Thermal structure

Altitude dependence. The composition varies with altitude. Part of that vertical structure is due to the physical behavior of the atmosphere while part is due to the influence of trace substances (notably ozone and condensed water) on thermal structure and mixing. 

Role of composition in atmospheric physical process. The composition of the atmosphere plays a distinct set of roles in controlling and affecting certain physical processes of the atmosphere, most notably the thermal structure. 

Fluids on the Earth s surface that are in hydrostatic equilibrium may be stable or unstable depending on their thermal structure. In the case of freshwater (an incompressible fluid), density decreases with temperature above ca. 4°C. Warm water lying over cold water is said to be stable. If warm water underlies cold, it is buoyant it rises and is unstable. The buoyant force, F, on the parcel of fluid of unit volume and density p is ... 

Another major feature of the vertical thermal structure of the atmosphere is due to the presence of ozone, O3, in the stratosphere. This layer is caused by photochemical reactions involving oxygen. The absorption of solar UV radiation by O3 causes the temperature in the stratosphere and mesosphere to be much higher than expected from an extension of the... 

The resultant O3 layer is critically important to life on Earth as a shield against LTV radiation. It also is responsible for the thermal structure of the upper atmosphere and controls the lifetime of materials in the stratosphere. Many substances that are short-lived in the troposphere (e.g. aerosol particles) have lifetimes of a year or more in the stratosphere due to the near-zero removal by precipitation and the presence of the permanent thermal inversion and lack of vertical mixing that it causes. 

Since feedbacks may have a large potential for control of albedo and therefore temperature, it seems necessary to highlight them as targets for study and research. Besides the simple example above of cloud area or cloud extent, there are others that can be identified. High-altitude ice clouds, for example, (cirrus) have both an albedo effect and a greenhouse effect. Their occurrence is very sensitive to the amount of water vapor in the upper troposphere and to the thermal structure of the atmosphere. There may also be missing feedbacks. 

PIV velocity measurements made it possible to evaluate the flame temperature field [23], following the method demonstrated in Ref. [25]. The calculated thermal structure of lean limit methane flame is shown in Figure 3.1.7. The differences between the structures of lean limit methane and propane flames are fundamental. The most striking phenomenon seen from Figure 3.1.7 is the low temperature in the stagnation zone (the calculated temperatures near the tube axis seem unrealistically low, probably due to very low gas velocities in the stagnation core). 

Thermal structure of lean limit methane flame. Isotherms calculated from the measured gas velocity distribution. 

Loper DE, Stacey FD (1983) The dynamical and thermal structure of deep mantle plume. Phys Earth Planet Int 33 304-317... 

Mohammad Jafar Soltanian Fard-Jahromi and Ali Morsali (2010) Sonochemical synthesis of nanoscale mixed-ligands lead(II) coordination polymers as precursors for preparation of Pb2(S04)0 and PbO nanoparticles thermal, structural and X-ray powder diffraction studies. Ultrason Sonochem 17(2) 435-440... 

Pfilzner, M., A. Mack, N. Brehm, A. Leonard, and I. Romaschov (1999). Implementation and validation of a PDF transport algorithm with adaptive number of particles in industrially relevant flows. In Computational Technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications, vol. 397-1, pp. 93-104. ASME. 

Thermal/structural response models are related to field models in that they numerically solve the conservation of energy equation, though only in solid elements. Finite difference and finite element schemes are most often employed. A solid region is divided into elements in much the same way that the field models divide a compartment into regions. Several types of surface boundary conditions are available adiabatic, convection/radiation, constant flux, or constant temperature. Many ofthese models allow for temperature and spatially dependent material properties. 

The structural fire endurance of a structural system is a measure of its ability to resist collapse during exposure to a fire. The thermal/structural response models evaluate the time-temperature history within a solid exposed to a fire environment. The time-temperature history, or design fire exposure, can be a... 

Fig. 3.10 Thermal structure of a combustion wave and heat feedback processes therein.

The thermal structure of the combustion wave of a double-base propellant is revealed by its temperature profile trace. In the solid-phase reaction zone, the temperature increases rapidly from the initial temperature in the heat conduction zone, Tq, to the onset temperature of the solid-phase reaction, T , which is just below the burning surface temperature, T. The temperature continues to increase rapidly from T to the temperature at the end of the fizz zone, T, which is equal to the temperature at the beginning of the dark zone. In the dark zone, the temperature increases relatively slowly and the thickness of the dark zone is much greater than that of the solid-phase reaction zone or the fizz zone. Between the dark zone and the flame zone, the temperature increases rapidly once more and reaches the maximum flame temperature in the flame zone, i. e., the adiabatic flame temperature, Tg. 

Ramaswamy, V., and V. Ramanathan, Solar Absorption by Cirrus Clouds and the Maintenance of the Tropical Upper Troposphere Thermal Structure, J. Atmos. Sci., 46, 2293-2310 (1989). 

The red giant stage ends when helium in the core is exhausted. Again the core contracts and the thermal structure of the star becomes unstable. Convective mixing again reaches down toward the layers that have experienced nuclear burning. This mixing event is... 

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