean, the 1993–2022 heat-gain rates are approximately 0.64 to 0.83 Watts per square meter averaged over the surface of the Earth. Ocean water absorbs solar energy efficiently. It has far greater heat capacity than atmospheric gases. As a result, the top few meters of the ocean contain more thermal energy than the entire Earth's atmosphere. Ocean currents transfer heat through convection. Convection is the process of heat transfer by the movement of fluids such as water. When warm liquid is forced to travel away from the heat source, it carries energy with it. Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that uses the natural temperature difference in oceans to produce clean, reliable electricity, day and night, year-round. The heat from the warm ocean surface and cold from the deep ocean drives a Rankine Cycle, which produces electricity. Open Cycle OTEC uses seawater as the working fluid, Closed Cycle OTEC uses mostly ammonia. A variation of a Closed Cycle OTEC, called the Kalina Cycle, uses a mixture of water and ammonia. The use of ammonia as a working fluid reduces the size of the turbines and heat exchangers required. As, unequal warming of Earth's surface and atmosphere by the Sun drives convection within the atmosphere, producing winds, and influencing ocean currents. The primary source of energy that drives convection within the atmosphere and oceans is the Sun. The sun is the external source of energy that causes convection currents, which drive the winds, ocean currents, and the water cycle.The Sun also provides the energy that drives convection in the ocean and produces ocean currents.

RK - Do you have any idea whether or not there are OTEC systems proven out to be commercially viable (without very large subsidies)? We do know that ocean tidal systems are commercially viable in certain latitudes where tides and flow channels are physically appropriate (such as in the Orkney Island area.

sun radiation is the primary driving energy for both atmosphere and ocean currents

Paul and RK: Although thermodynamically feasible and intriguing, OTEC has not demonstrated financially competitiveness. Minor losses associated with pumping and heat transfer along the long pipes reduce the energy generated. Demonstration systems have been installed over the last 50 years but all rely on external funding to enable construction. Competitors such as solar panels are much cheaper. According to the US EIA, average utility construction costs for solar is less than $1.7 per watt. Still more expensive than natural gas construction at $1.0 per watt but independant of the need for fuel costs. Solar construction costs continue to drop.

OTEC cycles could benefit from combined cycles with water cooled solar panels, possibly improving the cost per watt over both OTEC alone and Solar alone since Solar efficiency improves with cooler temperatures with the possible benefit of desalinated water. More information can be found at tethys engineering.

RK, Good summary of the heat transfer from the sun to ocean. Almost all of the solar radiation is absorbed in the thin top layer of the ocean due to the optical properties. The surface of the ocean re-radiates a large portion of the heat to space as black body radiation at the ocean temperature of 297 Kelvin (need a weighted correction for temperature with latitude). Some is captured by the atmosphere in a hemispherical solid angle integrated over the water surface. Of the infrared frequency covered by CO2 absorption spectrum at a 200ppm concentration, almost 100% is captured and reradiated to space by the atmospheric black body radiation. Similarly, water vapor in the atmosphere has an absorption spectrum and reradiated in almost the same amount as CO2. You may infer that increasing CO2 concentration will have a very small effect on this process. Please see a physicist for details on this process and saturation. More information can be found from research by Happer and van Wijngaarden.

Dr Richard DeVos thank you for your contribution to the discussion

The primary source of energy that drives convection within the atmosphere and oceans is the Sun. Solar radiation, which includes visible light, ultraviolet (UV) radiation, and infrared (IR) radiation, provides the energy that heats the Earth's surface. The Sun also provides the energy that drives convection in the ocean and produces ocean currents. Convection currents are heat-driven cycles that occur in the air, ocean, and mantle. They are caused by a difference in temperature, often due to a differing proximity to a heat source. The difference in temperature relates directly to the density of the material, causing this effect. The heating of the Earth's surface and atmosphere by the sun drives convection within the atmosphere and ocean. This convection produces winds and ocean currents. The greater the pressure differences between a low-pressure area and a high-pressure area, the stronger the winds. The source of energy that drives mantle convection is heat whereas the source of energy that drives all other is solar energy. Mantle convection is how the Earth's mantle moves due to currents of convection. This global pattern along with prevailing global wind patterns and storm tracks, are driven by atmospheric convection. It all starts with solar radiation. Convection is the process of thermal energy exchange in fluids via the motion of matter within them. A bulk transfer of molecules within the fluid occurs. It occurs in both gases and liquids and leads to a cyclical effect. Both natural and forced convective heat transfer exist.