## 6 Discussion and Conclusions
In this way, it is possible to modify the operation of the two sensors to better investigate on demand particular events, for example by increasing the rate of collection and processing of sound clips or focusing on particular bands of energy. The graphical user interface (GUI) of each instrument is immediate to use even by non-experts and allows one to easily program and set-up the sampling options for any deployment or experiment. Furthermore, in the case that the developed software and hardware tools are embedded on other existing infrastructures able to provide data to international repositories, it will support the scientific community on issues related to underwater radioactivity and sound, since in-situ measurements of these parameters are very scarce up to now. Preliminary analysis of the first results of the combined use of continuous monitoring of radon progenies near the sea surface and of underwater ambient sound identified five cases of intense precipitation events. These data in combination with ancillary meteo-oceanographic parameters (wind speed and direction, seawater salinity, etc.) may provide an interesting multidisciplinary alternative for detecting and investigating precipitation characteristics (precipitation intensity, cloud heights, etc.) in remote oceanic areas. This alternative approach may contribute to validating satellite precipitation observations, while still providing valuable information about the local ecological status (radioactivity and noise budget levels, marine mammal identification, etc.) of the studied marine area. In conclusion, the integration of radioactivity and sound sensors in stationary observation systems, based on universally applicable methods, provides a modern and multidisciplinary scientific approach of gathering important new information to better understand the functionality of the marine environment. The meteorological data used for the analysis are freely available from the portal of the Copernicus Marine Environment Monitoring Service ([[http://marine.copernicus.eu](http://marine.copernicus.eu)]([http://marine.copernicus.eu](http://marine.copernicus.eu))) and from the web site of the Regional Environmental Protection Agency of Liguria ([[https://www.arpal.gov.it](https://www.arpal.gov.it)]([https://www.arpal.gov.it](https://www.arpal.gov.it))). Acoustic and radon data are available at the following address: [[http://www.w1m3a.cnr.it/OI1/modules/site_pages/fixo3_TNA.php](http://www.w1m3a.cnr.it/OI1/modules/site_pages/fixo3_TNA.php)]([http://www.w1m3a.cnr.it/OI1/modules/site_pages/fixo3_TNA.php](http://www.w1m3a.cnr.it/OI1/modules/site_pages/fixo3_TNA.php)). [PERSON], [PERSON], [PERSON] and [PERSON] conceived and designed the experiment. All authors equally contributed to perform the experiment and to carry out the data collection. [PERSON] and [PERSON] analyzed the radon progenies data. [PERSON], [PERSON], [PERSON] and [PERSON] analyzed the acoustic data. [PERSON] and [PERSON] were in charge of the hardware improvements of the sensors used in the experiment. [PERSON] and [PERSON] drafted the paper and all authors equally contributed to write the final manuscript. The research leading to these results has received part of the funding from the European Union Seventh Framework Programme (FP7/2013-2017) under Grant Agreement N\({}^{\circ}\) 312463, FixO3. The authors would like to acknowledge the contribution of the Agenzia Regionale per la Protezione Ambientale Liguria (ARPAL) who jointly operate the radar system with ARPA Piemonte for providing part of the radar data. The authors declare no conflict of interest.