Search results for "altitud"
showing 10 items of 193 documents
Speleothems in a north Cuban cave register sea-level changes and Pleistocene uplift rates
2018
Evolution of CO2, SO2, HCl, and HNO3in the volcanic plumes from Etna
2014
The volcanic plumes from degassing Etna (Italy) were extensively probed with instruments onboard the Deutsches Zentrum fur Luft- und Raumfahrt research aircraft Falcon during the contrail, volcano, and cirrus experiment CONCERT on 29/30 September 2011. Up to 10.4 ppmv SO2 and 0.3 ppmv HCl were detected with the atmospheric chemical ionization mass spectrometer AIMS at 3.1 km altitude and 20 km distance to the summit. HNO3 is the dominant reactive nitrogen component in the plumes. Linking aircraft and ground-based observations by Hybrid Single-Particle Lagrangian Integrated Trajectory dispersion modeling, we identify two crater plumes with different compositions primarily injected by the Boc…
Accurate measurement of volcanic SO2flux: Determination of plume transport speed and integrated SO2concentration with a single device
2005
[1] Ground-based measurements of volcanic sulfur dioxide fluxes are important indicators of volcanic activity, with application in hazard assessment, and understanding the impacts of volcanic emissions upon the environment and climate. These data are obtained by making traverses underneath the volcanic plume a few kilometers from source with an ultraviolet spectrometer, measuring integrated SO2 concentrations across the plume's cross section, and multiplying by the plume's transport speed. However, plume velocities are usually derived from ground-based anemometers, located many kilometers from the traverse route and hundreds of meters below plume altitude, complicating the experimental desi…
Vertical profile of atmospheric dimethyl sulfide in the Arctic Spring and Summer
2017
Abstract. Vertical distributions of atmospheric dimethyl sulfide (DMS(g)) were sampled aboard the research aircraft Polar 6 near Lancaster Sound, Nunavut, Canada in July 2014 and on pan-Arctic flights in April 2015 that started from Longyearbyen, Spitzbergen, and passed through Alert and Eureka, Nunavut and Inuvik, Northwest Territories. Larger mean DMS(g) mixing ratios were present during April 2015 (campaign-mean of 116±8 pptv) compared to July 2014 (campaign-mean of 20±6 pptv). Observations in July 2014 indicated a decrease in DMS(g) mixing ratios with altitude up to about 3 km, and the largest mixing ratios were found near the surface above ice-edge and open water, coincident with incre…
Distribution patterns, ecological characteristic and conservation status of endemic plants of Tadzhikistan – A global hotspot of diversity
2011
Abstract Based on literature data and own fieldwork in Tadzhikistan (Middle Asia), the taxonomic structure, distribution, habitat preferences as well as conservation state of a group of 1486 species of vascular plants of endemic and sub-endemic character are presented. In addition to verifying the number of endemics, the present study has shown that Tadzhik endemics are the most numerous in the northwest of the country, in the Gissar-Darvasian and Zeravshan regions. An analysis of average richness of endemics per surface unit has revealed that Gissar-Darvasian F is the richest area. An assessment of the taxonomic similarity of geobotanical regions based on endemic species composition has sh…
Effet du relief sur la variabilité de descripteurs des saisons des pluies en Afrique de l’Est.
2011
6 pages; International audience; Les variations spatiales des différents descripteurs des saisons des pluies tropicales (durée, fréquence et intensitédes pluies…) sont mal connues, notamment en régions accidentées. Elles ont pourtant une réelle incidence agroclimatique.Au Kenya, ces descripteurs sont fortement contraints par la géographie, y compris aux échelles fines. L’exemple du versantest du Mont Kenya montre une gamme de conditions agro-écologiques, sous l’influence du schéma général reliantl’augmentation des pluies avec l’altitude. L’altitude influence principalement la durée des deux saisons des pluies (Long etShort rains). La fréquence des jours de pluies est également modulée par l…
Critical power and anaerobic work capacity at high altitude (HA)
2009
La intensidad de lluvia en entornos mediterráneos. Valores extremos según la escala de observación
2015
Este trabajo estudia la estructura de las intensidades máximas de lluvia a diferentes escalas de observación, entre los 5 minutos y las 24 horas, en la Confederación Hidrográfica del Júcar, en base a datos del SAIH (1994-2007). Aborda además la influencia de los factores de altitud y distancia al mar, así como de la exposición del territorio: litoral-interior y compartimentación general del relieve. Los resultados muestran una gran dependencia de la intensidad en relación con la escala de observación, una influencia significativa de la distancia al mar y dos patrones de intensidad.
Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters a…
2020
Altitude ascending represents an intriguing experimental model reproducing physiological and pathophysiological conditions sharing hypoxemia as the denominator. The aim of the present study was to investigate fractional oxygen extraction and blood dynamics in response to hypobaric hypoxia and to acute resistance exercises, taking into account several factors including different ethnic origin and muscle groups. As part of the “Kanchenjunga Exploration & Physiology” project, six Italian trekkers and six Nepalese porters took part in a high altitude trek in the Himalayas. The measurements were carried out at low (1,450 m) and high altitude (HA; 4,780 m). Near-infrared spectroscopy (NIRS)-d…
Aportaciones al conocimiento de los mosquitos (Diptera, Culicidae) de alta montaña presentes en la Península Ibérica
2009
Several larval samplings of mosquitoes (Diptera, Culicidae) in different mountainous regions of the peninsular Spain were carried out. A total of 2796 specimens belonging to 18 species were collected, nevertheless the 72.5 % of these finds includes only three of them (Cx. hortensis hortensis, Cx. pipiens and Cs. longiareolata). The adaptation capacity to a varied typology of water bodies together with the marked multivoltinism that characterizes their biotic cycles are postulated as two of the principal reasons that explain their abundances. The altitudinal distribution as well as some information about the bioecology of all the species captured are also exposed.