scholarly journals Empirical modelling of snow cover duration patterns in complex terrains of Italy

2021 ◽  
Author(s):  
Nazzareno Diodato ◽  
Fredrik Charpentier Ljungqvist ◽  
Gianni Bellocchi
Keyword(s):  
Snow Cover ◽  
Large Scale ◽  
Severity Index ◽  
Circulation Index ◽  
Central Mediterranean ◽  
Empirical Modelling ◽  
Spring Temperatures ◽  
Parsimonious Model ◽  
Snow Cover Duration ◽  
Short Time

AbstractSnow cover duration is a crucial climate change indicator. However, measurements of days with snow cover on the ground (DSG) are limited, especially in complex terrains, and existing measurements are fragmentary and cover only relatively short time periods. Here, we provide observational and modelling evidence that it is possible to produce reliable time-series of DSG for Italy based on instrumental measurements, and historical documentary data derived from various sources, from a limited set of stations and areas in the central-southern Apennines (CSA) of Italy. The adopted modelling approach reveals that DSG estimates in most settings in Italy can be driven by climate factors occurring in the CSA. Taking into account spatial scale-dependence, a parsimonious model was developed by incorporating elevation, winter and spring temperatures, a large-scale circulation index (the Atlantic Multidecadal Variability, AMV) and a snow-severity index, with in situ DSG data, based on a core snow cover dataset covering 97 years (88% coverage in the 1907–2018 period and the rest, discontinuously from 1683 to 1895, from historical data of the Benevento station). The model was validated on the basis of the identification of contemporary snow cover patterns and historical evidence of summer snow cover in high massifs. Beyond the CSA, validation obtained across terrains of varying complexity in both the northern and southern sectors of the peninsula indicate that the model holds potential for applications in a broad range of geographical settings and climatic situations of Italy. This article advances the study of past, present and future DSG changes in the central Mediterranean region.

scholarly journals Trends and regime shifts in climatic conditions and river runoff in Estonia during 1951–2015

2017 ◽  
Vol 8 (4) ◽  
pp. 963-976 ◽  
Author(s):  
Jaak Jaagus ◽  
Mait Sepp ◽  
Toomas Tamm ◽  
Arvo Järvet ◽  
Kiira Mõisja
Keyword(s):  
Time Series ◽  
Snow Cover ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Regime Shifts ◽  
The Arctic ◽  
Dry Period ◽  
Snow Cover Duration ◽  
Large Scale Atmospheric Circulation

Abstract. Time series of monthly, seasonal and annual mean air temperature, precipitation, snow cover duration and specific runoff of rivers in Estonia are analysed for detecting of trends and regime shifts during 1951–2015. Trend analysis is realised using the Mann–Kendall test and regime shifts are detected with the Rodionov test (sequential t-test analysis of regime shifts). The results from Estonia are related to trends and regime shifts in time series of indices of large-scale atmospheric circulation. Annual mean air temperature has significantly increased at all 12 stations by 0.3–0.4 K decade−1. The warming trend was detected in all seasons but with the higher magnitude in spring and winter. Snow cover duration has decreased in Estonia by 3–4 days decade−1. Changes in precipitation are not clear and uniform due to their very high spatial and temporal variability. The most significant increase in precipitation was observed during the cold half-year, from November to March and also in June. A time series of specific runoff measured at 21 stations had significant seasonal changes during the study period. Winter values have increased by 0.4–0.9 L s−1 km−2 decade−1, while stronger changes are typical for western Estonia and weaker changes for eastern Estonia. At the same time, specific runoff in April and May have notably decreased indicating the shift of the runoff maximum to the earlier time, i.e. from April to March. Air temperature, precipitation, snow cover duration and specific runoff of rivers are highly correlated in winter determined by the large-scale atmospheric circulation. Correlation coefficients between the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices reflecting the intensity of westerlies, and the studied variables were 0.5–0.8. The main result of the analysis of regime shifts was the detection of coherent shifts for air temperature, snow cover duration and specific runoff in the late 1980s, mostly since the winter of 1988/1989, which are, in turn, synchronous with the shifts in winter circulation. For example, runoff abruptly increased in January, February and March but decreased in April. Regime shifts in annual specific runoff correspond to the alternation of wet and dry periods. A dry period started in 1964 or 1963, a wet period in 1978 and the next dry period at the beginning of the 21st century.

scholarly journals Trends and regime shifts in climatic conditions and river runoff in Estonia during 1951–2015

2017 ◽  
Author(s):  
Jaak Jaagus ◽  
Mait Sepp ◽  
Toomas Tamm ◽  
Arvo Järvet ◽  
Kiira Mõisja
Keyword(s):  
Time Series ◽  
Snow Cover ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Regime Shifts ◽  
The Arctic ◽  
Dry Period ◽  
Snow Cover Duration ◽  
Large Scale Atmospheric Circulation

Abstract. Time series of monthly, seasonal and annual mean air temperature, precipitation, snow cover duration and specific runoff of rivers in Estonia are analysed for detecting trends and regime shifts during 1951–2015. Trend analysis is performed using the Mann-Kendall test and regime shifts are detected with the Rodionov test (Sequential T-test Analysis of Regime Shifts). The results from Estonia are related to trends and regime shifts in time series of indices of large-scale atmospheric circulation. Annual mean air temperature has significantly increased at 12 observed stations by 0.3–0.4 K per decade. The warming trend was detected in all seasons but with the higher magnitude in spring and winter. Snow cover duration has decreased in Estonia by 3–4 days per decade. Changes in precipitation are not clear and uniform due to their very high spatial and temporal variability. The most significant increase in precipitation was observed during the cold half-year, from November to March. Time series of specific runoff measured at 21 stations has had significant seasonal changes during the study period. Winter values have increased by 0.4–0.9 l/s per km2 per decade while stronger changes are typical for western Estonia and weaker changes for eastern Estonia. At the same time, specific runoff in April and May has notably decreased indicating the shift of the runoff maximum to earlier time, i.e. from April to March. All meteorological and hydrological variables are highly correlated in winter, determined by the large-scale atmospheric circulation. Correlation coefficients between the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices reflecting the intensity of westerlies, and the studied variables were 0.5–0.8. The main result of the analysis of regime shifts was the detection of coherent shifts for air temperature, snow cover duration and specific runoff in the late 1980s, mostly since the winter 1988/1989, which are, in turn, synchronous with the shifts in winter circulation. For example, runoff abruptly increased in January, February and March but decreased in April. Regime shifts in the annual specific runoff correspond to the alternation of wet and dry periods. A dry period started since 1964 or 1963, a wet period since 1978 and the next dry period since the beginning of the 21st century.

Towards Control of an Estuary

1987 ◽  
Vol 19 (9) ◽  
pp. 155-174
Author(s):  
Henk L. F. Saeijs
Keyword(s):  
Shallow Water ◽  
Storm Surge ◽  
Salt Marshes ◽  
Large Scale ◽  
Western Europe ◽  
Oxygen Depletion ◽  
Negative Effects ◽  
Intertidal Flats ◽  
Environmental Consequences ◽  
Short Time

The Delta Project is in its final stage. In 1974 it was subjected to political reconsideration, but it is scheduled now for completion in 1987. The final touches are being put to the storm-surge barrier and two compartment dams that divide the Oosterschelde into three areas: one tidal, one with reduced tide, and one a freshwater lake. Compartmentalization will result in 13% of channels, 45% of intertidal flats and 59% of salt marshes being lost. There is a net gain of 7% of shallow-water areas. Human interventions with large scale impacts are not new in the Oosterschelde but the large scale and short time in which these interventions are taking place are, as is the creation of a controlled tidal system. This article focusses on the area with reduced tide and compares resent day and expected characteristics. In this reduced tidal part salt marshes will extend by 30–70%; intertidal flats will erode to a lower level and at their edges, and the area of shallow water will increase by 47%. Biomass production on the intertidal flats will decrease, with consequences for crustaceans, fishes and birds. The maximum number of waders counted on one day and the number of ‘bird-days' will decrease drastically, with negative effects for the wader populations of western Europe. The net area with a hard substratum in the reduced tidal part has more than doubled. Channels will become shallower. Detritus import will not change significantly. Stratification and oxygen depletion will be rare and local. The operation of the storm-surge barrier and the closure strategy chosen are very important for the ecosystem. Two optional closure strategies can be followed without any additional environmental consequences. It was essential to determine a clearly defined plan of action for the whole area, and to make land-use choices from the outset. How this was done is briefly described.

scholarly journals Environmental Engineering Techniques to Restore Degraded Posidonia oceanica Meadows

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Cost Benefit ◽  
Cost Effective ◽  
Posidonia Oceanica ◽  
Environmental Engineering ◽  
Bottom Surface ◽  
Sessile Invertebrates ◽  
Set Up ◽  
Short Time

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.

scholarly journals Synthesis of Metal Organic Frameworks by Ball-Milling

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Cheng-An Tao ◽  
Jian-Fang Wang
Keyword(s):  
Ball Milling ◽  
Large Scale ◽  
Raw Materials ◽  
Metal Organic Frameworks ◽  
Research Topic ◽  
Mass Ratio ◽  
Time Consumption ◽  
Metal Organic ◽  
Short Time ◽  
Made In

Metal-organic frameworks (MOFs) have been used in adsorption, separation, catalysis, sensing, photo/electro/magnetics, and biomedical fields because of their unique periodic pore structure and excellent properties and have become a hot research topic in recent years. Ball milling is a method of small pollution, short time-consumption, and large-scale synthesis of MOFs. In recent years, many important advances have been made. In this paper, the influencing factors of MOFs synthesized by grinding were reviewed systematically from four aspects: auxiliary additives, metal sources, organic linkers, and reaction specific conditions (such as frequency, reaction time, and mass ratio of ball and raw materials). The prospect for the future development of the synthesis of MOFs by grinding was proposed.

scholarly journals Confocal laser endomicroscopy reveals alterations in duodenal permeability in patients with acute pancreatitis

2019 ◽  
Vol 47 (3) ◽  
pp. 1279-1287
Author(s):  
Lingjia Sun ◽  
Min Yue ◽  
Yining Dai ◽  
Chaohui Yu ◽  
Chunxiao Chen
Keyword(s):  
Acute Pancreatitis ◽  
Large Scale ◽  
Duodenal Bulb ◽  
Severity Index ◽  
Duodenal Mucosa ◽  
Confocal Laser Endomicroscopy ◽  
Confocal Laser ◽  
Mucosal Permeability ◽  
Reactive Protein ◽  
Severity Index Score

Objective Intestinal permeability increases during the course of acute pancreatitis (AP). We assessed duodenal permeability alterations in patients with AP by confocal laser endomicroscopy (CLE). Methods Thirty patients with AP underwent CLE evaluation of the antral and duodenal mucosa. Images were graded based on the appearance of capillaries and the degree of fluorescein leakage. Results Patients with AP had increased duodenal mucosal permeability that could be detected by CLE. The mucosal permeability progressively increased in the gastric antrum, duodenal bulb, and descending duodenum. The CLE parameters in the antrum and duodenal bulb were not significantly different between patients with mild and severe AP. The CLE grades in the descending duodenum were higher in patients with severe than mild AP. The C-reactive protein level in AP was positively correlated with the permeability in the duodenal bulb and descending duodenum, while the computed tomography severity index score was positively correlated with the mucosal permeability in the duodenal bulb and descending duodenum. Conclusion CLE revealed increased duodenal permeability in patients with AP. Higher permeability in the descending duodenum was observed in severe than mild AP. Further large-scale studies are needed to confirm the relationship between altered duodenal permeability and the severity of AP.

Lichen Colonization and Recolonization of Two Recently Deglaciated Zones in the Maritime Antarctic

1995 ◽  
Vol 27 (6) ◽  
pp. 485-493 ◽  
Author(s):  
Fernando Valladares ◽  
Leopoldo G. Sancho
Keyword(s):  
Snow Cover ◽  
South Shetland Islands ◽  
Homogeneous Distribution ◽  
Maritime Antarctic ◽  
Vegetation Development ◽  
Lichen Cover ◽  
Glacier Front ◽  
Ice Retreat ◽  
Snow Cover Duration ◽  
Rock Size

AbstractThe stages of vegetation development close to two glacier fronts on two of the South Shetland Islands (Livingston and Robert) within the Maritime Antarctic were studied with special reference to saxicolous lichens. A lichenometric study of the crustose lichen Caloplaca sublobulata was carried out at both sites. On the moraine of Livingston Island, rock size played an important role in lichen development, explaining most of the differences observed in the diameter of C. sublobulata, the number of species, and the percentage of cover among the rocks studied. On Robert Island, the distance from the glacier front was associated with the lichen cover of the rocks but not with diameter of C. sublobulata This homogeneous distribution of C. sublobulata thallus size on the Robert Island study area points to a simultaneous recolonization of the whole zone by this lichen. The lichen development in the area studied on Robert Island seems to have been drastically affected by fluctuations in the persistence of snow cover following glacier front retreat. Tentative associations between ice retreat and colonization, on the o e hand, and changes in snow cover duration and the dynamic processes of extinction and recolonization, on the other, are suggested from comparison of the two zones.

scholarly journals Seasonal Influence of Insolation on Fine-Resolved Air Temperature Variation and Snowmelt

2014 ◽  
Vol 53 (2) ◽  
pp. 323-332 ◽  
Author(s):  
Nikki Vercauteren ◽  
Steve W. Lyon ◽  
Georgia Destouni
Keyword(s):  
Solar Radiation ◽  
Snow Cover ◽  
Eastern Coast ◽  
Seasonal Influence ◽  
Near Surface ◽  
Average Temperature ◽  
Monthly Average ◽  
Air Temperatures ◽  
Low Performance ◽  
Snow Cover Duration

AbstractThis study uses GIS-based modeling of incoming solar radiation to quantify fine-resolved spatiotemporal responses of year-round monthly average temperature within a field study area located on the eastern coast of Sweden. A network of temperature sensors measures surface and near-surface air temperatures during a year from June 2011 to June 2012. Strong relationships between solar radiation and temperature exhibited during the growing season (supporting previous work) break down in snow cover and snowmelt periods. Surface temperature measurements are here used to estimate snow cover duration, relating the timing of snowmelt to low performance of an existing linear model developed for the investigated site. This study demonstrates that linearity between insolation and temperature 1) may only be valid for solar radiation levels above a certain threshold and 2) is affected by the consumption of incoming radiation during snowmelt.

scholarly journals Effects of a workplace prevention programme for problem gambling: study protocol for a cluster randomised controlled trial

BMJ Open ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. e015963 ◽  
Author(s):  
Jonas Rafi ◽  
Ekaterina Ivanova ◽  
Alexander Rozental ◽  
Per Carlbring
Keyword(s):  
Problem Gambling ◽  
Large Scale ◽  
Controlled Trial ◽  
Public Health Problem ◽  
Cluster Randomised Controlled Trial ◽  
Severity Index ◽  
The Body ◽  
Prevention Programme ◽  
Open Access Journals ◽  
Randomised Controlled

IntroductionDespite being considered a public health problem, no prevention programme for problem gambling in workplace settings has been scientifically evaluated. This study aims to fill a critical gap in the field of problem gambling by implementing and evaluating a large-scale prevention programme in organisations.Methods and analysisTen organisations, with a total of n=549 managers and n=8572 employees, will be randomised to either receiving a prevention programme or to a waitlist control condition. Measurements will be collected at the baseline and 3, 12 and 24 months after intervention. The primary outcome of interest is the managers’ inclination to act when worried or suspicious about an employee’s problem gambling or other harmful use. Additional outcomes of interest include the Problem Gambling Severity Index and gambling habits in both managers and employees. Furthermore, qualitative analyses of the responses from semistructured interviews with managers will be performed.Ethics and disseminationThis study has been approved by the regional ethics board of Stockholm, Sweden, and it will contribute to the body of knowledge concerning prevention of problem gambling. The findings will be published in peer-reviewed, open-access journals.Trial registration numberNCT02925286; Pre-results.

Sign in / Sign up

Export Citation Format

Share Document