Search

Tropical cyclones (TCs) are one of the most severe weather hazards in the tropics, causing many human deaths and substantial property loss. Therefore, it is always urgent to significantly reduce systematic errors that may hinder the accurate forecast of TC activity. To evaluate the ability of the Euro-Mediterranean Center for Climate Change (CMCC) forecast system to represent TC activity and to verify the feasibility of TCs forecast, we use a new version of the CMCC Seasonal Prediction System (SPS3.5), which configures with high spatial resolution (0.5 degrees) in the atmospheric component and a large (40) number of ensemble members. We compared SPS3.5 hindcasts from 1998 to 2016 July-September with observed TC tracks derived from the International Best Track Archive for Climate Stewardship (IBTrACS). To identify storms and track their trajectories in SPS3.5, we use the Geophysical Fluid Dynamics Laboratory (GFDL) Tropical Cyclone tracking algorithm and set strict thresholds to ensure the authenticity of the captured TCs. We find that the SPS3.5 system captures the spatial distributions in the North Hemisphere (R~0.8) well, although it underestimates TCs' number magnitude, which relates to the model resolution and thresholds. TCs spatial distribution is best captured over the Pacific, where the largest peak season (August) is covered by our dataset, while lower-skill is shown over the North Atlantic Ocean and the North Indian Ocean. For TC variability, the model performs well only in the Western North Pacific (R up to 0.6). We also investigate the relationship between TCs' intensity and interannual variability with ENSO., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Aspects of low-frequency variability of the atmospheric circulation in the Euro-Atlantic domain, such as the frequency of wintertime blocking and the North Atlantic Oscillation, have been found to exhibit significant predictability in large-ensemble seasonal and decadal forecasts. Part of this predictability arguably stems from the realistic initialization of the North Atlantic ocean, which influences the atmospheric circulation through air–sea interaction. Yet, various model deficiencies, such as systematic model biases and the misrepresentation of coupled processes may be limiting the emergence of the associated predictable signals. We present results from three recent studies indicating that increasing model resolution (typically moving to 0.25° in the ocean and 0.5° in the atmosphere) is crucial for mitigating various such deficiencies. Specifically, we show that: (i) increasing model resolution in a multi-model ensemble of coupled historical HighResMIP simulations leads to mitigating certain long-standing extratropical SST biases that contribute to the under-representation of European blocking, (ii) increasing the atmospheric model resolution in a multi-model set of historical HighResMIP simulations forced with observed sea surface temperatures allows for the realistic representation of the atmospheric circulation response to interannual Gulf Stream variability, expectedly important for predictability, and (iii) increasing model resolution in a multi-model ensemble of coupled HighResMIP simulations improves the realism of extratropical North Atlantic atmosphere–ocean variability through mitigating oceanic biases that control the variability of the deep ocean circulation at multi-annual and longer timescales. Current work focuses on evaluating how such model deficiencies affect seasonal and decadal predictability., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

As an important element in the regional containment of the COVID-19 pandemic a PCR testing laboratory with a cooperative character was founded in spring 2021 to screen for SARS-CoV-2 in the Nuremberg region, Germany. The aim was to detect asymptomatic infections in day care facilities for children, schools, and companies. The laboratory used an established RT-PCR protocol and analyzed approximately 18,500 pools of up to 25 pooled samples each from gargles or swabs ("lollipops") from up to 135 facilities between July 2021 and June 2022. Usually, the participating facilities were informed about positive pools within a few hours. Retention samples from positive pools were usually analyzed on the same day, and the results were reported to the facilities as well as the German Electronic Reporting and Information System (DEMIS). In the laboratory results, both the local incidences and the transition from the Delta- to the Omicron surge in early 2022 were well reflected. It is plausible that about 4,800 secondary infections could be prevented from the approximately 1,570 positive individual samples detected in conjunction with appropriate isolation measures. Such a PCR laboratory, which is characterized by short response times and high flexibility, can thus provide valuable services for regional surveillance of infection incidence. Als ein wichtiger Baustein zur regionalen Eindämmung der COVID-19 Pandemie wurde im Frühjahr 2021 ein PCR-Testlabor mit genossenschaftlichem Charakter zum Screening auf SARS-CoV-2 in der Region Nürnberger Land gegründet. Ziel war die Detektion asymptomatischer Infektionen in Kindertagesstätten, Schulen und Unternehmen. Das Labor nutzte ein etabliertes RT-PCR Verfahren und analysierte zwischen Juli 2021 und Juni 2022 aus bis zu 135 Einrichtungen rund 18.500 Pools mit je bis zu 25 vereinigten Proben aus Gurgelaten bzw. Abstrichtupfern ("Lollis"). In der Regel wurden die teilnehmenden Einrichtungen innerhalb weniger Stunden über positive Pools informiert, Rückstellproben positiver Pools wurden meist noch am selben Tag analysiert und die Ergebnisse an die Einrichtungen sowie das Deutsche Elektronische Melde- und Informationssystem (DEMIS) gemeldet. In den Laborergebnissen bildeten sich über den Zeitraum Juli 2021 bis Juni 2022 sowohl die lokalen Inzidenzen als auch der Übergang von der Delta- zur Omikron-Welle Anfang 2022 gut ab. Es ist plausibel, dass sich bei den ca. 1.570 detektierten positiven Einzelproben in Verbindung mit geeigneten Isolationsmaßnahmen etwa 4.800 Sekundärinfektionen verhindern ließen. Ein solches PCR-Labor, das sich durch kurze Antwortzeiten und hohe Flexibilität auszeichnet, kann somit wertvolle Dienste für die regionale Überwachung des Infektionsgeschehens leisten.

Since 2003, Europe has experienced several extreme summer heat waves. Such heat waves are projected to occur as often as every 2 years in the second half of the 21st century, under a high emissions scenario (RCP8.5). The impacts will beparticularly strong in southern Europe.Heavy precipitation events have increased in northern and north-eastern Europe since the 1960s, whereas different indices show diverging trends for south-western and southern Europe. Heavy precipitation events are projected tobecome more frequent in most parts of Europe.The number of very severe flood events in Europe has varied since 1980, but the economic losses have increased. It isnot currently possible to quantify the contribution due to increased heavy precipitation in parts of Europe compared with better reporting and land use changes.Observations of windstorm location, frequency and intensity have showed considerable variability across Europe during the 20th century. Models project an eastward extension of the North Atlantic storm track towards central Europe, with an increase in the number of cyclones in central Europe and a decreased number in the Norwegian and Mediterranean Seas.For medicanes (also termed Mediterranean Sea hurricanes), a decreased frequency but increased intensity of medicanes is projected in the Mediterranean area.Landslides are a natural hazard that cause fatalities and significant economic losses in various parts of Europe. Projected increases in temperature and changes in precipitation patterns will affect rock slope stability conditions and favour increases in the frequency of shallow landslides, especially in European mountains.The severity and frequency of droughts appear to have increased in parts of Europe, in particular in southern and south-eastern Europe. Droughts are projected to increase in frequency, duration, and severity in most of Europe, with the strongest increase projected for southern Europe.Forest fire risk depends on many factors, including climatic conditions, vegetation, forest management practices and other socio-economic factors. The burnt area in the Mediterranean region increased from 1980 to 2000; it has decreased thereafter. Projected increases in heat waves together with an expansion of the fire-prone area will increase the duration of fire seasons across Europe, in particular in southern Europe.Observational data between 1970 and 2015 show that alpine avalanches cause on average 100 fatalities every winter in the Alps. Increased temperatures are expected to lead to decreases in alpine snow cover and duration, and in turnto decreased avalanche activity below about 1 500-2 000 m elevation in spring, but increased avalanche activity above 2 000 m elevation, especially in winter.Hail is responsible for significant damage to crops, vehicles, buildings and other infrastructure. Despite improvements in data availability, trends and projections of hail events are still subject to large uncertainties owing to a lack of directobservation and inadequate microphysical schemes in numerical weather prediction and climate models.Extreme high coastal water levels have increased at most locations along the European coastline. This increase appears to be predominantly due to increases in mean local sea level rather than to changes in storm activity. Projected changes in the frequency and intensity of storm surges are expected to cause significant ecological damage, economic loss and other societal problems along low-lying coastal areas in northern and western Europe, unless additional adaptation measures are implemented.

The chapter analyzes the impacts of weather and climate-related natural hazards in Europe

The Mediterranean is expected to be one of the most prominent and vulnerable climate change "hotspots" of the twenty-first century, and the physical mechanisms underlying this finding are still not clear. Furthermore, complex interactions and feedbacks involving ocean-atmosphere-land-biogeochemical processes play a prominent role in modulating the climate and environment of the Mediterranean region on a range of spatial and temporal scales. Therefore, it is critical to provide robust climate change information for use in vulnerability-impact-adaptation assessment studies considering the Mediterranean as a fully coupled environmental system. The Mediterranean Coordinated Regional Downscaling Experiment (Med-CORDEX) initiative aims at coordinating the Mediterranean climate modeling community toward the development of fully coupled regional climate simulations, improving all relevant components of the system from atmosphere and ocean dynamics to land surface, hydrology, and biogeochemical processes. The primary goals of Med-CORDEX are to improve understanding of past climate variability and trends and to provide more accurate and reliable future projections, assessing in a quantitative and robust way the added value of using high-resolution and coupled regional climate models. The coordination activities and the scientific outcomes of Med-CORDEX can produce an important framework to foster the development of regional Earth system models in several key regions worldwide. ©2016 American Meteorological Society.

In recent years increasing interest has been put on the role that intense Tropical Cyclones can play in the climate system. The following study is aimed at highlighting the effects of strong Tropical Cyclones over the Tropical Atlantic on the mean climate. Their composite effect on the surface winds is made apparent by a wide cyclonic perturbation that affects a large portion of the Atlantic tropical Ocean. Teleconnection patterns, which are visible in the Sea Level Pressure anomalies associated with this Tropical Composite Cyclone, appear to link the activity of the hurricanes to the Arctic Ocean. A significant negative correlation between the energy dissipated by hurricanes in the Tropical atmosphere and the sea ice cover along the Transpolar Drift Stream path, has also been found. Citation: Scoccimarro, E., S. Gualdi, and A. Navarra (2012), Tropical cyclone effects on Arctic Sea ice variability, Geophys. Res. Lett., 39, L17704, doi:10.1029/2012GL052987.