A new lightning data assimilation method has been implemented and validated within the Finnish Meteorological Institute.
Accurate estimates of accumulated precipitation are needed for several applications such as flood protection, hydropower, road- and fire-weather models. "Our focus was to improve the precipitation accumulation analysis, with special focus on the intense precipitation events", says researcher Erik Gregow from Finnish Meteorological Institute.
A new lightning data assimilation method has been implemented and validated within the Finnish Meteorological Institute - Local Analysis and Prediction System, where lightning observations have been assimilated together with radar and surface station measurements. Lightning data do improve the precipitation accumulation analysis, and even with high resolution radar data available, lightning data have a positive impact on the results. The radar-surface station assimilation method is highly dependent on statistical relationships between radar and gauges, when performing the correction to the precipitation accumulation field. Therefore, we also investigated the usage of different time integration intervals: 1, 6, 12, 24 h and 7 days, which change the amount of data used and affect the statistical calculation of the radar-surface station relations. Verification shows that the real-time analysis using the 1 h integration time length gave the best results.
Researcher Erik Gregow, email@example.com
Gregow, E., Pessi, A., Mäkelä, A., and Saltikoff, E.: Improving the precipitation accumulation analysis using lightning measurements and different integration periods, Hydrol. Earth Syst. Sci., 21, 267-279, doi:10.5194/hess-21-267-2017, 2017.
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