scholarly journals Uncertainty and sensitivity in optode-based shelf-sea net community production estimates

2015 ◽  
Vol 12 (18) ◽  
pp. 15611-15654
Author(s):  
T. Hull ◽  
N. Greenwood ◽  
J. Kaiser ◽  
M. Johnson
Keyword(s):  
Open Source Software ◽  
Accurate Estimation ◽  
Net Community Production ◽  
Open Source Software Package ◽  
Shelf Sea ◽  
Shallow Area ◽  
Dynamic Regions ◽  
Vulnerable Habitats ◽  
Thames River ◽  
Community Production

Abstract. Coastal seas represent one of the most valuable and vulnerable habitats on Earth. Understanding biological productivity in these dynamic regions is vital to understanding how they may influence and be affected by climate change. A key metric to this end is net community production (NCP), the net effect of autotrophy and hetrotrophy, however accurate estimation of NCP has proved to be a difficult task. Presented here is a thorough exploration and sensitivity analysis of an oxygen mass-balance based NCP estimation technique applied to the Warp Anchorage monitoring station which is a permanently well mixed shallow area within the Thames river plume. We have developed an open source software package for calculating NCP estimates and air-sea gas flux. Our study site is identified as a region of net heteotrophy with strong seasonal variability. The annual cumulative net community oxygen production is calculated as (−5 ± 2.5) mol m−2 a−1. Short term daily variability in oxygen is demonstrated to make accurate individual daily estimates challenging. The effects of bubble induced supersaturation is shown to have a large influence on cumulative annual estimates, and is the source of much uncertainty.

scholarly journals Uncertainty and sensitivity in optode-based shelf-sea net community production estimates

2016 ◽  
Vol 13 (4) ◽  
pp. 943-959 ◽  
Author(s):  
Tom Hull ◽  
Naomi Greenwood ◽  
Jan Kaiser ◽  
Martin Johnson
Keyword(s):  
Open Source Software ◽  
Accurate Estimation ◽  
Net Community Production ◽  
Open Source Software Package ◽  
Shelf Sea ◽  
Shallow Area ◽  
Dynamic Regions ◽  
Vulnerable Habitats ◽  
Net Heterotrophy ◽  
Community Production

Abstract. Coastal seas represent one of the most valuable and vulnerable habitats on Earth. Understanding biological productivity in these dynamic regions is vital to understanding how they may influence and be affected by climate change. A key metric to this end is net community production (NCP), the net effect of autotrophy and heterotrophy; however accurate estimation of NCP has proved to be a difficult task. Presented here is a thorough exploration and sensitivity analysis of an oxygen mass-balance-based NCP estimation technique applied to the Warp Anchorage monitoring station, which is a permanently well-mixed shallow area within the River Thames plume. We have developed an open-source software package for calculating NCP estimates and air–sea gas flux. Our study site is identified as a region of net heterotrophy with strong seasonal variability. The annual cumulative net community oxygen production is calculated as (−5 ± 2.5) mol m−2 a−1. Short-term daily variability in oxygen is demonstrated to make accurate individual daily estimates challenging. The effects of bubble-induced supersaturation is shown to have a large influence on cumulative annual estimates and is the source of much uncertainty.

scholarly journals Simultaneous assessment of oxygen and nitrate-based net community production in a temperate shelf sea from a single ocean glider

2021 ◽  
Author(s):  
Tom Hull ◽  
Naomi Greenwood ◽  
Antony Birchill ◽  
Alexander Beaton ◽  
Mathew Palmer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Euphotic Zone ◽  
Global Scale ◽  
Net Community Production ◽  
Wide Range ◽  
Shelf Seas ◽  
Shelf Sea ◽  
Autonomous Underwater Glider ◽  
Community Production

Abstract. The continental shelf seas are important at a global scale for ecosystem services. These highly dynamic regions are under a wide range of stresses and as such future management requires appropriate monitoring measures. A key metric to understanding and predicting future change are the rates of biological productivity. We present here the use of a single autonomous underwater glider with oxygen (O2) and total oxidised nitrogen (NOx− = NO3− + NO2−) sensors during a spring bloom as part of a 2019 pilot autonomous shelf sea monitoring study. We find exceptionally high rates of net community production using both O2 and NOx− water column inventory changes, corrected for air-sea gas exchange in case of O2. We compare these rates with 2007 and 2008 mooring observations finding similar rates of NOx− consumption. With these complementary methods we determine the O:N amount ratio of the newly produced organic matter (7.8±0.4) and the overall O2:N ratio for the total water column (5.7±0.4). The former is close to the canonical Redfield O2:N ratio of 8.6±1.0, whereas the latter may be explained by a combination of new organic matter production and preferential remineralisation of more reduced organic matter at a higher O2:N ratio below the euphotic zone.

scholarly journals Simultaneous assessment of oxygen- and nitrate-based net community production in a temperate shelf sea from a single ocean glider

2021 ◽  
Vol 18 (23) ◽  
pp. 6167-6180
Author(s):  
Tom Hull ◽  
Naomi Greenwood ◽  
Antony Birchill ◽  
Alexander Beaton ◽  
Matthew Palmer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Euphotic Zone ◽  
Global Scale ◽  
Net Community Production ◽  
Wide Range ◽  
Shelf Seas ◽  
Shelf Sea ◽  
Autonomous Underwater Glider ◽  
Community Production

Abstract. The continental shelf seas are important at a global scale for ecosystem services. These highly dynamic regions are under a wide range of stresses, and as such future management requires appropriate monitoring measures. A key metric to understanding and predicting future change are the rates of biological production. We present here the use of an autonomous underwater glider with an oxygen (O2) and a wet-chemical microfluidic total oxidised nitrogen (NOx-=NO3-+NO2-) sensor during a spring bloom as part of a 2019 pilot autonomous shelf sea monitoring study. We find exceptionally high rates of net community production using both O2 and NOx- water column inventory changes, corrected for air–sea gas exchange in case of O2. We compare these rates with 2007 and 2008 mooring observations finding similar rates of NOx- consumption. With these complementary methods we determine the O2:N amount ratio of the newly produced organic matter (7.8 ± 0.4) and the overall O2:N ratio for the total water column (5.7 ± 0.4). The former is close to the canonical Redfield O2:N ratio of 8.6 ± 1.0, whereas the latter may be explained by a combination of new organic matter production and preferential remineralisation of more reduced organic matter at a higher O2:N ratio below the euphotic zone.

OnPoint: A package for online experiments in motor control and motor learning

2020 ◽  
Author(s):  
Jonathan Sanching Tsay ◽  
Alan S. Lee ◽  
Guy Avraham ◽  
Darius E. Parvin ◽  
Jeremy Ho ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Learning ◽  
Open Source Software ◽  
Research Progress ◽  
Global Pandemic ◽  
Large N ◽  
Open Source Software Package ◽  
Potential Applications ◽  
Temporal And Spatial ◽  
The One

Motor learning experiments are typically run in-person, exploiting finely calibrated setups (digitizing tablets, robotic manipulandum, full VR displays) that provide high temporal and spatial resolution. However, these experiments come at a cost, not limited to the one-time expense of purchasing equipment but also the substantial time devoted to recruiting participants and administering the experiment. Moreover, exceptional circumstances that limit in-person testing, such as a global pandemic, may halt research progress. These limitations of in-person motor learning research have motivated the design of OnPoint, an open-source software package for motor control and motor learning researchers. As with all online studies, OnPoint offers an opportunity to conduct large-N motor learning studies, with potential applications to do faster pilot testing, replicate previous findings, and conduct longitudinal studies (GitHub repository: https://github.com/alan-s-lee/OnPoint).

scholarly journals Integration of enabling methods for the automated flow preparation of piperazine-2-carboxamide

2014 ◽  
Vol 10 ◽  
pp. 641-652 ◽  
Author(s):  
Richard J Ingham ◽  
Claudio Battilocchio ◽  
Joel M Hawkins ◽  
Steven V Ley
Keyword(s):  
Open Source ◽  
Open Source Software ◽  
Software Package ◽  
Flow Chemistry ◽  
Raspberry Pi ◽  
Step Flow ◽  
Simultaneous Control ◽  
Open Source Software Package

Here we describe the use of a new open-source software package and a Raspberry Pi® computer for the simultaneous control of multiple flow chemistry devices and its application to a machine-assisted, multi-step flow preparation of pyrazine-2-carboxamide – a component of Rifater®, used in the treatment of tuberculosis – and its reduced derivative piperazine-2-carboxamide.

scholarly journals Benthic buffers and boosters of ocean acidification on coral reefs

2013 ◽  
Vol 10 (7) ◽  
pp. 4897-4909 ◽  
Author(s):  
K. R. N. Anthony ◽  
G. Diaz-Pulido ◽  
N. Verlinden ◽  
B. Tilbrook ◽  
A. J. Andersson
Keyword(s):  
Ocean Acidification ◽  
Benthic Communities ◽  
Time Of Day ◽  
High Flow ◽  
Net Community Production ◽  
Reef Environment ◽  
Saturation State ◽  
Low Co2 ◽  
Coral Reef Environment ◽  
Community Production

Abstract. Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (NCP) and calcification (NCC). Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia) contribute to changes in the seawater aragonite saturation state (Ωa). Results of flume studies using intact reef habitats (1.2 m by 0.4 m), showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm), macroalgae (Chnoospora implexa), turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm) and high flow (35 compared to 8 cm s−1). In contrast, branching corals (Acropora aspera) increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm) during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1) and exacerbated by acidification. Calcifying macroalgae (Halimeda spp.) raised Ωa by day (by around 0.13 h−1), but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from benthic communities with four different compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water-residence times in neighbouring areas dominated by turfs, macroalgae and carbonate sand.

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