Drone CO₂ measurements during the Tajogaite volcanic eruption

<p>We report in-plume carbon dioxide (CO<span class="inline-formula">₂</span>) concentrations and carbon isotope ratios during the 2021 eruption of Tajogaite volcano, island of La Palma, Spain. CO<span class="inline-formula">₂</span> measurements inform our understanding of volcanic contributions to the global climate carbon cycle and the role of CO<span class="inline-formula">₂</span> in eruptions. Traditional ground-based methods of CO<span class="inline-formula">₂</span> collection are difficult and dangerous, and as a result only about 5 % of volcanoes have been directly surveyed. We demonstrate that unpiloted aerial system (UAS) surveys allow for fast and relatively safe measurements. Using CO<span class="inline-formula">₂</span> concentration profiles we estimate the total flux during several measurements in November 2021 to be <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">1.76</mn><mo>±</mo><mn mathvariant="normal">0.20</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mn mathvariant="normal">3</mn></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="84pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="3264aa3cae14714f7df7f4ce1ccb11d6"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-17-4725-2024-ie00001.svg" width="84pt" height="14pt" src="amt-17-4725-2024-ie00001.png"/></svg:svg></span></span> to <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">2.23</mn><mo>±</mo><mn mathvariant="normal">0.26</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mn mathvariant="normal">4</mn></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="84pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="85d7db9f831418a258f8beedbdbcf277"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="amt-17-4725-2024-ie00002.svg" width="84pt" height="14pt" src="amt-17-4725-2024-ie00002.png"/></svg:svg></span></span> t d<span class="inline-formula">⁻¹</span>. Carbon isotope ratios of plume CO<span class="inline-formula">₂</span> indicate a deep magmatic source, consistent with the intensity of the eruption. Our work demonstrates the feasibility of UASs for CO<span class="inline-formula">₂</span> surveys during active volcanic eruptions, particularly for deriving rapid emission estimates.</p>