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1.
E-BOOK
Demystifying Climate Models : A Users Guide to Earth System Models (2016)
Berlin, Heidelberg, New York, London : SpringerOpen
Keywords: Civil engineering ; Climate change management
Notes: This book demystifies the models we use to simulate present and future climates, allowing readers to better understand how to use climate model results. In order to predict the future trajectory of the Earth’s climate, climate-system simulation models are necessary. When and how do we trust climate model predictions? The book offers a framework for answering this question. It provides readers with a basic primer on climate and climate change, and offers non-technical explanations for how climate models are constructed, why they are uncertain, and what level of confidence we should place in them. It presents current results and the key uncertainties concerning them. Uncertainty is not a weakness but understanding uncertainty is a strength and a key part of using any model, including climate models. Case studies of how climate model output has been used and how it might be used in the future are provided. The ultimate goal of this book is to promote a better understanding of the structure and uncertainties of climate models among users, including scientists, engineers and policymakers.
Pages: XVII, 274 S., 4 schwarz-weiß Abbildungen, 58 Farbabbildungen
ISBN: 978-3-662-48957-4
2.
NASA TECHNICAL REPORTS
Derivation of photochemical information near 1 mbar from ozone and temperature data (1986)
Other Sources
Publication Date: 2011-08-18
Description: An analysis procedure has been developed for derivation of information about the photochemical behavior of ozone near 1 mbar by explicitly accounting for the dynamical transport terms in the continuity equation for perturbations from the zonal mean. The procedure is shown to be valid using data from a numerical transport model and is then applied to LIMS ozone and temperature data, using geostrophic winds to estimate the transport terms. The data study is restricted to March at 2, 1, and 0.7 mbar. Because the temperature deviations are dynamically produced, large temperature deviations are associated with significant ozone transport terms. The anticorrelation between the deviations of ozone and temperature disappears when the transport terms are small. The derived photochemical information is compared to photochemical theory. Although there is overall agreement in the magnitude as well as the latitude, altitude, and time dependencies, discrepancies are suggested which may be related to the long-standing failure of photochemical models to calculate ozone accurately near 1 mbar. The theory suggests that the addition of Cl(x) to the stratosphere will affect the relationship of ozone and temperature at 2 and 1 mbar. Comparison of the photochemical information derived from future ozone and temperature measurements with the results of the present analysis should provide a critical test of the photochemical scheme thought to describe the behavior of odd chlorine in the stratosphere.
Keywords: GEOPHYSICS
Type: Journal of Geophysical Research(ISSN 0148-0227); 91; 13153-13
Format: text
3.
NASA TECHNICAL REPORTS
Chemistry and transport in a three-dimensional stratospheric model - Chlorine species during a simulated stratospheric warming (1989)
Other Sources
Publication Date: 2011-08-18
Description: The distributions in the stratosphere of a variety of chemical species were calculated for a 6-day period during the February 1979 stratospheric major warming, using winds derived from a spectral forecast model which included O(x), NO(x), HO(x), and ClO(x) chemistries as well as longitudinally varying reaction rate coefficients and photolysis rates for these molecules. The results obtained indicate a particular importance of chemistry and transport for the Cl-containing species ClO, ClONO2, HCl, and HOCl. Dynamical effects dominate the variability of HCl, while diurnal effects dominate that of ClONO2 and ClO. The effects of strong planetary wave activity may be seen in terms of large longitudinal variability of the total HCl and ClONO columns in the stratosphere; in the middle and high northern latitudes, it is sufficiently large to exceed the diurnal variability of the column.
Keywords: GEOPHYSICS
Type: Journal of Geophysical Research(ISSN 0148-0227); 94; 1057-108
Format: text
4.
NASA TECHNICAL REPORTS
The minor stratospheric warming of January 1989 - Results from STRATAN, a stratospheric-tropospheric data assimilation system (1992)
Other Sources
Publication Date: 2011-08-23
Description: Using a stratospheric-tropospheric data assimilation system, referred to as STRATAN, a minor sudden stratospheric warming that occurred in January 1989 is investigated. The event had a maximum influence on the stratospheric circulation near 2 hPa. The zonal mean circulation reversed briefly in the polar region as the temperature increased 34 K in 3 days. The cause of the warming is shown to be the rapid development and subsequent movement of a warm anomaly, which initially developed in the midlatitudes. The development of the warm anomaly is caused by adiabatic descent, and the dissipation by radiative cooling. A brief comparison with the NMC analysis and temperature sounding data is also presented.
Keywords: METEOROLOGY AND CLIMATOLOGY
Type: Monthly Weather Review(ISSN 0027-0644); 120; 221-229
Format: text
5.
NASA TECHNICAL REPORTS
Application of a monotonic upstream-biased transport scheme to three-dimensional constituent transport calculations (1991)
Other Sources
Publication Date: 2011-08-23
Description: The application of van Leer's scheme, a monotonic, upstream-biased differencing scheme, to three-dimensional constituent transport calculations is shown. The major disadvantage of the scheme is shown to be a self-limiting diffusion. A major advantage of the scheme is shown to be its ability to maintain constituent correlations. The scheme is adapted for a spherical coordinate system with a hybrid sigma-pressure coordinate in the vertical. Special consideration is given to cross-polar flow. The vertical wind calculation is shown to be extremely sensitive to the method of calculating the divergence. This sensitivity implies that a vertical wind formulation consistent with the transport scheme is essential for accurate transport calculations. The computational savings of the time-splitting method used to solve this equation are shown. Finally, the capabilities of this scheme are illustrated by an ozone transport and chemistry model simulation.
Keywords: GEOPHYSICS
Type: Monthly Weather Review(ISSN 0027-0644); 119; 2456-246
Format: text
6.
NASA TECHNICAL REPORTS
The dynamics of the HSCT environment (1991)
Other Sources
Publication Date: 2011-08-18
Description: Assessments of the impact of aircraft engine exhausts on stratospheric ozone levels are currently limited to 2D zonally-averaged models which, while completely representing chemistry, involve high parameterization of transport processes. Prospective 3D models under development by NASA-Goddard will use winds from a data-assimilation procedure; the upper troposphere/lower stratosphere behavior of one such model has been verified by direct comparison of model simulations with satellite, balloon, and sonde measurements. Attention is presently given to the stratosphere/troposphere exchange and nonzonal distribution of aircraft engine exhaust.
Keywords: GEOPHYSICS
Type: AIAA PAPER 91-3156
Format: text
7.
NASA TECHNICAL REPORTS
Numerical advection algorithms and their role in atmospheric transport and chemistry models (1987)
Other Sources
Publication Date: 2011-08-18
Description: During the last 35 years, well over 100 algorithms for modeling advection processes have been described and tested. This review summarizes the development and improvements that have taken place. The nature of the errors caused by numerical approximation to the advection equation are highlighted. Then the particular devices that have been proposed to remedy these errors are discussed. The extensive literature comparing transport algorithms is reviewed. Although there is no clear cut 'best' algorithm, several conclusions can be made. Spectral and pseudospectral techniques consistently provide the highest degree of accuracy, but expense and difficulties assuring positive mixing ratios are serious drawbacks. Schemes which consider fluid slabs bounded by grid points (volume schemes), rather than the simple specification of constituent values at the grid points, provide accurate positive definite results.
Keywords: GEOPHYSICS
Type: Reviews of Geophysics(ISSN 8755-1209); 25; 71-100
Format: text
8.
NASA TECHNICAL REPORTS
Global ozone minima in the historical record (1986)
Other Sources
Publication Date: 2011-08-18
Description: The magnitude and structure of the global total ozone minimum between 1958 and 1962 is similar to that observed between 1979 and 1983. Analysis of the single station data that exhibit the most pronounced minima suggest that the spatial structure of the global minimum is different from the currently observed reduction. Very low north polar values were observed, but there is no indication of anomalously low ozone in Antarctica. The temporal relationship to the sun spot cycle is similar in both time periods. Rather than solar terrestrial interaction, however, a more likely explanation of the early 1960's reduction is normal climatology caused by a persistent period of planetary wave activity. Such a natural explanation may also be appropriate for the current depletion.
Keywords: GEOPHYSICS
Type: 13; 1244-124
Format: text
9.
NASA TECHNICAL REPORTS
Tracer transport for realistic aircraft emission scenarios calculated using a three-dimensional model (1995)
Other Sources
Publication Date: 2011-08-23
Description: A three-dimensional transport model, which uses winds from a stratospheric data assimilation system, is used to study the transport of supersonic aircraft exhaust in the lower stratosphere. A passive tracer is continuously injected into the transport model. The tracer source distribution is based on realistic scenarios for the daily emission rate of reactive nitrogen species for all forecasted flight routes. Winds are from northern hemisphere winter/spring months for 1979 and 1989; there are minimal differences between the tracer integrations for the 2 years. During the integration, peak tracer mixing ratios in the flight corridors are compared with the zonal mean and found to be greater by a factor of 2 or less. This implies that the zonal mean assumption used in two dimensional models is reasonable during winter and spring. There is a preference for pollutant buildup in the heavily traveled North Pacific and North Atlantic flight corridors. Pollutant concentration in the corridors depends on the position of the Aleutian anticyclone and the northern hemisphere polar vortex edge.
Keywords: ENVIRONMENT POLLUTION
Type: Journal of Geophysical Research(ISSN 0148-0227); 100; D3; p. 5203-5214
Format: text
10.
NASA TECHNICAL REPORTS
Thermodynamic balance of three-dimensional stratospheric winds derived from a data assimilation procedure (1993)
Other Sources
Publication Date: 2011-08-23
Description: The NASA/Goddard three-dimensional chemistry and transport model is driven by winds from a stratospheric data assimilation system. Synoptic- and planetary-scale patterns, apparent in satellite observations of trace constituents, are successfully reproduced for seasonal integrations. As model integrations proceed, however, the quality of simulations decreases, and systematic differences between calculation and measurement appear. The differences are explained by examining the zonal-mean residual circulation. The vertical velocity w-bar (sup star) is calculated two ways: (1) from the diabatic heating rates and temperature tendency and (2) from the Eulerian vertical velocity and the horizontal eddy heat flux convergence. The results from these calculations differ substantially. Periodic insertion of observational data during the assimilation process continually shocks the general circulation model and produces these differences, which leads to an overestimate of the mean vertical heat and cconstituent transport. Such differences are expected to be general to all data assimilation products. This interpretation is corroborated by two-dimensional (2D) model calculations. When w-bar(sup star) is calculated from (2), the 2D ozone evolution is unrealistic and qualitatively similar to the 3D model simulation. The 2D ozone evolution is reasonable when w-bar (sup star) from (1).
Keywords: METEOROLOGY AND CLIMATOLOGY
Type: Journal of the Atmospheric Sciences(ISSN 0022-4928); 50; 17; p. 2987-2993
Format: text