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UWBRAD Modeling Summary. KCJ Version 1 Please update and improve. UWBRAD Modelling Summary. Uniform layer thickness Fresnel Reflection No attenuation. Assumptions. Constant layer thickness in firn Incoherent (energy) model Freq and temp independent e ’. Firn layering ignored
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UWBRAD Modeling Summary KCJ Version 1 Please update and improve
UWBRAD Modelling Summary Uniform layer thickness Fresnel Reflection No attenuation Assumptions • Constant layer thickness in firn • Incoherent (energy) model • Freq and temp independent e’ • Firn layering ignored • Seasonal temperature ignored • Freq and temp independent e’ UW Coherent Model • Firn layering required to match in situ data (is solution unique) • Statistical firn parameters can be deduced from in situ data • Number of firn layers influences the final Tb • Layers important to about 50 m depth • Surface temp, ice thickness and model can be used to explain SMOS data • Tb sensitive to temperature at depth • Scattering marginally important • Basal water extinguishes upwelling Cloud Model UW Scattering Model DMRT Reverberation is important at least under the assumptions Uniform layer thickness Fresnel Reflection No attenuation • Various thermodynamic constants - depth independent • Temperature Model • Ice/rock, ice/water, ice air boundary reflectivity • Rayleigh Scattering • Absorption Model • Ice thickness • Vertical Incidence • Oblique incidence • Firn layer reflectivity from density • Basal Reflectivity • Scattering (???) • Seasonal surface temperarture Simple Coherent Model + + Normal incidence Inputs
Some Questions • Given that observed Tb is an integrated effect, how unique are the model predictions? • Layering and reverberation seem to be important. How do these properties influence Tb as absorption, scattering and non uniform layer thickness are introduced into the models? • Are Fresnel reflection coefficients appropriate? • Is an improved scattering model required? • Is interface roughness important?
UWBRAD Modeling Paper Concept • Initial Tb model was limited by assumptions • Further analysis has indicated that assumptions must be further explored • Based on a progression of models and model intercomparisons, arrive at an optimal model for UWBRAD and for comparing modeled Tb with SMOS, Aquarius and SMAP. • Illustrate whether UWBRAD parameters need to be modified. • Illustrate how UWBRAD data can be processed in the context of the optimized modeling results to achieve desired temperature profiles