Atmosphere density

FIG. 2-8 Temperatnre-entropy diagram for carbon monoxide. Pressure P, in atmospheres density p, in grams per cubic enthalpy H, in joules per gram. (From Must and Stewart, NBS Tech. Note 202, 1963.)... 

Figure 2. Magnitude of Rayleigh and sodium backscatter return as a function of atmospheric density.

A. One Atmosphere Densities. The densities or volume properties of solutions have been studied by a number of methods which are extensively reviewed elsewhere (4,5. 6,7) of all of the methods, only the magnetic float (7-14), the hydrostatic balance (3,15-20), the vibrating flow densimeter (21,22), and dilatometric (23,24,25) methods give data with sufficient precision to study the densities of dilute solutions. For more concentrated... 

We will occasionally use the term dense gas which is meant to describe a gas of a density high enough for induced spectra to appear. In more practical terms, this means roughly atmospheric densities or higher, but we hasten to add that even at much lower densities certain induced features are often discernible as will be seen below (Chapter 3). One atmosphere is certainly not a threshold below which all induced effects miraculously disappear. 

The dependence of v on particle diameter is explicit, but the independence is still implicit through the z dependence of atmospheric density and viscosity. For this application, it is a good approximation to assume -q = constant and... 

TABLE 2. LEVEL ATMOSPHERIC DENSITY VERSUS ALTITUDE ABOVE SEA... 

Atmospheric density must be known to convert atmospheric depth to altitude. For midlatitudes, elevation can be converted to atmospheric depth via the standard atmosphere (Lide 1999) ... 

Secondary cosmic ray flux and cosmic ray composition at the Earth s surface are complex quantities to evaluate, and in practice assumptions about the constancy of cosmic rays over timescales relevant to paleoaltimetry research. Short time scale variations in production rates, such as might result from the 11-year cyclicity in the cosmic ray flux due to solar flares (Raisbeck et al. 1990), will average out of the data over million-year timescales. Likewise, assumptions about the constancy of atmospheric density must be made so that atmospheric depth can be converted to elevation. 

Uncertainty in the depth history of a sample is a primary source of uncertainty for the cosmogenic-nuclide paleoaltimeter. Because of the >2000-fold difference in rock density versus atmospheric density, a 0.5-m uncertainty in depth is equivalent to >l-km uncertainty in altitude. Uncertainty in the depth of a sample during exposure is particularly problematic in regions where loess deposits may episodically bury a surface. For example, Hancock et al. (1999) find cosmogenic evidence of an ephemeral 0.5-1.5 m silt cap on currently uncapped, 600-ka terraces in the Wind River basin, Wyoming. The duration of time required to deposit a sedimentary layer may also result in a complex exposure history that can only be deduced with depth profiles and multiple nuclides (Riihimaki et al. 2006). However, Dunai et al. (2005) suggest that some deposits in the hyperarid Atacama Desert, Chile, have remained at the same depth without erosion or deposition for >20 Ma. 

Table 2.22 Variation in Weight with Atmospheric Density"...

No measurements of the source strength or atmospheric density are currently available. It is most likely that Me2S is converted into either dimethyl sulfoxide or S02, but no detailed reaction mechanisms have been proposed. 

Elence W decreases only very slowly at wind speeds above 50 mi / h, at least assuming that if not Eq. (14) in its entirety then at least this aspect of Eq. (14) retains at least approximate validity at Neptune-like temperatures. The singularity in (dW/dV)T at V = Omi/h is sufficiently weak that it has no effect on values of W itself.] Since standard atmospheric pressure at sea level on Earth is approximately lbar, for illustrative purposes and for argument s sake let us assume that the standard wind chill formula [Eq. (14)] retains at least approximate validity at the 1 bar level on Neptune, especially since the atmospheric density of 0.45 kg / m3 at the 1 bar level on Neptune is at least comparable to that at the 1 bar level on Earth. (We will appraise this assumption later in this Sect. 4.2, especially in the second-to-last paragraph thereof.) The temperature in Neptune s atmosphere at the 0.1 bar level is T = 55 K = — 218 °C = — 361 °F [65], Since Eq. (14) was derived for standard conditions (lbar atmospheric pressure on Earth), its accuracy may be reduced if it is applied at the 0.1 bar level on Neptune. If we nevertheless apply it at the 0.1 bar level on Neptune, we obtain, even with a slow (by Neptune standards) V = 50 mi / h wind, W = -544 °F = -320 °C = -47 K. 

One such is Venera 4, launched on June 12, 1967. It reached the planet on October 18 and dropped an instrument package containing two thermometers, a barometer, a radio altimeter, an atmospheric density gauge, 11 gas analyzers, and two radio transmitters. Data collected by these instruments were transmitted to the space vehicle "bus parked in orbit around the planet and then sent on back to Earth. After completing the transmission, the bus deployed a parachute to reduce its speed. It then descended into the Venusian atmosphere to an altitude of 15.51 miles (24.96 km), at which point communications were lost. 

Because of the stability of HF, the atmospheric densities of F and FO are very small and the effect of fluorine on odd oxygen is insignificant. The reaction of HF with 0(1D) is chemically possible, but is negligible due to the low abundance of this excited atom. The distribution of HF is therefore largely determined by the rates of the surface emission of fluorine containing gases, of photochemical destruction of these gases, and atmospheric dynamics. 

The rate of this reaction varies with the atmospheric density (M), leading to a nearly complete disappearance of free electrons below a certain altitude. The attached electron can be liberated, however, by several reactions ... 

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