Journal of Radio Electronics. eISSN 1684-1719. 2025. ¹3
Full text in Russian (pdf)
DOI: https://doi.org/10.30898/1684-1719.2025.3.8
MODEL OF EMISSION FROM MELTING SNOWPACK
IN THE MICROWAVE RANGE
V.A. Golunov
Kotelnikov IRE RAS, Fryazino branch
141120, Russia, Fryazino, Vvedenskogo sq., 1
The paper was received December 4, 2024.
Abstract. To model the emission, the snowpack is considered as a two-layer medium, of which the top layer is melting, and the lower layer is dry snow. The model is based on experimental data at frequencies of 22.2 GHz, 37.5 and 140 GHz. The recording of the radio brightness temperature of the melting snow cover was accompanied by measurements of the volume density of the liquid phase of water in the top layer of snow. It has been experimentally established that the volumetric moisture content of the upper layer of snow increases linearly from zero to 3 % during the first hour of its melting in sunny weather conditions. In order to accurately reproduce the time dependence of the brightness temperature of the melting snow cover during modeling, it was necessary to assume that the effect of volume scattering in the melting layer is negligible compared to its absorption. It is shown that the model of a melting layer as a mixture of wet ice particles and inclusions of the liquid phase of water embedded in an air background is able to reproduce at frequencies of 37.5...140 GHz the properties of a medium with the dominance of absorption in comparison with volume scattering at wetness of ice particles of at least 2.5 %. Thus, the increase in the radio brightness temperature of melting snow is due to an increase in the contribution of the melting layer’s own radiation and an exponential weakening of the contribution of the radiation of the underlying dry snow by the melting layer. Retrieval of the melting layer thickness based on the developed model showed that the maximum value of the radio brightness temperature of melting coarse-grained snow cover, close to 273 K, is achieved with a layer thickness of 1 cm at 140 GHz, 5...7 cm at 37.5 GHz and 8 cm at 22.2 GHz.
Key words: microwaves, melting snow, brightness temperature, modeling, scattering, absorption, calorimeter, melting layer thickness.
Financing: The work was carried out within the framework of the state task of the Kotelnikov Institute of Radioengineering and Electronics (IRE) of Russian Academy of Sciences.
Corresponding author: Golunov Valery Alekseevich, golsnow@mail.ru
References
1. Boyarskii D. A. et al. Inclusion of scattering losses in the models of the effective permittivity of dielectric mixtures and applications to wet snow //Journal of electromagnetic waves and applications. – 1994. – Ò. 8. – ¹. 11. – Ñ. 1395-1410. http://doi.org/10.1163/156939394X00281
2. Boyarskii D. A., Tikhonov V. V. Microwave effective permittivity model of media of dielectric particles and applications to dry and wet snow //Proceedings of IGARSS'94-1994 IEEE International Geoscience and Remote Sensing Symposium. – IEEE, 1994. – Ò. 4. – Ñ. 2065-2067. http://doi.org/10.1109/IGARSS.1994.399652
3. Kuznetsov I. V., Fedoseev L. I., Shvetsov A. A. Snow cover radiometry in the near millimeter wavelength range //Radiophysics and quantum electronics. – 1997. – Ò. 40. – ¹. 9. – Ñ. 745-752. https://doi.org/10.1007/BF02676525
4. Boyarskii D. A., Tikhonov V. V. Modeling VHF emissivity of snow cover with account of its stratigraphy //Radiophysics and Quantum Electronics. – 1999. – Ò. 42. – ¹. 9. – Ñ. 742-752. http://doi.org/10.1007/BF02676860
5. Cagnati A. et al. Study of the snow melt–freeze cycle using multi-sensor data and snow modeling //Journal of Glaciology. – 2004. – Ò. 50. – ¹. 170. – Ñ. 419-426. https://doi.org/10.3189/172756504781830006
6. Macelloni G. et al. Monitoring of melting refreezing cycles of snow with microwave radiometers: The Microwave Alpine Snow Melting Experiment (MASMEx 2002-2003) //IEEE Transactions on Geoscience and Remote Sensing. – 2005. – Ò. 43. – ¹. 11. – Ñ. 2431-2442. http://doi.org/10.1109/TGRS.2005.855070
7. Tedesco M. et al. Brightness temperatures of snow melting/refreezing cycles: Observations and modeling using a multilayer dense medium theory-based model //IEEE Transactions on Geoscience and Remote Sensing. – 2006. – Ò. 44. – ¹. 12. – Ñ. 3563-3573. http://doi.org/10.1109/TGRS.2006.881759
8. Pan J., Jiang L., Zhang L. Wet snow detection in the south of China by passive microwave remote sensing //2012 IEEE International Geoscience and Remote Sensing Symposium. – Ieee, 2012. – Ñ. 4863-4866. http://doi.org/10.1109/IGARSS.2012.6352523
9. Ulaby F. T., Stiles W. H. Microwave response of snow //Advances in Space Research. – 1981. – Ò. 1. – ¹. 10. – Ñ. 131-149. https://doi.org/10.1029/JC085iC02p01037
10. Colbeck S.C. The geometry and permittivity of snow at high frequencies //Journal of Applied Physics. – 1982. – Ò. 53. – ¹. 6. – Ñ. 4495-4500. http://doi.org/10.1063/1.331186
11. Ulaby F., Moore R., Fung A. Microwave Remote Sensing: Active and Passive, vol. 3, Artech House //Inc., Norwood, Massachusetts. – 1986.
12. Sihvola A. H. Electromagnetic mixing formulas and applications. – Iet, 1999. – ¹. 47.
13. Golunov V.A. Spektral'nye osobennosti teplovogo izlucheniya tayushchego snezhnogo pokrova [Spectral features of emission from melting snow cover] // XIV Vses. konf. po raspr. r/voln. Tezisy dokladov, chast' 2. - Leningrad, 1982. - Ñ. 193-195 (In Russian).
14. Golunov V. A., Korotkov V. A., Sukhonin E. V. Effektyi rasseyaniya pri izluchenii millimetrovyih voln atmosferoy i snezhnyim pokrovom [Scattering effects under the millimeter wave emission from atmosphere and snow cover]. Itogi Nauki i Tekhniki. ser. //Radiotekhnika. – 1990. - Vol. 41. - P. 68-136. (In Russian).
15. Ishimaru A. et al. Wave propagation and scattering in random media. – New York : Academic press, 1978. – Ò. 2. – Ñ. 148-166.
16. Wiesmann A., Mätzler C. Microwave emission model of layered snowpacks //Remote sensing of environment. – 1999. – Ò. 70. – ¹. 3. – Ñ. 307-316. http://doi.org/10.1016/S0034-4257(99)00046-2
17. Golunov V. A. Spektral'naya zavisimost' koefficienta pogloshcheniya mikrovolnovogo izlucheniya v tayushchem snege [Spectral dependence of the microwave absorption coefficient of melting snow]. // Journal of Radio Electronics. – 2024. (in press).
18. Samojlov O.YA. Ob issledovaniyah struktury vody [On the study of water structure] // Zhurnal strukturnoj himii– 1963. - ¹4. - Ñ. 499-501.
19. Kuz'min P. P. Process tayaniya snezhnogo pokrova [The process of melting snow cover]. – L.: Gidrometeoizdat, 1961.
20. Dolov M. A., Halkechev V. A. Fizika snega i dinamika snezhnyh lavin [Physics of snow and dynamics of snow avalanches] //L.: Gidrometeoizdat. – 1972.
21. Kuz'min P. P. Formirovanie snezhnogo pokrova i metody opredeleniya snegozapasov [Formation of snow cover and methods for determining snow reserves]. – L.: Gidrometeoizdat, 1960.
22. Elachi C., Van Zyl J. J. Introduction to the physics and techniques of remote sensing. – John Wiley & Sons, 2021.
23. Dyunin A. K. V carstve snega [In the kingdom of snow]. / Otv. red. P. I. Mel'nikov. — Novosibirsk: Nauka, Sibirskoe otdelenienie, 1983.
For citation:
Golunov V.A. Model of emission from melting snowpack in the microwave range. // Journal of Radio Electronics. – 2025 – ¹ 3. https://doi.org/10.30898/1684-1719.2025.3.8 (In Russian)