A multi-year study of the anomalous propagation conditions along the coast of the Adriatic sea

Viher, Mladen; Prtenjak, Maja Telišman; Grisogono, Branko

doi:10.1016/j.jastp.2013.01.014

Cited by 8 publications

(17 citation statements)

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“…A comprehensive statistical analysis was performed by Viher et al . [] for the 15 year period from 1994 to 2009, from which three cases were selected. A criterion for case selection was the availability of 3‐D high sampling rate wind velocity measurements from Senj (45.0°N, 14.9°E, 26 m asl) [ Večenaj et al ., ] that exist for the period from 2004 to 2006.…”

Section: Methodsmentioning

confidence: 99%

“…Usual physical quantity for the analysis of AP conditions is done using modified refractivity, M which depends on atmospheric pressure ( p [hPa]), temperature ( T [K]), water vapor mixing ratio q [g/kg], and relative humidity ( rh [%]) [e.g., Viher et al ., ]. The M index is a dimensionless physical quantity represented in so‐called “ M units”; and its vertical gradient d M /d h determines the type of refractive conditions in the atmosphere (Figure ) taking into account the curvature of the layer relative to the Earth's curvature.…”

Section: Methodsmentioning

confidence: 99%

“…[] and Viher et al . [] (shown in ). From M profiles, the vertical gradients for the modified refractive index, d M /d h , were computed for both data sets, i.e., from the radio sounding data and from the model, using noncentral finite differences; and the refractive conditions correspond to the layers between two consecutive levels.…”

Section: Methodsmentioning

confidence: 99%

“…Various mesoscale phenomena such as the SB/LB in the coastal zone and the downdraft flow of cold air during thunderstorms were noted to affect radar signals. Furthermore, the area over the Adriatic, located at the northern edge of the central Mediterranean, has also been studied recently in further depth [e.g., Fornasiero et al ., , ; Viher , ; Viher and Prtenjak , ; Viher et al ., ]. For this purpose, Fornasiero et al .…”

Section: Introductionmentioning

confidence: 99%

“…[] used radar data in San Pietro Capofiume (SPC), Italy, and a numerical model (at a 7 km horizontal resolution) whereas Viher [], Viher and Prtenjak [], and Viher et al . [] analyzed radio sounding data collected along the Adriatic. Among others, later studies have revealed more frequent, nocturnal AP occurrences than daytime occurrences.…”

Section: Introductionmentioning

confidence: 99%

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Impact of mesoscale meteorological processes on anomalous radar propagation conditions over the northern Adriatic area

et al. 2015

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The impact of mesoscale structures on the occurrence of anomalous propagation (AP) conditions for radio waves, including ducts, superrefractive, and subrefractive conditions, was studied. The chosen meteorological situations are the bora wind and the sporadic sea/land breeze (SB/LB) during three selected cases over a large portion of the northern Adriatic. For this purpose, we used available radio soundings and numerical mesoscale model simulations (of real cases and their sensitivity tests) at a horizontal resolution of 1.5 km and 81 vertical levels. The model simulated the occurrences of AP conditions satisfactorily, although their intensities and frequency were underestimated at times. Certain difficulties appeared in reproducing the vertical profile of the modified refractive index, which is mainly dependent on the accuracy of the modeled humidity. The spatial distributions of summer AP conditions reveal that the surface layer above the sea (roughly between 30 and 100 m asl) is often covered by superrefractive conditions and ducts. The SB is highly associated with the formations of AP conditions: (i) in the first 100 m asl, where trapping and superrefractive conditions form because of the advection of cold and moist air, and (ii) inside the transition layer between the SB body and the elevated return flow in the form of subrefractive conditions. When deep convection occurs, all three types of AP conditions are caused by the downdraft beneath the cumulonimbus cloud base in its mature phase that creates smaller but marked pools of cold and dry air. The bora wind usually creates a pattern of AP conditions associated with the hydraulic jump and influences distribution of AP conditions over the sea surface.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%