Goto

Collaborating Authors

 Gulf of Guinea




Machine learning models for daily rainfall forecasting in Northern Tropical Africa using tropical wave predictors

Satheesh, Athul Rasheeda, Knippertz, Peter, Fink, Andreas H.

arXiv.org Artificial Intelligence

Numerical weather prediction (NWP) models often underperform compared to simpler climatology-based precipitation forecasts in northern tropical Africa, even after statistical postprocessing. AI-based forecasting models show promise but have avoided precipitation due to its complexity. Synoptic-scale forcings like African easterly waves and other tropical waves (TWs) are important for predictability in tropical Africa, yet their value for predicting daily rainfall remains unexplored. This study uses two machine-learning models--gamma regression and a convolutional neural network (CNN)--trained on TW predictors from satellite-based GPM IMERG data to predict daily rainfall during the July-September monsoon season. Predictor variables are derived from the local amplitude and phase information of seven TW from the target and up-and-downstream neighboring grids at 1-degree spatial resolution. The ML models are combined with Easy Uncertainty Quantification (EasyUQ) to generate calibrated probabilistic forecasts and are compared with three benchmarks: Extended Probabilistic Climatology (EPC15), ECMWF operational ensemble forecast (ENS), and a probabilistic forecast from the ENS control member using EasyUQ (CTRL EasyUQ). The study finds that downstream predictor variables offer the highest predictability, with downstream tropical depression (TD)-type wave-based predictors being most important. Other waves like mixed-Rossby gravity (MRG), Kelvin, and inertio-gravity waves also contribute significantly but show regional preferences. ENS forecasts exhibit poor skill due to miscalibration. CTRL EasyUQ shows improvement over ENS and marginal enhancement over EPC15. Both gamma regression and CNN forecasts significantly outperform benchmarks in tropical Africa. This study highlights the potential of ML models trained on TW-based predictors to improve daily precipitation forecasts in tropical Africa.


Guylingo: The Republic of Guyana Creole Corpora

Clarke, Christopher, Daynauth, Roland, Wilkinson, Charlene, Devonish, Hubert, Mars, Jason

arXiv.org Artificial Intelligence

While major languages often enjoy substantial attention and resources, the linguistic diversity across the globe encompasses a multitude of smaller, indigenous, and regional languages that lack the same level of computational support. One such region is the Caribbean. While commonly labeled as "English speaking", the ex-British Caribbean region consists of a myriad of Creole languages thriving alongside English. In this paper, we present Guylingo: a comprehensive corpus designed for advancing NLP research in the domain of Creolese (Guyanese English-lexicon Creole), the most widely spoken language in the culturally rich nation of Guyana. We first outline our framework for gathering and digitizing this diverse corpus, inclusive of colloquial expressions, idioms, and regional variations in a low-resource language. We then demonstrate the challenges of training and evaluating NLP models for machine translation in Creole. Lastly, we discuss the unique opportunities presented by recent NLP advancements for accelerating the formal adoption of Creole languages as official languages in the Caribbean.


DustNet: skillful neural network predictions of Saharan dust

Nowak, Trish E., Augousti, Andy T., Simmons, Benno I., Siegert, Stefan

arXiv.org Artificial Intelligence

Suspended in the atmosphere are millions of tonnes of mineral dust which interacts with weather and climate. Accurate representation of mineral dust in weather models is vital, yet remains challenging. Large scale weather models use high power supercomputers and take hours to complete the forecast. Such computational burden allows them to only include monthly climatological means of mineral dust as input states inhibiting their forecasting accuracy. Here, we introduce DustNet a simple, accurate and super fast forecasting model for 24-hours ahead predictions of aerosol optical depth AOD. DustNet trains in less than 8 minutes and creates predictions in 2 seconds on a desktop computer. Created by DustNet predictions outperform the state-of-the-art physics-based model on coarse 1 x 1 degree resolution at 95% of grid locations when compared to ground truth satellite data. Our results show DustNet has a potential for fast and accurate AOD forecasting which could transform our understanding of dust impacts on weather patterns.


Tencent's Multilingual Machine Translation System for WMT22 Large-Scale African Languages

Jiao, Wenxiang, Tu, Zhaopeng, Li, Jiarui, Wang, Wenxuan, Huang, Jen-tse, Shi, Shuming

arXiv.org Artificial Intelligence

This paper describes Tencent's multilingual machine translation systems for the WMT22 shared task on Large-Scale Machine Translation Evaluation for African Languages. We participated in the $\mathbf{constrained}$ translation track in which only the data and pretrained models provided by the organizer are allowed. The task is challenging due to three problems, including the absence of training data for some to-be-evaluated language pairs, the uneven optimization of language pairs caused by data imbalance, and the curse of multilinguality. To address these problems, we adopt data augmentation, distributionally robust optimization, and language family grouping, respectively, to develop our multilingual neural machine translation (MNMT) models. Our submissions won the $\mathbf{1st\ place}$ on the blind test sets in terms of the automatic evaluation metrics. Codes, models, and detailed competition results are available at https://github.com/wxjiao/WMT2022-Large-Scale-African.


Modelling spatio-temporal trends of air pollution in Africa

Gahungu, Paterne, Kubwimana, Jean Remy, Muhimpundu, Lionel Jean Marie Benjamin, Ndamuzi, Egide

arXiv.org Artificial Intelligence

Atmospheric pollution remains one of the major public health threat worldwide with an estimated 7 millions deaths annually. In Africa, rapid urbanization and poor transport infrastructure are worsening the problem. In this paper, we have analysed spatio-temporal variations of PM2.5 across different geographical regions in Africa. The West African region remains the most affected by the high levels of pollution with a daily average of 40.856 $\mu g/m^3$ in some cities like Lagos, Abuja and Bamako. In East Africa, Uganda is reporting the highest pollution level with a daily average concentration of 56.14 $\mu g/m^3$ and 38.65 $\mu g/m^3$ for Kigali. In countries located in the central region of Africa, the highest daily average concentration of PM2.5 of 90.075 $\mu g/m^3$ was recorded in N'Djamena. We compare three data driven models in predicting future trends of pollution levels. Neural network is outperforming Gaussian processes and ARIMA models.


Comment: how ships can outwit piracy with AI

#artificialintelligence

Deep learning is on the frontline in a new age of piracy, outwitting attacks with pre-emptive tech, explains Yarden Gross, CEO and co-founder of Orca AI. Almost a decade has passed since piracy raged off Somalia, and yet the danger posed by maritime hijackings is as present as ever. The global pandemic last year sparked a resurgence of attacks, with piracy incidents doubling across Asia, in a worrying uptick also seen in the Gulf of Mexico and West Africa. The fallout from coronavirus, including the loss of key security personnel, turned quarantined vessels into easy targets. This wave has since receded a little, with the International Maritime Bureau reporting a 44 per cent YoY dip in piracy and armed robbery incidents in 2021.


Steering With Artificial Intelligence To Combat Maritime Piracy

#artificialintelligence

Besides, the frailty of the human body can lead to lapses which are gleefully exploited by pirates to the detriment of the crew, sometimes with tragic consequences. It begs the uncomfortable question of whether the shipping industry is at the mercy of the pirates and robbers in the highs seas and what else, if any, can be done to improve the current situation. Seafarers who have encountered pirates hijack often say they never saw the pirates coming. In most of the cases, they are not able to identify it, especially when pirates use small fishing boats as a disguise. In order to curb unprecedented piracy attacks, maritime situational awareness is vital to provide crew members with a comprehensive understanding of the activities in surrounding waters and present opportunities to detect and mitigate threats or any vulnerabilities before any further damage or adversity happens.


Remarks by High Representative/Vice-President Federica Mogherini at the press conference following the Informal Meeting of EU Defence Ministers

#artificialintelligence

Let me start by thanking Antti [Kaikkonen, Minister of Defence of Finland] and all the Finnish colleagues for an excellent couple of days – 24 hours - of this informal meeting of the European Union Member States' Defence Ministers. It has been extremely productive and intense. Our agenda has been very heavy – heavy in terms of content, but light in terms of the kind of approach and relations we have had. The wonderful Helsinki sun has helped establishing a friendly atmosphere and I would say that the exchanges have been extremely consensual, productive and positive. Thank you for that, because your hospitality has contributed to set a positive and constructive tone.