Altitude effect on COPD in SPIROMICS cohort

Several prior studies investigated the use of stable isotopes of water in hydrogeological applications, most on a local scale and often involving the isotopic gradient (evaluated by exploiting the so-called altitude effect), calculated on the basis of rainwater isotopes. A few times, this gradient has been obtained using the stable isotopic contents of low-yield springs in a limited time series. Despite the fact that this method has been recognized by the hydrogeological community, marked differences have been observed with respect to the mean stable isotopes content of groundwater and rainwater. The present investigation compares the stable isotopic signatures of 23 low-yield springs discharging along two transects from the Tyrrhenian sea to the Po Plain of Italy, evaluates the different isotopic gradients and assesses their distribution in relation to some climatic and topographic conditions. Stable isotopes of water show that groundwater in the study area is recharged by precipitation and that the precipitation regime in the eastern portion of the study area is strongly controlled by a shadow effect caused by the Alps chain on the air masses from central Europe. Stable isotopes (in particular the δ18O and deuterium excess (d-excess) contents together with the obtained isotopic gradients) allow us to identify in the study area an opposite oriented orographic effect and a different provenance of the air masses. When the windward slope is located on the Tyrrhenian side, the precipitation shows a predominant oceanic origin; when the windward slope moves to the Adriatic side, the precipitation is characterized by a continental origin. The main results of this study confirm the usefulness of low-yield springs and the need for a highly detailed survey-scale hydrological investigation in the mountainous context.

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Hydrology of Mountain Blocks in Arizona and New Mexico as Revealed by Isotopes in Groundwater and Precipitation

Geosciences ◽

10.3390/geosciences9110461 ◽

2019 ◽

Vol 9 (11) ◽

pp. 461 ◽

Cited By ~ 3

Author(s):

Christopher J. Eastoe ◽

William E. Wright

Keyword(s):

Groundwater Age ◽

Winter Precipitation ◽

Precipitation Intensity ◽

Basin And Range Province ◽

Altitude Effect ◽

Weighted Means ◽

Mountain Front ◽

Tucson Basin ◽

Precipitation Season ◽

Data Plotting

Mountain-block groundwater in the Southern Basin-and-Range Province shows a variety of patterns of δ18O and δ2H that indicate multiple recharge mechanisms. At 2420 m above sea level (masl) in Tucson Basin, seasonal amount-weighted means of δ18O and δ2H for summer are −8.3, −53‰, and for winter, −10.8 and −70‰, respectively. Elevation-effect coefficients for δ18O and δ2H are as follows: summer, −1.6 and −7.7 ‰ per km and winter, −1.1 and −8.9 ‰ per km. Little altitude effect exists in 25% of seasons studied. At 2420 masl, amount-weighted monthly averages of δ18O and δ2H decrease in summer but increase in winter as precipitation intensity increases. In snow-banks, δ18O and δ2H commonly plots close to the winter local meteoric water line (LMWL). Four principal patterns of (δ18O, δ2H) data have been identified: (1) data plotting along LMWLs for all precipitation at >1800 masl; (2) data plotting along modified LMWLs for the wettest 30% of months at <1700 masl; (3) evaporation trends at all elevations; (4) other patterns, including those affected by ancient groundwater. Young, tritiated groundwater predominates in studied mountain blocks. Ancient groundwater forms separate systems and mixes with young groundwater. Recharge mechanisms reflect a complex interplay of precipitation season, altitude, precipitation intensity, groundwater age and geology. Tucson Basin alluvium receives mountain-front recharge containing 50%–90% winter precipitation.

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Spatio-temporal modelling of lightning climatologies for complex terrain

Natural Hazards and Earth System Science ◽

10.5194/nhess-17-305-2017 ◽

2017 ◽

Vol 17 (3) ◽

pp. 305-314 ◽

Cited By ~ 5

Author(s):

Thorsten Simon ◽

Nikolaus Umlauf ◽

Achim Zeileis ◽

Georg J. Mayr ◽

Wolfgang Schulz ◽

...

Keyword(s):

Complex Terrain ◽

Generalized Additive Models ◽

Weather Prediction ◽

Geographical Location ◽

Eastern Alps ◽

Spatial Effect ◽

Additive Models ◽

Seasonal Effect ◽

Altitude Effect ◽

North West

Abstract. This study develops methods for estimating lightning climatologies on the day−1 km−2 scale for regions with complex terrain and applies them to summertime observations (2010–2015) of the lightning location system ALDIS in the Austrian state of Carinthia in the Eastern Alps. Generalized additive models (GAMs) are used to model both the probability of occurrence and the intensity of lightning. Additive effects are set up for altitude, day of the year (season) and geographical location (longitude/latitude). The performance of the models is verified by 6-fold cross-validation. The altitude effect of the occurrence model suggests higher probabilities of lightning for locations on higher elevations. The seasonal effect peaks in mid-July. The spatial effect models several local features, but there is a pronounced minimum in the north-west and a clear maximum in the eastern part of Carinthia. The estimated effects of the intensity model reveal similar features, though they are not equal. The main difference is that the spatial effect varies more strongly than the analogous effect of the occurrence model. A major asset of the introduced method is that the resulting climatological information varies smoothly over space, time and altitude. Thus, the climatology is capable of serving as a useful tool in quantitative applications, i.e. risk assessment and weather prediction.

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Bronchial reactivity in asthmatic children at high and low altitude. Effect of budesonide.

American Journal of Respiratory and Critical Care Medicine ◽

10.1164/ajrccm.151.4.7697252 ◽

1995 ◽

Vol 151 (4) ◽

pp. 1194-1200

Author(s):

A L Boner ◽

A Comis ◽

M Schiassi ◽

P Venge ◽

G L Piacentini

Keyword(s):

Bronchial Reactivity ◽

Altitude Effect ◽

Asthmatic Children ◽

Low Altitude

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Assessing the altitude effect on distributions of volatile organic compounds from different sources by principal component analysis

Environmental Science Processes & Impacts ◽

10.1039/c3em00034f ◽

2013 ◽

Vol 15 (5) ◽

pp. 972 ◽

Cited By ~ 7

Author(s):

Jhih-Jhe Yang ◽

Chih-Chung Liu ◽

Wei-Hsiang Chen ◽

Chung-Shin Yuan ◽

Chitsan Lin

Keyword(s):

Principal Component Analysis ◽

Volatile Organic Compounds ◽

Organic Compounds ◽

Principal Component ◽

Component Analysis ◽

Altitude Effect ◽

Volatile Organic ◽

Different Sources

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Corrigendum - Growth and productivity of irrigated Sorghum bicolor (L. Moench) in Northern Australia. II. Low solar altitude as a possible constraint to productivity in the tropical dry season

Australian Journal of Agricultural Research ◽

10.1071/ar9840229c ◽

1984 ◽

Vol 35 (2) ◽

pp. 229

Author(s):

MA Foale ◽

GL Wilson ◽

DB Coates ◽

KP Haydock

Keyword(s):

Solar Radiation ◽

Canopy Structure ◽

Dry Season ◽

High Density ◽

Light Penetration ◽

Northern Australia ◽

Growth Study ◽

Altitude Effect ◽

Solar Altitude ◽

Sorghum Bicolor L

A growth study was carried out during the dry season on irrigated grain sorghum cultivar NK 300F at latitude 16�S. in northern Australia. The apparent efficiency of the canopy in the photosynthetic conversion of solar radiation increased progressively in high density stands between June and September, while low density stands showed no change. An hypothesis is advanced that the rise in canopy efficiency was due to increasing solar altitude combining with a suitable canopy structure at high density to give increased light penetration into the canopy. A parameter named weighted mean solar altitude (WMSA) is used in conjunction with noon solar altitude (NSA) to assist in the interpretation of published models of light penetration. This solar altitude effect, if verified by further work, would lower the expectations, based on mean daily solar radiation, for dry season yield of irrigated sorghum and possibly other cereals in the semi-arid tropics.

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A reassessment of the discrepancies in the annual variation of <i>δ</i>D-H<sub>2</sub>O in the tropical lower stratosphere between the MIPAS and ACE-FTS satellite data sets

Atmospheric Measurement Techniques ◽

10.5194/amt-13-287-2020 ◽

2020 ◽

Vol 13 (1) ◽

pp. 287-308

Author(s):

Stefan Lossow ◽

Charlotta Högberg ◽

Farahnaz Khosrawi ◽

Gabriele P. Stiller ◽

Ralf Bauer ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Annual Variation ◽

Lower Stratosphere ◽

Michelson Interferometer ◽

Tape Recorder ◽

Data Sets ◽

Altitude Effect ◽

Data Set ◽

Tropical Tropopause ◽

Tropopause Region

Abstract. The annual variation of δD in the tropical lower stratosphere is a critical indicator for the relative importance of different processes contributing to the transport of water vapour through the cold tropical tropopause region into the stratosphere. Distinct observational discrepancies of the δD annual variation were visible in the works of Steinwagner et al. (2010) and Randel et al. (2012). Steinwagner et al. (2010) analysed MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) observations retrieved with the IMK/IAA (Institut für Meteorologie und Klimaforschung in Karlsruhe, Germany, in collaboration with the Instituto de Astrofísica de Andalucía in Granada, Spain) processor, while Randel et al. (2012) focused on ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer) observations. Here we reassess the discrepancies based on newer MIPAS (IMK/IAA) and ACE-FTS data sets, also showing for completeness results from SMR (Sub-Millimetre Radiometer) observations and a ECHAM/MESSy (European Centre for Medium-Range Weather Forecasts Hamburg and Modular Earth Submodel System) Atmospheric Chemistry (EMAC) simulation (Eichinger et al., 2015b). Similar to the old analyses, the MIPAS data set yields a pronounced annual variation (maximum about 75 ‰), while that derived from the ACE-FTS data set is rather weak (maximum about 25 ‰). While all data sets exhibit the phase progression typical for the tape recorder, the annual maximum in the ACE-FTS data set precedes that in the MIPAS data set by 2 to 3 months. We critically consider several possible reasons for the observed discrepancies, focusing primarily on the MIPAS data set. We show that the δD annual variation in the MIPAS data up to an altitude of 40 hPa is substantially impacted by a “start altitude effect”, i.e. dependency between the lowermost altitude where MIPAS retrievals are possible and retrieved data at higher altitudes. In itself this effect does not explain the differences with the ACE-FTS data. In addition, there is a mismatch in the vertical resolution of the MIPAS HDO and H2O data (being consistently better for HDO), which actually results in an artificial tape-recorder-like signal in δD. Considering these MIPAS characteristics largely removes any discrepancies between the MIPAS and ACE-FTS data sets and shows that the MIPAS data are consistent with a δD tape recorder signal with an amplitude of about 25 ‰ in the lowermost stratosphere.

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