Water heavily fractionated as it ascends on Mars as revealed by ExoMars/NOMAD

Isotopic ratios and, in particular, the water D/H ratio are powerful tracers of the evolution and transport of water on Mars. From measurements performed with ExoMars/NOMAD, we observe marked and rapid variability of the D/H along altitude on Mars and across the whole planet. The observations (from April 2018 to April 2019) sample a broad range of events on Mars, including a global dust storm, the evolution of water released from the southern polar cap during southern summer, the equinox phases, and a short but intense regional dust storm. In three instances, we observe water at very high altitudes (>80 km), the prime region where water is photodissociated and starts its escape to space. Rayleigh distillation appears the be the driving force affecting the D/H in many cases, yet in some instances, the exchange of water reservoirs with distinctive D/H could be responsible.

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Contributions to the Knowledge of the Lichen Flora of the Himalayas III. On Lecanora Somervellii Paulson (Lichenized Ascomycotina, Lecanoraceae)

The Lichenologist ◽

10.1017/s0024282900500036 ◽

1992 ◽

Vol 24 (2) ◽

pp. 111-117

Author(s):

W. Obermayer ◽

J. Poelt

Keyword(s):

Usnic Acid ◽

Type Material ◽

Lemon Yellow ◽

High Altitudes ◽

Yellow Colour ◽

Alpine Species ◽

The Alps ◽

High Himalayas ◽

Very High ◽

Lichen Flora

Abstract The lichen Lecanora somervellii Paulson, first described from the northern slopes of Mt Everest in Tibet, has been collected at four other localities in the High Himalayas, at altitudes between 3750 and 5540 m. As the type material appears to be missing, a neotype is designated here. The species has an unusual lemon yellow colour due to the pigment calycin; this compound is in addition to usnic acid, which is widespread in Lecanora. Lecanora somervellii is otherwise very similar in essential characters to the complex including Lecanora concolor Ram. and L. orbicularis (Schaerer) Vainio, high alpine species well-known, for example, from the Alps. It is supposed, that L. somervellii is derived from this aggregate by the production of calycin (in addition to usnic acid), which acts as an additional protective pigment at these very high altitudes.

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Albedo models for the residual south polar cap on Mars: Implications for the stability of the cap under near-perihelion global dust storm conditions

Planetary and Space Science ◽

10.1016/j.pss.2007.08.003 ◽

2008 ◽

Vol 56 (2) ◽

pp. 181-193 ◽

Cited By ~ 12

Author(s):

Boncho P. Bonev ◽

Gary B. Hansen ◽

David A. Glenar ◽

Philip B. James ◽

Jon E. Bjorkman

Keyword(s):

Dust Storm ◽

Polar Cap ◽

The Stability ◽

South Polar

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Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m)

Frontiers in Physiology ◽

10.3389/fphys.2021.775240 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ivan Lopez ◽

Reinaldo Aravena ◽

Daniel Soza ◽

Alicia Morales ◽

Silvia Riquelme ◽

...

Keyword(s):

High Altitude ◽

Pressure Swing Adsorption ◽

Large Scale ◽

High Mobility ◽

Oxygen Enrichment ◽

Oxygen Availability ◽

Liquid Oxygen ◽

High Altitudes ◽

Pressure Swing ◽

Very High

The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.

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Electrodynamics of Auroral and Polar Cap Arcs at Very High Latitudes

Electromagnetic Coupling in the Polar Clefts and Caps ◽

10.1007/978-94-009-0979-3_19 ◽

1989 ◽

pp. 269-284 ◽

Cited By ~ 2

Author(s):

R. R. Vondrak ◽

R. M. Robinson

Keyword(s):

High Latitudes ◽

Polar Cap ◽

Very High

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Bernanos, Georges (1888–1948)

Routledge Encyclopedia of Modernism ◽

10.4324/9781135000356-rem632-1 ◽

2018 ◽

Author(s):

Vincent Valour

Keyword(s):

Driving Force ◽

Apparent Absence ◽

Catholic Faith ◽

Modern France ◽

Spiritual Conflict ◽

The Face ◽

Charles Maurras ◽

Good And Evil ◽

Very High ◽

Christian Message

Although still widely read in the 1950s, Bernanos has now become an out dated author, if not entirely forgotten. Though he had a very high reputation among his fellow writers — Claudel, Mauriac, and Malraux admired him — Bernanos has always remained an isolated figure. His Catholic faith was the driving force behind his whole work, as a novelist and a polemicist, and is likely to be the reason why his writings have become obsolete. Fulminating against the liberalizing spirit of modern France, which led to spiritual decadence, Bernanos was part of the circle of Charles Maurras and Léon Daudet until 1932. Maurras and Daudet were the intellectual leaders of the monarchist and extreme right movement L’Action Française. Nevertheless, Bernanos deeply denounces the violence of the pro-Franco, as well as the dangers associated with Fascism and Nazism, in his famous pamphlet Les GrandsCimetières sous la lune (1938). His novels, always extremely profound, present the spiritual conflict of good and evil. His two most famous novels, Sous le soleil de Satan (1926) and Journal d’un curé de campagne (1936), revolve around the humble figure of a country priest confronted with the apparent absence of God in the gloomy landscapes of Northern France; they exemplify the Christian message of salvation in the face of failure and death.

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Aerodynamics of typical lifting bodies under conditions simulating very high altitudes.

AIAA Journal ◽

10.2514/3.3946 ◽

1967 ◽

Vol 5 (2) ◽

pp. 226-232 ◽

Cited By ~ 12

Author(s):

D. E. BOYLAN ◽

J. L. POTTER

Keyword(s):

High Altitudes ◽

Very High

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RE-OS ISOTOPIC AGE OF THE CU-AG SULPHIDE ORE AND ITS MINERALOGICAL AND GEOCHEMICAL CHARACTERISTIC IN THE LUBIN–POLKOWICE MINING AREA (SW POLAND)

Biuletyn Państwowego Instytutu Geologicznego ◽

10.5604/01.3001.0010.0105 ◽

2017 ◽

pp. 79-96 ◽

Cited By ~ 2

Author(s):

Stanisław Z. Mikulski ◽

Holly J. Stein

Keyword(s):

Mining Area ◽

Late Triassic ◽

Isotopic Ratios ◽

Geochemical Characteristic ◽

Sulphide Ore ◽

Isotopic Studies ◽

Sw Poland ◽

Underground Workings ◽

Range Of Values ◽

Very High

In the paper we present the results of Re-Os isotopic studies as well as the mineralogical and geochemical characteristic of bornite veinlets with chalcopyrite ± chalcocite margins and chalcopyrite veinlets that are parallel to sub-parallel to bedding in Kupferschiefer from the underground workings of the Lubin and Polkowice mines in SW Poland. Kupferschiefer samples are of grade from 2.5 to 14.2% Cu and with silver admixtures from 40 to 900 ppm and organic matter contents ca. 6%. The ratios of Co/Ni = 0.1–0.7, V/Cr = 4–17 and Fe2O3/C org = 0.6–1.9 are in the range of values typical for the Kupferschiefer. Besides, copper sulphides, which commonly contain silver admixtures (e.g. chalcocite – 0.44–5.03 wt.%., bornite – 0.33–0.77 wt.%., chalcopyrite 0.09–0.20 wt.%) are associated with minor galena, sphalerite, Ag-minerals and common pyrite framboids. In the isotopically analysed bornite and chalcopyrite samples Re concentrations ranging from 5.7 to 12 ppb, and total Os concentrations ranging from 27 to 52 ppt. Significant common Os is present in all of the analysed sulphides. The isotopic ratios of 187Re/188Os are very high (range: 2269–2942), and of 187Os/188Os from 9.8 to ca. 12.4. Re-Os model ages calculated for these isotopic ratios are in the range from 256 to 268 Ma and for one of the chalcopyrite veinlet was 217 ±2 Ma. Taking into the account the values of the isotopic ratios of 187Re/188Os, it was possible to construct the Re-Os isochrone age for A Model 1 regression based on four different samples. They yields age of 212 ±7 Ma, with an initial 187Os/188Os ratio of 2.13 ±0.31 (MSWD = 1.3). Re-Os isochrone age indicates for bornite and chalcopyrite crystallization event of the Ag-bearing Cu sulphide mineralization within the Kupferschiefer in the Late Triassic (Norian), ca. 212 ±7 Ma.

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Physiological Changes at Altitude in Nonasthmatic and Asthmatic Subjects

Canadian Respiratory Journal ◽

10.1155/2004/734760 ◽

2004 ◽

Vol 11 (3) ◽

pp. 197-199 ◽

Cited By ~ 13

Author(s):

Dianna Louie ◽

Peter D Paré

Keyword(s):

Peak Expiratory Flow ◽

Arterial Oxygen Saturation ◽

Arterial Oxygen ◽

Physiological Changes ◽

High Altitudes ◽

Exercise Challenge ◽

Per Se ◽

Expiratory Flow ◽

Exercise Induced ◽

Very High

Exercised-induced asthma is not due to exercise itself per se, but rather is due to cooling and/or drying of the airway because of the increased ventilation that accompanies exercise. Travel to high altitudes is accompanied by increased ventilation of cool, often dry, air, irrespective of the level of exertion, and by itself, this could represent an 'exercise' challenge for asthmatic subjects. Exercise-induced bronchoconstriction was measured at sea level and at various altitudes during a two-week trek through the Himalayas in a group of nonasthmatic and asthmatic subjects. The results of this study showed that in mild asthmatics, there was a significant reduction in peak expiratory flow at very high altitudes. Contrary to the authors' hypothesis, there was not a significant additional decrease in peak expiratory flow after exercise in the asthmatic subjects at high altitude. However, there was a significant fall in arterial oxygen saturation postexercise in the asthmatic subjects, a change that was not seen in the nonasthmatic subjects. These data suggest that asthmatic subjects develop bronchoconstriction when they go to very high altitudes, possibly via the same mechanism that causes exercise-induced asthma.

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