This study measured CO2 fluxes and water turbulence in Jade Bay, Germany during winter to better understand how these parameters influence air-sea CO2 exchange. Researchers used a floating chamber method and infrared gas analyzer to measure the gas transfer velocity (k) and acoustic instruments to measure turbulent kinetic energy (TKE). Preliminary results found only a weak correlation between wind speed and TKE, and no significant correlation between wind speed and k. Further analysis will test for correlations between k and TKE and compare different instruments' TKE measurements, to improve models of air-sea CO2 flux.

1. Marine interfaces:
The relationship between
CO2 fluxes and turbulence
Measurements of the air-sea CO2 gas
transfer velocity and water turbulence
in winter Jade Bay
Mariana Ribas-Ribas, Leonie Esters,
Hannes Veerkamp, Carola Lehners
Institute for Chemistry and Biology of the Marine
Environment, University of Oldenburg

2. Objectives
 Getting a better
understanding of parameters
influencing air-sea CO2 flux
 Air-sea CO2 fluxes play
important role for climate
predictions
 Quantify influence of water
turbulence
 Improve parametrizations and
models describing air-sea CO2
flux
© Leonie Esters

3. Study area
Wilhelmshaven
Jade Bay
Hamburg
Bremen
North Sea

4. The Sniffle buoy
 Possibility to measure current speeds and air-sea gas transfer
simultaneously

5. Turbulent kinetic energy TKE
 Measuring of current speeds to
calculate TKE
 Point measurements: 2 Acoustic
Doppler velocimeters (ADV)
 Profile: 2 Acoustic Doppler current
profilers (ADCP)

6. Gas transfer
velocity k
 Floating chamber method
 Tube system connected to
infrared gas analyzer
(IRGA)
 Measures partial pressure
of carbon dioxide pCO2 in
water, atmosphere and
inside the chamber

7. Sequence of pCO2 measurements and
calculation of k
 Calculation of flux:
𝐹𝐶𝑂2
=
𝑑𝑝𝐶𝑂2
𝑑𝑡
𝑉
𝑆 𝑇 𝑅
 Calculation of gas transfer
velocity:
𝑘𝐶𝑂2
=
𝐹𝐶𝑂2
𝐾(𝑝𝐶𝑂2 𝑤𝑎𝑡𝑒𝑟 − 𝑝𝐶𝑂2 𝑎𝑖𝑟)
1. Water
2. Atmosphere
3. Floating chamber
V: Volume of floating chamber (FC)
S: Surface of FC R: Gas constant
T: Water temperature K: CO2 solubility

8. Results – Comparison with wind speeds
R² = 0.22
TKE – Data from ADVs kCO2

9. Conclusion and outlook
 Wind speed alone cannot
explain the differences in
magnitudes for TKE values for
the different days
 Also no significant correlation
between wind speed and gas
transfer velocity k could be
found
Further evaluations:
 Test for correlation between k
and TKE
 Compare TKE measurements
from ADVs to the ones from the
ADCPs
 Investigate other potential
influences on TKE and k, like
tides or surfactants