Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 8 3 2008 10.5194/acpd-8-11673-2008 http://www.atmos-chem-phys-discuss.net/8/11673/2008/ http://www.atmos-chem-phys-discuss.net/8/11673/2008/acpd-8-11673-2008.html http://www.atmos-chem-phys-discuss.net/8/11673/2008/acpd-8-11673-2008.pdf 11673 11684 2008-06-12 Technical Note: Novel method for water vapor monitoring using wireless communication networks measurements N. David noamda@post.tau.ac.il P. Alpert H. Messer The Department of Geophysics and Planetary Sciences, Tel-Aviv University, Tel-Aviv, Israel The School of Electrical Engineering, Tel-Aviv University, Tel-Aviv, Israel We propose a new technique that overcomes the obstacles of the existing methods for monitoring near-surface water vapor, by estimating humidity from data collected through existing wireless communication networks. <br><br> Weather conditions and atmospheric phenomena affect the electromagnetic channel, causing attenuations to the radio signals. Thus, wireless communication networks are in effect built-in environmental monitoring facilities. The wireless microwave links, used in these networks, are widely deployed by cellular providers for backhaul communication between base stations, a few tens of meters above ground level. As a result, the proposed method can provide moisture observations at high temporal and spatial resolution. Further, the implementation cost is minimal, since the data used are already collected and saved by the cellular operators. In addition &ndash; many of these links are installed in areas where access is difficult such as orographic terrain and complex topography. As such, our method enables measurements in places that have been hard to measure in the past, or have never been measured before. <br><br> We present results from real-data measurements taken from two microwave links used in a backhaul cellular network that show excellent correlation to surface station humidity measurements. The measurements were taken daily in two sites, one in northern Israel (28 measurements), the other in central Israel (29 measurements).The correlation of the microwave link measurements to those of the humidity gauges were 0.9 and 0.82 for the north and central sites, respectively. The RMSE were 20.8% and 33.1% for the northern and central site measurements, respectively. Allan, R. P., Shine, K. P., Slingo, A., and Pamment, J. A.: The dependence of clear-sky outgoing long-wave radiation on surface temperature and relative humidity, Q. J. Roy. Meteor. Soc., 125, 2103&ndash;2126, 1999. Bolton, D.: The Computation of Equivalent Potential Temperature, Mon. Weather Rev., 108, 1046&ndash;1053, 1980. Ducrocq, V., Ricard, D., Lafore, J. P., and Orain, F.: Storm-scale numerical rainfall prediction for five precipitating events over France: On the importance of the initial humidity field, Weather Forecast., 17, 1236&ndash;1256, 2002. Leijnse, H., Uijlenhoet, R., and Stricker, J. N. M.: Rainfall measurement using radio links from cellular communication networks, Water Resour. Res., 43, W03201, doi:10.1029/2006WR005631, 2007. Leijnse, H., Uijlenhoet, R. and Stricker, J. N. M.: Hydrometeorological application of a microwave link: 1. Evaporation, Water Resour. Res., 43, W04416, doi:10.1029/2006WR004988, 2007. Lilly, D. K. and Gal-Chen, T.: North Atlantic Treaty Organization & Scientific Affairs Division. Mesoscale meteorology-theories, observations, and models, Reidel, Dordrecht, Netherlands, 1983. Meeks, M. L.: Astrophysics, Academic Press, New York, 1976. Messer, H., Zinevich, A., and Alpert, P.: Environmental monitoring by wireless communication networks, Science, 312, p. 713, 2006. Messer, H.: Rainfall monitoring using cellular networks, IEEE Signal Proc. Mag., 24, 142&ndash;144, 2007. Raghavan, S.: Radar Meteorology. Kluwer Academic Publishers, Dordrecht, 2003. Rec. ITU-R P.676-6: Attenuation by atmospheric gases, ITU-R Recommendations, September, 2005. Shay-El, Y. and Alpert, P.: A Diagnostic Study of Winter Diabatic Heating in the Mediterranean in Relation to Cyclones, Q. J. Roy. Meteor. Soc., 117, 715&ndash;747, 1991.