Spaceborne radar identification of desert regions as suppliers of dust into the atmosphere
Atmosphere dust represents a mixture of minute particles of various salts and minerals. Also it contains remains of animal and vegetable organisms, spores of causative organisms and so forth. The dust is carried by winds over considerable distances and its presence in the atmosphere is among the factors which have essential influence on the global climate of the Earth. At present the Aeolian processes and their consequences are monitored from space using multispectral optical systems (TOMS, METEOSAT, MODIS etc.) only. These are not capable of reliable identification of the areas themselves that are sources of raising the dust in the atmosphere independently of the cloudiness, solar illumination and transparency of the atmosphere. This problem can be solved with the use of space radar systems of the Earth remote sensing. The paper presents the first results of the development of a radar technique of identification of desert regions in which dust from the surface is transported up into the atmosphere under the action of Aeolian processes. The work was performed using data of Earth remote sensing SAR Envisat-1 obtained over deserts of Mauritania. Specific features of display of the narrow-beam backscattering of radio waves in radar images in dependence on the surface wind speed and direction and direction of radar illumination of the surface. It is concluded that the radar means of remote sensing represent an efficient tool for detecting regions of dust raise into the atmosphere. Results of the study can be used for the development of new methods of remote monitoring of the processes in desert areas that affect the climate of vast regions of the Earth.
Anderson, R. S. Wind modification and bed response during saltation of sand in air / R. S. Anderson and P. K. Durham // Acta Mechanica, Mechanics. – 1991 - №1. – P. 21-54.
Archive data of the meteorological website [Electronic resource]. - Access mode: http://www.wetter3.de/Archiv/index.html (in German).
Carneiro, M. V. Midair collisions enhance saltation / M. V.Carneiro, N. A. M. Araújo, T. Pühtz, and H. J. Herrmann // [Electronic resource]. - Access mode: arxiv:1212.4603v2 [physics.ao-ph].
Geological activity of the wind. [Electronic resource]. - Access mode: www/URL: http://helpiks.org/1-55062.html (in Russian).
Blumberg, D. G. Field Measurements of the Flux and Speed of. Wind-Blown Sand / D. G. Blumberg and S. H. Williams // Sedimentology. - 1996 – Vol.43. - №1. – P. 41-52.
Herrmann, L. The importance of source region identification and their properties for soil-derived dust: the case of Harmattan dust sources for eastern West Africa / L. Herrmann, K. Stahr, and R. Jahn // Contributions to Atmospheric Phys. - 1999. - № 72(2). – P.141-150.
Ho, T. D. Aeolian sand transport: Length and height distributions of saltation trajectories / T. D.Ho, A.Valance, P. Dupont, and A. Ould // Aeolian Res. - 2014 - №12. – P. 65-74.
Ivanov V. K. Radar monitoring of aeolian sand and dust transporting manifestations in desert areas / V. K. Ivanov, A. Ya. Matveyev, V. N. Tsymbal, and S. Ye. Yatsevich // Physical Bases of Insrumentation – 2015 – Vol.4, №. 1. – P. 63-77 (in Russian).
Ivanov V. K. Radar identification of desert regions - sources of dust saturation of the atmosphere / V.K. Ivanov, A.Ya. Matveev, V.N. Tsymbal, S.E. Yatsevich, D.M. Bychkov // Physical Bases of Insrumentation - 2015. - Vol.4, №. 4. – P.48-58 (in Russian).
Kok, J. F. Electrostatics in wind-blown sand / J. F Kok and N. O. Renno // [Electronic resource]. - Access mode: http://arxiv.org/pdf/0711.1341.
LAADS Web – Granule Browser [Electronic resource]. - Access mode: https: //ladsweb.nascom.nasa. gov / browse_images.
Lämmel, M. A two-species continuum model for aeolian sand transport / M. Lämmel, D. Rings and K. Kroy // New J. of Phys. – 2012 - №.14 - p. 093037 (24 p.).
Lämmel, M. Analytical mesoscale modeling of aeolian sand transport / M. Lämmel, A. Meiwald, and K. Kroy // [Electronic resource]. - Access mode: arxiv.org/pdf/1405.0624.
Namikas, S. L. Field measurement and numerical modelling of aeolian mass flux distributions on a sandy beach / S. L. Namikas // Sedimentology. – Vol. 50 - №.2. – P. 303-326.
Ozer, P. Dust in the Wind and Public Health: Example from Mauritania / P. Ozer //Int. Conf. Desertification, Migration, Health, Remidiation and Local Governance, Royal Academy for Overseas Sciences United Nations Brussels. - 2006 – P.55-74.
Williams, K. K. Laboratory and field measurements of the modification of radar backscatter by sand / K. K. Williams and R. Greeley // Remote Sensing of Environment. – 2004 - №.89. – P. 29-40.