AYSENUR BICER Dr. Hans Schuessler

Why scientists examine ocean water ?

Outline How to get gas from natural sources  A moored autonomous system  Robust Sensor  Headspace analysis  Membrane gas separator Which technique to analyze the data Experimental results

At the beginning of each cycle, the system generates a zero standard by cycling a closed loop of air to remove all of the CO2 Next, the system is calibrated with a high standard reference gas, or “span "gas. The gas flows through the detector for CO2 analysis and is vented to the atmosphere through the air block. Once the detector is fully flushed, the flow is stopped and the system returns to atmospheric pressure. A high-frequency atmospheric and seawater pCO2 data set from 14 open-ocean sites using a moored autonomous system A. J. Sutton, C.L. Sabine, Earth System Science Data, A high-frequency atmospheric and seawater pCO2 dataset from 14 open-ocean sites using a moored autonomous system

h-shaped equilibrator, which is mounted in a float designed to ensure the optimum depth for equilibration. The air cycles through the system by pumping air out of flexible tubing. While the air bubbles through the column of water, the air comes into equilibrium with the dissolved gases in the surface seawater. This air then returns to the system, passing through a silica gel drying agent The air then circulates through the equilibrator again. The rising air bubbles in the equilibrator create seawater circulation in the equilibrator by pushing the water up and over the horizontal leg of the equilibrator and out the short leg of the equilibrator. This draws new water into the long leg of the equilibrator, ensuring that the recirculated air is always in contact with new seawater. A. J. Sutton, C.L. Sabine, Earth System Science Data, A high-frequency atmospheric and seawater pCO2 dataset from 14 open-ocean sites using a moored autonomous system

Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

For the zero calibration, air inside the system is recirculated in the Zero Loop Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

For the high xCO2 calibration, a compressed calibration gas is flushed through the LI-820 optical chamber in the Span Pathway Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

Air inside the instrument that was previously stripped of CO2 is bubbled through the acidified mixture and recirculated in the Equilibration Loop for ∼ 5 min to facilitate the transfer of CO2 from the liquid into the gas phase. Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

The acidified sample is then ejected from the equilibration chamber through the Evacuation Pathway Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

Calculation of DIC The sample DIC concentration is calculated by summing the number of moles of CO2 in the gas and liquid phases at equilibrium and dividing by the mass of the injected sample. Fugacity Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science

Determination of dissolved methane in natural waters using headspace analysis with cavity ring-down spectroscopy

Steps for headspace gas connections Add small amount of air into syringe while it is upright then the air and water expelled. Fill the syringe 70 ml of sample. 70 ml a volume of methane free zero air add to sample Disconnect from cylinder of zero air Open 3 way valve for pressure equilibrium within sample syringe Place the sample in a shaker table for 30 minutes Use a little head space gas to rinse pathway between two syringes Transfer the headspace to other syringe The head space was drown into the Picarro CRDS analyzer by pump. Hannah M. Roberts, Alan M. Shiller, Determination of dissolved methane in natural waters using headspace analysis with cavity ring-down spectroscopy, Analytica Chimica Acta

Membrane gas separator gas separation from liquid with a hollow fiber porous membrane James Bound’s set up

Reservoir Pump Filter Vacuum Pump Water Bypass Flow Controller Hollow Fiber membrane TC Vacuum Gauge Gas Cylinder Water Pump Sample ReturnSample Input Vacuum Pump PressureGauge Exhaust Gas output for Analysis James Bound’s set up

Cavity Ring-down Spectroscopy

Ocean water mix with air Pressure is 140 Torr

Sources A. J. Sutton, C.L. Sabine, Earth System Science Data, A high-frequency atmospheric and seawater pCO2 dataset from 14 open-ocean sites using a moored autonomous system, Hannah M. Roberts, Alan M. Shiller, Determination of dissolved methane in natural waters using headspace analysis with cavity ring-down spectroscopy, Analytica Chimica Acta Robust Sensor for Extended Autonomous Measurements of Surface Ocean Dissolved Inorganic Carbon, Andrea J. Fassbender,*,†, ∥ Christopher L. Sabine,‡ Noah Lawrence-Slavas,‡ Eric H. De Carlo,§ Christian Meinig,‡ and Stacy Maenner Jones‡, Environmental Science