HIPPO-1 MAGICC Trace Gas Concentrations with Merged 10-second Data

In order to assess the limits and applicability of Pitot tubes for the measurement of flow velocity in narrow ducts, e.g., biomass burning plants, an optical, dual function device was implemented. This sensor, based on spectroscopic techniques, targets a trace gas, injected inside the stack either in bursts, or continuously, so performing transit time or dilution measurements. A comparison of the two optical techniques with respect to Pitot readings was carried out in different flow conditions (speed, temperature, gas composition). The results of the two optical measurements are in agreement with each other and fit quite well the theoretical simulation of the flow field, while the results of the Pitot measurements show a remarkable dependence on position and inclination of the Pitot tube with respect to the duct axis. The implications for the metrology of small combustors’ emissions are outlined.

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Advances in fiber‐based quartz enhanced photoacoustic spectroscopy for trace gas sensing

Microwave and Optical Technology Letters ◽

10.1002/mop.32841 ◽

2021 ◽

Author(s):

Wei Feng ◽

Yanchen Qu ◽

Yachen Gao ◽

Yufei Ma

Keyword(s):

Photoacoustic Spectroscopy ◽

Gas Sensing ◽

Trace Gas ◽

Trace Gas Sensing

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The Influence of Ocean Acidification and Warming on DMSP & DMS in New Zealand Coastal Water

Atmosphere ◽

10.3390/atmos12020181 ◽

2021 ◽

Vol 12 (2) ◽

pp. 181

Author(s):

Alexia D. Saint-Macary ◽

Neill Barr ◽

Evelyn Armstrong ◽

Karl Safi ◽

Andrew Marriner ◽

...

Keyword(s):

Ocean Acidification ◽

Coastal Water ◽

Phytoplankton Community ◽

Dimethyl Sulfide ◽

Temperature Treatment ◽

Low Ph ◽

Trace Gas ◽

Mesocosm Experiments ◽

Future Warming ◽

Higher Temperature

The cycling of the trace gas dimethyl sulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) may be affected by future ocean acidification and warming. DMSP and DMS concentrations were monitored over 20-days in four mesocosm experiments in which the temperature and pH of coastal water were manipulated to projected values for the year 2100 and 2150. This had no effect on DMSP in the two-initial nutrient-depleted experiments; however, in the two nutrient-amended experiments, warmer temperature combined with lower pH had a more significant effect on DMSP & DMS concentrations than lower pH alone. Overall, this indicates that future warming may have greater influence on DMS production than ocean acidification. The observed reduction in DMSP at warmer temperatures was associated with changes in phytoplankton community and in particular with small flagellate biomass. A small decrease in DMS concentration was measured in the treatments relative to other studies, from −2% in the nutrient-amended low pH treatment to −16% in the year 2150 pH and temperature conditions. Temporal variation was also observed with DMS concentration increasing earlier in the higher temperature treatment. Nutrient availability and community composition should be considered in models of future DMS.

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