For half a decade, the night sky over Mindelo Bay on São Vicente Island has been illuminated by a remarkable green laser beam, stretching as high as 30 kilometers into the atmosphere. This striking beacon is not just a visual spectacle but the operating core of a sophisticated high-energy lidar system run by the Leibniz Institute for Tropospheric Research (TROPOS). Situated at the Ocean Science Centre Mindelo (OSCM), this continuous aerosol and cloud monitoring instrument embodies a pivotal advance in tropical atmospheric observation.
The lidar platform in Mindelo forms a crucial link in PollyNET, an extensive global network of both fixed and mobile lidar systems under the coordination of TROPOS. PollyNET’s design facilitates the detailed remote sensing of myriad airborne particles—ranging from Saharan desert dust and biomass burning smoke to anthropogenic pollutants and naturally occurring sea salt aerosols. By resolving the vertical layering and optical characteristics of these particles, PollyNET enables scientists worldwide to better understand aerosol transport paths, atmospheric composition, and their climatic impacts.
Over its operational lifespan, the Mindelo station has delivered invaluable insights into the behavior of Saharan dust plumes across the tropical Atlantic. Intensive analysis reveals pronounced vertical stratification within dust layers, pronounced seasonal fluctuations aligned with the Sahel and Saharan dust cycle, and episodic dust bursts influencing cloud microphysics. These lidar data have provided unprecedented detail on aerosol-cloud interactions—a critical factor in regional precipitation formation and radiation balance—that complements and extends the decades-long ground-based aerosol sampling programs conducted in São Vicente’s Calhau region.
The station’s expansion has proceeded methodically, beginning with continuous aerosol profiling since 2021 and incrementally adding sophisticated cloud remote sensing instruments. This upgrade has empowered comprehensive investigations into aerosol effects on cloud development and dynamics, augmenting meteorological understanding. Most recently, in 2024, an advanced radiometric array was integrated to quantify how atmospheric constituents modulate surface radiation fluxes—key to decoding energy budget perturbations in the tropical environment.
One of the system’s most dramatic demonstrations occurred during the volcanic eruption of La Palma’s Cumbre Vieja volcano in September 2021. The lidar unmistakably detected volcanic ash and sulfate aerosol layers aloft, evidencing its extraordinary capability to capture transient and extreme aerosol events. This has underscored the instrument’s value for both routine climate monitoring and rapid-response environmental assessments.
Supporting the Mindelo station’s breakthrough observations, three critical international field campaigns have enriched its data trove. The ASKOS exercises in 2021 and 2022 enabled meticulous cross-validation with the Aeolus satellite’s spaceborne lidar, enhancing retrieval accuracy for aerosol scattering profiles. Meanwhile, the 2024 ORCESTRA/CLARINET campaign focused on dissecting tropical storm genesis and evolution in the eastern Atlantic, embedding Mindelo’s lidar measurements in a broader climatological context.
The significance of this scientific infrastructure has been recognized at the highest political levels: a visit in October 2023 by the Presidents of Cabo Verde and Germany celebrated the complete operational capability of TROPOS’s lidar and radiation measurement suite. Such endorsements underscore the critical role of sustained atmospheric observation in informing climate policy and preparedness within the vulnerable tropical Atlantic region.
Data emerging from the Mindelo site delineate a vivid seasonal aerosol cycle: robust Saharan dust outbreaks from late winter through summer, contrasted with relative aerosol quiescence punctuated by cleaner, marine-dominated air masses during other months. This duality paints a nuanced picture of the region’s atmospheric baseline and episodic perturbations, essential for refining regional climate models and air quality forecasts.
The operational demands of such a cutting-edge observatory require sustained collaboration. TROPOS scientists undertake biannual maintenance missions, while OSCM and Instituto do Mar (IMar) staff manage daily operations and smaller upkeep tasks. This synergy extends to logistical and scientific partnerships with the GEOMAR Helmholtz Centre for Ocean Research, Instituto Nacional de Meteorologia e Geofísica (INMG), and other key regional institutions. Together, they maintain Mindelo’s unique vantage for continual atmospheric surveillance.
The Mindelo lidar station is now recognized as one of the few long-term atmospheric monitoring nodes crucial for tracking climate change signals across the tropics. Its integration into the European ACTRIS research infrastructure furthers multinational efforts to decode aerosol-cloud-radiation interactions which govern Earth’s climate system. By marrying oceanic and atmospheric observation through this collaboration, researchers are better equipped to understand the interconnected dynamics off West Africa’s coast.
In sum, the Mindelo lidar represents a vital scientific asset, uniquely positioned in the tropical Atlantic to probe fundamental aerosol properties and their climatic implications. Through meticulous observation, international collaboration, and technological innovation, it advances our grasp of atmospheric processes that are pivotal to regional weather, climate variability, and global environmental health. Its continued operation promises to yield critical data for emerging climate models and policy formulation aimed at addressing the impacts of natural and anthropogenic atmospheric constituents.
Subject of Research:
Not applicable
Article Title:
Validation of EarthCARE/ATLID aerosol profiling products with ground-based PollyNET lidars – case studies
News Publication Date:
12-Jun-2026
Web References:
10.5194/amt-19-3831-2026
Image Credits:
Ronny Engelmann, TROPOS
Keywords:
Lidar, Aerosol Remote Sensing, PollyNET, Saharan Dust, Tropical Atlantic, Aerosol-Cloud Interactions, Environmental Monitoring, Atmospheric Observations, Climate Change, EarthCARE, ATLID, Volcanic Aerosols
