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| : "Help! I'm lost" - Ghost Photon |
In the Dredd Blog series "The Ghost Photons, 2, 3" it was pointed out that the reason the word 'ghost' is used is because a large number of oceanographers, commentators, and lay folks are not aware of the importance of infrared photons in the ocean.
But there is a branch of science ("Radiometry") that is quite aware of the reality of photons in the ocean:
"Radiometry is the science of the measurement of electromagnetic, or radiant, energy. It forms the cornerstone of radiative transfer studies in natural waters. In this chapter we introduce the fundamental concepts of radiometry and discuss, in particular, geometrical radiometry ... In our choice of nomenclature and symbols we generally follow the recommendations of the Committee on Radiant Energy in the Sea of the International Association of Physical Sciences of the Ocean (IAPSO; see Morel and Smith, 1982)."
(University Of Maine, emphasis added, Chapter 1, PDF). The particular focus is on the work of André Morel et alia:
"André Morel (1933-2012) was a prominent pioneer of modern optical oceanography, enabling significant advances in this field. Through his forward thinking and research over more than 40 years, he made key contributions that this field needed to grow and to reach its current status. This article first summarizes his career and then successively covers different aspects of optical oceanography where he made significant contributions ..."
(Shedding light on the sea: André Morel's legacy, emphasis added). The quotes concerning infrared photon dynamics in the ocean comes from The University of Maine internet site linked to above.
Here are some more quotes from that source:
"Pure sea water consists of pure water plus various dissolved salts, which average about 35 parts per thousand (35‰) by weight ... These salts increase scattering above that of pure water by about 30% ...[but also] increase absorption tremendously at extremely long ... [such as infrared photon] wavelengths.
(University of Maine, Chapter 3, emphasis added). Further:
"As we have stated, the real part n ["n = (real) index of refraction"] of the index of refraction determines the scattering properties of a medium. If n were truly constant, there would be no scattering. However, there are always variations of n within a material medium ... In pure sea water, the ions of dissolved salts cause additional molecular-scale fluctuations in n, and hence greater scattering. Proper treatment of this fluctuation theory of n is a difficult problem in statistical thermodynamics, which was solved by Einstein and Smoluchowski between 1908 and 1910. Morel (1974) and Shifrin (1988) give excellent reviews of the associated physics and mathematics. Austin and Halikas (1976) exhaustively reviewed the literature on measurements of the real index of refraction of bulk samples of sea water. Their report contains extensive tables and interpolation algorithms for the index of refraction (relative to air), n(8,S,T,p), as a function of wavelength (8 = 400!700 nm), salinity (S = 0!43‰), temperature (T = 0!30°C), and pressure (p = 10 5 !10 8 Pa, or 1 to 1080 atm). Figure 3.5 illustrates the general dependence of n on these four parameters: n decreases with increasing wavelength or temperature, and n increases with increasing salinity or pressure."
(University of Maine, Chapter 3, @ 3.6 Real Index of Refraction, emphasis added). Dredd Blog also uses those in situ values (wavelength, salinity, temperature, and pressure).
Dredd Blog uses the TEOS-10 nomenclature (TEOS-10 C++ library [ZIP file]) to modernize in situ salinity, in situ temperature, and in situ pressure in order to calculate Absolute Salinity, Pressure (via "Z ... height"), and Conservative Temperature.
Dredd Blog does so to derive, among other things, Potential Enthalpy ("heat content"), and from that to calculate infrared photon content.
Those calculations include data at all measured depths (In Search Of Ocean Heat - 19, Appendix to In Search Of Ocean Heat - 19).
I use my own C++ library to calculate photon content within the "potential enthalpy", which in TEOS-10 terms is "ocean heat content":
"So, here is a link and a quote from it that as been posted here previously:
'Potential temperature is used in oceanography as though it is a conservative variable like salinity; however, turbulent mixing processes conserve enthalpy and usually destroy potential temperature. This negative production of potential temperature is similar in magnitude to the well-known production of entropy that always occurs during mixing processes. Here it is shown that potential enthalpy—the enthalpy that a water parcel would have if raised adiabatically and without exchange of salt to the sea surface—is more conservative than potential temperature by two orders of magnitude. Furthermore, it is shown that a flux of potential enthalpy can be called 'the heat flux' even though potential enthalpy is undefined up to a linear function of salinity. The exchange of heat across the sea surface is identically the flux of potential enthalpy. This same flux is not proportional to the flux of potential temperature because of variations in heat capacity of up to 5%. The geothermal heat flux across the ocean floor is also approximately the flux of potential enthalpy with an error of no more that 0.15%. These results prove that potential enthalpy is the quantity whose advection and diffusion is equivalent to advection and diffusion of 'heat' in the ocean. That is, it is proven that to very high accuracy, the first law of thermodynamics in the ocean is the conservation equation of potential enthalpy. It is shown that potential enthalpy is to be preferred over the Bernoulli function. A new temperature variable called “conservative temperature” is advanced that is simply proportional to potential enthalpy. It is shown that present ocean models contain typical errors of 0.1°C and maximum errors of 1.4°C in their temperature because of the neglect of the nonconservative production of potential temperature ... and potential temperature, rests on an incorrect theoretical foundation ... it is perfectly valid to talk of potential enthalpy, h0,as the 'heat content' ..."
(Potential Enthalpy: Trevor J. McDougall, 2003, emphasis added). Two decades later the science is still there:
"While in situ temperature is an observed variable, its dependence on pressure (even for adiabatic variations of pressure at constant salinity) and its non-conservative nature under turbulent mixing processes have led to the adoption of Conservative Temperature in order to approximate the 'heat content' per unit mass of seawater."
(McDougall, T. J., Barker, P. M., Feistel, R., and Roquet, F.: A thermodynamic potential of seawater in terms of Absolute Salinity, Conservative Temperature, and in situ pressure, Ocean Sci., 19, 1719–1741, 2023)."
(In Search of Ocean Heat - 15). I note that "it is perfectly valid to talk of potential enthalpy, h0, as the 'heat content' ..." according to scientists McDougal, Barker, Feistel, and Roquet.
Here are a few more quotes from the University of Maine documents for your perusal:
"Once photons from the sun and sky have passed through the air-water
surface, they initiate a complex chain of scattering and absorption events
within the water body. The primary goal of this chapter is to develop the basic
equation, known as the radiance transfer equation, governing the behavior of
radiance within natural water bodies [...] elastic scattering [...] When a photon interacts with an atom or molecule, the photon may be absorbed, leaving the atom or molecule in a state with higher internal (electronic, vibrational, or rotational) energy. If the molecule (say) almost immediately returns to its original internal energy state by emitting a photon of the same energy as the absorbed photon, the process is called elastic scattering [...] inelastic, or transpectral, scattering" [...] However, the excited molecule may emit a photon of less energy (longer wavelength) than the incident photon. The molecule thus remains in an intermediate excited state and may at a later time emit another photon and return to its original state, or the retained energy may be converted to thermal or chemical energy. Indeed, if the molecule is initially in an excited state, it may absorb the incident photon and then emit a photon of greater energy (shorter wavelength) than the absorbed photon, thereby returning to a lower energy state. In either case the scattered (emitted) photon has a different wavelength than the incident (absorbed) photon, and the processes is called inelastic, or transpectral, scattering ... true absorption [...] true emission [...] Finally, all or part of the absorbed photon's energy may be converted into thermal (kinetic) energy, or into chemical energy (manifested, for example, in the formation of new chemical compounds). The conversion of a photon's energy into a nonradiant form is called true absorption. The reverse process is also possible, as when chemical energy is converted into light [or infrared photons]; this process is called true emission [...] In order to formulate the radiance transfer equation, it is convenient to imagine light [or infrared photons] in the form of many beams of photons coursing in all directions through each point of a water body, and to think of all the ways in which each beam's population of photons may be decreased or increased. Bearing in mind the preceding comments, the following six [or seven] processes are both necessary and sufficient to write down an energy balance equation for a beam of photons on the phenomenological level:
(i) loss of photons from the beam through scattering to other directions without change in wavelength (elastic scattering)
(ii) loss of photons from the beam through scattering (perhaps to other directions) with change in wavelength (inelastic scattering)
(iii) loss of photons from the beam through annihilation of photons by conversion of radiant energy to nonradiant energy (true absorption)
(iv) gain of photons by the beam through scattering (from other directions) without change in wavelength (elastic scattering)
(v) gain of photons by the beam through scattering (perhaps from other directions) with change in wavelength (inelastic scattering)
(vi) gain of photons by the beam through creation of photons by conversion of nonradiant energy into radiant energy (true emission)
[(vii) Second Law of Thermodynamics ... "A simple statement of the law is that heat always flows spontaneously from hotter to colder regions of matter" (Wikipedia) cf. Radiant Heat]
[...]Raman scattering [...] The energy of the scattered photon equals the energy of the incident photon plus or minus a vibrational or rotational energy difference of the molecule. Because these energy differences are determined by the molecule's structure, Raman scattering was recognized as a powerful tool for probing molecular structure, long before its oceanographic significance was realized. The above observations imply that the incident and scattered light [or infrared photons] are related by a frequency shift that depends on the molecule. The corresponding wavelength shift between the incident and scattered light [or infrared photons] also depends on the incident wavelength [and surrounding in situ temperature per the Second Law of Thermodynamics], as we shall see below."
(University of Maine documents). Thanks to the work of André Morel et alia we can calculate the path those photons could take to get to those depths using Radiometry formulas shown in the works located in the University of Maine books linked to here.
And there's this: (The Photon Current, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19); Quantum Oceanography, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).
The next post in this series is here, the previous post in this series is here.
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