Theoretical analysis of retrieving atmospheric columnar mie optical depth from downward total solar radiative flux

1989 ◽  
Vol 6 (3) ◽  
pp. 313-323
Author(s):  
Qiu Jinhuan
Keyword(s):  
Theoretical Analysis ◽  
Optical Depth ◽  
Radiative Flux ◽  
Solar Radiative Flux

scholarly journals Relativistic Milne-Eddington Type Solutions with a Variable Eddington Factor for Relativistic Spherical Winds

2011 ◽  
Vol 2011 ◽  
pp. 1-10
Author(s):  
Jun Fukue
Keyword(s):  
Optical Depth ◽  
Power Law ◽  
Source Function ◽  
Flow Speed ◽  
Radiative Flux ◽  
Exponential Behavior ◽  
Background Density ◽  
Relativistic Treatment ◽  
Parallel Case ◽  
Expansion Effect

Relativistic radiative transfer in a relativistic spherical flow is examined in the fully special relativistic treatment. Under the assumption of a constant flow speed and using a variable (prescribed) Eddington factor, we analytically solve the relativistic moment equations in the comoving frame for several restricted cases, and obtain relativistic Milne-Eddington type solutions. In contrast to the plane-parallel case where the solutions exhibit the exponential behavior on the optical depth, the solutions have power-law forms. In the case of the radiative equilibrium, for example, the radiative flux has a power-law term multiplied by the exponential term. In the case of the local thermodynamic equilibrium with a uniform source function in the comoving frame, the radiative flux has a power-law form on the optical depth. This is because there is an expansion effect (curvature effect) in the spherical wind and the background density decreases as the radius increases.

scholarly journals Discovery of the Major Mechanism of Global Warming and Climate Change

2018 ◽  
Author(s):  
Paul C. Rivera
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Greenhouse Gases ◽  
Solar Irradiance ◽  
Radiative Forcing ◽  
Climate Model ◽  
Radiative Flux ◽  
North Pole ◽  
Major Mechanism ◽  
Solar Radiative Flux

Statistical analysis of the number of destructive earthquakes versus global temperature and greenhouse gases revealed very significant correlations. The motion of the North Pole, deduced from the geomagnetic polar shift data, is highly correlated with major earthquakes. This is an indication that the frequent occurrence of major earthquakes had increased earth’s obliquity and possibly induced global warming and emission of greenhouse gases. It was shown by a simple model developed here that seismic-induced oceanic force could enhance the obliquity leading to increased solar radiative flux on earth. The increase of the absorbed solar radiation due to polar tilt was also confirmed by SOLRAD model which computed a net gain of solar radiative forcing due to enhanced obliquity. SOLRAD also revealed a poleward gain of solar radiative flux which could have facilitated the observed polar amplification of global warming. Multiple regression analysis also showed that polar shift and solar irradiance played a major role in the temperature rise and CO2 increase in recent years. The analysis showed that obliquity change due to North Pole shift and total solar irradiance accounted for 63.5% and 36.4% respectively, while CO2 changes accounted for 0.1% of the observed global warming. Preliminary simulations conducted with EdGCM climate model also showed that enhanced obliquity increases the absorbed solar radiative flux, surface air and ocean temperatures, and decreases ocean ice cover. This study confirmed in several ways that earthquake-perturbed obliquity change, and not greenhouse effect, is the major mechanism governing the present global warming and climate change problem.

scholarly journals Computation of longwave radiative flux and vertical heating rate with 4A-Flux v1.0 as integral part of the radiative transfer code 4A/OP v1.5

2021 ◽  
Author(s):  
Yoann Tellier ◽  
Cyril Crevoisier ◽  
Raymond Armante ◽  
Jean-Louis Dufresne ◽  
Nicolas Meilhac
Keyword(s):  
Radiative Transfer ◽  
Heating Rate ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Specular Reflection ◽  
Radiative Flux ◽  
High Spectral Resolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Very High

Abstract. Based on advanced spectroscopic databases, line-by-line and layer-by-layer radiative transfer codes numerically solve the radiative transfer equation with a very high accuracy. Taking advantage of its pre-calculated optical depth look-up table, the fast and accurate radiative transfer model Automatized Atmospheric Absorption Atlas OPerational (4A/OP) calculates the transmission and radiance spectra for a user defined layered atmospheric model. Here we present a module, called 4A-Flux, developed and implemented into 4A/OP in order to include the calculation of the clear-sky longwave radiative flux profiles and heating rate profiles at a very high spectral resolution. Calculations are performed under the assumption of local thermodynamic equilibrium, plane-parallel atmosphere and specular reflection on the surface. The computation takes advantage of pre-tabulated exponential integral functions that are used instead of a classic angular quadrature. Furthermore, the sublayer variation of the Planck function is implemented to better represent the emission of layers with a high optical depth. Thanks to the implementation of 4A-Flux, 4A/OP model have participated in the Radiative Forcing Model Intercomparison Project (RFMIP-IRF) along with other state-of-the-art radiative transfer models. 4A/OP hemispheric flux profiles are compared to other models over the 1800 representative atmospheric situations of RFMIP, yielding an Outgoing Longwave Radiation (OLR) mean difference between 4A/OP and other models of −0.148 W .m−2 and a mean standard deviation of 0.218 W .m−2, showing a good agreement between 4A/OP and other models. 4A/OP is applied to the Thermodynamic Initial Guess Retrieval (TIGR) atmospheric database to analyze the response of the OLR and vertical heating rate to several perturbations of temperature or gas concentration. This work shows that 4A/OP with 4A-Flux module can successfully be used to simulate accurate flux and heating rate profiles and provide useful sensitivity studies including sensitivities to minor trace gases such as HFC134a, HCFC22 and CFC113. We also highlight the interest for the modeling community to extend intercomparison between models to comparisons between spectroscopic databases and modelling to improve the confidence in model simulations.

scholarly journals Discovery of the major mechanism of global warming and climate change

2018 ◽  
Author(s):  
Paul C. Rivera
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Solar Radiation ◽  
Greenhouse Gases ◽  
Forest Fires ◽  
Radiative Flux ◽  
Major Mechanism ◽  
Climate Simulations ◽  
Solar Radiation Model ◽  
Solar Radiative Flux

Statistical analysis of the number of destructive earthquakes versus global temperature and greenhouse gases revealed very significant correlations. This is a strong indication that the frequent occurrence of major earthquakes had increased earth’s obliquity and induced both global warming and emission of greenhouse gases (GHG) in recent years. It is further shown by a simple model developed here that seismic-induced oceanic pressure could enhance the obliquity leading to increased solar radiative flux on earth. The possible increase in the planetary obliquity was substantiated by the solar radiation model SOLRAD, which simulated an associated increase of absorbed solar radiation. The model also revealed a net poleward gain of solar radiative flux with enhanced obliquity which could be the cause of the observed polar amplification of global warming and climate change. Multiple regression analysis also showed that the sudden obliquity change since 1995 played a major role in the temperature rise and GHG increase, and coincided with the 10 warmest years on record. Climate simulations conducted with the EdGCM also showed that enhanced obliquity causes increased solar radiative flux, increased air and ocean temperature, and decline of ocean ice cover. The enhanced obliquity and absorbed solar radiation could have accelerated the melting of ice sheets and glaciers, exposure and degradation of permafrost regions, increased CO2 respiration fluxes from soil, and forest fires during summer. This study confirmed in several ways that earthquake-pressured obliquity change, and not greenhouse effect, is the major mechanism governing global warming and climate change presently occurring on earth.

scholarly journals Parameterization of The Single-Scattering Properties of Dust Aerosols in Radiative Flux Calculations

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 728 ◽  
Author(s):  
Meihua Wang ◽  
Jing Su ◽  
Xugang Li ◽  
Chen Wang ◽  
Jinming Ge
Keyword(s):  
Optical Depth ◽  
Radiative Forcing ◽  
Climate Model ◽  
Single Scattering ◽  
Radiative Flux ◽  
Dust Particles ◽  
Nonspherical Particle ◽  
Parameterization Schemes ◽  
Relative Errors ◽  
The Impact

In this study, we present parameterization schemes of dust single-scattering properties (SSPs) in order to establish a fast and accurate way to obtain the SSPs for dust shortwave radiative flux calculation. Based on the assumption that dust particles are spheroids, we represent a single nonspherical particle with a collection of monodisperse spheres that contain the same total surface area and volume as the original particle to convert the spheroid to a sphere. The SSPs of dust particles were parameterized in terms of the effective radius ( R e ) and imaginary part of the refractive index ( M i ). The averaged relative errors of the parameterized to the “exact” single-scattering properties, which refer to the results from the Mie theory program, are below 1.5%. To further quantify the impact of parametrization on the radiative flux simulation, we computed the radiative fluxes at both the top of the atmosphere (TOA) and the surface by using SSPs from the parameterization and the “exact”, respectively. The maximum relative errors were below 1% at both the TOA and the surface, proving that the SSPs of dust calculated by our parameterization schemes are well suited for radiative flux calculations. This parameterization differs from previous works by being formulated not only with R e but also with M i . We also investigated the sensitivity of dust-aerosol forcing to R e , M i , optical depth (τ), and solar zenith angle (SZA). The results show that the value of shortwave (SW) radiative forcing (RF) at the TOA changes from negative to positive as the M i is increasing, which means that, as the absorption of dust particles becomes stronger, more energy is kept in the atmosphere to heat the earth–atmosphere system. The SW RF gradually becomes less negative at the TOA and more negative at the surface with increasing R e , due to the decreases of reflection and transmission along with the single-scattering albedo decreasing. As the optical depth increases, the values of the SW RF decrease because of the strong attenuation for heavy loading. When SZA increases, the SW RF becomes more negative at both the TOA and the surface due to the long optical path at a large SZA. The errors induced from the parameterized SSPs of dust in the SW RF calculation are very small, which are less than 2.1%, demonstrating the accuracy of the parameterization and its reliability for climate model applications.

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