scholarly journals Spatio-temporal variations of dissolved inorganic carbon and its isotopes in river-reservoir continuum: A case study on Yunnan Section of the Lancang River

2020 ◽  
Vol 32 (1) ◽  
pp. 173-186
Author(s):  
YUAN Bo ◽  
◽  
WU Wei ◽  
GUO Mengjing ◽  
ZHOU Xiaode ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Temporal Variations ◽  
Lancang River ◽  
River Reservoir ◽  
Spatio Temporal

scholarly journals Groundwater data improve modelling of headwater stream CO<sub>2</sub> outgassing with a stable DIC isotope approach

2017 ◽  
Author(s):  
Anne Marx ◽  
Marcus Conrad ◽  
Vadym Aizinger ◽  
Alexander Prechtel ◽  
Robert van Geldern ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stream Water ◽  
Temporal Variations ◽  
Headwater Stream ◽  
Integral Approach ◽  
Gas Transfer ◽  
Transfer Velocity ◽  
Outgassing Rate ◽  
Carbon Dioxide Co2

Abstract. A large portion of terrestrially-derived carbon outgasses as carbon dioxide (CO2) from streams and rivers to the atmosphere. Particularly, the amount of CO2 outgassing from small headwater streams was indicated as highly uncertain. Conservative estimates suggest that they contribute 36 % (i.e., 0.93 petagrams C yr−1) of total CO2 outgassing from all rivers and streams worldwide. In this study, stream pCO2, dissolved inorganic carbon (DIC) and δ13CDIC data were used to determine CO2 outgassing from an acidic headwater stream in the Uhlirska catchment (Czech Republic). This stream drains a catchment with silicate bedrock. The applied stable isotope model is based on the principle, that the 13C / 12C ratio of its sources and the intensity of CO2 outgassing control the isotope ratio of DIC in stream water. It avoids the use of the gas transfer velocity parameter (k) that is highly variable and mostly difficult to constrain. Model results indicate that CO2 outgassing contributed 80 % to the annual stream inorganic carbon loss in the Uhlirska catchment. This translated to a CO2 outgassing rate from the stream of 5.2 t C yr−1 and to 2.9 g C m−2 yr−1, when normalised to the catchment area. Large temporal variations with maximum values during spring snowmelt and summer emphasise the need for investigations at higher temporal resolution. We improved the model uncertainty by incorporating groundwater data to better constrain the isotope compositions of initial DIC. Due to the large global abundance of acidic, humic-rich headwaters, we underline the importance of this integral approach for global applications.

Are non-loricate ciliates a primary contributor to ecological pattern of planktonic ciliate communities? A case study in Jiaozhou Bay, northern China

2012 ◽  
Vol 92 (6) ◽  
pp. 1301-1308 ◽  
Author(s):  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
Henglong Xu
Keyword(s):  
Jiaozhou Bay ◽  
Northern China ◽  
Temporal Variations ◽  
Species Number ◽  
Protozoan Community ◽  
Planktonic Ciliate ◽  
Spatio Temporal ◽  
Soluble Reactive Phosphorous ◽  
Ecological Pattern

The contribution of non-loricate ciliate assemblage to the ecological pattern of a ciliated protozoan community was studied based on a 1-year (June 2007–May 2008) dataset collected from Jiaozhou Bay, northern China. Samples were collected biweekly from five sampling sites. Results showed that: (1) the non-loricate ciliate assemblages were the primary components and significantly correlated with the total ciliate communities in terms of species number, abundance and biomass; (2) the ecological pattern of non-loricate ciliate assemblages was significantly related to that of both total ciliate communities and variations in environmental variables; and (3) spatio-temporal variations in biodiversity (richness, diversity and evenness of species) indices of non-loricate ciliate assemblages were significantly correlated with those of total ciliate communities and the environmental conditions, especially nutrients nitrate nitrogen, nitrite nitrogen and soluble reactive phosphorous. These results suggest that the non-loricate ciliates are a primary contributor to the ecological pattern of total ciliate communities and might be used as a potential bioindicator for bioassessment in marine ecosystems.

scholarly journals Spatio-temporal variability of the CO<sub>2</sub> system on the Scotian Shelf

2011 ◽  
Vol 8 (6) ◽  
pp. 12013-12050 ◽  
Author(s):  
E. H. Shadwick ◽  
H. Thomas ◽  
A. E. F. Prowe ◽  
E. Horne
Keyword(s):  
Temporal Variability ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Large Fraction ◽  
Monitoring Program ◽  
Total Alkalinity ◽  
Surface Mixed Layer ◽  
Scotian Shelf ◽  
Lawrence Estuary ◽  
Spatio Temporal

Abstract. Relative to their surface areas, coastal oceans and continental shelves host a disproportionately large fraction of ocean productivity. The Scotian Shelf is a biologically productive coastal region of the Northwestern Atlantic Ocean. This subpolar region is influenced by the outflow of the St. Lawrence Estuary system and acts as an annual source for atmospheric CO2. As part of the Atlantic Zone Monitoring Program, dissolved inorganic carbon (DIC), total alkalinity, and surface CO2 partial pressure measurements were made throughout the Scotian Shelf in 2007. A shelf-wide assessment of the spatio-temporal variability of the inorganic carbon system was made relying on observations in April and September. Between these periods, biological production results in a significant drawdown of inorganic nutrients and DIC in the surface mixed-layer, while hydrographic controls also influence seasonal changes in DIC. Net community production (NCP) over the spring and summer seasons was estimated on the basis of inorganic carbon data. We find significant spatial variability in NCP with the largest values in the Southwestern Browns Bank region and a general trend of increasing NCP with distance offshore. A bulk seasonal carbon budget suggests that along-shore and cross-shelf transport may result in the export of subsurface DIC from this region.

δ pattern of dissolved inorganic carbon in a small granitic catchment: the Strengbach case study (Vosges mountains, France)

1999 ◽  
Vol 159 (1-4) ◽  
pp. 129-145 ◽  
Author(s):  
P. Amiotte-Suchet ◽  
D. Aubert ◽  
J.L. Probst ◽  
F. Gauthier-Lafaye ◽  
A. Probst ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Vosges Mountains

scholarly journals H<sub>2</sub><sup>16</sup>O and HDO measurements with IASI/MetOp

2009 ◽  
Vol 9 (2) ◽  
pp. 9267-9290 ◽  
Author(s):  
H. Herbin ◽  
D. Hurtmans ◽  
C. Clerbaux ◽  
L. Clarisse ◽  
P.-F. Coheur
Keyword(s):  
Water Vapour ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Temporal Variations ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Inversion Procedure ◽  
Spatio Temporal ◽  
The Vertical Distribution

Abstract. In this paper we analyze distributions of water vapour isotopologues in the troposphere using infrared spectra recorded by the Infrared Atmospheric Sounding Interferometer (IASI), which operates onboard the Metop satellite in nadir geometry. The simultaneous uncorrelated retrieval of H216O and HDO was performed on radiance measurements using a line-by-line radiative transfer model and an inversion procedure based on the Optimal Estimation Method (OEM). The characterizations of the retrieved products in terms of vertical sensitivity and error budgets show that IASI measurements contain up to 6 independent pieces of information on the vertical distribution of H216O and up to 3.5 for HDO from the surface up to the upper troposphere (0–20 km). The H216O retrieved profiles are in good agreement with local sonde measurements at different latitudes during different times of the year. Our results demonstrate the ability of the IASI instrument to monitor atmospheric isotopologic water vapour distributions with unprecedented sensitivity. As a case study, we analyse concentration distributions and spatio-temporal variations of H216O and HDO during the October 2007 Krosa super-typhoon over South-East Asia and show with this example the IASI potential to capture variations in the HDO/H216O isotopologic ratio values over space and time.

Sign in / Sign up

Export Citation Format

Share Document