Environmental conditions at the South Col of Mount Everest and their impact on hypoxia and hypothermia experienced by mountaineers

BACKGROUND: Hypoxia and hypothermia are acknowledged risk factors for those who venture into high-altitude regions. There is, however, little in situ data that can be used to quantify these risks. Here, we use 7 months of continuous meteorological data collected at the South Col of Mount Everest (elevation 7,896 m above sea level) to provide the first in situ characterization of these risks near the summit of Mount Everest. METHODS: This is accomplished through the analysis of barometric pressure, temperature and wind speed data collected by an automatic weather station installed at the South Col. These data were also used as inputs to parameterizations of wind chill equivalent temperature (WCT) and facial frostbite time (FFT). RESULTS: The meteorological data show clear evidence of seasonality, with evidence of pre-monsoon, monsoon and post-monsoon conditions. Low pressures, cold temperatures and high wind speeds characterize the pre- and post-monsoon periods with significant variability associated with the passage of large-scale weather systems. In contrast, the monsoon period is characterized by higher pressures, warmer temperatures and lower wind speeds with a pronounced reduction in variability. These environmental conditions are reflected in WCTs as low as −50°C and FFTs as short as 2 min during the pre- and post-monsoon periods. During the monsoon, the risk of cold injury is reduced with WCTs of order −20°C and FFTs longer than 60 min. The daily cycle in the various parameters is also investigated in order to assess the changes in conditions that would be experienced during a typical summit day. The post-monsoon period in particular shows a muted daily cycle in most parameters that is proposed to be the result of the random timing of large-scale weather systems. CONCLUSIONS: Our results provide the first in situ characterization of the risk of hypoxia and hypothermia on Mount Everest on daily, weekly and seasonal timescales, and provide additional confirmation as to the extreme environment experienced by those attempting to summit Mount Everest and other high Himalayan mountains

Evidence and Implications for the Regional Climate

Abstract This paper presents a detailed review of atmospheric pollution observed in the Hindu Kush–Himalaya (HKH) region and its implications for regional climate. Data from in situ measurements made at high-altitude stations in the HKH region, observations from satellite-based instruments, and global climate modeling study results are discussed. Experimental observations discussed include both atmospheric measurements and data from snow and ice core sampling from different glaciers in the HKH region. The paper focuses on the atmospheric brown cloud loadings over the Himalayas, particularly black carbon (BC) and ozone, which have links to regional climate and air-pollution–related impacts. Studies show elevated levels of anthropogenic ozone and BC over the Himalayas during the pre-monsoon season with concentrations sometimes similar to those observed over an average urban environment. The elevated concentration observed over the Himalayas is thought to come from the lowlands, especially the highly populat..

Third trimester intrauterine fetal death: proposal for the assessment of the chronology of umbilical cord and placental thrombosis

: The timing of umbilical cord and placental thrombosis in the third trimester intrauterine fetal death (TT-IUFD) may be fundamental for medico-legal purposes, when it undergoes medical litigation due to the absence of risk factors. Authors apply to human TT-IUFD cases a protocol, which includes histochemistry and immunohistochemistry (IHC) for the assessment of thrombi's chronology. A total of 35 thrombi of umbilical cord and/or placenta were assessed: 2 in umbilical artery, 6 in umbilical vein, 15 in insertion, 10 in chorionic vessels, 1 in fetal renal vein, 1 in fetal brachiocephalic vein. Thrombi's features were evaluated with hematoxylin-eosin, Picro-Mallory, Von Kossa, Perls, and immunohistochemistry for CD15, CD68, CD31, CD61, and Smooth Muscle Actin. The estimation of the age of the thrombi was established by applying neutrophils/macrophages ratio taking into consideration, according to literature, the presence of hemosiderophagi, calcium deposition, and angiogenesis. To estimate an approximate age of fresh thrombi (< 1 day), a non-linear regression model was tested. Results were compared to maternal risk factors, fetal time of death estimated at autopsy, mechanism, and cause of death. Our study confirms that the maternal risk factors for fetal intrauterine death and the pathologies of the cord, followed by those of the placental parenchyma, are the conditions that are most frequently associated with the presence of thrombi. Results obtained with histological stainings document that the neutrophile/macrophage ratio is a useful tool for determining placental thrombi's age. Age estimation of thrombi on the first day is very challenging; therefore, the study presented suggests the N/M ratio as a parameter to be used, together with others, i.e., hemosiderophagi, calcium deposition, and angiogenesis, for thrombi's age determination, and hypothesizes that its usefulness regards particularly the first days when all other parameters are negative

Seasonal budgets of ozone and oxidant precursors in an industrial coastal area of northern Italy

The seasonal budgets and evolution of photochemical oxidants reported for greater Ravenna's urban-industrial area in the present study were calculated using the combined data from on-site systematic surveys (1978-1989) and from the monitoring network of the local environmental authorities. The notable differences in the concentrations of ozone and nitrogen oxides depended on season, and meteorological variables showed a marked correlation to the seasonal budget of trace constituents. The weak local circulation, the land-sea breeze system, and high solar radiation in summer, which may persist at length because of the anticyclonic conditions, can produce episodes of intense photochemical reactions. In winter, by contrast, low solar radiation and the absence of the breeze system results in very different evolutions of both pollutant concentrations and their seasonal budget

Characterization of atmospheric aerosols at Monte Cimone, Italy, during summer 2004: Source apportionment and transport mechanisms

Atmospheric aerosols in the PM10 and PM1 fractions have been sampled at the Global Atmospheric Watch station Mount Cimone, Italy (2165 m above mean sea level) for 3 months during summer 2004, and simultaneous size distributions have been derived by means of an optical particle counter. Samples have been analyzed by X-ray fluorescence, ion chromatography, and thermal-optical methodology in order to quantify their elemental, ionic, and carbonaceous constituents. The concentration of PM10 was 16.1 \ub1 9.8 mg m3 (average and standard deviation). Source apportionment allowed us to identify, quantify and characterize the following aerosol classes: anthropogenic pollution (10 mg m3), mineral dust (4 mg m3), and sea salt (0.2 mg m3). Pollution has been further split into ammonium sulfate (44%), organic matter (42%), and other compounds (14%). The nitrate/sulfate ratio in the polluted aerosol was 0.1. Fine particles have been completely related to the polluted aerosol component, and they represented 70% in weight of pollution. Coarse particles characterized the dust and salt components, and crustal oxides have been found to be the largest responsible for the aerosol concentration variations that occurred during the campaign. Nitrate has also been found in the coarse particles, representing 10% of mineral dust. The analysis of the transport mechanisms responsible for aerosol fluctuations permitted us to identify the origin of the major aerosol components: Pollution has been ascribed to regional transport driven by boundary layer meteorology, whereas mineral dust has been related to long-range transport events originating in the Sahara and Sahel. A particularly significant Saharan episode has been identified on 10 August 2004 (PM10 daily concentration, 69.9 mg m3). Average elemental ratios for the African dust events were as follows: Si/Al = 2.31, Fe/Ca = 0.94, Ca/Al = 0.90, K/Ca = 0.44, Ti/Ca = 0.11, and Ti/Fe = 0.12

Three-year observations of halocarbons at the Nepal Climate Observatory at Pyramid (NCO-P, 5079 m a.s.l.) on the Himalayan range

A monitoring programme for halogenated climate-altering gases has been established in the frame of the SHARE EV-K<sup>2</sup>-CNR project at the Nepal Climate Laboratory – Pyramid in the Himalayan range at the altitude of 5079 m a.s.l. The site is very well located to provide important insights on changes in atmospheric composition in a region that is of great significance for emissions of both anthropogenic and biogenic halogenated compounds. Measurements are performed since March 2006, with grab samples collected on a weekly basis. The first three years of data have been analysed. After the identification of the atmospheric background values for fourteen halocarbons, the frequency of occurrence of pollution events have been compared with the same kind of analysis for data collected at other global background stations. The analysis showed the fully halogenated species, whose production and consumption are regulated under the Montreal Protocol, show a significant occurrence of "above the baseline" values, as a consequence of their current use in the developing countries surrounding the region, meanwhile the hydrogenated gases, more recently introduced into the market, show less frequent spikes. <br><br> Atmospheric concentration trends have been calculated as well, and they showed a fast increase, ranging from 5.7 to 12.6%, of all the hydrogenated species, and a clear decrease of methyl chloroform (−17.7%). The comparison with time series from other stations has also allowed to derive Meridional gradients, which are absent for long living well mixed species, while for the more reactive species, the gradient increases inversely with respect to their atmospheric lifetime. The effect of long range transport and of local events on the atmospheric composition at the station has been analysed as well, allowing the identification of relevant source regions the Northern half of the Indian sub-continent. Also, at finer spatial scales, a smaller, local contribution of forest fires from the Khumbu valley has been detected

Ship-board report on atmospheric CO2 concentrations recorded on continuous from Mediterranean sea to Antarctica

We present the results obtained from continuous measurements performed during two cruises with hemispherical courses. In this way, we obtained the latitudinal trend of CO2 in continuity of space and time along two hemispheric courses in 1994-95 and 1996-97 from Europe to Antarctica. The results are compared with measurements from the National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostic Laboratory (CMDL) cooperative air sampling network. The fitting of data recorded on board with the historical data sets recorded at Palmer Station is also presented, highlighting the current annual increase in atmospheric CO2 concentrations

Implementation of a webGIS service platform for high mountain climate research: the SHARE GeoNetwork project

The implementation of a webGIS service platform dedicated to the management and sharing of climatological data acquired by high elevation stations is the core of the Station at High Altitude for Research on the Environment (SHARE) GeoNetwork project, promoted by the Ev-K2 CNR Committee. The web platform basically will provide three types of services: structured metadata archive, data and results from high-altitude environments research and projects; access to high-altitude Ev-K2 CNR stations and creation of a network of existing stations; dedicated webGIS for geo-referenced data collected during the research. High elevation environmental and territorial data and metadata are catalogued in a single integrated platform to get access to the information heritage of the SHARE project, using open-source tools: Geonetwork for the metadata catalogue and webGIS resources, and the open-source Weather and Water Database (WDB), developed by the Norwegian Meteorological Institute, for the database information system implementation. The information system is designed to have a main node, with the possibility to install relocated subsystems based on the same technology, named focal point of SHARE, which will contain metadata and data connected to the main node. In this study, a new structure of metadata for the description of the climatological stations is proposed and WDB adaptation and data preprocessing are described in detail, giving code and script samples

An Assessment of Stratospheric Intrusions in Italian Mountain Regions Using STEFLUX

The Mediterranean basin is considered a global hot-spot region for climate change and air quality, especially concerning summer-time ozone (O3). Previous investigations indicated that the Mediterranean basin is a preferred region for stratosphere-to-troposphere exchange (STE) and deep stratospheric intrusion (SI) events. The Lagrangian tool STEFLUX, based on a STE climatology that uses the ERA Interim data, was hereby used to diagnose the occurrence of deep SI events in four mountain regions over the Italian peninsula, spanning from the Alpine region to the southern Apennines. By using near-surface O3 and relative humidity (RH) observations at three high-mountain observatories, we investigated the performance of STEFLUX in detecting deep SI events. Both experimental and STEFLUX detections agreed in describing the seasonal cycle of SI occurrence. Moreover, STEFLUX showed skills in detecting "long-lasting" SI events, especially in the Alps and in the northern Apennines. By using STEFLUX, we found positive tendencies in the SI occurrence during 1979–2017. However, in contrast to similar studies carried out in the Alpine region, the negative long-term (1996–2016) trend of O3 in the northern Apennines did not appear to be related to the SI's variability