A Drought Alert system based on seasonal forecasts

Water resources are under stress in many areas of the world, because of a combination of climatic and anthropogenic factors. The Mediterranean area is one of the regions mostly vulnerable to climate alterations. These alterations have direct impacts on the surface water balance and groundwater recharge, and thus changes in the reservoir inputs and the management of water utilities (WUs) are severe challenges for water resources in the future. However, WUs management routines scarcely consider climate information and are based on the stationarity assumption, working on weekly or daily time scale. The use of seasonal forecasts for guiding a strategic planning of the resources has been increasing across several climate-sensitive sectors, including water management and energy. This is due to the fact that it is generally preferred to focus on the upcoming season rather than taking decisions on the basis of a 100-year climate projection. The project EUPORIAS promoted the use of climate information for decision support by involving both providers and potential users of seasonal data. It was demonstrated that seasonal forecasts may give important contributions in the fields of drought-risk assessment and mid-term reservoir management. This study aims at providing some insights in using seasonal forecasts to derive supporting information for water management decision-makers based on drought assessment. Indeed, the exploitation of climate information as precipitation in a mid-term scale, as the seasonal scale, allows for understanding the possible shifts in water resource availability. In this study we describe some results obtained for a case study in Greece

A Multi-Hazard Extreme Climate Index across Europe

The ECI is a multi-hazard index which has been developed in the context of the eXtreme Climate Facilities (XCF) project lead by ARC (African Risk Capacity) with the objective of detecting the occurrence of climate extremes over the African continent. The main hazards covered by ECI are the extreme dry, wet and heat events. However, the definition of ECI allows for the integration of additional hazards in the same index. The index has been designed and widely tested across Africa. The objective of this study is to test the usability and potential application of the same index under different climate regimes that are typical of the mid-latitudes, including the Mediterranean area and northern Europe. The analysis presented in this study shows that the ECI allows an accurate detection of extreme cold/heat waves as well as events of abundant precipitation across Europe over the last decade

An innovative approach for detecting the effect of climate change on the hydrometeorological extremes

In a future climate, extreme hydrometeorological events are expected to increase in magnitude and frequency. However, changes in the extreme event characteristics on a relatively short time-scale could be attributed to either climate fluctuations or the effect of anthropogenic climate change. How to distinguish between these two cases is still a field of research. This study presents a novel technique to detect systematic changes in the hydrometeorological extremes in Africa, as part of the eXtreme Climate Facilities project (XCF) lead by the African Risk Capacity (ARC). In a first step, we introduce the Extreme Climate Index (ECI), an objective, multi-hazard index constructed to identify intense droughts, storms, and heat weaves. Subsequently, a new method that estimates the probability of anthropogenic climate change to be the cause of the changes in the hydrometeorological extremes is introduced. This technique is applied to the case of XCF, which is aimed at designing a new financial tool to mitigate the anthropogenic effect on extremes. The method is calibrated with synthetic datasets as well as with the results of the pre-industrial experiment of the CMIP5 database. At the same time, this analysis explores the extent to which such a technique is generally applicable to the identification of systematic changes in the hydrometeorological extremes

SOON: The Station Observation Outlier finder

In the climate change era, it is fundamental to monitor the availability of water resources. One of the possible causes for a change in the water availability is related to variations in the meteorological conditions. To track this change, ground-based observations are one of the commonly used measurements. However, these datasets might include both extreme but realistic values and erroneous information. A necessary but not trivial preliminary process for exploiting the observations is to filter the former while retailing the latter. The Station Observation Outlier fiNder (SOON) is a highly innovative algorithm, that identifies errors in large dataflows. SOON can be used on historical datasets as well as in real-time dataflows. A first prototype has been tested on 8 years (2007-2014) of hourly data recorded by about 10000 stations around Europe, which includes 7 meteorological variables: temperature, dewpoint temperature, pressure, precipitation, wind speed, wind gusts, and cloudiness. The dataset belongs to the Ubimet archive and has been provided within the EDI incubator programme

Seasonal forecasts to support water management decisions

6noWater resources are under stress in many areas of the world, because of a combination of climatic and anthropogenic factors. One of the regions mostly vulnerable to climate change is the Mediterranean area, where alterations in temperature, precipitation and frequency of extreme events have been experienced. In recent years, water shortage has become an increasing concern and water availability is expected to decline in southern Europe. These alterations have direct impacts on the surface water balance and groundwater recharge, and thus changes in the reservoir inputs and the management of water utilities are severe challenges for water resources in the future. Water Utilities (WUs) management routines scarcely consider climate information and are based on the stationarity assumption, working on weekly or daily time scale. This study aims at providing some insights in using seasonal forecasts to support a decision system for water management based on long term planning. The integration of long term climate information with water balance modeling will produce suitable seasonal hydrological forecasts for understanding the possible shifts in water resource availability. Over Europe, practical applications of seasonal forecasts are still rare, because of the uncertainties of their skills, but the results of more recent studies are promising although the predictability varies depending on seasons and areas of application. In this study we describe the preliminary results of the use of the seasonal forecast products released by the Copernicus Climate Change Service (C3S), mainly air temperature and precipitation, in two study areas, i.e. Italy and Greece. The forecasts are updated every month and cover a time range of 6 months.openopenE. Arnone, S. Dal Gesso, M. Cucchi, L. Ortolani, M. Petitta, S. CamantiArnone, E.; Dal Gesso, S.; Cucchi, M.; Ortolani, L.; Petitta, M.; Camanti, S

Single‐Column Model Simulations of Subtropical Marine Boundary‐Layer Cloud Transitions Under Weakening Inversions

Results are presented of the GASS/EUCLIPSE single‐column model intercomparison study on the subtropical marine low‐level cloud transition. A central goal is to establish the performance of state‐of‐the‐art boundary‐layer schemes for weather and climate models for this cloud regime, using large‐eddy simulations of the same scenes as a reference. A novelty is that the comparison covers four different cases instead of one, in order to broaden the covered parameter space. Three cases are situated in the North‐Eastern Pacific, while one reflects conditions in the North‐Eastern Atlantic. A set of variables is considered that reflects key aspects of the transition process, making use of simple metrics to establish the model performance. Using this method, some longstanding problems in low‐level cloud representation are identified. Considerable spread exists among models concerning the cloud amount, its vertical structure, and the associated impact on radiative transfer. The sign and amplitude of these biases differ somewhat per case, depending on how far the transition has progressed. After cloud breakup the ensemble median exhibits the well‐known “too few too bright” problem. The boundary‐layer deepening rate and its state of decoupling are both underestimated, while the representation of the thin capping cloud layer appears complicated by a lack of vertical resolution. Encouragingly, some models are successful in representing the full set of variables, in particular, the vertical structure and diurnal cycle of the cloud layer in transition. An intriguing result is that the median of the model ensemble performs best, inspiring a new approach in subgrid parameterization

Forcing single-column models using high-resolution model simulations

To use single column models (SCMs) as a research tool for parametrisation development and process studies, the SCM must be supplied with realistic initial profiles, forcing fields and boundary conditions. We propose a new technique for deriving these required profiles, motivated by the increase in number and scale of high-resolution convection-permitting simulations. We suggest that these high-resolution simulations be coarse-grained to the required resolution of an SCM, and thereby be used as a proxy for the ‘true’ atmosphere. This paper describes the implementation of such a technique. We test the proposed methodology using high-resolution data from the UK Met Office’s Unified Model (MetUM), with a resolution of 4 km, covering a large tropical domain. This data is coarse grained and used to drive the European Centre for Medium-Range Weather Forecast’s (ECMWF) Integrated Forecasting 26 System (IFS) SCM. The proposed method is evaluated by deriving IFS SCM forcing profiles from a consistent T639 IFS simulation. The SCM simulations track the global model, indicating a consistency between the estimated forcing fields and the ‘true’ dynamical forcing in the global model. We demonstrate the benefits of selecting SCM forcing profiles from across a large-domain, namely robust statistics, and the ability to test the SCM over a range of boundary conditions. We also compare driving the SCM with the coarse-grained datase to driving it using the ECMWF operational analysis. We conclude by highlighting the importance of understanding biases in the high-resolution dataset, and suggest that our approach be used in combination with observationally derived forcing datasets

Impact of Flavonoids on Cellular and Molecular Mechanisms Underlying Age-Related Cognitive Decline and Neurodegeneration

Purpose of Review This review summarises the most recent evidence regarding the effects of dietary flavonoids on age-related cognitive decline and neurodegenerative diseases. Recent Findings Recent evidence indicates that plant-derived flavonoids may exert powerful actions on mammalian cognition and protect against the development of age-related cognitive decline and pathological neurodegeneration. The neuroprotective effects of flavonoids have been suggested to be due to interactions with the cellular and molecular architecture of brain regions responsible for memory. Summary Mechanisms for the beneficial effects of flavonoids on age-related cognitive decline and dementia are discussed, including modulating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation, promoting vascular effects capable of stimulating new nerve cell growth in the hippocampus, bidirectional interactions with gut microbiota and attenuating the extracellular accumulation of pathological proteins. These processes are known to be important in maintaining optimal neuronal function and preventing age-related cognitive decline and neurodegeneration

The tropical Atlantic observing system

The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world’s largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set of research priorities and operational challenges. This paper discusses the tropical Atlantic observing system, including emerging scientific questions that demand sustained ocean observations, the potential for further integration of the observing system, and the requirements for sustaining and enhancing the tropical Atlantic observing system