A convenient practical model for accurately estimating the total entropy (ΣS_i) of atmospheric gases based on physical action is proposed. This realistic approach is fully consistent with statistical mechanics, but reinterprets its partition functions as measures of translational, rotational, and vibrational action or quantum states, to estimate the entropy. With all kinds of molecular action expressed as logarithmic functions, the total heat required for warming a chemical system from 0 K (ΣS_iT) to a given temperature and pressure can be computed, yielding results identical with published experimental third law values of entropy. All thermodynamic properties of gases including entropy, enthalpy, Gibbs energy, and Helmholtz energy are directly estimated using simple algorithms based on simple molecular and physical properties, without resource to tables of standard values; both free energies are measures of quantum field states and of minimal statistical degeneracy, decreasing with temperature and declining density. We propose that this more realistic approach has heuristic value for thermodynamic computation of atmospheric profiles, based on steady state heat flows equilibrating with gravity. Potentially, this application of an action principle can provide better understanding of emergent properties of many natural or evolving complex systems, including modelling of predictions for global warming.

Action mechanics showing torques result from rates of variation in impulsive action motivated a new method to estimate maximum power from wind turbines. Newton’s third law of equality of action and reaction provides a strictly causal mechanism of wind power from the deflection of wind momentum by twice its angle (θ) of incidence on rotor blades. The transverse reaction needed to conserve deflected wind momentum provides the turning moment for turbine rotation. Action mechanics integrates impulsive wind action on turbine blades as differing torques (ʃmrvdθ/dt ≡ mv2 ) exerted on rotor surfaces at each radius. Windward torque (Tw) is estimated from rotor dimensions, the angle of wind incidence and radial action of wind impulses on the blade surfaces (also ʃmrvdθ/dt ≡ mv2). A leeward torque (Tb) is exerted as back reaction on turbine blades parallel to the plane of rotation of the blade. Net torque is then converted to potential power (Tw - Tb)Ω by the angular velocity (Ω) of the turbine rotors, a function of tip speed ratio to wind speed. Better predictions of limits to wind power can be made, by including control of optimal wind angle and blade length. An analysis of the equivalence of deflected air momentum on turbine blades or air foils for aircraft reveals that even the lifting action on air foils can be explained by the normal reaction to the momentum in an air stream, also deflected by an angle twice that (2θ) of incidence. Release of vortical field energy from laminar flow of air in winds as heat is predicted in turbulent wakes, possibly affecting achievement of maximum power output by wind farms. Significant heat release by downwind turbulence from vortical energy requires their careful location. Diligence demands that use of windfarms as sources of renewable energy should minimize any environmental impacts, such as drying of landscapes. Received: 7 July 2023 | Revised: 23 August 2023 | Accepted: 28 August 2023 Conflicts of Interest The authors declare that they have no conflicts of interest to this work.

Seasonal oscillations in the partial pressure of carbon dioxide (pCO₂) in the Earth’s atmosphere, stronger in northern latitudes, are assumed to show that terrestrial photosynthesis exceeds respiration in summer, reducing the pCO₂ in air but increasing its value in winter when respiration exceeds photosynthesis. We disagree, proposing that variation in the temperature of the surface mixing zone of seawater also reversibly regulates the pCO₂ in air as a non-equilibrium process between air and seawater. We predict by thermal modelling that carbonate (CO₃²⁻) concentration in the surface mixed layer seawater declines in winter by conversion to bicarbonate with CaCO₃ (calcite or aragonite) becoming more soluble and, proportional to the fall of temperature, calcite decalcifying more strongly, allowing more CO₂ emission to air. Paradoxically, the increasing CO₂ concentration in seawater favoring photosynthesis peaking in mid-summer declines simultaneously in autumn and early winter, forced by boundary layer fugacity into phase transfer to the atmosphere, supporting peak atmospheric pCO₂ by late winter. These physico-chemical processes reverse in late winter and spring as seawater warms favoring calcification, fugacity forcing CO₂ from the atmosphere as bicarbonate declines and carbonate increases, augmenting suspended calcite particles by several percent. Our numerical computation predicts that the larger range of thermal fluctuations in the northern hemisphere could reversibly favor absorption from air of more than one mole of CO₂ per square meter in summer with calcite formation potentially augmenting shallow limestone reefs, despite falling pH, if there is a trend for increasing seawater temperature. Another assumption we challenge is that upwelling and advection from deeper water is the sole cause of increases in dissolved inorganic carbon (DIC) and alkalinity in surface waters, even in the southern hemisphere. Instead, some calcite dissolution is favored as water temperature falls near the surface. Standard enthalpy analysis of key DIC reactions indicates why this oscillation is more obvious in the northern hemisphere with seasonal variations in water temperature (ca. 7.1 °C) being almost twice those in the southern hemisphere (ca. 4.7 °C) with a greater depth of the surface mixing zone of seawater in the southern oceans. Questions remain regarding the relative rates of biotic and abiotic inorganic precipitation and dissolution of CaCO₃ in the mixing zone. In summary, rapid biogenic calcification is favored by summer photosynthesis, but slower abiotic calcification is also more likely in warmer water. We conclude that the relative significance of terrestrial biotic and seawater abiotic processes in seawater on the seasonal oscillation in the atmosphere can only be assessed by direct seasonal measurements in seawater.

In the modern era, agriculture must seek to be environmentally sustainable, an obligation now considered as a social contract. This demands that its activities do no significant harm, where the natural resources sustaining it are fully safeguarded, but of necessity in the context of profitable agriculture. The requirement to minimise the environmental impact of the necessary agrochemicals and pesticides in waterways is especially demanding. In the past 20 years, the Australian cotton industry has approached this obligation in various ways, needing extensive planning, learning from past experiences, but it can be legitimately claimed, with significant success. This success has been achieved at some cost, requiring large numbers of personnel, time and resources. This review aims to document the strategies that have been employed, how these required effective research management and how the research data generated was applied. To the extent that this complex program of participatory action has succeeded, while also acknowledging some dramatic failures, other areas of agriculture can also benefit by identification of the key factors contributing to success.