1. UWBRAD meeting May 20, 2014 Leung Tsang, Shurun Tan, Tianlin Wang Coherent Wave Effects in Layering & Incoherent Model Inter-Comparison

2. Physics behind coherent wave effects Part I

3. Model of Layering Effects Density profile: (Drinkwater 2004) Modified by damping Gaussian Noise (Macelloni and Brogioni) Standard deviation Damping factor Layer thickness: Average of layer thickness Standard deviation of layer thickness Total layer thickness

4. Reflection and Emission Effective permittivity: Absorption coefficient: No scattering effects included in current model. Focus on coherent wave interference. Maxwell-Garnett mixing formula Ice permittivity empirical model of Matzler and Wegmuller, 2006

5. Temperature Profile Temperature profile (Jezek et al. 2013)

6. Tb of coherent model shows resonance for fixed layer thickness with density fluctuation. 150 realization

7. Incoherent model is not sensitive to layer thickness variation. Tb of coherent model shows resonance for low frequency, and the resonance mitigates for higher frequency. With moderate layer thickness variation, Tb of coherent model gets a minimum around 1GHz. 1950 realization

8. 150 realization

9. When average layer thickness is large, Tb of coherent model converges to incoherent model as standard deviation of layer thickness increases. 150 realization

10. Note there is no strong resonance over angle after statistical average. The difference in Tb between coherent and incoherent model is due to the resonance with respect to frequency. 150 realization

11. Incoherent approach Part II Incoherent model Inter-comparison Temperature profile with seasonal swing near surface

12. Smooth density profile Layer thickness: 0 to 100m  1000 layers 10 cm each 100 to 300m  400 layers 50 cm each 300 to 3200m  579 layers 5.0086m each At 3200m  water base at ~269K (temp of the last ice layer) with ε =85.9 + 12.72i

13. Noisy density profile 1 realization

14. Noisy density profile 150 realization average UW model with scattering is lower than UW model without scattering by about 3K. UW model without scattering is slightly larger than Marco’s result for H- pol implying that the scattering effects accounts more with multiple reflection. UW model with scattering is closer to Marco’s results also implying the increase of scattering importance with multiple reflection.