scholarly journals Stream Metabolism and Groundwater Discharge to Coastal Waters: Applications of the Eddy Correlation Technique

2013 ◽  
Author(s):  
Dirk Koopmans
Keyword(s):  
Coastal Waters ◽  
Groundwater Discharge ◽  
Eddy Correlation ◽  
Correlation Technique ◽  
Stream Metabolism ◽  
Eddy Correlation Technique

scholarly journals Oxygen exchange and ice melt measured at the ice-water interface by eddy correlation

2011 ◽  
Vol 8 (6) ◽  
pp. 11255-11284 ◽  
Author(s):  
M. H. Long ◽  
D. Koopmans ◽  
P. Berg ◽  
S. Rysgaard ◽  
R. N. Glud ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Eddy Correlation ◽  
Correlation Technique ◽  
Water Interface ◽  
Algal Communities ◽  
Ice Melt ◽  
Eddy Correlation Technique ◽  
Time Periods ◽  
Ice Water

Abstract. This study uses the eddy correlation technique to examine fluxes across the ice-water interface. Temperature eddy correlation systems were used to determine rates of ice melting and freezing, and O2 eddy correlation systems were used to examine O2 exchange rates as driven by biological and physical processes. The research was conducted below 0.7 m thick sea ice in mid March 2010 in a southwest Greenland fjord and revealed low average rates of ice melt amounting to a maximum of 0.80 ± 0.09 mm d−1 (SE, n=31). The corresponding calculated O2 flux associated with release of O2 depleted melt water was less than 13 % of the average daily O2 respiration rate. Ice melt and insufficient vertical turbulent mixing due to low current velocities caused periodic stratification immediately below the ice. This prevented the determination of fluxes during certain time periods, amounting to 66 % of total deployment time. The identification of these conditions was evaluated by examining the velocity and the linearity and stability of the cumulative flux. The examination of unstratified conditions through velocity and O2 spectra and their cospectra revealed characteristic fingerprints of well-developed turbulence. From the observed O2 fluxes, a photosynthesis/irradiance curve was established by least-squares fitting. This relation showed that light limitation of net photosynthesis began at 4.2 μmol photons m−2 s−1, and that the algal communities were well-adapted to low-light conditions as they were light saturated for 75 % of the day during this early spring period. However, the sea ice associated microbial and algal community was net heterotrophic with a daily gross primary production of 0.69 ± 0.02 mmol O2 m−2 d−1 (SE, n=4) and a respiration rate of −2.13 mmol O2 m−2 d−1 (no SE, see text for details) leading to a net primary production of −1.45 ± 0.02 mmol O2 m−2 d−1 (SE, n=4). Modeling the observed fluxes allowed for the calculation of fluxes during time periods when no O2 fluxes were extracted. This application of the eddy correlation technique produced high temporal resolution O2 fluxes and ice melt rates that were measured without disturbing the environmental conditions while integrating over a large area of approximately 50 m2 which encompassed the highly variable activity and spatial distributions of sea ice algal communities.

scholarly journals STUDIES ON SEASONAL VARIATION IN EVAPOTRANSPIRATION OVER WHEAT CROP USING EDDY CORRELATION TECHNIQUE

MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 101-102
Author(s):  
J. K. SARMAH ◽  
M. C. VARSHNEYA ◽  
T. R. V. NAIDU ◽  
A. S. JADHAV
Keyword(s):  
Seasonal Variation ◽  
Eddy Correlation ◽  
Wheat Crop ◽  
Correlation Technique ◽  
Eddy Correlation Technique
Sign in / Sign up

Export Citation Format

Share Document