## 1 Introduction
In the same paper, the authors monitored the impact of eruptions of several volcanoes on the atmosphere and ionosphere. Still, they concentrated on co-eruption (or dust storm effects) rather than pre-eruption. On the other hand, those works are also a substantial base to determine the impact of a desertic dust storm over the ocean and not confuse it as a \"pre-eruption\" anomaly. While the lithosphere-atmosphere-ionosphere bottom-up influence prior to earthquakes and volcano eruptions is a more debated topic among the scientific community, the possibility of predicting volcano eruption by seismic, geodetic, and geochemical measurements is more accepted and has proved to be effective [18]. Recent studies have focused on the incredible explosion of the Hunga Tonga-Hunga Ha'apai volcano that occurred on 15 January 2022. It was a powerful enough explosion to bring some water into the troposphere, impacting Earth's climate [19] and producing a pressure wave (Lamb wave) that travelled all around the globe. Some studies also found an upward disturbance from the troposphere to the ionosphere during the propagation of the pressure wave, for example, analysing ground Total Electron Content _TEC_ in Japan [20], or by CSES satellite and also _TEC_ from Global Navigation Satellite System (GNSS) de tectors [21]. Despite the Hunga Tonga-Hunga Ha'apai and La Palma volcanoes being different (the first one is a submarine stratovolcano, while the second one is an emersed stratovolcano) and the intensity of the explosions being significantly different (VEI = 6 and second one VEI = 3), a similar approach used in [21] is here applied to pre-activity of \"La Palma\" volcano eruption, by a comprehensive analysis of the lithosphere atmosphere and ionosphere geophysical layers. La Palma is a volcanic island part of \"Las Canarias\" archipelagos composed of several islands, all of them of volcanic origin, as visible in Figure 1. Las Canarias archipelagos are located westward of the African continent at the same latitude as the Sahara Desert, but jurisdictionally are part of Spain (European Union). In such archipelagos, and in particular, in La Palma Island, there are several optical telescopes (the National Italian telescope Galileo [22], and the Cherenkov one, like MAGIC [23]). In fact, due to the low light pollution present in the place, it deserves special interest as an elected place for the installation of astrophysical instrumentation. From a tectonic point of view, the Atlantic Ocean is divided in its middle by the Mid-Atlantic Ridge, which is an accretion plate boundary with the continuous formation of the new lithosphere. Among the Atlantic Ocean's East side, due to the interaction with Eurasian and African plates, several volcano arcs are present from northern Iceland to the southern Capo Verde archipelagos. In the middle are the Las Canarias ones, the object of study of this paper. In the investigated area during the last 40 years, only an eruption of the El Hierro volcano has been documented, from 10 October 2011 until 5 March 2012 [24; 25]. This eruption was a submarine event associated with pre-seismic, geomagnetic, and gravity field anomalies that started in July 2011 [26]. Figure 1: Location of La Palma Volcano. (**A**) Global view showing the position in the North Atlantic Ocean of Canarias Islands with respect to African and European continents. (**B**) Details of Las Canarias archipelagos. (**C**) La Palma Island. The position of the Cumbre Vieja volcanic orifice responsible for the eruption on 19 September 2021 is underlined. The figure is an original composition of views obtained by GoogleEarth Pro software (version 7.3.4.8642, freely provided by Google LLC.). On 19 September 2021, an eruption preceded by high seismic activity started at La Cumbre Vieja vent of \"La Palma\" volcano [27]. The eruption lasted until 13 December 2021, covering lava, an area of about 12.2 km\({}^{2}\) located west of the vent toward the sea [25]. The last previous eruption of \"La Palma\" volcano was in 1971 at a site called Teneguia [27].