Submitted Videos

Radar-Based Analysis of Convective Storms in Lake Victoria: Capacity-Building and International Collaboration Through Knowledge Exchange and Observations

Anna del Moral Mendez

YouTube link: https://youtu.be/MCr2spwXxD0?si=Alg-wG0lUlMXcAPm

Lake Victoria Basin (LVB), home to over 40 million people in East Africa, plays a vital role in the region’s economy, particularly through fishing and agriculture. However, this densely populated area lies in a global hotspot for convective activity, making it highly vulnerable to severe weather hazards. With one of the world’s fastest-growing populations and climate change projections suggesting a future with more extreme weather and stronger thunderstorms, the region faces increasing societal exposure to natural hazards.

The region’s complex topography and land–lake interactions contribute to frequent nocturnal severe storms. Convective winds, high waves, and the rise in destructive hailstorms and heavy precipitation pose a threat to fishermen, agricultural communities, as well as the wider basin population. Unfortunately, despite the growing risk, less than 4% of global climate change research funding is allocated to the continent.

Building effective research-to-operations pathways remains difficult due to limited sustainable observational systems for weather monitoring, forecasting, and warning. Nevertheless, several initiatives under the UN Early Warnings for All drive have made impressive progress in boosting the continent's observational and operational capacities in recent years. Capacity building also continues through workshops led by WMO projects and international collaboration.

This work highlights the current state of radar-based severe weather research in the Lake Victoria Basin, showcasing severe weather events using data from the Mwanza S-band radar collected during the 2019 HIGHWAY (WMO) project. It shares lessons learned from regional training and collaboration during the two most recent WMO workshops in Kigali, Rwanda (2023), and Entebbe, Uganda (2025), while identifying critical gaps and opportunities for international cooperation. In this talk, we aim to start a broader discussion on science drivers, training needs, and cross-border collaboration, with the ultimate goal of supporting a more resilient Lake Victoria Basin.

Moisture and Dust in Motion: The Dual Role of Integrated Vapour Transport over West Africa

Peace Awoleye

YouTube link: https://youtu.be/Po5DeuQ5cLo?si=HnJ0R9iAPM8Fg1Lh

Integrated vapour transports (IVTs) are important drivers of tropical moisture transport; however, their structure, seasonality, and meteorological impacts over West Africa remain poorly characterised. This study provides a comprehensive evaluation of detected IVTs using a transport threshold of ≥250 kg m-1 s-1 during the 2024 West African monsoon season, combining reanalysis and gridded in situ datasets. Results show a strong seasonal signal, with IVT frequency and intensity peaking between June and September, particularly over the Guinean and southern Sudano-Sahelian zones. Case studies of three extreme IVT (≥750 kg m-1 s-1) events (June 18, August 16, and September 25) revealed distinct structures, strong zonal wind cores at 700 hpa, and vertically coupled moisture fluxes that enhanced organised convection and upward motion. Moderate IVTs (250 - 500 kg m-1 s-1) contributed significantly to daily rainfall in coastal regions, while extreme transport (≥750 kg m-1 s-1) delivered intense, spatially focused precipitation in the Sahel. Also, the IVT played a critical role in the dynamics of atmospheric dust, where periods of extreme IVTs were associated with strong negative correlations with aerosol optical depth and dust concentrations, along with increased dust wet deposition. However, dust scavenging efficiency peaked beyond an IVT threshold of ~300 kg m-1 s-1, suggesting that rainfall variability, rather than moisture flux alone, contributes immensely to aerosol removal. These findings position IVTs as key synoptic-scale systems that shape West African rainfall patterns and aerosol dynamics, with implications for seasonal weather variability, air quality, and convective organization across the monsoon belt.

Vapor lakes coming ashore in East Africa from the Indian Ocean

Brian Mapes

YouTube link: https://youtu.be/nY0Rnf_V4g4?si=Y0ON4alxCmKoGzVI

Airmasses with sufficient column water vapor (CWV), over about 50 mm, support deep convection over the ocean, while slightly less humid columns like 45 mm to not. This steep dependence of deep convection on vapor finds its most interesting application over the equatorial western Indian Ocean, where “lakes” of vapor drift westward to the African coast. We suspect based on satellite data that lowland coastal East Africa rainfall must be enhanced when these vapor lakes come ashore, but have too little knowledge from ground observations from the region. We have compiled a catalogue of these landfalling rainy airmasses, and will discuss their seasonality, dynamics, and impacts as seen in satellite and reanalysis datasets. We hope to discover local interests and knowledge in this little-studied phenomenon.

Weak, low-level dry convection over Angola determines offshore stratocumulus cloud droplet number concentrations

Tyler Tatro

YouTube link: https://youtu.be/L_3ZzMO_dso?si=EPeGavOpVCABLu4T

Boundary-layer cloud interactions involving shortwave-absorbing aerosols remain one of the least understood aerosol influences on climate. Here, we find the highest stratocumulus cloud droplet number concentrations over the southeast Atlantic occur when agricultural fires coincide with synoptically weakened surface warming over Angola, occurring June-early August. Dry convection fills a shallow continental boundary layer with smoke, and a nighttime land breeze transports the aerosol into the marine boundary layer. Offshore aerosol  transport is strengthened by low-level easterlies from a continental pressure high southeast of Angola. A stronger continental high ventilates more smoke westward off a cooler Angola. Simultaneously, the south Atlantic subtropical high is weaker, allowing extensive dispersal of aerosol offshore and obscuring marine cloud brightening from shipping. Meteorological co-variation at synoptic scales  compensates for any cloud brightening by the smoke, increasing outgoing shortwave radiation by an additional 15%-20% of the monthly-mean in June and July.

Potential effect of inhalation exposure to the organic and inorganic constituents of ambient PM2.5 could modulate Amyotrophic Lateral Sclerosis progression

Praphulla Chandra Boggarapu

YouTube link: https://youtu.be/daz4aPOUHg4?si=TwNWRrAexJseytkK

Air pollution pertaining to particulate matter (PM) is a major issue in most of the metropolitan cities across the world. Inhalation exposure to organic species like polycyclic aromatic hydrocarbons (PAHs), derivatives of PAHs (oxygenated and nitrated PAHs), and phthalic acid esters (PAEs) bound to PM is of major concern owing to its carcinogenic, mutagenic, and endocrine disrupting nature. Studies have shown that the exposure to the toxic compounds like pesticides and metal ions could serve as potential risk factors for Neuro degenerative diseases like Amyotrophic Lateral Sclerosis (ALS) (Nunez et al. 2022; Oggiano et al. 2021). Amyotrophic Lateral Sclerosis (ALS) is a progressive, incurable, degenerative motor neuron disease eventually leading to the death of patient. The disease can be sporadic accounting for 90% of ALS cases or genetic accounting for 10%, with SNPs (Single Nucleotide Polymorphism) in SOD1 (Superoxide dismutase), FUS (Fused in Sarcoma), TDP43 (TAR DNA Binding Protein 43) and C9orf72 (C9 open reading frame 72) contributing to the bulk of the genetic contributors. Studies have demonstrated that the exposure to ambient PM2.5 is associated with neurodegenerative diseases like Alzheimer’s, and Parkinson’s disease as well as ALS. PM2.5 is known to influence protein aggregation by inducing oxidative stress or mitochondrial dysfunction.  In order to study the protein aggregation in diseases like ALS, yeast serves as a good model (Swaroop et al. 2022). Yeast has also emerged as a good model to study the role of reactive oxygen species on protein aggregation in ALS (Pradhan et al. 2022). We have studied the aggregation of wild type TDP43 in the yeast model of ALS using the screened organic and inorganic constituents of ambient PM2.5 samples collected in Bangalore. Individually tested organic and inorganic constituents of PM2.5 like Benzo [a] anthracene (B[a]A), Benzo [a] Pyrene (B[a]P), Benzo [b] fluoranthene (B[b]F), Dibenz [ah] anthracene (D[ah]A), Indeno [1,2,3-cd] pyrene (Ind) as well as Cd2+, Fe2+, Cr6+, and Ni2+ have shown a significant increase in TDP43 aggregation. Further we have observed that the ambient sample with elevated levels of PAHs had induced aggregation of TDP43 significantly. Thus, this pilot study demonstrates PM2.5 induced, elevated level of TDP43 aggregates in the yeast model which indicates the exacerbation of ALS disease in the highly polluted environments.

Towards Climate-Smart Urbanism: Future Directions for Enhancing Food Security and Resilient Farming Systems in Lagos Metropolis, Nigeria

Catherine Esuola

YouTube link: https://youtu.be/1XXUvQDL3rM?si=JnWNNQn-r6JmZeCY

Lagos Metropolis, a preeminent coastal megacity, faces a dual-threat paradigm where rapid, often unplanned urbanization intersects with the escalating impacts of climate change. This study examines the synergistic effects of these phenomena on the viability of sustainable agriculture within the metropolitan fringes and urban cores. As the built environment expands, the conversion of arable peri-urban land into residential and industrial zones has significantly fragmented traditional farming systems, leading to a precarious dependence on external food supplies. Concurrently, climatic shifts, characterized by intensified Atlantic storm surges, unpredictable precipitation patterns, and rising sea levels, exacerbate the vulnerability of urban agrarian livelihoods. The "urban heat island" effect, coupled with seasonal flooding, creates a hostile microclimate that reduces crop yields and increases the prevalence of heat-stressed livestock. This research utilizes a mixed-methods approach, synthesizing longitudinal satellite imagery of land-use changes with localized climate data and farmer-led surveys. Findings indicate that while urbanization provides a proximity advantage to high-demand markets, the lack of integrated spatial planning and the degradation of ecosystem services threaten long-term food security. Future directions for Lagos must prioritize "Climate-Smart Urbanism." This involves the institutionalization of vertical farming, the protection of wetlands as natural flood buffers, and the adoption of hydroponics and aeroponics to bypass land scarcity. Furthermore, the integration of circular economy principles, such as urban waste-to-fertilizer programs, is essential for a resilient agricultural framework. This study concludes that for Lagos to achieve a sustainable future, policy interventions must bridge the gap between urban development and ecological preservation, ensuring that the metropolis can feed itself in an era of environmental uncertainty.

A web interface for the flexible particle dispersion model FLEXPART

Marina Dütsch

YouTube link: https://youtu.be/-b4kijK65t0?si=AS8lcVbnzlRnllwx

The FLEXible PARTicle dispersion model (FLEXPART) is a widely used atmospheric transport model simulating the dispersion of gases and aerosols in the atmosphere. FLEXPART relies on gridded meteorological fields, including winds, temperature, pressure, and humidity to determine the movement of its computational particles. Typically, these fields are provided by atmospheric (re-)analyses or operational weather forecast models. While the ever-increasing resolution of such data sets is beneficial to the accuracy of FLEXPART, it is also a challenge to its users, as the data sets require a large amount of storage space and become increasingly computationally expensive to read and process. Many researchers, specifically in the Global South, do not have access to the necessary infrastructure for storing the input data, running the model, storing the model output and visualising it. Consequently, FLEXPART is inaccessible to a large part of the scientific community despite its open-source nature. We are therefore developing an easily accessible web service (called FLEXWEB), where FLEXPART can be run in the cloud via a web interface. As soon as the simulation is complete, the model output is made available for download and displayed graphically in the web browser. In this way, we aim to simplify access to FLEXPART for researchers worldwide.

Monsoons and Cloud Microphysics Campaigns: Lessons from CAIPEEX and Opportunities for Tropical Collaboration

Thara Prabhakaran

YouTube link: https://youtu.be/ROiWn5WtrDc?si=uDwcplB-kHWA5Inh

This recorded presentation introduces recent Indian efforts to understand monsoon cloud microphysics across scales and highlights opportunities for collaboration with African and wider tropical meteorology communities. The Indian Institute of Tropical Meteorology studies the monsoon from climate to minute scales through observational networks, high-impact weather prediction, atmospheric chemistry and air-quality forecasting, weather modification research, capacity development, and frontier observing-system development under India’s Ministry of Earth Sciences. The talk places this work in the broader context of global monsoon domains and notes the relative scarcity of intensive aircraft and field campaigns over India and Africa compared with other regions.

Particular attention is given to the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX), a long-running programme directed at fundamental aerosol-cloud-precipitation interactions and strategies for weather modification. CAIPEEX observations are used to illustrate enhanced cloud droplet number concentrations in polluted continental monsoon clouds, the seasonal lowering of cloud base from pre-monsoon to monsoon conditions, changes in liquid water content, and the role of warm-cloud depth and freezing-level structure in determining cloud microphysics. These findings are compared with West African DACCIWA observations, including contrasts between inland and offshore aerosol and droplet concentrations and the influence of biomass-burning, urban, and local emissions. The presentation concludes by calling for more field campaigns across tropical monsoon regions and by introducing the International Commission on Tropical Meteorology as a platform for broader regional collaboration.