The data describes net primary productivity data obtained from 14C-uptake standard 24h incubation... more The data describes net primary productivity data obtained from 14C-uptake standard 24h incubations during several cruises across the Southwest Pacific. The data spans 25 years (1993 - 2018) and includes measurements obtained in subantarctic and subtropical water masses and in the Subtropical Front that separates both. The dataset contains depth-resolved chlorophyll a concentration (mgChla/m³) and primary productivity measurements (mgC/m³/day) as well as areal chlorophyll a (mgChla/m²) and primary productivity (mgC/m²/day) calculated for the euphotic zone using trapezoidal integration. Environmental data including surface temperature, daily incident irradiance, attenuation coefficient and depth of the euphotic zone are provided when available
New Zealand Journal of Marine and Freshwater Research, 2015
Global Drifter Program (GDP) drifter data and Argo float data from 2006 to 2013 are used to provi... more Global Drifter Program (GDP) drifter data and Argo float data from 2006 to 2013 are used to provide quantitative description and comparison of the mean near-surface (15 m) and 1000 m velocity fields in the New Zealand region. These fields are estimated both from bin-averaging the drifter/float velocities and by fitting non-divergent streamfunctions to the velocities. At both levels, our velocity fields are broadly consistent with previous drifter/float estimates, but provide more detail on the local structure of the mean fields. North of the Subantarctic Front there are large differences between the surface and 1000 m flows, with the Tasman Front being largely absent at 1000 m. South of the Subantarctic Front, where the flow is expected to be more barotropic, there is a closer correspondence between the flows at both levels. Several previously undocumented eddies in the mean flows at both levels are described.
Observations from two research cruises made in 2008 and 2012 to east of New Zealand are put into ... more Observations from two research cruises made in 2008 and 2012 to east of New Zealand are put into context with satellite data to contrast and compare surface chlorophyll a evolution in the two years in order to explore mechanisms of phytoplankton bloom development in the southwest Pacific Ocean. In 2008, surface chlorophyll a largely followed the long-term climatological cycle, and 2008 can be considered a canonical year, where the autumn bloom is triggered by increasing vertical mixing at the end of summer and the spring bloom is triggered by decreasing vertical mixing at the end of winter. In contrast, 2012 was anomalous in that there was no autumn bloom, and in early spring there were several periods of sustained increase in surface chlorophyll a that did not become fully developed spring blooms. (In this region, we consider spring blooms to occur when surface chlorophyll a exceeds 0.5 mg m-3). These events can be related to alternating episodes of increased or decreased vertical ...
The Hawaii Ocean Time-series (HOT) project has been making repeated observations of the hydrograp... more The Hawaii Ocean Time-series (HOT) project has been making repeated observations of the hydrography, chemistry, and biology at a station north of Hawaii since October 1988, with the objective of describing the oceanography at a site representative of the central north Pacific Ocean. Cruises are made approximately once a month to the HOT deep-water station (22 ° 45'N, 158°W) located about 100 km north of Oahu, Hawaii. Measurements of the hydrography, water column chemistry, primary production, and particle sedimentation rates are made over three days. This document reports the data collected during 1990; however, we have included some data from 1988 and 1989 in order to place the data collected in 1990 within the context of our time-series observations. The data reported here are a screened subset of the complete data set. Summary plots are given for CTD, biogeochemical, optical, meteorological, and ADCP observations. In order to conserve paper and to provide easy computer acces...
When SST anomalies are defined with respect to a changing baseline and normalised by their 90th p... more When SST anomalies are defined with respect to a changing baseline and normalised by their 90th percentile, the Tasman Sea is one of the southern hemisphere hotspots of marine heat waves (MHW) and marine cool spells (MCS). There is little evidence that MHW or MCS are increasing in either frequency or intensity, although the duration of MHW has increased from 8 d four decades ago to 26 d now. On average, Tasman Sea MHW/MCS co-occur with MHW/MCS in the Atlantic, Indian, and eastern-Pacific Oceans, in a wavenumber 4 (W4) pattern. Canonical MHW and MCS show they are likely driven by a stalling of the eastward propagation of a W4 atmospheric wave. During MHW, this slow down leads to near-stationary anomalously high and low air pressure areas driving anomalous north-easterly winds over the Tasman Sea. During MCS, similar a slow-down occurs, but shifted by one-half wavelength zonally.
Marine heat waves (MHW) and cool spells (MCS) can both positively and negatively impact marine ec... more Marine heat waves (MHW) and cool spells (MCS) can both positively and negatively impact marine ecosystems with potentially large societal and economic impacts. Here, I examine the global teleconnections of MHW/MCS in the southern hemisphere and Tasman Sea. When MHW/MCS are defined with respect to a linear warming trend, there is little evidence that MHW in the Tasman Sea are changing in either frequency or intensity but may be lasting longer. MCS may be becoming weaker and less frequent. I show that MHW/MCS in the Tasman Sea co-occur with corresponding events in the Atlantic, Indian, and eastern-Pacific Oceans, and these southern hemisphere events are likely driven by stalling of a global wavenumber-4 (W4) atmospheric wave, leading to anomalously weak north-easterly winds during MHW or strong south-westerly winds during MCS. Thus, the key to predicting MHW/MCS is in understanding what causes the atmospheric W4 wave to stall.
The data describes net primary productivity data obtained from 14C-uptake standard 24h incubation... more The data describes net primary productivity data obtained from 14C-uptake standard 24h incubations during several cruises across the Southwest Pacific. The data spans 25 years (1993 - 2018) and includes measurements obtained in subantarctic and subtropical water masses and in the Subtropical Front that separates both. The dataset contains depth-resolved chlorophyll a concentration (mgChla/m³) and primary productivity measurements (mgC/m³/day) as well as areal chlorophyll a (mgChla/m²) and primary productivity (mgC/m²/day) calculated for the euphotic zone using trapezoidal integration. Environmental data including surface temperature, daily incident irradiance, attenuation coefficient and depth of the euphotic zone are provided when available
New Zealand Journal of Marine and Freshwater Research, 2015
Global Drifter Program (GDP) drifter data and Argo float data from 2006 to 2013 are used to provi... more Global Drifter Program (GDP) drifter data and Argo float data from 2006 to 2013 are used to provide quantitative description and comparison of the mean near-surface (15 m) and 1000 m velocity fields in the New Zealand region. These fields are estimated both from bin-averaging the drifter/float velocities and by fitting non-divergent streamfunctions to the velocities. At both levels, our velocity fields are broadly consistent with previous drifter/float estimates, but provide more detail on the local structure of the mean fields. North of the Subantarctic Front there are large differences between the surface and 1000 m flows, with the Tasman Front being largely absent at 1000 m. South of the Subantarctic Front, where the flow is expected to be more barotropic, there is a closer correspondence between the flows at both levels. Several previously undocumented eddies in the mean flows at both levels are described.
Observations from two research cruises made in 2008 and 2012 to east of New Zealand are put into ... more Observations from two research cruises made in 2008 and 2012 to east of New Zealand are put into context with satellite data to contrast and compare surface chlorophyll a evolution in the two years in order to explore mechanisms of phytoplankton bloom development in the southwest Pacific Ocean. In 2008, surface chlorophyll a largely followed the long-term climatological cycle, and 2008 can be considered a canonical year, where the autumn bloom is triggered by increasing vertical mixing at the end of summer and the spring bloom is triggered by decreasing vertical mixing at the end of winter. In contrast, 2012 was anomalous in that there was no autumn bloom, and in early spring there were several periods of sustained increase in surface chlorophyll a that did not become fully developed spring blooms. (In this region, we consider spring blooms to occur when surface chlorophyll a exceeds 0.5 mg m-3). These events can be related to alternating episodes of increased or decreased vertical ...
The Hawaii Ocean Time-series (HOT) project has been making repeated observations of the hydrograp... more The Hawaii Ocean Time-series (HOT) project has been making repeated observations of the hydrography, chemistry, and biology at a station north of Hawaii since October 1988, with the objective of describing the oceanography at a site representative of the central north Pacific Ocean. Cruises are made approximately once a month to the HOT deep-water station (22 ° 45'N, 158°W) located about 100 km north of Oahu, Hawaii. Measurements of the hydrography, water column chemistry, primary production, and particle sedimentation rates are made over three days. This document reports the data collected during 1990; however, we have included some data from 1988 and 1989 in order to place the data collected in 1990 within the context of our time-series observations. The data reported here are a screened subset of the complete data set. Summary plots are given for CTD, biogeochemical, optical, meteorological, and ADCP observations. In order to conserve paper and to provide easy computer acces...
When SST anomalies are defined with respect to a changing baseline and normalised by their 90th p... more When SST anomalies are defined with respect to a changing baseline and normalised by their 90th percentile, the Tasman Sea is one of the southern hemisphere hotspots of marine heat waves (MHW) and marine cool spells (MCS). There is little evidence that MHW or MCS are increasing in either frequency or intensity, although the duration of MHW has increased from 8 d four decades ago to 26 d now. On average, Tasman Sea MHW/MCS co-occur with MHW/MCS in the Atlantic, Indian, and eastern-Pacific Oceans, in a wavenumber 4 (W4) pattern. Canonical MHW and MCS show they are likely driven by a stalling of the eastward propagation of a W4 atmospheric wave. During MHW, this slow down leads to near-stationary anomalously high and low air pressure areas driving anomalous north-easterly winds over the Tasman Sea. During MCS, similar a slow-down occurs, but shifted by one-half wavelength zonally.
Marine heat waves (MHW) and cool spells (MCS) can both positively and negatively impact marine ec... more Marine heat waves (MHW) and cool spells (MCS) can both positively and negatively impact marine ecosystems with potentially large societal and economic impacts. Here, I examine the global teleconnections of MHW/MCS in the southern hemisphere and Tasman Sea. When MHW/MCS are defined with respect to a linear warming trend, there is little evidence that MHW in the Tasman Sea are changing in either frequency or intensity but may be lasting longer. MCS may be becoming weaker and less frequent. I show that MHW/MCS in the Tasman Sea co-occur with corresponding events in the Atlantic, Indian, and eastern-Pacific Oceans, and these southern hemisphere events are likely driven by stalling of a global wavenumber-4 (W4) atmospheric wave, leading to anomalously weak north-easterly winds during MHW or strong south-westerly winds during MCS. Thus, the key to predicting MHW/MCS is in understanding what causes the atmospheric W4 wave to stall.
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