The Isotopic Composition of Cyprus Precipitation. A Tool of Isotope Hydrology.

2021 ◽  
Author(s):  
Christos Christofi ◽  
Adriana Bruggeman ◽  
Christoph Kuells
Keyword(s):  
Isotopic Composition ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Soil Column ◽  
Seasonal Effect ◽  
Isotope Hydrology ◽  
Fractured Aquifer ◽  
Air Masses ◽  
Northern European ◽  
D Values

<p>Monitoring and profiling the isotopic composition of soil water in combination with groundwater isotope hydrology are commonly used in studying flow and transport in soils as well as in estimating groundwater recharge. Establishing the isotopic composition of local precipitation is of essence. Towards this end and in facilitating the application of isotope hydrology in Troodos Fractured Aquifer (TFA), precipitation was monitored in 16 precipitation sampling stations, stretching from the shoreline up to 1725 m above m.s.l., from January of 2015 to December of 2017. A seasonal trend was discerned, with isotopically depleted rainfall occurring in December as opposed to the more enriched autumn and spring rainfall. Northern European air masses appear to prevail during the months of December to January during which d values tend to be on average above 25‰ whereas the more enriched rain with the lowest d values occurs in July. The averaged seasonal effect between 2015 and 2017 on δ18O, δ2H and d values are 4.53‰, 30.98‰ and 14.93‰, respectively. Cyprus’ Local Meteoric Water Line (LMWL) was found to be equal to δ2H = (6.58±0.13)*δ18O + (12.64±0.91) and a general decrease of 1.22‰ for δ2H and 0.20‰ for δ18O in precipitation was calculated per 100 m altitude.  Similar values have been found by other researchers for the region. These variations in the isotope composition of rainfall can be used to earmark seasonal input of recharge water and for deriving percolation rates from tracing their movement in the soil column.</p>

scholarly journals Long-Term Isotope Records of Precipitation in Zagreb, Croatia

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 226 ◽  
Author(s):  
Ines Krajcar Bronić ◽  
Jadranka Barešić ◽  
Damir Borković ◽  
Andreja Sironić ◽  
Ivanka Lovrenčić Mikelić ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Isotope Composition ◽  
Eastern Mediterranean ◽  
Meteorological Data ◽  
Precipitation Amount ◽  
Monthly Precipitation ◽  
Air Masses ◽  
Water Line ◽  
Meteoric Water Line

The isotope composition of precipitation has been monitored in monthly precipitation at Zagreb, Croatia, since 1976. Here, we present a statistical analysis of available long-term isotope data (3H activity concentration, δ2H, δ18O, and deuterium excess) and compare them to basic meteorological data. The aim was to see whether isotope composition reflected observed climate changes in Zagreb: a significant increase in the annual air temperature and larger variations in the precipitation amount. Annual mean δ18O and δ2H values showed an increase of 0.017‰ and 0.14‰ per year, respectively, with larger differences in monthly mean values in the first half of the year than in the second half. Mean annual d-excess remained constant over the whole long-term period, with a tendency for monthly mean d-excess values to decrease in the first half of the year and increase in the second half due to the influence of air masses originating from the eastern Mediterranean. Changes in the stable isotope composition of precipitation thus resembled changes in the temperature, the circulation pattern of air masses, and the precipitation regime. A local meteoric water line was obtained using different regression methods, which did not result in significant differences between nonweighted and precipitation-weighted slope and intercept values. Deviations from the Global Meteoric Water Line GMWL (lower slopes and intercepts) were observed in two recent periods and could be explained by changes in climate parameters. The temperature gradient of δ18O was 0.33‰/°C. The tritium activity concentrations in precipitation showed slight decreases during the last two decades, and the mean A in the most recent period, 2012–2018, was 7.6 ± 0.8 Tritium Units (TU).

scholarly journals Determination of isotopic composition of rainwater to generate local meteoric water line in Thohoyandou, Limpopo Province, South Africa

Water SA ◽  
2019 ◽  
Vol 45 (2 April) ◽  
Author(s):  
Olatunde S Durowoju ◽  
John O Odiyo ◽  
Georges-Ivo E Ekosse
Keyword(s):  
Isotopic Composition ◽  
Meteoric Water ◽  
Limpopo Province ◽  
Seasonal Effect ◽  
Weighted Mean ◽  
Water Line ◽  
Meteoric Water Line ◽  
Wide Range ◽  
Continental Effect ◽  
Rain Formation

Hydrogen (D) and oxygen (18O) isotopic compositions of precipitation are useful tools to delineate the nature of precipitation, groundwater recharge and climatological investigations. This study investigated the isotopic composition of 12 rainfall occurrences at Thohoyandou, with the objective of generating the local meteoric water line (LMWL) and determining the factors controlling the isotopic composition of the rain. The delta (δ) values for D and 18O of the samples were determined using a Thermo Delta V mass spectrometer connected to a Gasbench. Thohoyandou rainwater showed a wide range of stable isotope values; δD values of the rainwater varied from −76.3‰ to +22.7‰ (SMOW) with a weighted mean of −9.8‰ and δ18O values ranged from −10.78‰ to +3.07‰ (SMOW) with a weighted mean of −2.7‰. δ-values of rainwater were more enriched during winter and more depleted during summer, due to the amount of rainfall and seasonal effect. The LMWL in Thohoyandou is defined by δD = 7.56δ18O + 10.64, which shows a similar slope to the global meteoric water line (GMWL) but with a slightly higher intercept, of 10.64‰ instead of 10‰. This implies that the process of rain formation in Thohoyandou occurred under equilibrium conditions which are not significantly affected by evaporation. The slightly higher d-intercept value above the GMWL reflects an additional supply of recycled moisture across the regions. This implies that there is no continental effect but inland moisture from various water bodies and vegetation.

scholarly journals Comment on “Origin of water in the Badain Jaran Desert, China: new insight from isotopes” by Wu et al. (2017)

2018 ◽  
Author(s):  
Lucheng Zhan ◽  
Jiansheng Chen ◽  
Ling Li ◽  
David Andrew Barry
Keyword(s):  
Isotopic Composition ◽  
Lake Water ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Qilian Mountains ◽  
Precipitation Rate ◽  
Badain Jaran Desert ◽  
Isotope Data ◽  
Local Areas ◽  
The Qilian Mountains

Abstract. Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotopic composition vary seasonally, so arithmetic averages of precipitation isotope values poorly represent the isotope composition of meteoric water. Their finding that the BJD groundwater is recharged by modern meteoric water from local areas including the southeastern adjacent mountains was based on arithmetic averaging. However, this conclusion is not supported by the corrected mean precipitation isotope values, which are weighted by the precipitation rate. Indeed, the available isotopic evidence shows that modern precipitation on the Qilian Mountains is more likely to be the main source of the groundwater and lake water in the BJD, as found by Chen et al. (2004).

scholarly journals Isotopic composition of daily precipitation along southern foothills of the Himalayas: impact of marine and continental sources of atmospheric moisture

2017 ◽  
Author(s):  
Ghulam Jeelani ◽  
Rajendrakumar D. Deshpande ◽  
Michal Galkowski ◽  
Kazimierz Rozanski
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Daily Precipitation ◽  
Isotope Composition ◽  
Daily Rainfall ◽  
Himalayan Region ◽  
Water Evaporation ◽  
Atmospheric Moisture ◽  
Air Masses ◽  
Continental Origin

Abstract. The flow of the Himalayan rivers, a key source of fresh water to more than a billion people primarily depends upon the strength, behaviour and duration of Indian Summer Monsoon (ISM) and Western Disturbances (WD), two contrasting circulation regimes of the regional atmosphere. Analysis of 2H and 18O isotope composition of daily precipitation collected along the southern foothills of the Himalayas combined with extensive backward trajectory modelling was used to gain deeper insight into the mechanisms controlling isotopic composition of precipitation and the origin of atmospheric moisture and precipitation during ISM and WD periods. Daily precipitation samples have been collected during the period September 2008 – December 2011 at six stations, extending from Srinagar in the west (Kashmir state) to Dibrugarh in the east (Assam state). In total, 548 daily precipitation samples have been collected and analysed for their stable isotope composition. It is suggested that gradual reduction in 2H and 18O content of precipitation in the studied region, progressing from δ18O values close to zero down to ca. −10 ‰ in the course of ISM evolution, stems from regional, large-scale recycling of moisture-driven monsoonal circulation. Superimposed on this general trend are short-term fluctuations of the isotopic composition of rainfall, having their roots in the local effects such as enhanced convective activity and associated higher degree of rainout of moist air masses (local amount effect), cyclonic storms or impact of isotopically heavy moisture of continental origin. Seasonal footprint maps constructed for three stations representing western, central and eastern portion of the Himalayan region indicate that influence of monsoonal circulation reaches western edges of the Himalayan region. While characteristic imprint of monsoon air masses (increase of monthly rainfall amount) can be completely absent in the western Himalaya, the onset of ISM period in this region is still clearly visible in the isotopic composition of daily precipitation. Characteristic feature of daily precipitation collected during WD period is a gradual increase of 2H and 18O content, reaching positive δ2H and δ18O values towards the end of this period. This trend can be explained by growing importance of moisture of continental origin as a source of daily precipitation. High d-excess values of daily rainfall recorded at the monitoring stations (38 cases in total, range from 20.6 to 44.0 ‰) are attributed to moisture of continental origin released into the atmosphere during evaporation of surface water bodies and/or soil water evaporation.

scholarly journals Isotopic composition of daily precipitation along the southern foothills of the Himalayas: impact of marine and continental sources of atmospheric moisture

2018 ◽  
Vol 18 (12) ◽  
pp. 8789-8805 ◽  
Author(s):  
Ghulam Jeelani ◽  
Rajendrakumar D. Deshpande ◽  
Michal Galkowski ◽  
Kazimierz Rozanski
Keyword(s):  
Isotopic Composition ◽  
Daily Precipitation ◽  
Isotope Composition ◽  
Himalayan Region ◽  
Water Evaporation ◽  
Western Himalayas ◽  
Atmospheric Moisture ◽  
Air Masses ◽  
Continental Origin ◽  
The Impact

Abstract. The flow of the Himalayan rivers, a key source of fresh water for more than a billion people primarily depends upon the strength, behaviour and duration of the Indian summer monsoon (ISM) and the western disturbances (WD), two contrasting circulation regimes of the regional atmosphere. An analysis of the 2H and 18O isotope composition of daily precipitation collected along the southern foothills of the Himalayas, combined with extensive backward trajectory modelling, was used to gain deeper insight into the mechanisms controlling the isotopic composition of precipitation and the origin of atmospheric moisture and precipitation during ISM and WD periods. Daily precipitation samples were collected during the period from September 2008 to December 2011 at six stations, extending from Srinagar in the west (Kashmir state) to Dibrugarh in the east (Assam state). In total, 548 daily precipitation samples were collected and analysed for their stable isotope composition. It is suggested that the gradual reduction in the 2H and 18O content of precipitation in the study region, progressing from δ18O values close to zero down to ca. −10 ‰ in the course of ISM evolution, stems from regional, large-scale recycling of moisture-driven monsoonal circulation. Superimposed on this general trend are short-term fluctuations of the isotopic composition of rainfall, which might have stem from local effects such as enhanced convective activity and the associated higher degree of rainout of moist air masses (local amount effect), the partial evaporation of raindrops, or the impact of isotopically heavy moisture generated in evapotranspiration processes taking place in the vicinity of rainfall sampling sites. Seasonal footprint maps constructed for three stations representing the western, central and eastern portions of the Himalayan region indicate that the influence of monsoonal circulation reaches the western edges of the Himalayan region. While the characteristic imprint of monsoonal air masses (increase of monthly rainfall amount) can be completely absent in the western Himalayas, the onset of the ISM period in this region is still clearly visible in the isotopic composition of daily precipitation. A characteristic feature of daily precipitation collected during the WD period is the gradual increase of 2H and 18O content, reaching positive δ2H and δ18O values towards the end of the period. This trend can be explained by the growing importance of moisture of continental origin as a source of daily precipitation. High deuterium-excess (d-excess) values of daily rainfall recorded at the monitoring stations (38 cases in total, range from 20.6 to 44.0 ‰) are attributed to moisture of continental origin released into the atmosphere during the evaporation of surface water bodies and/or soil water evaporation.

scholarly journals Lake water based isoscape in central-south Chile reflects meteoric water

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wesley P. Scott ◽  
Sergio Contreras ◽  
Gabriel J. Bowen ◽  
T. Elliott Arnold ◽  
Ramón Bustamante-Ortega ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotopic Composition ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Global Network ◽  
Ancillary Data ◽  
Energy Agency ◽  
Significant Information ◽  
Field Equipment ◽  
Central South

AbstractWarming across the globe is expected to alter the strength and amount of regional precipitation, but there is uncertainty associated with the magnitude of these expected changes, and also how these changes in temperature and the hydrologic cycle will affect humans. For example, the climate in central-south Chile is projected to become significantly warmer and drier over the next several decades in response to anthropogenically driven warming, but these anthropogenic changes are superimposed on natural climate variability. The stable isotope composition of meteoric water provides significant information regarding the moisture source, pathways, and rain-out history of an air mass, but precipitation samples suitable for stable isotope measurements require long-term placement of field equipment making them difficult to obtain. The International Atomic Energy Agency (IAEA) Global Network of Isotopes in Precipitation (GNIP) stations generate isotopic and ancillary data of precipitation from many locations around the world, but remote areas of developing countries like Chile typically have sparse networks of meteorological stations, which inhibit our ability to accurately model regional precipitation. Central-south Chile, in particular, has a sparse network of GNIP stations and, as a result, the isotopic composition of meteoric water is underrepresented in the global database complicating efforts to constrain modern day hydroclimate variability as well as paleohydrologic reconstruction for southern South America. In this study, we measured the stable isotope compositions of hydrogen (δ2H) and oxygen (δ18O) in surface lacustrine waters of central-south Chile to determine what physical and/or climatic features are the dominant controls on lacustrine δ18O and δ2H composition, assess whether or not the isotopic composition of the lakes record time-averaged isotope composition of meteoric water, and determine whether an isoscape map based on lake surface waters could predict the H and O isotope compositions of precipitation at the few GNIP stations in the region.

scholarly journals An Overview of Aquifer Physiognomies and the δ18O and δ2H Distribution in the South African Groundwaters

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 68
Author(s):  
Tamiru A. Abiye ◽  
Molla B. Demlie ◽  
Haile Mengistu
Keyword(s):  
Stable Isotope ◽  
Isotopic Composition ◽  
South African ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Isotopic Signature ◽  
Shallow Aquifer ◽  
Arid Zones ◽  
Mixing Effect ◽  
Groundwater Systems

A comprehensive assessment of the stable isotope distribution in the groundwater systems of South Africa was conducted in relation to the diversity in the aquifer lithology and corresponding hydraulic characteristics. The stable isotopes of oxygen (18O) and hydrogen (2H) in groundwater show distinct spatial variation owing to the recharge source and possibly mixing effect in the aquifers with the existing water, where aquifers are characterized by diverse hydraulic conductivity and transmissivity values. When the shallow aquifer that receives direct recharge from rainfall shows a similar isotopic signature, it implies less mixing effect, while in the case of deep groundwater interaction between recharging water and the resident water intensifies, which could change the isotope signature. As aquifer depth increases the effect of mixing tends to be minimal. In most cases, the isotopic composition of recharging water shows depletion in the interior areas and western arid zones which is attributed to the depleted isotopic composition of the moisture source. The variations in the stable isotope composition of groundwater in the region are primarily controlled by the isotope composition of the rainfall, which shows variable isotope composition as it was observed from the local meteoric water lines, in addition to the evaporation, recharge and mixing effects.

Epithermal Fluorite Deposits in Transbaikalia (Geochemical Features, Sources of Matter and Fluids, and Genesis)

2021 ◽  
Vol 62 (4) ◽  
pp. 415-426
Author(s):  
E.I. Lastochkin ◽  
G.S. Ripp ◽  
D.S. Tsydenova ◽  
V.F. Posokhov ◽  
A.E. Murzintseva
Keyword(s):  
Meteoric Water ◽  
Isotope Composition ◽  
Spatial Proximity ◽  
Thermal Waters ◽  
Sr Isotope ◽  
Light Isotope ◽  
Geochemical Parameters ◽  
Nd Systems ◽  
Deep Source ◽  
The Impact

Abstract —We consider the isotope-geochemical features of epithermal fluorite deposits in Transbaikalia, including the REE compositions, Sr isotope ratios, Sm–Nd systems, and isotope compositions of oxygen, carbon, hydrogen, and sulfur. The 87Sr/86Sr ratios in fluorites are within 0.706–0.708, and the εNd values are negative. Oxygen in quartz, the main mineral of the deposits, has a light isotope composition (δ18O = –3.4 to +2.6‰), and the calculated isotope composition of oxygen in the fluid in equilibrium with quartz (δ18O = –9 to –16‰) indicates the presence of meteoric water. The latter is confirmed by analysis of the isotope compositions of oxygen and hydrogen in gas–liquid inclusions in fluorites from three deposits. These isotope compositions are due to recycling caused by the impact of shallow basic plutons. The isotope composition of sulfur indicates its deep source. During ascent, sulfur became enriched in its light isotope (δ34S = –1.8 to –7.7‰). We assess the association of fluorite ores with basaltoids widespread in the study area. The isotope and geochemical parameters suggest their spatial proximity. Probably, the basaltoids were responsible for the recycling of meteoric water. It is shown that the epithermal fluorite deposits formed by the same mechanism as fissure–vein thermal waters in western Transbaikalia.

scholarly journals Comment on “Origin of water in the Badain Jaran Desert, China: new insight from isotopes” by Wu et al. (2017)

2018 ◽  
Vol 22 (8) ◽  
pp. 4449-4454 ◽  
Author(s):  
Lucheng Zhan ◽  
Jiansheng Chen ◽  
Ling Li ◽  
David A. Barry
Keyword(s):  
Lake Water ◽  
Meteoric Water ◽  
Isotope Composition ◽  
Qilian Mountains ◽  
Precipitation Rate ◽  
Badain Jaran Desert ◽  
Isotopic Evidence ◽  
Isotope Data ◽  
Local Areas ◽  
The Qilian Mountains

Abstract. Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotope composition vary seasonally, so arithmetic averages of precipitation isotope values poorly represent the isotope composition of meteoric water. Their finding that the BJD groundwater is recharged by modern meteoric water from local areas including the southeastern adjacent mountains was based on arithmetic averaging. However, this conclusion is not supported by the corrected mean precipitation isotope values, which are weighted by the precipitation rate. Indeed, the available isotopic evidence shows that modern precipitation on the Qilian Mountains is more likely to be the main source of the groundwater and lake water in the BJD, as found by Chen et al. (2004).

scholarly journals Seasonal variations in nitrate isotope composition of three rivers draining into the North Sea

2010 ◽  
Vol 7 (4) ◽  
pp. 6051-6088 ◽  
Author(s):  
A. Deek ◽  
K. Emeis ◽  
U. Struck
Keyword(s):  
Isotopic Composition ◽  
North Sea ◽  
Isotope Composition ◽  
Atmospheric Oxygen ◽  
Isotope Effects ◽  
Nitrate Sources ◽  
Particulate Nitrogen ◽  
Soil Nitrification ◽  
Mean Values ◽  
Δ 15N

Abstract. Nitrate loading of coastal ecosystems by rivers that drain industrialised catchments continues to be a problem in the South Eastern North Sea, in spite of significant mitigation efforts over the last 2 decades. To identify nitrate sources, sinks, and turnover in three German rivers that discharge into the German Bight, we determined δ 15N-NO3- and δ18O- NO3- in nitrate and δ 15N of particulate nitrogen for the period 2006–2009 (biweekly samples). The nitrate loads of Rhine, Weser and Ems varied seasonally in magnitude and δ 15N-NO3- (6.5–21‰), whereas the δ 18O-NO3- (-0.3–5.9‰) and δ 15N-PN (4–14‰) were less variable. Overall temporal patterns in nitrate mass fluxes and isotopic composition suggest that a combination of nitrate delivery from nitrification of soil ammonia in the catchment and assimilation of nitrate in the rivers control the isotopic composition of nitrate. Nitrification in soils as a source is indicated by low δ 18O-NO3- in winter, which traces the δ 18O of river water. Mean values of δ 18O-H2O were between –9.4‰ and –7.3‰; combined in a ratio of 2:1 with the atmospheric oxygen δ 18O of 23.5‰ agrees with the found δ 18O of nitrate in the rivers. Parallel variations of δ 15N-NO3- and δ 18O-NO3- within each individual river are caused by isotope effects associated with nitrate assimilation in the water column, the extent of which is determined by residence time in the river. Assimilation is furthermore to some extent mirrored both by the δ 15N of nitrate and particulate N. Although δ 15-NO3- observed in Rhine, Weser and Ems are reflected in high average δ 15N-PN (between 6‰ and 9‰, both are uncorrelated in the time series due to lateral and temporal mixing of PN. That a larger enrichment was consistently seen in δ 15N-NO3- relative to δ 18O-NO3- is attributed to constant additional diffuse nitrate inputs deriving from soil nitrification in the catchment area. A statistically significant inverse correlation exists between increasing δ 15N-NO3- values and decreasing NO3- concentrations. This inverse relationship – observed in each seasonal cycle – together with a robust relationship between human dominated land use and δ 15N-NO3- values demonstrates a strong influence of human activities and riverine nitrate consumption efficiency on the isotopic composition of riverine nitrate.

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