Article
Meteorology & Atmospheric Sciences
Craig A. Ramseyer, Paul W. Miller
Summary: This study fills the gap in understanding the climatology and evolution of trade wind inversion (TWI) in the tropical North Atlantic (TNA) region using high-resolution ERA5 reanalysis data. The results show stronger and more frequent TWIs in the central TNA across all seasons. Analysis also reveals increasing trends in TWI frequency and strength, with a particularly strong signal from December to July. Regional forcing mechanisms responsible for these changes are discussed.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Lorenzo Minola, Gangfeng Zhang, Tinghai Ou, Julia Kukulies, Julia Curio, Jose A. Guijarro, Kaiqiang Deng, Cesar Azorin-Molina, Cheng Shen, Alessandro Pezzoli, Deliang Chen
Summary: This study explores the climatology of near-surface wind speed over the Tibetan Plateau using homogenized observations, reanalysis products, and regional climate model simulations. It finds that wind speed increases with increasing altitude in the plateau and identifies three regions with distinct wind regimes. The ERA5 reanalysis shows closer agreement to measured wind conditions compared to ERA-Interim, but the ERA5-Land product does not show improvements. Additionally, two dynamical downscalings of ERA5 fail to capture observed wind statistics and exhibit biases and discrepancies.
Article
Meteorology & Atmospheric Sciences
Cheng Shen, Jinlin Zha, Jian Wu, Deming Zhao, Cesar Azorin-Molina, Wenxuan Fan, Yue Yu
Summary: Global reanalysis products are essential for understanding past climates, especially in the wind energy industry. The CRA-40 dataset released by China Meteorological Administration provides the best agreement and reproduces observed multi-decadal variability in near-surface wind speed (NSWS) across China, compared to other state-of-the-art reanalysis products.
ATMOSPHERIC RESEARCH
(2022)
Article
Environmental Sciences
L. Erikson, J. Morim, M. Hemer, I. Young, X. L. Wang, L. Mentaschi, N. Mori, A. Semedo, J. Stopa, V. Grigorieva, S. Gulev, O. Aarnes, J. -R. Bidlot, O. Breivik, L. Bricheno, T. Shimura, M. Menendez, M. Markina, V. Sharmar, C. Trenham, J. Wolf, C. Appendini, S. Caires, N. Groll, A. Webb
Summary: By using a global wave product ensemble, we quantify trends in global ocean surface wave characteristics between 1980 and 2014 and establish regions with robust trends. Our findings show that 30-40% of the global ocean experienced seasonal trends in wave characteristics, with the Southern Hemisphere exhibiting significant upward trends in wave height and period. Basins with positive trends are larger than those with negative trends.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Linh N. Luu, Erik van Meijgaard, Sjoukje Y. Philip, Sarah F. Kew, Jouke H. S. de Baar, Andrew Stepek
Summary: The study investigates the temporal trend of wind speed near the surface over land, particularly in western Europe. The impact of changes in surface roughness due to land-use and vegetation cover changes on this variable is examined using the regional climate model RACMO driven by ERA5 reanalysis. The findings indicate that the decline in wind speed is attributed to the slowing down of upper-level large-scale circulation, and changes in surface roughness intensify this trend. However, the trends observed from the model simulations and ERA5 are inconsistent with those derived from the gridded observations database E-OBS, possibly due to the complexity of integrating in-situ measurements with uncorrectable inhomogeneity.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Geosciences, Multidisciplinary
Alessio C. C. Spassiani, Matthew S. S. Mason, Vincent Y. S. Cheng
Summary: A spatially complete climatology of severe convective wind gusts in Australia was developed by using observational and global reanalysis data. Different weather indices were found to explain gust frequencies for different seasons, with minimal events in winter and maximum events in summer. The models were also applied to a longer time period, showing similar trends.
Article
Water Resources
Elisabeth Probst, Wolfram Mauser
Summary: The study evaluates the use of ERA5 and WFDE5 for driving hydrological models in the Danube River Basin, finding that bias correction of precipitation data is essential, especially in mountainous regions. The ERA5-driven simulation bias-corrected with a GLOWA-PRISM-WorldClim 2 mosaic performed best in terms of model efficiency and discharge bias. Regional high-resolution precipitation climatologies, such as GLOWA and PRISM, are recommended for bias correction in mountainous terrain.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2022)
Article
Environmental Sciences
Michal Kozubek, Jan Lastovicka, Radek Zajicek
Summary: This study analyzed long-term trends in temperature and wind climatology based on ERA5 data, focusing on pressure levels in the stratosphere. The largest differences were identified between 1990-2000 and 2000-2010, possibly related to the different occurrence frequency of SSWs.
Article
Environmental Sciences
S. C. Scherrer, M. Hirschi, C. Spirig, F. Maurer, S. Kotlarski
Summary: The Alpine region has been experiencing increasingly dry summers, which have had significant negative impacts on the economy, society, and ecology. This study analyzes drought indicators, evapotranspiration, and meteorological data to assess the trends and drivers of summer drought in Switzerland from 1981 to 2020. The results suggest that both increasing evapotranspiration and a non-significant decrease in precipitation are important drivers of summer drought in the region.
ENVIRONMENTAL RESEARCH COMMUNICATIONS
(2022)
Article
Meteorology & Atmospheric Sciences
Lorenzo Minola, Heather Reese, Hui-Wen Lai, Cesar Azorin-Molina, Jose A. Guijarro, Seok-Woo Son, Deliang Chen
Summary: This study examines the break in the stilling phenomenon detected around 2010, with a focus on Sweden using wind speed observations from 1997 to 2019. It found that the stilling reversed after 2003, with changes in wind speed driven by large-scale atmospheric circulation and surface roughness variations. Strong winds played a significant role in wind speed changes, with gusts showing greater increases compared to mean wind speeds.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
S. Khanal, S. Tiwari, A. F. Lutz, B. V. D. Hurk, W. W. Immerzeel
Summary: The climate of High Mountain Asia (HMA) has been changing in recent decades, with increasing temperatures and inconsistent precipitation changes. This study used daily ERA5 reanalysis data to explore changes in climate variables in HMA along the full altitudinal range. The results showed winter warming and summer wetting dominating in the interior part of HMA, with significant increasing trends in heatwave occurrences and heavy precipitation in certain areas. The changes in climatic extremes indicate potential increases in hazards such as floods, landslides, and droughts, impacting economic production and infrastructure.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Terhi K. Laurila, Victoria A. Sinclair, Hilppa Gregow
Summary: This study analyzes the monthly 10-m wind speed climatology, decadal variability and possible trends in the North Atlantic and Europe, as well as investigates the physical reasons for the decadal variability. Results show distinct land-sea contrast and seasonal variation in wind speeds, with large annual and decadal variability identified. The decadal changes in wind speeds are largely influenced by the positioning of the jet stream and storm tracks.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Green & Sustainable Science & Technology
Sylvia Tramberend, Robert Burtscher, Peter Burek, Taher Kahil, Gunther Fischer, Junko Mochizuki, Peter Greve, Richard Kimwaga, Philip Nyenje, Risper Ondiek, Prossie Nakawuka, Canute Hyandye, Claver Sibomana, Hilda Pius Luoga, Ali Said Matano, Simon Langan, Yoshihide Wada
Summary: By considering the integrated impact of various factors such as climate change, land use, and increasing human water use, it is expected that the flow regime of the Nile may remain relatively stable. To achieve this goal, reliance on advanced, often costly technologies and management is necessary.
Article
Meteorology & Atmospheric Sciences
Samar Minallah, Allison L. Steiner
Summary: This study evaluates the performance of two reanalysis models over the world's largest lakes, finding that differences in lake representation affect hydrometeorological variables and can lead to biases in regional hydroclimatic assessments.
MONTHLY WEATHER REVIEW
(2021)
Article
Meteorology & Atmospheric Sciences
Natalia Pilguj, Mateusz Taszarek, John T. Allen, Kimberly A. Hoogewind
Summary: This study compares long-term trends in convective parameters between ERA5, MERRA-2, and observed rawinsonde profiles over Europe and the United States. The results show that the reanalyses provide signals that are similar to the observations, but ERA5 has lower biases. The trend agreement between rawinsondes and reanalyses is better in Europe, particularly for instability, low-level moisture, and 0-3-km lapse rates. However, robust increases in convective inhibition, downdraft CAPE, and decreases in mean 0-4-km relative humidity are consistent signals for all three datasets and both domains. The study also highlights the importance of comparing trends between different datasets to reduce uncertainties and increase confidence in parameter changes over time.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
Jerome Kopp, Katharina Schroeer, Cornelia Schwierz, Alessandro Hering, Urs Germann, Olivia Martiusl
Article
Meteorology & Atmospheric Sciences
Sam Allen, Jonas Bhend, Olivia Martius, Johanna Ziegel
Summary: To mitigate the impacts of adverse weather, meteorological services issue weather warnings based on forecasts from prediction systems. Evaluating forecasts for high-impact weather is challenging due to the complexity of compound weather events. This paper discusses weighted verification tools to evaluate probabilistic forecasts for specific outcomes such as extreme heat events.
WEATHER AND FORECASTING
(2023)
Article
Multidisciplinary Sciences
Bart J. J. M. van den Hurk, Christopher J. White, Alexandre M. Ramos, Philip J. Ward, Olivia Martius, Indiana Olbert, Kathryn Roscoe, Henrique M. D. Goulart, Jakob Zscheischler
Summary: Consideration of compound drivers, hazards, and impacts is often overlooked in the Disaster Risk Reduction (DRR) cycle, leading to limited understanding of risk and actions. This article provides examples of how compound thinking can affect different areas of disaster risk management and emphasizes the need for practical guidelines. The authors identify five DRR categories and present studies that highlight the role of considering compound factors in early warning, emergency response, infrastructure management, long-term planning, and capacity building.
Article
Environmental Sciences
Noelia Otero, Pascal Horton, Olivia Martius, Sam Allen, Massimiliano Zappa, Tobias Weschler, Bettina Schaefli
Summary: Hydropower is an important renewable energy source that can complement solar and wind power in achieving a low-carbon power system. However, its production is dependent on local weather conditions and climate variability. A study in Switzerland, where hydropower provides the largest share of electricity production, found that the impacts of hot-dry conditions on hydropower are case-specific.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
Alessio Ciullo, Eric Strobl, Simona Meiler, Olivia Martius, David N. Bresch
Summary: This study finds that global pooling generally provides greater financial resilience and risk diversification compared to regional pooling in sovereign catastrophe risk pools. Extreme weather events can severely impact national economies, leading to reliance on slow and uncertain foreign financial aid. The study introduces a method for maximizing risk diversification and finds that global pooling always provides higher risk diversification and benefits more countries.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Angela-Maria Burgdorf, Stefan Broennimann, George Adamson, Tatsuya Amano, Yasuyuki Aono, David Barriopedro, Teresa Bullon, Chantal Camenisch, Dario Camuffo, Valeerie Daux, Maria del Rosario Prieto, Petr Dobrovolny, David Gallego, Ricardo Garcia-Herrera, Joelle Gergis, Stefan Grab, Matthew J. Hannaford, Jari Holopainen, Clare Kelso, Zoltan Kern, Andrea Kiss, Elaine Kuan-Hui Lin, Neil J. Loader, Martin Mozny, David Nash, Sharon E. Nicholson, Christian Pfister, Fernando S. Rodrigo, This Rutishauser, Sapna Sharma, Katalin Takacs, Ernesto T. Vargas, Inmaculada Vega
Summary: Documentary climate data, derived from written historical documents, provide evidence of past climate. A global dataset of documentary climate time series has not been compiled before. This study presents the first global collection of documentary climate records, consisting of 621 time series, including temperature, precipitation, and wind regime variations. The results show strong correlations, particularly for temperature-sensitive series, indicating the considerable potential of documentary records as climate data.
Article
Environmental Sciences
Evan de Schrijver, Sidharth Sivaraj, Christoph C. Raible, Oscar H. Franco, Kai Chen, Ana M. Vicedo-Cabrera
Summary: Climate change and population development are impacting the temporal patterns of temperature-related mortality in Switzerland. Limited evidence exists on how these trends will evolve in the future and their specific contributions to mortality impacts.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
Jerome Kopp, Agostino Manzato, Alessandro Hering, Urs Germann, Olivia Martius
Summary: We present the first study of hailstorms using a network of 80 automatic hail sensors from Switzerland. The sensors provide live recording of hailstone kinetic energy and precise timing of impacts. By comparing the sensor observations with hailpad observations, we find that both devices measure the same hail size distributions. Using the timing information, we measure the local duration of hail events, the cumulative time distribution of impacts, and the time of the largest hailstone.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Geosciences, Multidisciplinary
Kathrin Wehrli, Fei Luo, Mathias Hauser, Hideo Shiogama, Daisuke Tokuda, Hyungjun Kim, Dim Coumou, Wilhelm May, Philippe Le Sager, Frank Selten, Olivia Martius, Robert Vautard, Sonia Seneviratne
Summary: The mechanisms leading to extreme weather and climate events are varied and complex, involving dynamic and thermodynamic processes as well as external drivers such as greenhouse gas emissions and land use change. The ExtremeX experiment investigates the contribution of these processes using three Earth system models. The results show that both atmospheric circulation patterns and soil moisture conditions play a significant role in heatwaves and warm spells.
EARTH SYSTEM DYNAMICS
(2022)
Article
Geosciences, Multidisciplinary
Patricio Velasquez, Martina Messmer, Christoph C. Raible
Summary: This study investigates the sensitivity of the glacial Alpine hydro-climate to northern hemispheric and local ice-sheet changes. The findings suggest that dynamics processes, such as changes in wind speed and direction, contribute to wetter conditions in the southern part of the Alps during the Last Glacial Maximum (LGM) winter compared to present day. Thermodynamics suggests drier conditions in most of the Alpine region during LGM summer. The study also highlights the importance of northern hemispheric and local ice-sheet topography in regulating the Alpine hydro-climate.
CLIMATE OF THE PAST
(2022)
Article
Geosciences, Multidisciplinary
Helen Mackay, Gill Plunkett, Britta J. L. Jensen, Thomas J. Aubry, Christophe Corona, Woon Mi Kim, Matthew Toohey, Michael Sigl, Markus Stoffel, Kevin J. Anchukaitis, Christoph Raible, Matthew S. M. Bolton, Joseph G. Manning, Timothy P. Newfield, Nicola Di Cosmo, Francis Ludlow, Conor Kostick, Zhen Yang, Lisa Coyle McClung, Matthew Amesbury, Alistair Monteath, Paul D. M. Hughes, Pete G. Langdon, Dan Charman, Robert Booth, Kimberley L. Davies, Antony Blundell, Graeme T. Swindles
Summary: The eruption of Mount Churchill in Alaska in 852/3 CE was one of the largest volcanic events of the first millennium. It had a significant impact on atmospheric cooling, but its broader effects on climate and society are still uncertain. The study suggests that the estimated climate forcing potential of the eruption may have been underestimated, highlighting the need for greater understanding of the role of halogens and volcanic ash in eruption climate forcing potential. Additionally, the comparison of paleoenvironmental records from peatlands reveals that there were no long-term climatic or societal impacts beyond the immediate eruption area.
CLIMATE OF THE PAST
(2022)
Article
Environmental Sciences
Stefan Broennimann
Summary: The recovery of the ozone layer over the past 25 years is difficult to detect, but there are indications of changes in stratospheric circulation. Chemical recovery is counteracted by dynamical effects.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Alexandre Tuel, Bettina Schaefli, Jakob Zscheischler, Olivia Martius
Summary: River discharge is significantly influenced by the temporal clustering of extreme precipitation events. Clustered events result in a longer and greater response in discharge compared to isolated events. The probability of exceeding the 95th discharge percentile within 5 days following extreme precipitation is up to twice as high for clustered events. The impact of clustering decreases as the time window increases, and is also affected by catchment area, streamflow regime and precipitation magnitude. Additionally, persistent periods of high discharge often coincide with temporal clusters of precipitation extremes.
HYDROLOGY AND EARTH SYSTEM SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Stefan Broennimann, Peter Stucki, Joerg Franke, Veronika Valler, Yuri Brugnara, Ralf Hand, Laura C. Slivinski, Gilbert P. Compo, Prashant D. Sardeshmukh, Michel Lang, Bettina Schaefli
Summary: European flood frequency and intensity have changed on a multidecadal scale. Floods were more frequent in the 19th and early 20th century, less frequent in the mid-20th century, and more frequent again since the 1970s. The causes of this variability are not well understood, and the connection to climate change remains unclear.
CLIMATE OF THE PAST
(2022)
Article
Geosciences, Multidisciplinary
Emmanuele Russo, Bijan Fallah, Patrick Ludwig, Melanie Karremann, Christoph C. Raible
Summary: Using climate models to simulate paleoclimate can help us better understand and predict the response of the climate system to external changes. This study investigates the mid-Holocene European climate using the COSMO-CLM model and finds that the model has limited sensitivity to climate forcing changes. Further sensitivity tests suggest that soil-atmosphere interactions play a role in the temperature differences between northern and southern Europe during summer.
CLIMATE OF THE PAST
(2022)