ORCID Profile
0000-0002-5059-5271
Current Organisation
CSIRO
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Publisher: American Meteorological Society
Date: 08-2020
DOI: 10.1175/JTECH-D-20-0010.1
Abstract: Current carbon measurement strategies leave spatiotemporal gaps that hinder the scientific understanding of the oceanic carbon biogeochemical cycle. Data products and models are subject to bias because they rely on data that inadequately capture mesoscale spatiotemporal (kilometers and days to weeks) changes. High-resolution measurement strategies need to be implemented to adequately evaluate the global ocean carbon cycle. To augment the spatial and temporal coverage of ocean–atmosphere carbon measurements, an Autonomous Surface Vehicle CO 2 (ASVCO 2 ) system was developed. From 2011 to 2018, ASVCO 2 systems were deployed on seven Wave Glider and Saildrone missions along the U.S. Pacific and Australia’s Tasmanian coastlines and in the tropical Pacific Ocean to evaluate the viability of the sensors and their applicability to carbon cycle research. Here we illustrate that the ASVCO 2 systems are capable of long-term oceanic deployment and robust collection of air and seawater p CO 2 within ±2 μ atm based on comparisons with established shipboard underway systems, with previously described Moored Autonomous p CO 2 (MAPCO 2 ) systems, and with companion ASVCO 2 systems deployed side by side.
Publisher: Springer Science and Business Media LLC
Date: 20-05-2019
DOI: 10.1038/S41598-019-44109-2
Abstract: To improve estimates of the long-term response of the marine carbon system to climate change a better understanding of the seasonal and interannual variability is needed. We use high-frequency multi-year data at three locations identified as climate change hotspots: two sites located close to South Pacific boundary currents and one in the Subantarctic Zone (SAZ). We investigate and identify the main drivers involved in the seasonal an interannual (2012–2016) variability of the carbon system. The seasonal variability at boundary current sites is temporally different and highly controlled by sea surface temperature. Advection processes also play a significant role on the monthly changes of the carbon system at the western boundary current site. The interannual variability at these sites most likely responds to long-term variability in oceanic circulation ultimately related to climatic indices such as the El Niño Southern Oscillation, the Pacific Decadal Oscillation and the Southern Annular Mode (SAM). In the SAZ, advection and entrainment processes drive most of the seasonality, augmented by the action of biological processes in spring. Given the relevance of advection and entrainment processes at SAZ, the interannual variability is most probably modulated by changes in the regional winds linked to the variability of the SAM.
Publisher: Springer Science and Business Media LLC
Date: 18-04-2008
Publisher: Optica Publishing Group
Date: 2008
DOI: 10.1364/OE.16.001405
Abstract: We propose and investigate a technique for generating smooth two-dimensional potentials for ultra-cold atoms based on the rapid scanning of a far-detuned laser beam using a two-dimensional acousto-optical modulator (AOM). We demonstrate the implementation of a feed-forward mechanism for fast and accurate control of the spatial intensity of the laser beam, resulting in improved homogeneity for the atom trap. This technique could be used to generate a smooth toroidal trap that would be useful for static and dynamic experiments on superfluidity and persistent currents with ultra-cold atoms.
Publisher: American Physical Society (APS)
Date: 21-03-2012
Publisher: CSIRO
Date: 2018
Publisher: American Physical Society (APS)
Date: 12-10-2009
Publisher: IEEE
Date: 10-2012
Publisher: American Physical Society (APS)
Date: 31-01-2011
Publisher: American Physical Society (APS)
Date: 02-06-2008
Publisher: Springer Science and Business Media LLC
Date: 07-2004
Publisher: Frontiers Media SA
Date: 24-01-2018
Publisher: AIP Publishing
Date: 2007
DOI: 10.1063/1.2424439
Abstract: We describe the setup to create a large Bose-Einstein condensate containing more than 120×106 atoms. In the experiment a thermal beam is slowed by a Zeeman slower and captured in a dark-spot magneto-optical trap (MOT). A typical dark-spot MOT in our experiments contains 2.0×1010 atoms with a temperature of 320μK and a density of about 1.0×1011atoms∕cm3. The s le is spin polarized in a high magnetic field before the atoms are loaded in the magnetic trap. Spin polarizing in a high magnetic field results in an increase in the transfer efficiency by a factor of 2 compared to experiments without spin polarizing. In the magnetic trap the cloud is cooled to degeneracy in 50s by evaporative cooling. To suppress the three-body losses at the end of the evaporation, the magnetic trap is decompressed in the axial direction.
Publisher: Springer Science and Business Media LLC
Date: 27-10-2020
DOI: 10.1038/S41598-020-75293-1
Abstract: Coral reefs are highly sensitive to ocean acidification due to rising atmospheric CO 2 concentrations. We present 10 years of data (2009–2019) on the long-term trends and sources of variation in the carbon chemistry from two fixed stations in the Australian Great Barrier Reef. Data from the subtropical mid-shelf GBRWIS comprised 3-h instrument records, and those from the tropical coastal NRSYON were monthly seawater s les. Both stations recorded significant variation in seawater CO 2 fugacity ( f CO 2 ), attributable to seasonal, daytime, temperature and salinity fluctuations. Superimposed over this variation, f CO 2 progressively increased by 2.0 ± 0.3 µatm year −1 at both stations. Seawater temperature and salinity also increased throughout the decade, whereas seawater pH and the saturation state of aragonite declined. The decadal upward f CO 2 trend remained significant in temperature- and salinity-normalised data. Indeed, annual f CO 2 minima are now higher than estimated f CO 2 maxima in the early 1960s, with mean f CO 2 now ~ 28% higher than 60 years ago. Our data indicate that carbonate dissolution from the seafloor is currently unable to buffer the Great Barrier Reef against ocean acidification. This is of great concern for the thousands of coral reefs and other erse marine ecosystems located in this vast continental shelf system.
Location: Australia
No related grants have been discovered for Erik van Ooijen.