| Model ID: | M00026 | ||||||
| Model Name: | One Dimensional Microwave Atmospheric Radiative Transfer Mode | ||||||
| Encoders: |
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| Key words: | Atmosphere, Microwave, Radiative transfer, Microwave Radiometer | ||||||
| Model Type: | Theoretical model | ||||||
| Latest Modified: | 2014/3/29 0:00:00 | ||||||
| Submission Date: | 2014/3/29 0:00:00 | ||||||
| Abstract: | The model is able to simulate radiance at top of atmosphere received by Satellite by input of atmospheric profiles (include height profiles, pressure profiles, temperature profiles, humidity profiles, cloud and other hydrometer profiles), microwave radiometer characterization (include frequency bands information, incident angle and so on), radiance and reflectance information of surface and cosmic background radiation information. The information of radiance and reflectance of underlying surface can also be supplied by other surface radiance and reflectance models, which can combine with this radiative transfer model to build an integrated model to simulate the interaction of underlying surface and atmosphere. This version of program can be used to simulate the observed brightness temperature by AMSR-E. | ||||||
| Equation: |
| 1 |
Name: Land surface temperature
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Parameter type: double
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Physic Entity: Temperature of land surface, (Unit: K)
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| 2 |
Name: Land surface emissivity
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Parameter type: double
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Physic Entity: Land surface emissivity corresponding to bands of AMSR-E
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| 3 |
Name: Number of Atmosphere layers
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Parameter type: double
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Physic Entity: Number of Atmosphere layers
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| 4 |
Name: Atmospheric Profiles
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Parameter type: double
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Physic Entity: Atmospheric profiles, include: height profile, relative humidity profile, temperature profile, pressure profile, cloud liquid water profile, rain profile, ice profile, graupel profile, hail profile
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| Title: | A melting-layer model for passive/active microwave remote sensing applications. Part I: Model formulation and comparison with observations | ||||||||||||||||||||||||
| Authors: |
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| Cited by: | Journal of Applied Meteorology | ||||||||||||||||||||||||
| Abstract: | In this study, a 1D steady-state microphysical model that describes the vertical distribution of melting precipitation particles is developed. The model is driven by the ice-phase precipitation distributions just above the freezing level at applicable grid points of “parent” 3D cloud-resolving model (CRM) simulations. It extends these simulations by providing the number density and meltwater fraction of each particle in finely separated size categories through the melting layer. The depth of the modeled melting layer is primarily determined by the initial material density of the ice-phase precipitation. The radiative properties of melting precipitation at microwave frequencies are calculated based upon different methods for describing the dielectric properties of mixed-phase particles. Particle absorption and scattering efficiencies at the Tropical Rainfall Measuring Mission Microwave Imager frequencies (10.65–85.5 GHz) are enhanced greatly for relatively small (0.1) meltwater fractions. The relatively large number of partially melted particles just below the freezing level in stratiform regions leads to significant microwave absorption, well exceeding the absorption by rain at the base of the melting layer. Calculated precipitation backscatter efficiencies at the precipitation radar frequency (13.8 GHz) increase with particle meltwater fraction, leading to a “bright band” of enhanced radar reflectivities in agreement with previous studies. The radiative properties of the melting layer are determined by the choice of dielectric models and the initial water contents and material densities of the “seeding” ice-phase precipitation particles. Simulated melting-layer profiles based upon snow described by the Fabry–Szyrmer core-shell dielectric model and graupel described by the Maxwell-Garnett water matrix dielectric model lead to reasonable agreement with radar-derived melting-layer optical depth distributions. Moreover, control profiles that do not contain mixed-phase precipitation particles yield optical depths that are systematically lower than those observed. Therefore, the use of the melting-layer model to extend 3D CRM simulations is likely justified, at least until more-realistic spectral methods for describing melting precipitation in high-resolution, 3D CRMs are implemented. |
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