scholarly journals Controlling Factors of the Stable Isotope Composition in the Precipitation of Islamabad, Pakistan

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Shakir Hussain ◽  
Song Xianfang ◽  
Iqtidar Hussain ◽  
Liu Jianrong ◽  
Han Dong Mei ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Precipitation Amount ◽  
Temporal Variations ◽  
Isotopic Signature ◽  
Global Network ◽  
Water Vapor Transport ◽  
Energy Agency ◽  
Vapor Flux ◽  
Statistical Correlations ◽  
Deuterium Isotopes

Significant temporal variations inδ18O and deuterium isotopes were found in the rainfall water of Islamabad, Pakistan, over a 15-year period (1992–2006). The data were obtained from the International Atomic Energy Agency/Global Network of Isotopes in Precipitation (IAEA/GNIP) database, and statistical correlations were investigated. In particular, this study provides the first detailed analysis of GNIP data for Islamabad. Both dry (1999-2000) and wet years (1994, 1997, and 2000) were chosen to investigate the correlations between precipitation amount, vapor flux, and temperature. We observed obvious differences between the dry and wet years and among seasons as well. Long-term features in the isotope composition agreed with the global meteorological water line, whereas short-term values followed rainfall amounts; that is, a total of 72% of the precipitation’s isotopic signature was dependent on the rainfall amount, and temperature controlled 73% of the isotopic features during October to May. The lowerd-excess values were attributed to conditions during the spring season and a secondary evaporation boost during dry years; precipitation originating from the Mediterranean Sea showed highd-excess values. Overall, the results of this study contribute to the understanding of precipitation variations and their association with water vapor transport over Islamabad, Pakistan.

scholarly journals Investigating late Holocene variations in hydroclimate and the stable isotope composition of precipitation using southern South American peatlands: an hypothesis

2012 ◽  
Vol 8 (5) ◽  
pp. 1457-1471 ◽  
Author(s):  
T. J. Daley ◽  
D. Mauquoy ◽  
F. M. Chambers ◽  
F. A. Street-Perrott ◽  
P. D. M. Hughes ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Air Temperature ◽  
Regional Differences ◽  
Late Holocene ◽  
Isotope Composition ◽  
Precipitation Amount ◽  
Surface Air Temperature ◽  
Global Network ◽  
Stable Isotope Composition ◽  
Δd And Δ18o

Abstract. Ombrotrophic raised peatlands provide an ideal archive for integrating late Holocene records of variations in hydroclimate and the estimated stable isotope composition of precipitation with recent instrumental measurements. Modern measurements of mean monthly surface air temperature, precipitation, and δD and δ18O-values in precipitation from the late twentieth and early twenty-first centuries provide a short but invaluable record with which to investigate modern relationships between these variables, thereby enabling improved interpretation of the peatland palaeodata. Stable isotope data from two stations in the Global Network for Isotopes in Precipitation (GNIP) from southern South America (Punta Arenas, Chile and Ushuaia, Argentina) were analysed for the period 1982 to 2008 and compared with longer-term meteorological data from the same locations (1890 to present and 1931 to present, respectively). δD and δ18O-values in precipitation have exhibited quite different trends in response to local surface air temperature and precipitation amount. At Punta Arenas, there has been a marked increase in the seasonal difference between summer and winter δ18O-values. A decline in the deuterium excess of summer precipitation at this station was associated with a general increase in relative humidity at 1000 mb over the surface of the Southeast Pacific Ocean, believed to be the major vapour source for the local precipitation. At Ushuaia, a fall in δ18O-values was associated with an increase in the mean annual amount of precipitation. Both records are consistent with a southward retraction and increase in zonal wind speed of the austral westerly wind belt. These regional differences, observed in response to a known driver, should be detectable in peatland sites close to the GNIP stations. Currently, insufficient data with suitable temporal resolution are available to test for these regional differences over the last 3000 yr. Existing peatland palaeoclimate data from two sites near Ushuaia, however, provide evidence for changes in the late Holocene that are consistent with the pattern observed in modern observations.

scholarly journals Recharge and dynamics of a karst groundwater system in Kakheti (Eastern Georgia)

2019 ◽  
Vol 112 (1) ◽  
pp. 42-49
Author(s):  
Sopio Vepkhvadze ◽  
George Melikadze ◽  
Mariam Todadze ◽  
Peter Malík ◽  
Aleksandre Gventsadze
Keyword(s):  
Surface Water ◽  
Isotope Composition ◽  
Stream Water ◽  
Shallow Groundwater ◽  
Upper Jurassic ◽  
Temporal Variations ◽  
Winter Precipitation ◽  
Isotopic Signature ◽  
Clear Correlation ◽  
Altitude Effect

AbstractMonitoring temporal variations of 18O and 2H isotopes in precipitation, groundwater and surface water was performed in the region of Kakheti (East Georgia). Data were collected from three meteorological stations at altitudes between 400 - 1,100 m a.s.l., from two shallow and one deep hydrogeological boreholes, and from two surface water monitoring stations (Alazani River and Patmasuri karstic stream). 18O values in precipitation show an annual variation between -22 ‰ and +1 ‰ and a distinct altitude effect. A clear correlation exists between the seasonal isotope composition of precipitation, shallow groundwater and surface water. A five-fold amplitude dampening and a delay of 10-15 days was observed. The data show that precipitation in the Caucasus Mountains to the North infiltrates into the Upper Jurassic - Lower Cretaceous karstic aquifer and travels to the Alazani valley towards south-east. The isotopic signature of winter precipitation is reflected in stream water as well as in shallow groundwater isotope data of groundwater in a 2,000-m-deep hydrogeological borehole at Heretiskari show a distinctly different character with δ18O ranging between -2.8 ‰ to -2.2 ‰ and a deuterium excess of -25 ‰.

scholarly journals Year-to-Year Variations of the Stable Isotopes in Precipitation in February at Cuiabá, Located on the Northern Fringe of Pantanal, Brazil

2005 ◽  
Vol 6 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Hiroshi Matsuyama ◽  
Kunihide Miyaoka ◽  
Kooiti Masuda
Keyword(s):  
Stable Isotopes ◽  
International Atomic Energy Agency ◽  
Amazon Basin ◽  
Meteoric Water ◽  
Global Network ◽  
Energy Agency ◽  
Vapor Flux ◽  
Common Features ◽  
Northern Fringe

Abstract Large year-to-year variations of δ18O were found in the precipitation recorded in the International Atomic Energy Agency/Global Network of Isotopes in Precipitation (IAEA/GNIP) database for February at Cuiabá, located on the northern fringe of Pantanal, Brazil. Three depleted years (1963, 1978, and 1968) and three enriched years (1966, 1984, and 1983) were chosen to investigate this phenomenon and to correlate the amount of precipitation, the occurrences of storm precipitation, and the vapor flux field. In the depleted years, precipitation exceeding the long-term mean was observed at Cuiabá, while the southward vapor flux from the Amazon basin was less than the long-term mean. Since d-excesses in these years were large in general, fast evaporation must contribute to the greater precipitation observed in these depleted years. In contrast, such common features were not found in the vapor flux field in the enriched years. The occurrences of storm precipitation are important in 1966, while the amount effect is responsible for 1984. In 1983, enriched meteoric water is attributed to both the occurrences of storm precipitation and vapor flux field.

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 Wine origin authentication linked to terroir – wine fingerprint

2019 ◽  
Vol 15 ◽  
pp. 02033
Author(s):  
B. Gabel
Keyword(s):  
Pore Water ◽  
Isotope Composition ◽  
Food Product ◽  
Isotopic Signature ◽  
Original Method ◽  
Economic Problem ◽  
Red Wines ◽  
Table Grapes ◽  
Mineral Phases

Global wine and alcohol trade faces a serious economic problem linked to counterfeiting of these commodities. Recently applied authentication methods and techniques pose more difficulties for counterfeiters but they are apparently not effective once we consider economical losses identified by EU legal authorities. The presented solution links isotopic characteristics of the soil, plant, technological intermediate product and the final food product (wine, grapes) on the basis of 87Sr/86Sr isotopes ratios. For the isotopic signature of wines, the average isotope composition of the substrate cannot be a reliable indicator. Only the isotopic composition of pore water can, as it leaches various mineral phases at different stages and passes into vine root system. Instead of complicated sampling of pore water, an original method of preparing and processing soil samples and consequently must & wine samples was developed. Based on both, soil and biological material analysis, we can unquestionably determine not only geographical but also regional and local authenticity of the wine. Determination of red wines isotopic signature is more straightforward process in comparison to white wines, because of technologically different processing of grapes. That is the reason why, in case of white vines, the 87Sr/86Sr ratio of bentonites (natural purifier and absorbent useful in the process of winemaking) must also be taken into consideration. Results of analyses of Slovak wines from geographically diverse regions as well as from sites in close-by distances have clearly established reliability of presented concept, in which the soil is linked to the plant and to the final food product (wine or table grapes).

scholarly journals Environmental and taxonomic controls of carbon and oxygen stable isotope composition in <i>Sphagnum</i> across broad climatic and geographic ranges

2018 ◽  
Vol 15 (16) ◽  
pp. 5189-5202 ◽  
Author(s):  
Gustaf Granath ◽  
Håkan Rydin ◽  
Jennifer L. Baltzer ◽  
Fia Bengtsson ◽  
Nicholas Boncek ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Isotope Composition ◽  
Explanatory Power ◽  
Isotopic Signature ◽  
Co2 Uptake ◽  
Δ13c Values ◽  
Site Variation ◽  
Species Specific

Abstract. Rain-fed peatlands are dominated by peat mosses (Sphagnum sp.), which for their growth depend on nutrients, water and CO2 uptake from the atmosphere. As the isotopic composition of carbon (12,13C) and oxygen (16,18O) of these Sphagnum mosses are affected by environmental conditions, Sphagnum tissue accumulated in peat constitutes a potential long-term archive that can be used for climate reconstruction. However, there is inadequate understanding of how isotope values are influenced by environmental conditions, which restricts their current use as environmental and palaeoenvironmental indicators. Here we tested (i) to what extent C and O isotopic variation in living tissue of Sphagnum is species-specific and associated with local hydrological gradients, climatic gradients (evapotranspiration, temperature, precipitation) and elevation; (ii) whether the C isotopic signature can be a proxy for net primary productivity (NPP) of Sphagnum; and (iii) to what extent Sphagnum tissue δ18O tracks the δ18O isotope signature of precipitation. In total, we analysed 337 samples from 93 sites across North America and Eurasia using two important peat-forming Sphagnum species (S. magellanicum, S. fuscum) common to the Holarctic realm. There were differences in δ13C values between species. For S. magellanicum δ13C decreased with increasing height above the water table (HWT, R2=17 %) and was positively correlated to productivity (R2=7 %). Together these two variables explained 46 % of the between-site variation in δ13C values. For S. fuscum, productivity was the only significant predictor of δ13C but had low explanatory power (total R2=6 %). For δ18O values, approximately 90 % of the variation was found between sites. Globally modelled annual δ18O values in precipitation explained 69 % of the between-site variation in tissue δ18O. S. magellanicum showed lower δ18O enrichment than S. fuscum (−0.83 ‰ lower). Elevation and climatic variables were weak predictors of tissue δ18O values after controlling for δ18O values of the precipitation. To summarize, our study provides evidence for (a) good predictability of tissue δ18O values from modelled annual δ18O values in precipitation, and (b) the possibility of relating tissue δ13C values to HWT and NPP, but this appears to be species-dependent. These results suggest that isotope composition can be used on a large scale for climatic reconstructions but that such models should be species-specific.

scholarly journals Speleothem Stable Isotope Records from Eastern Europe & Turkey

2018 ◽  
Author(s):  
Zoltán Kern ◽  
Attila Demény ◽  
István Gábor Hatvani
Keyword(s):  
Stable Isotope ◽  
Eastern Europe ◽  
Oxygen Isotope ◽  
Temporal Resolution ◽  
Isotope Composition ◽  
Precipitation Amount ◽  
Temporal Distribution ◽  
Elevation Gradients ◽  
The Holocene ◽  
Carbon And Oxygen Isotope

The region of Eastern Europe &amp; Turkey contributed to the SISAL (Speleothem Isotopes Synthesis and AnaLysis) global database with stable carbon- and oxygen isotope time-series from 18 entities from 14 cave systems. The currently available oldest record from this region is the ABA-2 flowstone record (Abaliget Cave; Hungary) reaching back to MIS 6. The temporal distribution of the compiled 18 entities points out a ~20-kyr-long period, centering around 100 ka, lacking speleothem stable isotope record in the region. The regional subset of SISAL_v1 records displays a continuous coverage for the past ~90 kyr for both &delta;18O and &delta;13C, with a mean temporal resolution of ~12 yr for the Holocene, and &gt;50 yr for the pre-Holocene period. The highest temporal resolution both for the Holocene and the pre-Holocene was achieved in the So-1 record (Sofular Cave; Turkey). Assessing the data, an important split was found regarding the climatic interpretation of speleothem &delta;18O. While the oxygen isotope composition of more continental formations is thought to reflect mainly temperature variations and changes in moisture transport trajectories, it may strongly reflect fluctuations of precipitation amount in the southern part of the region. Variations of &delta;13C primarily interpreted as humidity changes reflecting dry/wet periods across the region. Elevation gradients from three non-overlapping time periods from the region - for the last 5kyr - indicated systematically prevailing elevational gradients around -0.26&permil;&nbsp;100m-1 in &delta;18O. The regional comparison of SISAL_v1 speleothem &delta;18O and the temporal distribution of coarsely crystalline cryogenic cave carbonate occurrences back to 45ka does not appear to confirm the finding that occurrence of the latter coincides with the warming from stadial to interstadial conditions.

Estimation of the precipitable water and water vapor flux using MAX-DOAS in two typical  cities of China

2021 ◽  
Author(s):  
Hongmei Ren ◽  
Ang Li ◽  
Pinhua Xie ◽  
Zhaokun Hu ◽  
Jin Xu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Precipitable Water ◽  
Reanalysis Data ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Optical Absorption Spectroscopy ◽  
Water Vapor Flux ◽  
Vapor Flux ◽  
The North ◽  
Two Cities

&lt;p&gt;&amp;#160; &amp;#160; &amp;#160; Water vapor transport affects regional precipitation and climate change. The measurement of precipitable water and water vapor flux is of great significance to the study of precipitation and water vapor transport. In the study, a new method of computing the precipitable water and estimating the water vapor transport flux using multi-axis differential optical absorption spectroscopy (MAX-DOAS) were presented. The calculated precipitable water and water vapor flux were compared to the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data and the correlation coefficient of the precipitable water, the zonal and meridional water vapor flux and ECMWF are r&amp;#8805;0.92, r=0.77 and r&amp;#8805;0.89, respectively. The seasonal and diurnal climatologies of precipitable water and water vapor flux in the coastal (Qingdao) and inland (Xi&amp;#8217;an) cities of China using this method were analyzed from June 1, 2019 to May 31, 2020. The results indicated that the seasonal and diurnal variation characteristics of the precipitable water in the two cities were similar. The zonal fluxes of the two cities were mainly transported from west to east, Qingdao's meridional flux was mainly transported to the south, and Xi'an was mainly transported to the north. The results also indicated that the water vapor flux transmitting belts appear near 2km and 1.4km above the surface in Qingdao and appeared around 2.8km, 1.6km and 1.0km in Xi'an.&amp;#160;&lt;/p&gt;

Distinguishing human related, biological, and geological carbon dioxide in the air through isotopic surveying

2021 ◽  
Author(s):  
Giorgio Capasso ◽  
Roberto M.R. Di Martino ◽  
Antonio Caracausi ◽  
Rocco Favara
Keyword(s):  
Carbon Dioxide ◽  
Source Identification ◽  
Isotope Composition ◽  
Strong Dependence ◽  
Landfill Gas ◽  
Molar Fraction ◽  
Data Interpretation ◽  
Isotopic Signature ◽  
Atmospheric Sciences ◽  
Gas Source

&lt;p&gt;Stable isotopes have several applications in geosciences and specifically in volcanology, fluids vs earthquakes studies, environmental surveying, and atmospheric sciences. Both geological and human-related gas sources emit carbon dioxide promoting its molar fraction increase in the lower levels of the atmosphere. The strong dependence of global warming from the carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) concentration in the air promoted the detailed investigation of the sources of CO&lt;sub&gt;2&lt;/sub&gt;. Land use inspection and the correlated increase of air CO&lt;sub&gt;2&lt;/sub&gt; concentration proved often the potential identification of the gas sources. Both the precise identification of the gas source and the specific contribution are still open challenges in environmental surveying. Isotopic signature allows both source identification and tracking fate of carbon dioxide (i.e. natural degassing in volcanic and active tectonic regions, photosynthetic fractionation in tree forests, and human-related emissions in urban zones). The isotopic signature allows evaluating the environmental impact of specific actions and better addressing the mitigation efforts by tracking fate of CO&lt;sub&gt;2&lt;/sub&gt;.&lt;/p&gt;&lt;p&gt;This study aims to identify the CO&lt;sub&gt;2&lt;/sub&gt; sources in different ecosystems by using a laser spectrometer that allowed to determine rapidly and with high precision the isotope composition of CO&lt;sub&gt;2&lt;/sub&gt; in the space and/or at high frequency (up to 1Hz). Various environments include both volcanic, seismic and urban zones because of their strong effects on the low levels of the atmosphere were considered, showing how this kind of instruments can disclose new horizons, in many different applications and especially in the time domain. In the considered zones, both the anthropogenic and geological sources caused the increases of CO&lt;sub&gt;2&lt;/sub&gt; molar fraction in the last few centuries. Suitable case studies were: i) the air CO&lt;sub&gt;2&lt;/sub&gt; surveying at Palermo; ii) the soil CO&lt;sub&gt;2&lt;/sub&gt; emissions at Vulcano (Aeolian Islands - Italy), and iii) the punctual vent CO&lt;sub&gt;2&lt;/sub&gt; emissions at Umbertide (Perugia - Italy).&lt;/p&gt;&lt;p&gt;The results of this study show detailed investigation of both sources and fate of the CO&lt;sub&gt;2&lt;/sub&gt; in various environments. The results of the isotope surveying in Palermo show that air CO&lt;sub&gt;2&lt;/sub&gt; correlated with human activities (i.e. house heating, urban mobility, and landfill gas emissions). Comparison with air CO&lt;sub&gt;2&lt;/sub&gt; at Umbertide shows the greater contribution of the geogenic reservoir near the active fault of Alto Tiberina Valley. Volcanic CO&lt;sub&gt;2&lt;/sub&gt; distinguished from biological CO&lt;sub&gt;2&lt;/sub&gt; by different isotopic signature in the soil gases of Vulcano. The soil CO&lt;sub&gt;2&lt;/sub&gt; partitioning at the settled zone of Vulcano Porto occurred through both gas source identification and data interpretation through a specifically designed isotopic mixing model.&lt;/p&gt;&lt;p&gt;This study provides several innovative experimental solutions that are suitable to understand the complexity of carbon cycle and unexplored so far environmental scenarios.&lt;/p&gt;

scholarly journals Analysis of local ice crystal growth in snow

2016 ◽  
Vol 62 (232) ◽  
pp. 378-390 ◽  
Author(s):  
QUIRINE KROL ◽  
HENNING LÖWE
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Mean Curvature ◽  
Driving Forces ◽  
Interface Velocity ◽  
Water Vapor Transport ◽  
Secondary Process ◽  
Theoretical Understanding ◽  
Vapor Flux ◽  
Air Interface

ABSTRACTThe structural evolution of snow under metamorphism is one of the key challenges in snow modeling. The main driving forces for metamorphism are curvature differences and temperature gradients, inducing water vapor transport and corresponding crystal growth, which is detectable by the motion of the ice/air interface. To provide quantitative means for a microscopic validation of metamorphism models, a VTK-based image analysis method is developed to track the ice/air interface in time-lapse μCT experiments to measure local interface velocities under both, isothermal and temperature gradient conditions. Using estimates of local temperatures from microstructure-based finite element simulations, a quantitative comparison of measured interface velocities with theoretical expressions is facilitated. For isothermal metamorphism, the data are compared with a kinetics and a diffusion limited growth law. In both cases the data are largely scattered but consistently show a mean curvature dependency of the interface velocity. For temperature gradient metamorphism, we confirm that the main contribution stems from the temperature gradient induced vapor flux, accompanied by effects of mean curvature as a secondary process. The scatter and uncertainties are discussed in view of the present theoretical understanding, the experimental setup and complications such as mechanical deformations.

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