Articles | Volume 21, issue 3
Research article 19 Mar 2021
Research article | 19 Mar 2021
Wet and dry spells in Senegal: comparison of detection based on satellite products, reanalysis, and in situ estimates
Cheikh Modou Noreyni Fall et al.
No articles found.
Cedric G. Ngoungue Langue, Christophe Lavaysse, Mathieu Vrac, Philippe Peyrillé, and Cyrille Flamant
Weather Clim. Dynam., 2, 893–912,Short summary
This work assesses the forecast of the temperature over the Sahara, a key driver of the West African Monsoon, at a seasonal timescale. The seasonal models are able to reproduce the climatological state and some characteristics of the temperature during the rainy season in the Sahel. But, because of errors in the timing, the forecast skill scores are significant only for the first 4 weeks.
Christophe Lavaysse, Jürgen Vogt, Andrea Toreti, Marco L. Carrera, and Florian Pappenberger
Nat. Hazards Earth Syst. Sci., 18, 3297–3309,Short summary
Forecasting droughts in Europe 1 month in advance would provide valuable information for decision makers. However, these extreme events are still difficult to predict. In this study, we develop forecasts based on predictors using the geopotential anomalies, generally more predictable than precipitation, derived from the ECMWF model. Results show that this approach outperforms the prediction using precipitation, especially in winter and in northern Europe, where 65 % of droughts are predicted.
Lala Kounta, Xavier Capet, Julien Jouanno, Nicolas Kolodziejczyk, Bamol Sow, and Amadou Thierno Gaye
Ocean Sci., 14, 971–997,Short summary
The currents along the West African seaboard are poorly known. Based on a carefully evaluated numerical simulation the present study describes these currents in the sector 8–20°N and the physical processes that drive them. Prevailing northward flow with two intensification periods per year is identified. Both local and distant coastal winds (blowing as far as thousands of kilometers away in the Gulf of Guinea) contribute to the circulation in this sector.
Youssouph Sane, Geremy Panthou, Ansoumana Bodian, Theo Vischel, Thierry Lebel, Honore Dacosta, Guillaume Quantin, Catherine Wilcox, Ousmane Ndiaye, Aida Diongue-Niang, and Mariane Diop Kane
Nat. Hazards Earth Syst. Sci., 18, 1849–1866,Short summary
Urbanization, resulting from a sharply increasing demographic pressure and the development of infrastructure, has made the population of many tropical areas more vulnerable to extreme rainfall hazards. Characterizing extreme rainfall distribution is thus becoming an overarching need in hydrological applications. Using 14 tipping-bucket rain-gauge series, this study provides IDF curves and uncertainties over Senegal. Climate change requires warning end-users that they should be used with care.
Christophe Lavaysse, Carmelo Cammalleri, Alessandro Dosio, Gerard van der Schrier, Andrea Toreti, and Jürgen Vogt
Nat. Hazards Earth Syst. Sci., 18, 91–104,Short summary
Extreme-temperature anomalies such as heat and cold waves may have strong impacts on human activities and health. Providing a robust operational system to monitor extreme-temperature anomalies in Europe, developed and validated in this study, is thus of prime importance. This work exposes the methodology and the climatology of these events. It also discusses the associated uncertainties according to the datasets and the methods used.
Peter Knippertz, Andreas H. Fink, Adrien Deroubaix, Eleanor Morris, Flore Tocquer, Mat J. Evans, Cyrille Flamant, Marco Gaetani, Christophe Lavaysse, Celine Mari, John H. Marsham, Rémi Meynadier, Abalo Affo-Dogo, Titike Bahaga, Fabien Brosse, Konrad Deetz, Ridha Guebsi, Issaou Latifou, Marlon Maranan, Philip D. Rosenberg, and Andreas Schlueter
Atmos. Chem. Phys., 17, 10893–10918,Short summary
In June–July 2016 DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa), a large, EU-funded European–African project, organised an international field campaign in densely populated southern West Africa, including measurements from ground sites, research aircraft, weather balloons and urban sites. This paper gives an overview of the atmospheric evolution during this period focusing on meteorological (precipitation, cloudiness, winds) and composition (gases, particles) aspects.
Habib Senghor, Éric Machu, Frédéric Hourdin, and Amadou Thierno Gaye
Atmos. Chem. Phys., 17, 8395–8410,Short summary
This work focus on the distribution of dust particles emitted in western Africa and having consequences on human health and marine ecosystems. The understanding of their fate requires a better understanding of the processes governing their variability. Using satellite observations and ground measurements, we present the seasonality of their distribution and explain the processes responsible for this distribution as well as their transition from the African continent towards the Atlantic Ocean.
C. Lavaysse, J. Vogt, and F. Pappenberger
Hydrol. Earth Syst. Sci., 19, 3273–3286,Short summary
This paper assesses the predictability of meteorological droughts over Europe 1 month in advance using ensemble prediction systems. It has been shown that, on average and using the most relevant method, 40 % of droughts in Europe are correctly forecasted, with less than 25 % false alarms. This study is a reference for other studies that are motivated to improving the drought forecasting.
G. Panthou, T. Vischel, T. Lebel, G. Quantin, and G. Molinié
Hydrol. Earth Syst. Sci., 18, 5093–5107,
Related subject area
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downward lightning flashes – Part 1: ObservationsGlobal ground strike point characteristics in negative downward lightning flashes – Part 2: Algorithm validationAssessing internal changes in the future structure of dry–hot compound events: the case of the PyreneesChanges in drought features at the European level over the last 120 yearsAssimilation of Himawari-8 imager radiance data with the WRF-3DVAR system for the prediction of Typhoon SoudelorAtmospheric conditions leading to an exceptional fatal flash flood in the Negev Desert, IsraelReview article: Towards resilient vital infrastructure systems – challenges, opportunities, and future research agendaFatalities associated with the severe weather conditions in the Czech Republic, 2000–2019Drought propagation and construction of a comprehensive drought index based on the Soil and Water Assessment Tool (SWAT) and empirical Kendall distribution function (KC′): a case study for the Jinta River basin in northwestern ChinaExtreme wind return periods from tropical cyclones in Bangladesh: insights from a high-resolution convection-permitting numerical modelReview article: Observations for high-impact weather and their use in verificationAn analysis of temporal scaling behaviour of extreme rainfall in Germany based on radar precipitation QPE dataA tailored multi-model ensemble for air traffic management: Demonstration and evaluation for the Eyjafjallajökull eruption in May 2010A climatology of sub-seasonal temporal clustering of extreme precipitation in Switzerland and its impactsThe heavy precipitation event of 14–15 October 2018 in the Aude catchment: a meteorological study based on operational numerical weather prediction systems and standard and personal observationsDrought impact in the Bolivian Altiplano agriculture associated with the El Niño–Southern Oscillation using satellite imagery dataA statistical–parametric model of tropical cyclones for hazard assessmentThe impact of drought on soil moisture trends 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Patricia Tarín-Carrasco, Sofia Augusto, Laura Palacios-Peña, Nuno Ratola, and Pedro Jiménez-Guerrero
Nat. Hazards Earth Syst. Sci., 21, 2867–2880,Short summary
Uncontrolled wildfires have a substantial impact on the environment and local populations. Although most southern European countries have been impacted by wildfires in the last decades, Portugal has the highest percentage of burned area compared to its whole territory. Under this umbrella, associations between large fires, PM10, and all-cause and cause-specific mortality (circulatory and respiratory) have been explored using Poisson regression models for 2001–2016.
Vincenzo Mazzarella, Rossella Ferretti, Errico Picciotti, and Frank Silvio Marzano
Nat. Hazards Earth Syst. Sci., 21, 2849–2865,Short summary
Forecasting precipitation over the Mediterranean basin is still a challenge. In this context, data assimilation techniques play a key role in improving the initial conditions and consequently the timing and position of the precipitation forecast. For the first time, the ability of a cycling 4D-Var to reproduce a heavy rain event in central Italy, as well as to provide a comparison with the largely used cycling 3D-Var, is evaluated in this study.
Avaronthan Veettil Sreenath, Sukumarapillai Abhilash, and Pattathil Vijaykumar
Nat. Hazards Earth Syst. Sci., 21, 2597–2609,Short summary
Lightning is a multifaceted hazard with widespread negative consequences for the environment and society. We explore how El Niño–Southern Oscillation (ENSO) phases impact the lightning over India by modulating the deep convection and associated atmospheric thermodynamics. Results show that ENSO phases directly influence lightning during monsoon and postmonsoon seasons by pushing the mean position of subtropical westerlies southward.
Michelle D. Spruce, Rudy Arthur, Joanne Robbins, and Hywel T. P. Williams
Nat. Hazards Earth Syst. Sci., 21, 2407–2425,Short summary
Despite increased use of impact-based weather warnings, the social impacts of extreme weather events lie beyond the reach of conventional meteorological observations and remain difficult to quantify. This study compares data collected from the social media platform Twitter with a manually curated database of high-impact rainfall events across the globe between January–June 2017. Twitter is found to be a good detector of impactful rainfall events and, therefore, a useful source of impact data.
Folmer Krikken, Flavio Lehner, Karsten Haustein, Igor Drobyshev, and Geert Jan van Oldenborgh
Nat. Hazards Earth Syst. Sci., 21, 2169–2179,Short summary
In this study, we analyse the role of climate change in the forest fires that raged through large parts of Sweden in the summer of 2018 from a meteorological perspective. This is done by studying observationally constrained data and multiple climate models. We find a small reduced probability of such events, based on reanalyses, but a small increased probability due to global warming up to now and a more robust increase in the risk for such events in the future, based on climate models.
Florian Pappenberger, Florence Rabier, and Fabio Venuti
Nat. Hazards Earth Syst. Sci., 21, 2163–2167,Short summary
The European Centre for Medium-Range Weather Forecasts mission is to deliver high-quality global medium‐range (3–15 d ahead of time) weather forecasts and monitoring of the Earth system. We have published a new strategy, and in this paper we discuss what this means for forecasting and monitoring natural hazards.
Elissavet Galanaki, Konstantinos Lagouvardos, Vassiliki Kotroni, Theodore Giannaros, and Christos Giannaros
Nat. Hazards Earth Syst. Sci., 21, 1983–2000,Short summary
A two-way coupled hydrometeorological model (WRF-Hydro) is used for flood forecasting purposes in medium-catchment-size basins in Greece. The results showed the capability of WRF-Hydro to adequately simulate the observed discharge and the slight improvement in terms of quantitative precipitation forecasting compared to the WRF-only simulations.
Frederick W. Letson, Rebecca J. Barthelmie, Kevin I. Hodges, and Sara C. Pryor
Nat. Hazards Earth Syst. Sci., 21, 2001–2020,Short summary
Windstorms during the last 40 years in the US Northeast are identified and characterized using the spatial extent of extreme wind speeds at 100 m height from the ERA5 reanalysis. During all of the top 10 windstorms, wind speeds exceeding the local 99.9th percentile cover at least one-third of the land area in this high-population-density region. These 10 storms followed frequently observed cyclone tracks but have intensities 5–10 times the mean values for cyclones affecting this region.
Panagiotis T. Nastos, Nicolas R. Dalezios, Ioannis N. Faraslis, Kostas Mitrakopoulos, Anna Blanta, Marios Spiliotopoulos, Stavros Sakellariou, Pantelis Sidiropoulos, and Ana M. Tarquis
Nat. Hazards Earth Syst. Sci., 21, 1935–1954,Short summary
Risk assessment consists of three steps: identification, estimation and evaluation. Nevertheless, the risk management framework also includes a fourth step, the need for feedback on all the risk assessment undertakings. However, there is a lack of such feedback, which constitutes a serious deficiency in the reduction of environmental hazards at the present time. The objective of this review paper consists of addressing meteorological hazards and extremes within the risk management framework.
Dieter R. Poelman, Wolfgang Schulz, Stephane Pedeboy, Dustin Hill, Marcelo Saba, Hugh Hunt, Lukas Schwalt, Christian Vergeiner, Carlos T. Mata, Carina Schumann, and Tom Warner
Nat. Hazards Earth Syst. Sci., 21, 1909–1919,Short summary
Information about lightning properties is important in order to advance the current understanding of lightning, whereby the characteristics of ground strike points are in particular helpful to improving the risk estimation for lightning protection. High-speed video recordings of 1174 negative downward lightning flashes are taken in different regions around the world and analyzed in terms of flash multiplicity, duration, interstroke intervals and ground strike point properties.
Dieter R. Poelman, Wolfgang Schulz, Stephane Pedeboy, Leandro Z. S. Campos, Michihiro Matsui, Dustin Hill, Marcelo Saba, and Hugh Hunt
Nat. Hazards Earth Syst. Sci., 21, 1921–1933,Short summary
The lightning flash density is a key input parameter for assessing the risk of occurrence of a lightning strike. Flashes tend to have more than one ground termination point on average; therefore the use of ground strike point densities is more appropriate. The aim of this study is to assess the ability of three distinct ground strike point algorithms to correctly determine the observed ground-truth strike points.
Marc Lemus-Canovas and Joan Albert Lopez-Bustins
Nat. Hazards Earth Syst. Sci., 21, 1721–1738,Short summary
We present research that attempts to address recent and future changes in hot and dry compound events in the Pyrenees, which can induce severe environmental hazards in this area. The results show that during the last few decades, these kinds of compound events have only increased due to temperature increase. However, for the future, it is expected that the risk associated with these compound events will be raised by both the thermal increase and the longer duration of drought periods.
Monica Ionita and Viorica Nagavciuc
Nat. Hazards Earth Syst. Sci., 21, 1685–1701,Short summary
By analyzing the joint frequency of compound events (e.g., high temperatures and droughts), we show that the potential evapotranspiration and mean air temperature are becoming essential components for drought occurrence over Central Europe and the Mediterranean region. This, together with the projected increase in potential evapotranspiration under a warming climate, has significant implications concerning the future occurrence of drought events over these regions.
Feifei Shen, Aiqing Shu, Hong Li, Dongmei Xu, and Jinzhong Min
Nat. Hazards Earth Syst. Sci., 21, 1569–1582,Short summary
The Advanced Himawari Imager (AHI) on Himawari-8 can continuously monitor high-impact weather events with high frequency in space and time. The assimilation of AHI radiance data was implemented with the three-dimensional variational data assimilation system of the Weather Research and Forecasting Model for the analysis and prediction of Typhoon Soudelor (2015) in the Pacific typhoon season.
Uri Dayan, Itamar M. Lensky, Baruch Ziv, and Pavel Khain
Nat. Hazards Earth Syst. Sci., 21, 1583–1597,Short summary
An intense rainstorm hit the Middle East between 24 and 27 April 2018. The storm reached its peak over Israel on 26 April when a heavy flash flood took the lives of 10 people. The rainfall was comparable to the long-term annual rainfall in the southern Negev. The timing was the end of the rainy season when rain is rare and spotty. The study analyses the dynamic and thermodynamic conditions that made this rainstorm one of the latest spring severe events in the region during the last 3 decades.
Seyedabdolhossein Mehvar, Kathelijne Wijnberg, Bas Borsje, Norman Kerle, Jan Maarten Schraagen, Joanne Vinke-de Kruijf, Karst Geurs, Andreas Hartmann, Rick Hogeboom, and Suzanne Hulscher
Nat. Hazards Earth Syst. Sci., 21, 1383–1407,Short summary
This review synthesizes and complements existing knowledge in designing resilient vital infrastructure systems (VIS). Results from a systematic literature review indicate that (i) VIS are still being built without taking resilience explicitly into account and (ii) measures to enhance the resilience of VIS have not been widely applied in practice. The main pressing topic to address is the integration of the combined social, ecological, and technical resilience of these systems.
Rudolf Brázdil, Kateřina Chromá, Lukáš Dolák, Jan Řehoř, Ladislava Řezníčková, Pavel Zahradníček, and Petr Dobrovolný
Nat. Hazards Earth Syst. Sci., 21, 1355–1382,Short summary
We present an analysis of fatalities attributable to weather conditions in the Czech Republic during the 2000–2019 period based on our own database created from newspaper reports, on the database of the Czech Statistical Office, and on the database of the police of the Czech Republic as well as on their comparison. Despite some uncertainties, generally declining trends in the number of fatalities appear for the majority of weather variables. The structure of fatalities is described in detail.
Zheng Liang, Xiaoling Su, and Kai Feng
Nat. Hazards Earth Syst. Sci., 21, 1323–1335,Short summary
In view of the shortage of data in alpine mountainous areas and the difficulty of a single drought index to reflect all the characteristics of drought, this paper constructs a comprehensive drought index (MAHDI) based on the SWAT model and the empirical Kendall distribution function, which connects multiple drought elements. The results show that MAHDI can simultaneously characterize meteorological, agricultural and hydrological drought and has strong applicability and comprehensiveness.
Hamish Steptoe and Theodoros Economou
Nat. Hazards Earth Syst. Sci., 21, 1313–1322,Short summary
We use high-resolution computer simulations of tropical cyclones to investigate extreme wind speeds over Bangladesh. We show that some northern provinces, up to 200 km inland, may experience conditions equal to or exceeding a very severe cyclonic storm event with a likelihood equal to coastal regions less than 50 km inland. We hope that these kilometre-scale hazard maps facilitate one part of the risk assessment chain to improve local ability to make effective risk management decisions.
Chiara Marsigli, Elizabeth Ebert, Raghavendra Ashrit, Barbara Casati, Jing Chen, Caio A. S. Coelho, Manfred Dorninger, Eric Gilleland, Thomas Haiden, Stephanie Landman, and Marion Mittermaier
Nat. Hazards Earth Syst. Sci., 21, 1297–1312,Short summary
This paper reviews new observations for the verification of high-impact weather and provides advice for their usage in objective verification. New observations include remote sensing datasets, products developed for nowcasting, datasets derived from telecommunication systems, data collected from citizens, reports of impacts and reports from insurance companies. This work has been performed in the framework of the Joint Working Group on Forecast Verification Research (JWGFVR) of the WMO.
Judith Marie Pöschmann, Dongkyun Kim, Rico Kronenberg, and Christian Bernhofer
Nat. Hazards Earth Syst. Sci., 21, 1195–1207,Short summary
We examined maximum rainfall values for different durations from 16 years of radar-based rainfall records for whole Germany. Unlike existing observations based on rain gauge data no clear linear relationship could be identified. However, by classifying all time series, we could identify three similar groups determined by the temporal structure of rainfall extremes observed in the study period. The study highlights the importance of using long data records and a dense measurement network.
Matthieu Plu, Barbara Scherllin-Pirscher, Delia Arnold Arias, Rocio Baro, Guillaume Bigeard, Luca Bugliaro, Ana Carvalho, Laaziz El Amraoui, Kurt Eschbacher, Marcus Hirtl, Christian Maurer, Marie Mulder, Dennis Piontek, Lennart Robertson, Carl-Herbert Rokitansky, Fritz Zobl, and Raimund Zopp
Nat. Hazards Earth Syst. Sci. Discuss.,
Revised manuscript accepted for NHESSShort summary
Past volcanic eruptions that spread out ash over large areas, like Eyjafjallajökull in 2010, forced to cancel thousands of flights and have huge economic consequences. In this article, an international team in the H2020 EU-funded EUNADICS-AV project has designed a probabilistic model approach to quantify the ash concentrations, evaluates it against measurements and discusses its potential use to mitigate the impact of future large-scale eruptions.
Alexandre Tuel and Olivia Martius
Nat. Hazards Earth Syst. Sci. Discuss.,
Revised manuscript accepted for NHESSShort summary
Flood events may be triggered by large accumulations of precipitation over short time periods, which can result from the successive occurrence of extreme precipitation events. We find a distinct spatio-temporal pattern in the temporal clustering behavior of precipitation extremes over Switzerland, with clustering occurring on the northern side of the Alps in winter and on their southern side in fall. Clusters tend to be followed by flood events, particularly in the southern Alps.
Olivier Caumont, Marc Mandement, François Bouttier, Judith Eeckman, Cindy Lebeaupin Brossier, Alexane Lovat, Olivier Nuissier, and Olivier Laurantin
Nat. Hazards Earth Syst. Sci., 21, 1135–1157,Short summary
This study focuses on the heavy precipitation event of 14 and 15 October 2018, which caused deadly flash floods in the Aude basin in south-western France. The case is studied from a meteorological point of view using various operational numerical weather prediction systems, as well as a unique combination of observations from both standard and personal weather stations. The peculiarities of this case compared to other cases of Mediterranean heavy precipitation events are presented.
Claudia Canedo-Rosso, Stefan Hochrainer-Stigler, Georg Pflug, Bruno Condori, and Ronny Berndtsson
Nat. Hazards Earth Syst. Sci., 21, 995–1010,Short summary
Drought is a major natural hazard that causes large losses for farmers. This study evaluated drought severity based on a drought classification scheme using NDVI and LST, which was related to the ENSO anomalies. In addition, the spatial distribution of NDVI was associated with precipitation and air temperature at the local level. Our findings show that drought severity increases during El Niño years, and as a consequence the socio-economic drought risk of farmers will likely increase.
William C. Arthur
Nat. Hazards Earth Syst. Sci., 21, 893–916,Short summary
We have developed a statistical–parametric model of tropical cyclones (TCs), to undertake hazard and risk assessments at continental scales. The model enables users to build an understanding of the likelihood and magnitude of TC-related wind speeds across full ocean basins but at a fine spatial resolution. The model can also be applied to single events, either scenarios or forecast events, to inform detailed impact assessments.
Flavio Lopes Ribeiro, Mario Guevara, Alma Vázquez-Lule, Ana Paula Cunha, Marcelo Zeri, and Rodrigo Vargas
Nat. Hazards Earth Syst. Sci., 21, 879–892,Short summary
The main objective of this paper was to analyze differences in soil moisture responses to drought for each biome of Brazil. For that we used satellite data from the European Space Agency from 2009 to 2015. We found an overall soil moisture decline of −0.5 % yr−1 at the country level and identified the most vulnerable biomes of Brazil. This information is crucial to enhance the national drought early warning system and develop strategies for drought risk reduction and soil moisture conservation.
Kees Nederhoff, Jasper Hoek, Tim Leijnse, Maarten van Ormondt, Sofia Caires, and Alessio Giardino
Nat. Hazards Earth Syst. Sci., 21, 861–878,Short summary
The design of coastal protection affected by tropical cyclones is often based solely on the analysis of historical tropical cyclones (TCs). The simulation of numerous synthetic TC tracks based on historical data can overcome this limitation. In this paper, a new method for the generation of synthetic TC tracks is proposed, called the Tropical Cyclone Wind Statistical Estimation Tool (TCWiSE). TCWiSE can simulate thousands of tracks and wind fields in any oceanic basin based on any data source.
Elody Fluck, Michael Kunz, Peter Geissbuehler, and Stefan P. Ritz
Nat. Hazards Earth Syst. Sci., 21, 683–701,Short summary
Severe convective storms (SCSs) and the related hail events constitute major atmospheric hazards in parts of Europe. In our study, we identified the regions of France, Germany, Belgium and Luxembourg that were most affected by hail over a 10 year period (2005 to 2014). A cell-tracking algorithm was computed on remote-sensing data to enable the reconstruction of several thousand SCS tracks. The location of hail hotspots will help us understand hail formation and improve hail forecasting.
Kelvin S. Ng and Gregor C. Leckebusch
Nat. Hazards Earth Syst. Sci., 21, 663–682,Short summary
Due to the rarity of high-impact tropical cyclones (TCs), it is difficult to achieve a robust TC hazard assessment based on historical observations only. Here we present an approach to construct a TC event set that contains more than 10 000 years of TC events by using a computationally simple and efficient method. This event set has similar characteristics as the historical observations but includes a better representation of intense TCs. Thus, a robust TC hazard assessment can be achieved.
Nadia Fourrié, Mathieu Nuret, Pierre Brousseau, and Olivier Caumont
Nat. Hazards Earth Syst. Sci., 21, 463–480,Short summary
The assimilation impact of four observation data sets on forecasts is studied in a mesoscale weather model. The ground-based Global Navigation Satellite System (GNSS) zenithal total delay data set with information on humidity has the largest impact on analyses and forecasts, representing an evenly spread and frequent data set for each analysis time over the model domain. Moreover, the reprocessing of these data also improves the forecast quality, but this impact is not statistically significant.
Joan Gilabert, Anna Deluca, Dirk Lauwaet, Joan Ballester, Jordi Corbera, and Maria Carmen Llasat
Nat. Hazards Earth Syst. Sci., 21, 375–391,Short summary
Trends of extreme temperature episodes in cities are increasing due to regional climate change in interaction with urban effects. Urban morphologies and thermal properties of the materials used to build them are factors that influence climate variability and are one of the main reasons for the climatic singularity of cities. This paper presents a methodology to evaluate the urban and peri-urban effect on extreme-temperature exposure using land cover and land use maps.
David MacLeod, Mary Kilavi, Emmah Mwangi, Maurine Ambani, Michael Osunga, Joanne Robbins, Richard Graham, Pedram Rowhani, and Martin C. Todd
Nat. Hazards Earth Syst. Sci., 21, 261–277,Short summary
Forecasts of natural hazards save lives. But the accuracy of forecasts must be evaluated before use. Here we evaluate heavy rainfall advisories over Kenya. We assess their ability to anticipate heavy rainfall and show how well they warned of recent floods which had significant impacts. We find that although they effectively warn of heavy rainfall and flooding, issues such as a lack of spatial detail limit their utility for systematic approaches to preparedness.
Linda van Garderen, Frauke Feser, and Theodore G. Shepherd
Nat. Hazards Earth Syst. Sci., 21, 171–186,Short summary
The storyline method is used to quantify the effect of climate change on a particular extreme weather event using a global atmospheric model by simulating the event with and without climate change. We present the method and its successful application for the climate change signals of the European 2003 and the Russian 2010 heatwaves.
Raphaël Cécé, Didier Bernard, Yann Krien, Frédéric Leone, Thomas Candela, Matthieu Péroche, Emmanuel Biabiany, Gael Arnaud, Ali Belmadani, Philippe Palany, and Narcisse Zahibo
Nat. Hazards Earth Syst. Sci., 21, 129–145,Short summary
The present innovative modeling aims to combine the most realistic simulated strongest gusts driven by tornado-scale vortices within the eyewall and the most realistic complex terrain effects. The present modeling method could be easily extended to other small mountainous islands to improve the understanding of observed past damage and to develop safer urban management and appropriate building standards.
Shunya Koseki, Priscilla A. Mooney, William Cabos, Miguel Ángel Gaertner, Alba de la Vara, and Juan Jesus González-Alemán
Nat. Hazards Earth Syst. Sci., 21, 53–71,Short summary
This study investigated one case of a tropical-like cyclone over the Mediterranean Sea under present and future climate conditions with a regional climate model. A pseudo global warming (PGW) technique is employed to simulate the cyclone under future climate, and our simulation showed that the cyclone is moderately strengthened by warmer climate. Other PGW simulations where only ocean and atmosphere are warmed reveal the interesting results that both have counteracting effects on the cyclone.
Marcus Hirtl, Barbara Scherllin-Pirscher, Martin Stuefer, Delia Arnold, Rocio Baro, Christian Maurer, and Marie D. Mulder
Nat. Hazards Earth Syst. Sci., 20, 3099–3115,Short summary
The paper shows the application of a new volcanic emission preprocessor for the chemical transport model WRF-Chem. The model is evaluated with different observational data sets for the eruption of the Grimsvötn volcano 2011.
Alexander Krug, Daniel Fenner, Hans-Guido Mücke, and Dieter Scherer
Nat. Hazards Earth Syst. Sci., 20, 3083–3097,Short summary
This study investigates hot weather episodes in eight German cities which are statistically associated with increased mortality. Besides air temperature, ozone concentrations partly explain these mortality rates. The strength of the respective contributions of the two stressors varies across the cities. Results highlight that during hot weather episodes, not only high air temperature affects urban populations; concurrently high ozone concentrations also play an important role in public health.
Nico Becker, Henning W. Rust, and Uwe Ulbrich
Nat. Hazards Earth Syst. Sci., 20, 2857–2871,Short summary
A set of models is developed to forecast hourly probabilities of weather-related road accidents in Germany at the spatial scale of administrative districts. Model verification shows that using precipitation and temperature data leads to the best accident forecasts. Based on weather forecast data we show that skilful predictions of accident probabilities of up to 21 h ahead are possible. The models can be used to issue impact-based warnings, which are relevant for road users and authorities.
Alberto Caldas-Alvarez and Samiro Khodayar
Nat. Hazards Earth Syst. Sci., 20, 2753–2776,Short summary
Heavy precipitation causes serious losses and several casualties in the western Mediterranean every year. To predict this phenomenon better, we aim at understanding how the models represent the interaction between atmospheric moisture and precipitation by nudging a 10 min, state-of-the-art GPS data set. We found, for the selected case in autumn 2012, that the improvement in the modelling of precipitation stems from relevant variations of atmospheric instability and humidity above 1.5 km.
Sean D. Egan, Martin Stuefer, Peter W. Webley, Taryn Lopez, Catherine F. Cahill, and Marcus Hirtl
Nat. Hazards Earth Syst. Sci., 20, 2721–2737,Short summary
The Weather Research Forecasting with Chemistry (WRF-Chem) model was modified to include volcanic ash aggregation. The modified WRF-Chem model was run with and without aggregation, and changes in the model output were measured. Changes in the lifetime of volcanic ash a function of the chosen fractal dimension were quantified. A case study using the 2010 eruptions of Eyjafjallajökull revealed that the aggregation modifications result in tephra fallout and ash concentrations near observed values.
Joan Albert Lopez-Bustins, Laia Arbiol-Roca, Javier Martin-Vide, Antoni Barrera-Escoda, and Marc Prohom
Nat. Hazards Earth Syst. Sci., 20, 2483–2501,Short summary
We considered the Western Mediterranean Oscillation index (WeMOi) to analyse the occurrence of extreme torrential episodes (≥ 200 mm in 24 h) over Catalonia (NE Iberia) during the 1951–2016 period. Principal results reveal the occurrence of 50 episodes, mainly in autumn, especially during the second 10 d period of October (11–20), coinciding with the most negative WeMOi values of the year. Seasonal changes in these episodes and in WeMOi values might be due to sea warming.
Leah Hayward, Malcolm Whitworth, Nick Pepin, and Steve Dorling
Nat. Hazards Earth Syst. Sci., 20, 2463–2482,Short summary
This review article outlines the state of thunderstorm climatologies, which are underrepresented in the literature. Thunderstorms overlap with lightning and intense precipitation events, both of which create important hazards. This article compiles and evaluates information on datasets, research approaches and methodologies used in quantifying thunderstorm distribution, providing an introduction to the topic and signposting new and established researchers to research articles and datasets.
Xian Luo, Xuemei Fan, Yungang Li, and Xuan Ji
Nat. Hazards Earth Syst. Sci., 20, 2243–2254,Short summary
In this study, we corrected Asian Precipitation Highly Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE) in the Yarlung Tsangpo–Brahmaputra River Basin using both linear and nonlinear methods, and their influences on resulting extreme precipitation indices were assessed. Results showed that all methods were able to correct mean precipitation, but their ability to correct wet-day frequency and coefficient of variation were markedly different.
Milica M. Pecelj, Milica Z. Lukić, Dejan J. Filipović, Branko M. Protić, and Uroš M. Bogdanović
Nat. Hazards Earth Syst. Sci., 20, 2021–2036,Short summary
The variation in UTCI heat stress grade was observed during heat waves over the past 20 years in order to identify patterns of biothermal heat stress conditions in Serbia.
Very strong heat stressdescribes an alarming biothermal state and has occurred frequently in the last 10 years. The findings indicate the UTCI14 h index
very strong heat stress event(VSHSE) as an indicator of biothermal heat hazard.
Deanna Nash and Leila M. V. Carvalho
Nat. Hazards Earth Syst. Sci., 20, 1931–1940,Short summary
On 6 March 2019, during an atmospheric river (AR) event, over 8000 lightning flashes were recorded near southern California in under 24 h, resulting in a unique meteorological event for this region. This study examines the characteristics of this AR compared to previous landfalling ARs in Santa Barbara and explores how the conditions led to the formation of hail and enhanced electrification in a region that sees little to no lightning.
Kuo Li and Gyilbag Amatus
Nat. Hazards Earth Syst. Sci., 20, 1889–1901,Short summary
In recent years, heat waves have become more frequent in the world, e.g., in Europe, Australia, China and the US, at huge detriment to human health and natural resources. Thus we establish an integrated index of heat waves and extreme-temperature days to provide unified standards for assessing heat waves and hot years. It provides a clear picture of the evolution and spatial distribution of heat waves and hot years in China.
Michael Kunz, Jan Wandel, Elody Fluck, Sven Baumstark, Susanna Mohr, and Sebastian Schemm
Nat. Hazards Earth Syst. Sci., 20, 1867–1887,Short summary
Severe convective storms are major loss drivers across Europe. We reconstructed several thousand storm tracks from radar reflectivity over a 10-year period for parts of Europe. The tracks were additionally combined with hail reports, reanalysis data, and front detections based on ERA-Interim (ECMWF Reanalysis). It is found that frontal hailstorms on average produce larger hailstones and have longer tracks and that wind shear is important not only for the hail diameter but also for track length.
Anita Verpe Dyrrdal, Ketil Isaksen, Jens Kristian Steen Jacobsen, and Irene Brox Nilsen
Nat. Hazards Earth Syst. Sci., 20, 1847–1865,Short summary
We have studied changes in winter weather known to trigger road closures and isolation of small seaside communities in northern Norway. We find that snow amounts and heavy snowfall events have increased in the past, while future projections for 2040–2100 show a decrease in snow-related indices. Events of heavy water supply and zero crossings are expected to increase. Our results imply fewer dry-snow-related access disruptions in the future, while wet-snow avalanches and slushflows may increase.
Rogert Sorí, Marta Vázquez, Milica Stojanovic, Raquel Nieto, Margarida L. R. Liberato, and Luis Gimeno
Nat. Hazards Earth Syst. Sci., 20, 1805–1832,
ARC: Risk Pool I, available at: https://www.africanriskcapacity.org/impact/ (last access: 28 January 2021), 2014. a
Beck, H. E., Pan, M., Roy, T., Weedon, G. P., Pappenberger, F., van Dijk, A. I. J. M., Huffman, G. J., Adler, R. F., and Wood, E. F.: Daily evaluation of 26 precipitation datasets using Stage-IV gauge-radar data for the CONUS, Hydrol. Earth Syst. Sci., 23, 207–224, https://doi.org/10.5194/hess-23-207-2019, 2019. a
Da, J., Jale, S., Fernando, S., Junior, S. F., Fialho, E., Xavier, M., Stosic, T., Stosic, B., Alessandro, T., and Ferreira, E.: Application of Markov chain on daily rainfall data in Paraíba-Brazil from 1995–2015, Acta Sci. Technol., 41, 1–10, https://doi.org/10.4025/actascitechnol.v41i1.37186, 2019. a
Descroix, L., Diongue Niang, A., Panthou, G., Bodian, A., Sane, Y., Dacosta, H., Malam Abdou, M., Vandervaere, J.-P., and Quantin, G.: Évolution récente de la pluviométrie en Afrique de l'ouest à travers deux régions: la Sénégambie et le Bassin du Niger Moyen, Climatologie, 12, 25–43, https://doi.org/10.4267/climatologie.1105, 2016. a
Dieng, O., Roucou, P., and Louvet, S.: Variabilité intra-saisonnière des précipitations au Sénégal (1951–1996), Sécheresse, 19, 87–93, 2008. a
Dinku, T., Funk, C., Peterson, P., Maidment, R., Tadesse, T., Gadain, H., and Ceccato, P.: Validation of the CHIRPS Satellite Rainfall Estimates over Eastern of Africa: Validation of the CHIRPS Satellite Rainfall Estimates, Q. J. Roy. Meteorol. Soc., 144, 292–312, https://doi.org/10.1002/qj.3244, 2018. a
Engel, T., Fink, A. H., Knippertz, P., Pante, G., and Bliefernicht, J.: Extreme Precipitation in the West African Cities of Dakar and Ouagadougou: Atmospheric Dynamics and Implications for Flood Risk Assessments, J. Hydrometeorol., 18, 2937–2957, 2017. a
Fowe, T., Diarra, a., Kabore, R., Ibrahim, B., BOLOGO/TRAORE, M., TRAORE, K., and Karambiri, H.: Trends in flood events and their relationship to extreme rainfall in an urban area of West African Sahel: The case of the Ouagadougou area in Burkina Faso, J. Flood Risk Manage., 12, e12507, https://doi.org/10.1111/jfr3.12507, 2018. a
Funk, C., Peterson, P., Landsfeld, M., Pedreros, D., Verdin, J., Shukla, S., Husak, G., Rowland, J., Harrison, L., Hoell, A., and Michaelsen, J.: The climate hazards infrared precipitation with stations – A new environmental record for monitoring extremes, Sci. Data, 2, 150066, https://doi.org/10.1038/sdata.2015.66, 2015. a
Gaye, A. T., Fongang, S., Garba, A., and Badiane, D.: Etude des pluies de Heug sur le Senegal a l'aide de donnees conventionnelles et imagerie Meteosat (Study of Heug rainfall in Senegal using conventional data and Meteosat imagery), Veille Climatique Satellitaire, 61–71, available at: http://www.documentation.ird.fr/hor/fdi:41383 (last access: 19 November 2020), 1994. a
Huffman, G., Adler, R., Bolvin, D., Gu, G., Nelkin, E., Bowman, K., Stocker, E., and Wolff, D.: The TRMM multi-satellite precipitation analysis: Quasi-global, multi-year, combined-sensor precipitation estimates at fine scale, J. Hydrometeorol., 8, 28–55, 2007. a
Joyce, R., Janowiak, J., Arkin, P., and Xie, P.: CMORPH: A Method That Produces Global Precipitation Estimates From Passive Microwave and Infrared Data at High Spatial and Temporal Resolution, J. Hydrometeorol., 5, 487–503, https://doi.org/10.1175/1525-7541(2004)005<0487:CAMTPG>2.0.CO;2, 2004. a
Kummerow, C., Barnes, W., Kozu, T., Shiue, J., and Simpson, J.: The Tropical Rainfall Measuring Mission (TRMM) sensor package, J. Atmos. Ocean Tech., 15, 809–817, https://doi.org/10.1175/1520-0426(1998)015<0809:TTRMMT>2.0.CO;2, 1998. a, b
Lafore, J.-P., Beucher, F., Peyrillé, P., Diongue-Niang, A., Chapelon, N., Bouniol, D., Caniaux, G., Favot, F., Ferry, F., Guichard, F., Poan, D., Roehrig, R., and Vischel, T.: A multi-scale analysis of the extreme rain event of Ouagadougou in 2009, Q. J. Roy. Meteorol. Soc., 143, 3094–3109, https://doi.org/10.1002/qj.3165, 2017. a
Le Barbé, L., Lebel, T., and Tapsoba, D.: Rainfall Variability in West Africa during the Years 1950–90, J. Climate, 15, 187–202, https://doi.org/10.1175/1520-0442(2002)015<0187:RVIWAD>2.0.CO;2, 2002. a
Maidment, R., Grimes, D., Black, E., Tarnavsky, E., Young, M., Greatrex, H., Allan, R., Stein, T., Nkonde, E., Senkunda, S., and Uribe, E.: A new, long-term daily satellite-based rainfall dataset for operational monitoring in Africa, Sci. Data, 4, 170063, https://doi.org/10.1038/sdata.2017.63, 2017. a
Malardel, S., Wedi, N., Deconinck, W., Diamantakis, M., Kühnlein, C., Mozdzynski, G., Hamrud, M., and Smolarkiewicz, P.: A new grid for the IFS, ECMWF Newslett., 146, 23–28, 2016. a
Sagna, P., Ndiaye, O., Diop, C., Diongue-Niang, A., and Corneille, S.: Are recent climate variations observed in Senegal in conformity with the descriptions given by the IPCC scenarios?, available at: http://lodel.irevues.inist.fr/pollution-atmospherique/index.php?id=5320 (last access: 18 March 2021), 2015. a
Saha, S., Moorthi, S., Pan, H.-L., Wu, X., Wang, J., Nadiga, S., Tripp, P., Kistler, R., Woollen, J., Behringer, D., Liu, H., Stokes, D., Grumbine, R., Gayno, G., Wang, J., Hou, Y.-T., Chuang, H.-Y., Juang, H.-M., Sela, J., and Goldberg, M.: The NCEP climate forecast system reanalysis, B. Am. Meteorol. Soc., 91, 1015–1057, https://doi.org/10.1175/2010BAMS3001.1, 2010. a
Sane, Y., Panthou, G., Bodian, A., Vischel, T., Lebel, T., Dacosta, H., Quantin, G., Wilcox, C., Ndiaye, O., Diongue-Niang, A., and Diop Kane, M.: Intensity–duration–frequency (IDF) rainfall curves in Senegal, Nat. Hazards Earth Syst. Sci., 18, 1849–1866, https://doi.org/10.5194/nhess-18-1849-2018, 2018. a
Sivakumar, M.: Empirical analysis of dry spells for agricultural applications in west Africa, J. Climate, 24, 532–539, 1992. a
Tabios, G. and Salas, J.: A Comparative Analysis of Techniques for Spatial Interpolation of Precipitation, J. Am. Water Resour. Assoc., 21, 365–380, https://doi.org/10.1111/j.1752-1688.1985.tb00147.x, 1985. a
UCDP: UCDP Conflict Encyclopedia, Uppsala University, available at: https://www.ucdp.uu.se (last access: 19 November 2020), 2017. a
WFP: WFP Senegal Country Brief, January 2018, Senegal, available at: https://reliefweb.int/report/senegal/wfp-senegal-country-brief-january-2018 (last access: 19 November 2020), 2018. a
Extreme wet and dry rainfall periods over Senegal provided by satellite, reanalyses, and ground observations are compared. Despite a spatial coherence of seasonal rainfall accumulation between all products, discrepancies are found at intra-seasonal timescales. All datasets highlight comparable seasonal cycles of dry and wet spells. Nevertheless, CHIRPS and TAMSAT are close to observations for the dry spells, whereas TRMM obtains the closest values of wet spells as regards the observations.
Extreme wet and dry rainfall periods over Senegal provided by satellite, reanalyses, and ground...