Scale dependence of hydrological effects from different climatic conditions on glacierized catchments

The high altitude environments are particularly sensitive to climate change and very rapid and intense effects are affecting the Alpine cryosphere. Knowledge of the hydrological responses of high-altitude watershed is critical to manage water resources, especially in the context of current climate change, resulting in a lower percentage of solid precipitation, temporal redistribution and quantitative variations in precipitation inputs, higher temperatures, and more persistent drought conditions during the summer. Although the remaining glacial masses are still able to secure sufficient water supplies, the rate of reduction of the glaciers, however, is now very rapid. Mountain glaciers have generally experienced worldwide retreat since the second half of XIX Century, and for example in the Alps they lost about two/thirds of the initial area, with area loss rates accelerating since 2003. At this pace, the hydrological buffering effect of the glaciers will run out quickly. Several years in the last decades, which have been particularly warm and dry, have shown that glaciers can compensate scarce rainfall with a significant contribution to the runoff of rather large basins, especially in summer. The aim of this work was to understand how different climatic and glacier cover conditions can modify the hydrological response of glacierized catchments, and to analyze the scale dependency of the hydrological response and the resulting impacts on fresh water availability. The investigations were carried out in the Noce catchment, a 1050 km2 watershed located in the Eastern Italian Alps, and in three sub-catchments of the same basin, with area ranging from 8 to 385 km2 and different percent glacierization. Valuable information on past and current evolution of climate and glaciers exist in this study area. In particular, precious data series of high-altitude meteorological and hydrometric data, reconstructions of glacier fluctuations since the Little Ice Age, and measurements of glacier mass balance were available. Based on this availability, and considering the high uncertainties affecting model studies that use future projections of climate and glaciers, we decided to do a sensitivity analysis based on past observations. This approach has the advantage of analyzing the sensitivity of the glacio-hydrological system of the study area under actually observed climatic and glacier cover conditions, likely reducing the main source of error caused by model approaches based on future projections. Moreover using real observations has the potential of increasing the internal consistency of the glacio-hydrological model employed in this sensitivity analysis, during calibration and validation. A drawback of this method is that it does not take into consideration future change in climate and glacier cover. For this reason, we analyzed also a condition with complete absence of glaciers, and recent ‘extreme’ years, like 2003, that has been frequently referred to as a possible example of future climatic conditions during summer in the Alps. The results of this study confirm previous research that indicate a progressive transition from a glacial to a nival hydrological regime in the analyzed catchments, with a tendency to a strong decrease in runoff after the seasonal snow has melted, in the second half of summer. The runoff peak tends to shift from mid- to early summer. Different glacier cover scenarios (LIA, current and absence of glaciers) have highest impacts in August runoff, during periods of glacier wastage as in the 1940s and in the 2000s, and in the smaller catchments with high percent glacierization. Compared to the absence of glaciers, current glaciers still ensure higher runoff during summer, in all climatic conditions considered. However, this glacier damping effect is largely decreased if compared to the LIA conditions, and this decrease is directly related to catchment area. If smaller and highly glacierized catchment still preserves ~50% of the initial damping effect in August, the larger catchments keep only 25-30% of it. The glacier contribution to late summer runoff decreases obviously from headwater to lower and larger catchments. However, the decreasing rate tends to flatten for catchment area larger than 80 km2, and for the larger analyzed catchment it still reaches 26%. Most importantly, the current glacier contribution to late summer runoff in the larger catchment reaches ~60% in extremely warm and dry summers, like in 2003. However, increased runoff due to glacier wastage in 2003 occurred only in the headwater and most glacierized catchment, whereas using the LIA glacier cover would have ensured increased runoff in all analyzed catchments. This suggests that the expected peak in runoff under warming climate, attributable to glacier melt, has already passed in the study area

Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was-0.42 \ub1 1.72 and 0.03 \ub1 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between-5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 \ub1 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively. Technical improvements such as using an aerial platform and/or placing artificial targets could significantly improve the results but run the risk of being more demanding in terms of costs and logistics

Consistency of safety monitoring using routine national databases: results using a quality of care interpretative model.

Abstract Background In the framework of targeted action for continuous safety monitoring, we aimed to evaluate the consistency of indicators derived from available databases for regular reporting. Methods We used a quality of care interpretative model to select characteristics from five national databases, aggregated and linked by homogeneous groups of providers. The target population included all subjects admitted to public hospitals for acute care in four regions of Italy between 2011 and 2013. The association between structures, processes and safety-related outcomes was investigated using odds ratios from generalized estimating equations logistic regression. Outcome measures included claims of malpractice and five patient safety indicators calculated from discharge abstracts using standardized algorithms. Results Over 3 years, claims of malpractice and sepsis increased, whereas deep vein thrombosis and pulmonary embolism decreased. Hospitals with high vs. low volume of discharges were associated with −16% lower rates of claims, but +12% increased risk of sepsis. Compared with research institutes, university clinics had −17% lower rates of claims and −41% cases of dehiscence, with a +32% increased risk of deep vein thrombosis. Local health care authorities recorded −49% deep vein thrombosis, −26% pulmonary embolism, −40% sepsis and +37% risk of claims. Hospitals submitting cases of safe practices and implementing safety recommendations showed significantly higher rates for most outcome measures. Conclusions Indicators from regular databases can be conveniently used to develop a national safety monitoring system for hospital care. Although deeper analysis is needed, institutions with a higher propensity to implement safe practices and recommendations consistently showed higher rates of adverse events

A Pinus cembra L. tree-ring record for late spring to late summer temperature in the Rhaetian Alps, Italy

Abstract Ongoing climate change strongly affects high-elevation environments in the European Alps, influencing the cryosphere and the biosphere and causing widespread retreat of glaciers and changes in biomes. Nevertheless, high-elevation areas often lack long meteorological series, and global datasets cannot represent local variations well. Thus, proxy data, such as tree rings, provide information on past climatic variations from these remote sites. Although maximum latewood density (MXD) chronologies provide better temperature information than those based on tree-ring width (TRW), MXD series from the European Alps are lacking. To derive high-quality temperature information for the Rhaetian Alps, Pinus cembra L. trees sampled at approximately 2000 m a.s.l. were used to build one MXD chronology spanning from 1647 to 2015. The MXD data were significantly and highly correlated with seasonal May-September mean temperatures. The MXD chronology showed a generally positive trend since the middle of the 19th century, interrupted by short phases of climatic deterioration in the beginning of the 20th century and in the 1970s, conforming with the temperature trends. Our results underline the potential for using Pinus cembra L. MXD to reconstruct mean temperature variations, especially during the onset and latter part of the growing season, providing additional information on parts of the growing season not inferred from TRW. Future studies on MXD for this species will increase the availability of temporal and spatial data, allowing detailed climate reconstructions

Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry for the Analysis of Vanillic and Syringic Acids in Ice Cores

The development of new analytical systems and the improvement of the existing ones to obtain high-resolution measurements of chemical markers in samples from ice cores, is one of the main challenges the paleoclimatic scientific community is facing. Different chemical species can be used as markers for tracking emission sources or specific environmental processes. Although some markers, such as methane sulfonic acid (a proxy of marine productivity), are commonly used, there is a lack of data on other organic tracers in ice cores, making their continuous analysis analytically challenging. Here, we present an innovative combination of fast liquid chromatography coupled with tandem mass spectrometry (FLC-MS/MS) to continuously determine organic markers in ice cores. After specific optimization, this approach was applied to the quantification of vanillic and syringic acids, two specific markers for biomass burning. Using the validated method, detection limits of 3.6 and 4.6 pg mL–1 for vanillic and syringic acids, respectively, were achieved. Thanks to the coupling of FLC-MS/MS with the continuous flow analytical system, we obtained one measurement every 30 s, which corresponds to a sampling resolution of a sample every 1.5 cm with a melting rate of 3.0 cm min–1. To check the robustness of the method, we analyzed two parallel sticks of an alpine ice core over more than 5 h. Vanillic acid was found with concentrations in the range of picograms per milliliter, suggesting the combustion of coniferous trees, which are found throughout the Italian Alps.publishedVersio

Ventricular pacemaker lead in the left hemithorax: Mechanisms and evidence-based management of a late-onset hazardous complication

Late-onset migration of pacing leads in the left hemithorax is a rare but potentially life-threatening complication. Radiological examinations are required to detect any involvement of either left ventricle or lung parenchyma, prompting immediate surgical extraction in this setting. Identification of high-risk patients is mandatory to prevent this complex iatrogenic complication

An upgraded CFA - FLC - MS/MS system for the semi-continuous detection of levoglucosan in ice cores

A new Continuous Flow Analysis (CFA) system coupled with Fast Liquid Chromatography – tandem Mass Spectrometry (FLC-MS/MS) has been recently developed for determining organic markers in ice cores. In this work we present an upgrade of this innovative technique, optimized for the detection of levoglucosan in ice cores, a crucial tracer for reconstructing past fires. The upgrade involved a specific optimization of the chromatographic and mass spectrometric parameters, allowing for a higher sampling resolution (down to 1 cm) and the simultaneous collection of discrete samples, for off-line analysis of water stable isotopes and additional chemical markers. The robustness and repeatability of the method has been tested by the analysis of multiple sticks of ice cut from the same shallow alpine ice core, and running the system for several hours on different days. The results show similar and comparable trends between the ice sticks. With this upgraded system, a higher sensitivity and a lower limit of detection (LOD) was achieved compared to discrete analysis of alpine samples for levoglucosan measurements. The new LOD was as low as 66 ng L−1, a net improvement over the previous LOD of 600 ng L−1