scholarly journals Experimental investigation of the stable water isotope distribution in an Alpine lake environment (L-WAIVE)

2021 ◽  
Vol 21 (14) ◽  
pp. 10911-10937
Author(s):  
Patrick Chazette ◽  
Cyrille Flamant ◽  
Harald Sodemann ◽  
Julien Totems ◽  
Anne Monod ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Liquid Water ◽  
Lake Water ◽  
Weather Conditions ◽  
Small Scale ◽  
Free Troposphere ◽  
Stable Water Isotopes ◽  
Valley Wind ◽  
Field Campaign ◽  
Wind Regimes

Abstract. In order to gain understanding on the vertical structure of atmospheric water vapour above mountain lakes and to assess its link with the isotopic composition of the lake water and with small-scale dynamics (i.e. valley winds, thermal convection above complex terrain), the L-WAIVE (Lacustrine-Water vApor Isotope inVentory Experiment) field campaign was conducted in the Annecy valley in the French Alps during 10 d in June 2019. This field campaign was based on an original experimental synergy between a suite of ground-based, boat-borne, and two ultra-light aircraft (ULA) measuring platforms implemented to characterize the thermodynamic and isotopic composition above and in the lake. A cavity ring-down spectrometer and an in-cloud liquid water collector were deployed aboard one of the ULA to characterize the vertical distribution of the main stable water isotopes (H216O, H218O and H2H16O) both in the air and in shallow cumulus clouds. The temporal evolution of the meteorological structures of the low troposphere was derived from an airborne Rayleigh–Mie lidar (embarked on a second ULA), a ground-based Raman lidar, and a wind lidar. ULA flight patterns were repeated several times per day to capture the diurnal evolution as well as the variability associated with the different weather events encountered during the field campaign, which influenced the humidity field, cloud conditions, and slope wind regimes in the valley. In parallel, throughout the campaign, liquid water samples of rain, at the air–lake water interface, and at 2 m depth in the lake were taken. A significant variability of the isotopic composition was observed along time, depending on weather conditions, linked to the transition from the valley boundary layer towards the free troposphere, the valley wind intensity, and the vertical thermal stability. Thus, significant gradients of isotopic content have been revealed at the transition to the free troposphere, at altitudes between 2.5 and 3.5 km. The influence of the lake on the atmosphere isotopic composition is difficult to isolate from other contributions, especially in the presence of thermal instabilities and valley winds. Nevertheless, such an effect appears to be detectable in a layer of about 300 m thickness above the lake in light wind conditions. We also noted similar isotopic compositions in cloud drops and rainwater.

scholarly journals An Optimized Snowmelt Lysimeter System for Monitoring Melt Rates and Collecting Samples for Stable Water Isotope Analysis

2019 ◽  
Vol 67 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Andrea Rücker ◽  
Massimiliano Zappa ◽  
Stefan Boss ◽  
Jana von Freyberg
Keyword(s):  
Isotopic Composition ◽  
Isotope Analysis ◽  
Ground Level ◽  
Isotopic Signature ◽  
Small Scale ◽  
Spatial And Temporal Variability ◽  
Environmental Tracers ◽  
Hydrograph Separation ◽  
Stable Water Isotopes ◽  
Restricted Volume

Abstract The contribution of snow meltwater to catchment streamflow can be quantified through hydrograph separation analyses for which stable water isotopes (18O, 2H) are used as environmental tracers. For this, the spatial and temporal variability of the isotopic composition of meltwater needs to be captured by the sampling method. This study compares an optimized snowmelt lysimeter system and an unheated precipitation collector with focus on their ability to capture snowmelt rates and the isotopic composition of snowmelt. The snowmelt lysimeter system consists of three individual unenclosed lysimeters at ground level with a surface of 0.14 m2 each. The unheated precipitation collector consists of a 30 cm-long, extended funnel with its orifice at 2.3 m above ground. Daily snowmelt samples were collected with both systems during two snowfall-snowmelt periods in 2016. The snowmelt lysimeter system provided more accurate measurements of natural melt rates and allowed for capturing the small-scale variability of snowmelt process at the plot scale, such as lateral meltwater flow from the surrounding snowpack. Because of the restricted volume of the extended funnel, daily melt rates from the unheated precipitation collector were up to 43% smaller compared to the snowmelt lysimeter system. Overall, both snowmelt collection methods captured the general temporal evolution of the isotopic signature in snowmelt.

scholarly journals Phosphorous Supply to a Eutrophic Artificial Lake: Sedimentary versus Groundwater Sources

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 563
Author(s):  
Wiebe Förster ◽  
Jan C. Scholten ◽  
Michael Schubert ◽  
Kay Knoeller ◽  
Nikolaus Classen ◽  
...  
Keyword(s):  
Water Quality ◽  
Stable Isotope ◽  
Pore Water ◽  
Lake Water ◽  
Sediment Cores ◽  
Eutrophic Lake ◽  
Stable Water Isotopes ◽  
Artificial Lake ◽  
Sediment Pore Water ◽  
Mass Balance Models

The eutrophic Lake Eichbaumsee, a ~1 km long and 280 m wide (maximum water depth 16 m) dredging lake southeast of Hamburg (Germany), has been treated for water quality improvements using various techniques (i.e., aeration plants, removal of dissolved phosphorous by aluminum phosphorous precipitation, and by Bentophos® (Phoslock Environmental Technologies, Sydney, Australia), adsorption) during the past ~15 years. Despite these treatments, no long-term improvement of the water quality has been observed and the lake water phosphorous content has continued to increase by e.g., ~670 kg phosphorous between autumn 2014 and autumn 2019. As no creeks or rivers drain into the lake and hydrological groundwater models do not suggest any major groundwater discharge into the lake, sources of phosphorous (and other nutrients) are unknown. We investigated the phosphorous fluxes from sediment pore water and from groundwater in the water body of the lake. Sediment pore water was extracted from sediment cores recovered by divers in August 2018 and February 2019. Diffusive phosphorous fluxes from pore water were calculated based on phosphorus gradients. Stable water isotopes (δ2H, δ18O) were measured in the lake water, in interstitial waters in the banks surrounding the lake, in the Elbe River, and in three groundwater wells close to the lake. Stable isotope (δ2H, δ18O) water mass balance models were used to compute water inflow/outflow to/from the lake. Our results revealed pore-water borne phosphorous fluxes between 0.2 mg/m2/d and 1.9 mg/m2/d. Assuming that the measured phosphorous fluxes are temporarily and spatially representative for the whole lake, about 11 kg/a to 110 kg/a of phosphorous is released from sediments. This amount is lower than the observed lake water phosphorous increase of ~344 kg between April 2018 and November 2018. Water stable isotope (δ2H, δ18O) compositions indicate a water exchange between an aquifer and the lake water. Based on stable isotope mass balances we estimated an inflow of phosphorous from the aquifer to the lake of between ~150 kg/a and ~390 kg/a. This result suggests that groundwater-borne phosphorous is a significant phosphorous source for the Eichbaumsee and highlights the importance of groundwater for lake water phosphorous balances.

scholarly journals Southeast Pacific stratocumulus clouds, precipitation and boundary layer structure sampled along 20° S during VOCALS-REx

2010 ◽  
Vol 10 (21) ◽  
pp. 10639-10654 ◽  
Author(s):  
C. S. Bretherton ◽  
R. Wood ◽  
R. C. George ◽  
D. Leon ◽  
G. Allen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Liquid Water ◽  
Vertical Structure ◽  
Layer Structure ◽  
Cloud Droplet ◽  
Free Troposphere ◽  
Liquid Water Path ◽  
Typical Structure ◽  
Southeast Pacific ◽  
Over The Top

Abstract. Multiplatform airborne, ship-based, and land-based observations from 16 October–15 November 2008 during the VOCALS Regional Experiment (REx) are used to document the typical structure of the Southeast Pacific stratocumulus-topped boundary layer and lower free troposphere on a~transect along 20° S between the coast of Northern Chile and a buoy 1500 km offshore. Strong systematic gradients in clouds, precipitation and vertical structure are modulated by synoptically and diurnally-driven variability. The boundary layer is generally capped by a strong (10–12 K), sharp inversion. In the coastal zone, the boundary layer is typically 1 km deep, fairly well mixed, and topped by thin, nondrizzling stratocumulus with accumulation-mode aerosol and cloud droplet concentrations exceeding 200 cm−3. Far offshore, the boundary layer depth is typically deeper (1600 m) and more variable, and the vertical structure is usually decoupled. The offshore stratocumulus typically have strong mesoscale organization, much higher peak liquid water paths, extensive drizzle, and cloud droplet concentrations below 100 cm−3, sometimes with embedded pockets of open cells with lower droplet concentrations. The lack of drizzle near the coast is not just a microphysical response to high droplet concentrations; smaller cloud depth and liquid water path than further offshore appear comparably important. Moist boundary layer air is heated and mixed up along the Andean slopes, then advected out over the top of the boundary layer above adjacent coastal ocean regions. Well offshore, the lower free troposphere is typically much drier. This promotes strong cloud-top radiative cooling and stronger turbulence in the clouds offshore. In conjunction with a slightly cooler free troposphere, this may promote stronger entrainment that maintains the deeper boundary layer seen offshore. Winds from ECMWF and NCEP operational analyses have an rms difference of only 1 m s−1 from collocated airborne leg-mean observations in the boundary layer and 2 m s−1 above the boundary layer. This supports the use of trajectory analysis for interpreting REx observations. Two-day back-trajectories from the 20° S transect suggest that eastward of 75° W, boundary layer (and often free-tropospheric) air has usually been exposed to South American coastal aerosol sources, while at 85° W, neither boundary-layer or free-tropospheric air has typically had such contact.

Meteorological study for Gangotri Glacier and its comparison with other high altitude meteorological stations in central Himalayan region

2007 ◽  
Vol 38 (1) ◽  
pp. 59-77 ◽  
Author(s):  
Pratap Singh ◽  
Umesh K. Haritashya ◽  
Naresh Kumar
Keyword(s):  
High Altitude ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Meteorological Station ◽  
Himalayan Region ◽  
Valley Wind ◽  
Maximum Rainfall ◽  
Garhwal Himalayas ◽  
Wind Speeds ◽  
Gangotri Glacier

In spite of the vital role of high altitude climatology in melting of snow and glaciers, retreat or advancement of glaciers, flash floods, erosion and sediment transport, etc., weather conditions are not much studied for the high altitude regions of Himalayas. In this study, a comprehensive meteorological analysis has been made for the Gangotri Meteorological Station (Bhagirathi Valley, Garhwal Himalayas) using data observed for four consecutive melt seasons (2000–2003) covering a period from May to October for each year. The collected meteorological data includes rainfall, temperature, wind speed and direction, relative humidity, sunshine hours and evaporation. The results and their distribution over the different melt seasons were compared with available meteorological records for Dokriani Meteorological Station (Dingad Valley, Garhwal Himalayas) and Pyramid Meteorological Station (Khumbu Valley, Nepal Himalayas). The magnitude and distribution of temperature were found to be similar for different Himalayan regions, while rainfall varied from region to region. The influence of the monsoon was meagre on the rainfall in these areas. July was recorded to be the warmest month for all the regions and, in general, August had the maximum rainfall. For all the stations, daytime up-valley wind speeds were 3 to 4 times stronger than the nighttime down-valley wind speeds. It was found that the Gangotri Glacier area experienced relatively low humidity and high evaporation rates as compared to other parts of the Himalayas. Such analysis reveals the broad meteorological characteristics of the high altitude areas of the Central Himalayan region.

scholarly journals Seed production of lemon balm and the quality of its seeds in the middle of the Volga region

2019 ◽  
pp. 34-36
Author(s):  
Ilya Alexandrovich Khapugin
Keyword(s):  
Seed Production ◽  
Weather Conditions ◽  
Mineral Fertilizers ◽  
Small Scale ◽  
Melissa Officinalis ◽  
Seed Productivity ◽  
Lemon Balm ◽  
Maximum Productivity ◽  
Scale Experiment

The influence of mineral fertilizers on seed productivity and quality of obtained seeds of lemon balm (Melissa officinalis L.) was studied in the field small-scale experiment under conditions of unstable moistening of the Mordovia Republic. As a result, it was found that seed productivity varied depending on weather conditions and the types of fertilizers introduced. It was shown that the maximum productivity of Melissa officinalis plants was on the variant with the use of phosphorus-potassium fertilizers at a dose of P60K90 (71.2±78.5 g/m2 in 2017 and 48.8±4.3 g/m2 in 2018), while it exceeded the control variant by 74-91 %. The total germination of seeds of Melissa officinalis practically did not change over the years, and was in the range of 37-39 %. Separation of seeds according to the degree of aging allowed to increase germination 11.4-13.3 %.  

Improving Unpaved Roads in Virginia: Case Study

2003 ◽  
Vol 1819 (1) ◽  
pp. 149-154
Author(s):  
Michael W. Dunn ◽  
S. Noelle On
Keyword(s):  
Cost Effective ◽  
Weather Conditions ◽  
Small Scale ◽  
Elected Officials ◽  
Unpaved Roads ◽  
The Road ◽  
Improvement Process ◽  
Key Factor ◽  
Low Volume ◽  
Virginia Department

Minimizing costs and streamlining the construction of low-volume roads offers an opportunity for transportation agencies to effectively meet the needs of rural citizens. The Virginia Department of Transportation (VDOT) maintains approximately 56,941 mi of the state’s roads, including Interstate, primary, and secondary facilities. Between 1987 and 1994, VDOT paved nearly 1,900 mi of unpaved roads. In rural parts of the state, many miles of state-maintained roads still have gravel and dirt surfaces. Each year the local transportation residency offices, in conjunction with local elected officials, contractors, and area citizens, strive to improve and pave as many miles of gravel and dirt roads as possible. The Hillsville Residency of VDOT, located in rural Carroll and Floyd Counties, has developed an efficient and cost-effective method for improving low-volume gravel and dirt roads. This process relies heavily on cooperative efforts by VDOT, contractors, elected officials, and especially citizens. Land donations from citizens represent the cornerstone of this process, signifying that citizen cooperation is the key factor in a project’s success. Because most of the decisions in the improvement process are at the local residency level, trusting relationships and frequent communication can be established, small-scale and local contractors are given more business opportunities, and local VDOT personnel can better understand citizen concerns and perform road improvements accordingly. In addition, the time line for the road improvement process is based on seasons—the most appropriate weather conditions are considered for the work being performed. This program enables more roads to be paved each year, improving the level of service and quality of life for local citizens.

scholarly journals Evidence of the complexity of aerosol transport in the lower troposphere on the Namibian coast during AEROCLO-sA

2019 ◽  
Vol 19 (23) ◽  
pp. 14979-15005
Author(s):  
Patrick Chazette ◽  
Cyrille Flamant ◽  
Julien Totems ◽  
Marco Gaetani ◽  
Gwendoline Smith ◽  
...  
Keyword(s):  
Sea Level ◽  
Southern Africa ◽  
Optical Thickness ◽  
Aerosol Optical Thickness ◽  
Back Trajectory ◽  
Aerosol Layer ◽  
Free Troposphere ◽  
Aerosol Composition ◽  
Mean Sea Level ◽  
Field Campaign

Abstract. The evolution of the vertical distribution and optical properties of aerosols in the free troposphere, above stratocumulus, is characterized for the first time over the Namibian coast, a region where uncertainties on aerosol–cloud coupling in climate simulations are significant. We show the high variability of atmospheric aerosol composition in the lower and middle troposphere during the Aerosols, Radiation and Clouds in southern Africa (AEROCLO-sA) field campaign (22 August–12 September 2017) around the Henties Bay supersite using a combination of ground-based, airborne and space-borne lidar measurements. Three distinct periods of 4 to 7 d are observed, associated with increasing aerosol loads (aerosol optical thickness at 550 nm ranging from ∼0.2 to ∼0.7), as well as increasing lofted aerosol layer depth and top altitude. Aerosols are observed up to 6 km above mean sea level during the later period. Aerosols transported within the free troposphere are mainly polluted dust (predominantly dust mixed with smoke from fires) for the first two periods (22 August–1 September 2017) and smoke for the last part (3–9 September) of the field campaign. As shown by Lagrangian back-trajectory analyses, the main contribution to the aerosol optical thickness over Henties Bay is shown to be due to biomass burning over Angola. Nevertheless, in early September, the highest aerosol layers (between 5 and 6 km above mean sea level) seem to come from South America (southern Brazil, Argentina and Uruguay) and reach Henties Bay after 3 to 6 d. Aerosols appear to be transported eastward by the midlatitude westerlies and towards southern Africa by the equatorward moving cut-off low originating from within the westerlies. All the observations show a very complex mixture of aerosols over the coastal regions of Namibia that must be taken into account when investigating aerosol radiative effects above stratocumulus clouds in the southeast Atlantic Ocean.

scholarly journals Evidence of the complexity of aerosol transport in the lower troposphere on the Namibian coast during AEROCLO-sA

2019 ◽  
Author(s):  
Patrick Chazette ◽  
Cyrille Flamant ◽  
Julien Totems ◽  
Marco Gaetani ◽  
Gwendoline Smith ◽  
...  
Keyword(s):  
South America ◽  
Sea Level ◽  
Complex Mixture ◽  
Lower Troposphere ◽  
Back Trajectory ◽  
Aerosol Layer ◽  
Free Troposphere ◽  
Aerosol Composition ◽  
Mean Sea Level ◽  
Field Campaign

Abstract. The evolution of the vertical distribution and optical properties of aerosols in the free troposphere, above stratocumulus, is analysed for the first time over the Namibian coast, a region where uncertainties on aerosol-cloud coupling in climate simulations are significant. We show the high variability of atmospheric aerosol composition in the lower and middle troposphere during the AEROCLO-sA field campaign (22 August–12 September 2017) around the Henties Bay supersite, using a combination of ground-based, airborne and space-borne lidar measurements. Three distinct periods of 4 to 7 days are observed, associated with increasing aerosol loads (aerosol optical thickness at 550 nm ranging from ~ 0.2 to ~ 0.7), as well as increasing aerosol layer depth and top altitude. Aerosols are observed up to 6 km above mean sea level during the later period. Aerosols transported within the free troposphere are mainly polluted dust (dust mixed with smoke from fires in Angola) for the first 2 periods (22 August–1 September 2017) and smoke (from Angola and South America) for the last part (3–9 September) of the field campaign. Lagrangian back trajectory analyses highlight that the highest aerosol layers (between 5 and 6 km above mean sea level) come from South America (Brazil, Argentina and Paraguay) and reach Henties Bay after 4 to 5 days. They are transported eastward by the mid latitude westerlies and towards Southern Africa by the equatorward moving cut-off low originating within the westerlies. This results in a very complex mixture of aerosols over the coastal regions of Namibia that must be taken into account when investigating aerosols radiative effects above stratocumulus clouds in the south east Atlantic Ocean.

scholarly journals O, H and C isotopic systematics of Icelandic groundwater

2019 ◽  
Vol 98 ◽  
pp. 07031
Author(s):  
Arny E. Sveinbjörnsdóttir ◽  
Andri Stefánsson ◽  
Jan Heinemeier
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopes ◽  
Upper Mantle ◽  
Lower Crust ◽  
Natural Waters ◽  
Large Range ◽  
Carbon Sources ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Range Of Values

Stable water isotopes of oxygen and hydrogen have been studied in Icelandic natural waters since 1960 for hydrological and geothermal research. All the waters are of meteoric and seawater origin. The measured range in δD and δ18O is large -131 to +3.3‰ and -20.8 to +2.3‰ respectively. Some of the waters are more depleted than any present-day precipitation suggesting a pre-Holocene component in the groundwater. Carbon isotopes of streams, rivers, soil and groundwater have been studied since 1990 in order to evaluate the carbon sources and reactions that possibly influence the carbon systematics of the water. Results show large range of values, for δ13CDIC -27.4 to +4.5‰ and for 14CDIC +0.6 to +118 pMC. Apart from atmospheric, organic and rock leaching, input of gas at depth with similar isotopic composition as the pre-erupted melt of the upper mantle and lower crust beneath Iceland have been identified as sources for carbon in the deeper groundwater.

scholarly journals Geological interpretation of the cosmic materials from the South of Western Siberia in connection with the petroleum potential of the sedimentary cover

2020 ◽  
Vol 149 ◽  
pp. 02007
Author(s):  
Andrew Belonosov ◽  
Anton Kudryavtsev ◽  
Sergey Sheshukov ◽  
Dmitry Borisov
Keyword(s):  
Western Siberia ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Thermal Inertia ◽  
Far Infrared ◽  
Weather Conditions ◽  
Gas Condensate ◽  
Small Scale ◽  
The South ◽  
Geological Interpretation

In the South of Western Siberia oil-perspectivity Jurassic deposits are characterized by multi – and small-scale. The interpretation of earth remote sensing materials in the visible, near and far infrared ranges allowed to evaluate the oil potential of numerous domes and depressions on the basis of combining geodynamically stressed zones and calculating the physical characteristics of the earth's surface (albedo, radiation coefficient, thermal inertia, convective heat flow, daily evaporation of moisture, DEM, weather conditions, etc.), including the procedure of reference classification, where the standards are the nearest oil and gas condensate fields. The forecast boundary of “oil and gas condensate” lands of the South of Western Siberia is displaced to the latitude of u.v. Lebyazhye of the Eastern part of the Kurgan region.

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