Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy
<p>There is a growing interest in emerging opportunistic sensors for precipitation, motivated by the need to improve its quantitative estimates at the ground. The scope of this work is to present a preliminary assessment of the accuracy of commercial microwave link (CML) retrieved rainfall ra...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-10-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/13/5779/2020/amt-13-5779-2020.pdf |
| _version_ | 1818340876506628096 |
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| author | G. Roversi P. P. Alberoni A. Fornasiero F. Porcù |
| author_facet | G. Roversi P. P. Alberoni A. Fornasiero F. Porcù |
| author_sort | G. Roversi |
| collection | DOAJ |
| description | <p>There is a growing interest in emerging opportunistic sensors for
precipitation, motivated by the need to improve its quantitative
estimates at the ground. The scope of this work is to present a
preliminary assessment of the accuracy of commercial microwave link (CML) retrieved rainfall
rates in Northern Italy. The CML product, obtained by the open-source
RAINLINK software package, is evaluated on different scales (single
link, <span class="inline-formula">5 km×5 km</span> grid, river basin) against the
precipitation products operationally used at Arpae-SIMC, the regional
weather service of Emilia-Romagna, in Northern Italy. The results of
the 15 <span class="inline-formula">min</span> single-link validation with nearby rain gauges
show high variability, which can be caused by the complex physiography and precipitation patterns. Known sources of errors
(e.g. the attenuation caused by the wetting of the antennas or random
fluctuations in the baseline) are particularly hard to mitigate in
these conditions without a specific calibration, which has not been
implemented. However, hourly cumulated spatially interpolated CML
rainfall maps, validated with respect to the established regional
gauge-based reference, show similar performance (<span class="inline-formula"><i>R</i><sup>2</sup></span> of 0.46 and
coefficient of variation, CV, of 0.78) to adjusted radar-based precipitation gridded products and
better performance than satellite-based ones. Performance improves when basin-scale
total precipitation amounts are considered (<span class="inline-formula"><i>R</i><sup>2</sup></span> of 0.83 and CV of
0.48). Avoiding regional-specific calibration therefore does not
preclude the algorithm from working but has some limitations in probability of detection (POD)
and accuracy. A widespread underestimation is evident at both the grid box scale
(mean error of <span class="inline-formula">−0.26</span>) and the basin scale (multiplicative bias of 0.7),
while the number of false alarms is generally low and becomes even lower
as link coverage increases. Also taking into account delays in the
availability of the data (latency of 0.33 <span class="inline-formula">h</span> for CML against
1 <span class="inline-formula">h</span> for the adjusted radar and 24 <span class="inline-formula">h</span> for the
quality-controlled rain gauges), CML appears as a valuable data source
in particular from a local operational framework perspective. Finally,
results show complementary strengths for CMLs and radars, encouraging
joint exploitation.</p> |
| first_indexed | 2024-12-13T15:49:52Z |
| format | Article |
| id | doaj.art-05cfe1e1014f4d02a85592cf05ed69db |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-12-13T15:49:52Z |
| publishDate | 2020-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-05cfe1e1014f4d02a85592cf05ed69db2022-12-21T23:39:33ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482020-10-01135779579710.5194/amt-13-5779-2020Commercial microwave links as a tool for operational rainfall monitoring in Northern ItalyG. Roversi0P. P. Alberoni1A. Fornasiero2F. Porcù3Department of Physics and Astronomy, University of Bologna, Bologna, 40100, ItalyStruttura Idro-Meteo-Clima, Arpae Emilia Romagna, Bologna, 40122, ItalyStruttura Idro-Meteo-Clima, Arpae Emilia Romagna, Bologna, 40122, ItalyDepartment of Physics and Astronomy, University of Bologna, Bologna, 40100, Italy<p>There is a growing interest in emerging opportunistic sensors for precipitation, motivated by the need to improve its quantitative estimates at the ground. The scope of this work is to present a preliminary assessment of the accuracy of commercial microwave link (CML) retrieved rainfall rates in Northern Italy. The CML product, obtained by the open-source RAINLINK software package, is evaluated on different scales (single link, <span class="inline-formula">5 km×5 km</span> grid, river basin) against the precipitation products operationally used at Arpae-SIMC, the regional weather service of Emilia-Romagna, in Northern Italy. The results of the 15 <span class="inline-formula">min</span> single-link validation with nearby rain gauges show high variability, which can be caused by the complex physiography and precipitation patterns. Known sources of errors (e.g. the attenuation caused by the wetting of the antennas or random fluctuations in the baseline) are particularly hard to mitigate in these conditions without a specific calibration, which has not been implemented. However, hourly cumulated spatially interpolated CML rainfall maps, validated with respect to the established regional gauge-based reference, show similar performance (<span class="inline-formula"><i>R</i><sup>2</sup></span> of 0.46 and coefficient of variation, CV, of 0.78) to adjusted radar-based precipitation gridded products and better performance than satellite-based ones. Performance improves when basin-scale total precipitation amounts are considered (<span class="inline-formula"><i>R</i><sup>2</sup></span> of 0.83 and CV of 0.48). Avoiding regional-specific calibration therefore does not preclude the algorithm from working but has some limitations in probability of detection (POD) and accuracy. A widespread underestimation is evident at both the grid box scale (mean error of <span class="inline-formula">−0.26</span>) and the basin scale (multiplicative bias of 0.7), while the number of false alarms is generally low and becomes even lower as link coverage increases. Also taking into account delays in the availability of the data (latency of 0.33 <span class="inline-formula">h</span> for CML against 1 <span class="inline-formula">h</span> for the adjusted radar and 24 <span class="inline-formula">h</span> for the quality-controlled rain gauges), CML appears as a valuable data source in particular from a local operational framework perspective. Finally, results show complementary strengths for CMLs and radars, encouraging joint exploitation.</p>https://amt.copernicus.org/articles/13/5779/2020/amt-13-5779-2020.pdf |
| spellingShingle | G. Roversi P. P. Alberoni A. Fornasiero F. Porcù Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy Atmospheric Measurement Techniques |
| title | Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy |
| title_full | Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy |
| title_fullStr | Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy |
| title_full_unstemmed | Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy |
| title_short | Commercial microwave links as a tool for operational rainfall monitoring in Northern Italy |
| title_sort | commercial microwave links as a tool for operational rainfall monitoring in northern italy |
| url | https://amt.copernicus.org/articles/13/5779/2020/amt-13-5779-2020.pdf |
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