Die Wechselwirkung von Aerosol und Strahlung in der Atmosphäre beeinflusst stark die Energiebilanz der Erde. Durch die großräumige Erfassung der horizontalen und vertikalen Verteilung von Aerosoleigenschaften in der Atmosphäre liefern Fernerkundungstechniken einen wichtigen Beitrag zu unserem Verständnis des Klimasystems. Genaue Beobachtungen durch langfristige operationelle Satellitenmissionen und zuverlässige Referenzmessungen vom Boden aus sind auch für die Ableitung und Verbesserung satelliten- und modellgestützter Aerosoldatensätze unerlässlich. Dies gilt insbesondere über dem Ozean. Mittels Fernerkundungsmethoden werden in dieser Dissertation bestimmte optische Eigenschaften von Aerosol und dessen Strahlungseffekt untersucht. Ein Teil der Datengrundlage hierfür wurde auf fünf Fahrten mit dem Forschungsschiff Polarstern mittels eines multispektralen Schattenbandradiometers erhoben. Anhand dieser Daten werden die aus theoretischen Betrachtungen abgeleitete Unsicherheit der Irradianzmessung von etwa 2 % anhand eines Vergleichs mit Sonnenphotometerbeobachtungen an Land und auf dem Schiff bestätigt. Unter Verwendung Schiffs-gestützter Referenzdaten werden im Rahmen dieser Dissertation mehrere weitere Aerosoldatensätze evaluiert. Für zwei satellitengestützte Datensätze können die erwarteten Fehlergrenzen bestätigt und die vom Aerosoltyp abhängigen Einschränkungen aufgrund von Modellannahmen diskutiert werden. Darüber hinaus werden die optischen Eigenschaften von Aerosol in der CAMS-Reanalyse betrachtet. Dabei findet sich die größte Diskrepanz in der Aerosolabsorption, die von der CAMS-Reanalyse um etwa 30 % überschätzt wird. Schließlich wird der Strahlungseffekt von Aerosol für die Region Deutschland und das Jahr 2015 unter unbewölkten Bedingungen mit zwei komplementären Ansätzen untersucht. Hierbei werden Messungen der solaren Einstrahlung an 25 Stationen des Beobachtungsnetzes des Deutschen Wetterdienstes als Datengrundlage verwendet. Einerseits wird ein Ensemble von empirischen Modellen verwendet, um die direkte Strahlungswirkung von Aerosol am Boden mithilfe einer Fehlerminimierung zu bestimmen. Die zugrundeliegenden Annahmen über Aerosol- und atmosphärische Eigenschaften in diesen Modellen werden kritisch analysiert und diskutiert. Im zweiten Ansatz werden explizite Strahlungstransfersimulationen des Strahlungseffekts unter Verwendung der CAMS-Reanalyse genutzt. Weiterhin wird die Sensitivität der Simulationen auf Unsicherheiten in den Eingangsgrößen untersucht, und damit die resultierende Unsicherheit im Strahlungseffekt abgeschätzt. Nach Korrektur von systematischen Abweichungen in der CAMS-Reanalyse hat Aerosol im Jahre 2015 einen mittleren abkühlenden Strahlungseffekt von -10.6 Wm-2 am Boden in Deutschland. / The interaction of aerosol and radiation in the atmosphere exerts a strong influence on the Earth's energy balance. Remote sensing techniques provide an important contribution to our understanding of the climate system, by observing the horizontal and vertical distribution of aerosol properties in the atmosphere on a large scale. Accurate observations from long-term operational satellite missions and reliable ground-based reference measurements are essential for deriving and improving satellite- and model-based aerosol data sets. This is especially true over the ocean. In this dissertation, certain optical properties of aerosol particles and their radiation effect are investigated using remote sensing methods. Parts of the considered data basis were collected on five cruises with the research vessel Polarstern using a multispectral shadow-band radiometer. This unique data set contributes to the global available reference observations over the ocean by partially filling known gaps. On this database, an algorithm to evaluate shadow-band radiometer observations for the determination of spectral irradiance and optical properties of aerosol has been advanced. The basis algorithm was developed by the author as part of his master's thesis. The uncertainty of the irradiance measurement of about 2 % derived from theoretical considerations is validated by comparison with sun photometer observations on land and on ship. Using ship-borne reference data, several aerosol products are evaluated as part of this dissertation. For two satellite-based datasets, the expected error bounds has been confirmed and the aerosol-type dependent limitations due to model assumptions in the satellite retrievals are discussed. Furthermore, the optical properties of aerosol considered in the CAMS reanalysis are evaluated. The largest discrepancy is found in the aerosol absorption, which is overestimated by the CAMS reanalysis by about 30 %. Finally, the radiative effect of aerosol is investigated for the region of Germany and the year 2015 under cloud-free conditions using two complementary approaches. Here, measurements of solar irradiance at 25 stations of the observation network of the German Weather Service are used as a data basis. In the first approach, an ensemble of empirical models is used to determine the direct radiative effect of aerosols on the ground using error minimization. The underlying assumptions about aerosol and atmospheric properties in these models are critically analysed and discussed. The second approach quantifies the radiative effect by applying explicit radiative transfer simulations using CAMS reanalysis. The uncertainty in the radiative effect is estimated by studying the sensitivity of the simulations to uncertainties in the input variables. After correcting for systematic deviations in the CAMS reanalysis, aerosol has a cooling radiative effect of -10.6 Wm-2 on the ground in Germany in the annual mean of 2015.

Der Einfluss der direkten Sonnenstrahlung kann trotz Strahlungsschutz und Ventilation zu deutlichen Fehlern bei der Bestimmung der Lufttemperatur führen. Zur Verringerung des Strahlungsfehlers in einer ventilierten Hütte wurde um die Temperatur- und Feuchtesensoren doppelte Strahlungsschutzrohre angebracht. Vergleichsexperimente haben gezeigt, dass damit ein wesentlich besserer Schutz vor der direkten Sonnenstrahlung erreicht wurde. / The influence of direct solar radiation and – despite a radiation shelter and sufficient ventilation – may cause an overestimation of the air temperature. To reduce the influence of the direct radiation, a double radiation protection tube was mounted around the temperature sensor. A cross validation has demonstrated, that consequently a much better radiation protection was realized.

Shortwave solar radiation was measured in the late winter of 1967 by means of actinographs below the canopy of two lodgepole pine stands, one thinned and the other unthinned, in northern Utah. Observations were made at four randomly selected stations in each stand and at one station in a large clearing. Radiation available below the thinned and unthinned stands was compared, and radiation in the open was compared with radiation beneath each stand. Nearly a ll differences between stands were significant as were the differences between each stand and the open area. A close correlation was shown between total radiation in the open and total radiation beneath forest stands. It was concluded that the radiation beneath either the thinned or the unthinned stand was above the minimum (ca. 10 percent of full sunlight) required for adequate reproduction of Engelmann spruce and subalpine fir.

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography : leaves 120-121. / M.S.

No description available.

The transwall system, proposed and developed by Fuchs and McClelland, fulfills the function of a passive solar heating device as well as an architectural element the window. The significance of the transwall system, in the author's opinion, lies in its expression of technologies in an architectural way. Several directions for further development are suggested to modify the transwall system into a multifunction architectural element so as to maximize utility. These architectural uses are: (1) an adjustable thermal mass; (2) a passive cooling device; (3) an interior design element; (4) a component of a convertible greenhouse and living space; and (5) a shading device. / M. Arch.

Solar radiation pressure (SRP) is one of the major non-gravitational forces acting on spacecraft. Acceleration by radiation pressure depends on the radiation flux; on spacecraft shape, attitude, and mass; and on the optical properties of the spacecraft surfaces. Precise modeling of SRP is needed for dynamic satellite orbit determination, space mission design and control, and processing of data from space-based science instruments. During Earth penumbra transitions, sunlight is passing through Earth's lower atmosphere and, in the process, its path, intensity, spectral composition, and shape are significantly affected. This dissertation presents a new method for highly physical SRP modeling in Earth's penumbra called Solar radiation pressure with Oblateness and Lower Atmospheric Absorption, Refraction, and Scattering (SOLAARS). The fundamental geometry and approach mirrors past work, where the solar radiation field is modeled using a number of light rays, rather than treating the Sun as a single point source. This dissertation aims to clarify this approach, simplify its implementation, and model previously overlooked factors. The complex geometries involved in modeling penumbra solar radiation fields are described in a more intuitive and complete way to simplify implementation. Atmospheric effects due to solar radiation passing through the troposphere and stratosphere are modeled, and the results are tabulated to significantly reduce computational cost. SOLAARS includes new, more efficient and accurate approaches to modeling atmospheric effects which allow us to consider the spatial and temporal variability in lower atmospheric conditions. A new approach to modeling the influence of Earth's polar flattening draws on past work to provide a relatively simple but accurate method for this important effect. Previous penumbra SRP models tend to lie at two extremes of complexity and computational cost, and so the significant improvement in accuracy provided by the complex models has often been lost in the interest of convenience and efficiency. This dissertation presents a simple model which provides an accurate alternative to the full, high precision SOLAARS model with reduced complexity and computational cost. This simpler method is based on curve fitting to results of the full SOLAARS model and is called SOLAARS Curve Fit (SOLAARS-CF). Both the high precision SOLAARS model and the simpler SOLAARS-CF model are applied to the Gravity Recovery and Climate Experiment (GRACE) satellites. Modeling results are compared to the sub-nm/s^2 precision GRACE accelerometer data and the results of a traditional penumbra SRP model. These comparisons illustrate the improved accuracy of the SOLAARS and SOLAARS-CF models. A sensitivity analyses for the GRACE orbit illustrates the significance of various input parameters and features of the SOLAARS model on results. The SOLAARS-CF model is applied to a study of penumbra SRP and the Earth flyby anomaly. Beyond the value of its results to the scientific community, this study provides an application example where the computational efficiency of the simplified SOLAARS-CF model is necessary. The Earth flyby anomaly is an open question in orbit determination which has gone unsolved for over 20 years. This study quantifies the influence of penumbra SRP modeling errors on the observed anomalies from the Galileo, Cassini, and Rosetta Earth flybys. The results of this study prove that penumbra SRP is not an explanation for or significant contributor to the Earth flyby anomaly. / Ph. D.

The Earth Radiation Budget Experiment (ERBE) active-cavity radiometers are used to measure the incoming solar, reflected solar, and emitted longwave radiation from the Earth and its atmosphere. The radiometers are carried by the National Aeronautics and Space Administration's Earth Radiation Budget Satellite (ERBS) and the National Oceanic and Atmospheric Administration's NOAA-9 and NOAA-10 spacecraft. Four Earth-viewing nonscanning active-cavity radiometers are carried by each platform. Two of the radiometers are sensitive to radiation in the spectral range from 0.2 to 50 μm, while the other two radiometers are sensitive to radiation in the spectral range from 0.2 to 5.0 μm. Each set of radiometers comes in a wide-field-of-view (WFOV) and a medium-field-of-view (MFOV) configuration. The cavities of the shortwave (visible) radiometers are covered with a Suprasil® hemispherical dome to filter out the incoming longwave radiation. Knowledge of the optical and physical properties of the radiometers allows their responses to be predicted using a low-order physical model. A high-level, dynamic electrothermal end-to-end model which accurately predicts the radiometers dynamic output has also been completed. This latter model is used to numerically simulate the calibration procedures of the actual instruments. With calibration of the end-to-end model complete, a simulation of a phenomena referred to as the "solar blip" is conducted to investigate the instruments' responses to steep transient events. The solar blip event occurs when direct solar radiation is briefly incident to the active-cavity radiometric channels as the spacecraft passes into and out of the Earth's shadow. / Master of Science

This diploma thesis deals with the optimization of microclimate of an industrial building. There is required constant temperature with minimal fluctuations during manufacturing process in the building. Due to insufficient cooling power of air-conditioning system was objective to design a solution that ensures stability of internal temperature during production especially in summer and simultaneously should be the solution economically acceptable. Simulation shows original state defined problems. Some new or unusual materials for solar shading are reviewed in the thesis by the experimental measurements and by the comparative method. To each material is assigned shading coefficient according to Czech standards, thereby is achieved universality for calculations of heat gains resulting from solar radiation. By one part of the experiments and their evaluation is determined thickness of the standard single glass glazing. It is also determined proportional transmittance of solar radiation for certain multiwall polycarbonates, which are currently used as fillers of industrial skylights and production hall‘s window openings. From experiments resulting design is subjected to the simulation. Comparison of temperatures is shown for the time before the installation of designed solar shading and after the installation of the solar shading.

PhD (Physics) / Department of Physics / The knowledge of solar radiation in this dispensation is crucial. The lack of grid lines in the remote rural areas of South Africa necessitates the use of solar energy as an alternative energy resource. Solar radiation data is one of the primary factors considered for the installation of renewable energy devices and they are very useful for solar technology designers and engineers. In some developing countries, estimation of solar radiation becomes a challenge due to the lack of weather data. This scenario is also applicable to South Africa (SA) wherein there are limited weather stations and hence there is a dire need of estimating the global solar radiation data for all climatic regions. Using a five year global solar radiation (𝐻) and bright sunshine (𝑆) data from the Agricultural Research Council (ARC) and South African Weather Service (SAWS) in SA, linear Angstrom – Prescott solar empirical model was used to determine regression coefficients. MATLAB interface was used whereby the linear regression plots were drawn. Annual empirical coefficients of 22 stations were determined and later the provincial values. The range of the regression coefficients, a and b were 0.216 – 0.301 and 0.381 – 0.512 respectively. The 2006 estimated global solar radiation per station in a province calculated from the modified models were compared with the observed and statistically tested. The root mean square errors were less than 0.600 MJm−2day−1 while the correlation relation ranged from 0.782 – 0.986 MJm−2day−1. The results showed the regression coefficients performed well in terms of prediction accuracy. / NRF