<p><strong>Abstract.</strong> In the atmospheric boundary layer (ABL), incomplete mixing (i.e., segregation) results in reduced chemical reaction rates compared to those expected from mean values and rate constants derived under well mixed conditions. Recently, segregation has been suggested as a potential cause of discrepancies between modelled and measured OH radical concentrations, especially under high isoprene conditions. Therefore, the influence of segregation on the reaction of OH radicals with isoprene has been investigated by modelling studies and one ground-based and one aircraft campaign.</p> <p>In this study, we measured isoprene and OH radicals with high time resolution in order to directly calculate the influence of segregation in a low-NO<sub>x</sub> and high-isoprene environment in the central Amazon basin. The calculated intensities of segregation (<i>I</i><sub>s</sub>) at the Amazon Tall Tower Observatory (ATTO) above canopy top are in the range of values determined at a temperate deciduous forest (ECHO-campaign) in a high-NO<sub>x</sub> low-isoprene environment, but stay below 10&#8201;%. To establish a more general idea about the causes of segregation and their potential limits, further analysis was based on the budget equations of isoprene mixing ratios, the variance of mixing ratios, and the balance of the intensity of segregation itself. Furthermore, it was investigated if a relation of <i>I</i><sub>s</sub> to the turbulent isoprene surface flux can be established theoretically and empirically, as proposed previously. A direct relation is not given and the amount of variance in <i>I</i><sub>s</sub> explained by the isoprene flux will be higher the less the influence from other processes (e.g., vertical advection) is and will therefore be greater near the surface. Although ground based values of <i>I</i><sub>s</sub> from ATTO and ECHO are in the same range, we could identify different dominating processes driving <i>I</i><sub>s</sub>. For ECHO the normalized variance of isoprene had the largest contribution, whereas for ATTO the different transport terms expressed as a residual were dominating. To get a more general picture of <i>I</i><sub>s</sub> and its potential limits in the ABL, we also compared these ground based measurements to ABL modelling studies and results from an aircraft campaign. The ground based measurements show the lowest values of the degree of inhomogenous mixing (<&#8201;20&#8201;%, mostly below 10&#8201;%). These values increase if the contribution of lower frequencies is added. Values integrated over the whole boundary layer (modelling studies) are in the range from 10&#8201;% to 30&#8201;% and aircraft measurements integrating over different landscapes are amongst the largest reported. This presents evidence that larger scale heterogeneities in land surface properties contribute substantially to <i>I</i><sub>s</sub>.</p>
The zonal averages of temperature (the so-called normal temperatures) for numerous parallels of latitude published between 1852 and 1913 by Dove, Forbes, Ferrel, Spitaler, Batchelder, Arrhenius, von Bezold, Hopfner, von Hann, and Börnstein were used to quantify the global (spherical) and spheroidal mean near-surface temperature of the terrestrial atmosphere. Only the datasets of Dove and Forbes published in the 1850s provided global averages below
The solar climate of our Moon is analyzed using the results of numerical simulations and the recently released data of the Diviner Lunar Radiometer Experiment (DLRE) to assess (a) the resulting distribution of the surface temperature, (b) the related global mean surface temperature s T , and (c) the effective radiation temperature e T often considered as a proxy for s T of rocky planets and/or their natural satellites, where e T is based on the global radiation budget of the well-known "thought model" of the Earth in the absence of its atmosphere. Because the Moon consists of similar rocky material like the Earth, it comes close to this thought model. However, the Moon's astronomical features (e.g., obliquity, angular velocity of rotation, position relative to the disc of the solar system) differ from that of the Earth. Being tidally locked to the Earth, the Moon's orbit around the Sun shows additional variation as compared to the Earth's orbit. Since the astronomical parameters affect the solar climate, we predicted the Moon's orbit coordinates both relative to the Sun and the Earth for a period of 20 lunations starting May 24, 2009, 00:00 UT1 with the planetary and lunar ephemeris DE430 of the Jet Propulsion Laboratory of the California Institute of Technology. The results revealed a mean heliocentric distance for the Moon and Earth of 1.00124279 AU and 1.00166376 AU, respectively. The mean geocentric distance of the Moon was 384792 km. The synodic and draconic months deviated from their respective means in a range of −5.7 h to 6.9 h and ±3.4 h, respectively. The deviations of the anomalistic months from their mean range between −2.83 d and 0.97 d with the largest negative deviations occurring around the points of inflection in the curve that represents the departure of the Open Access slab e M T T , 0.743 ≅. The DLRE observations suggest that in the case of rocky planets and their natural satellites, the globally averaged surface temperature is notably lower than the effective radiation temperature. They differ by a factor that depends on the astronomical parameters especially on the angular velocity of rotation.
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