scholarly journals Analysis of a 39-year continuous atmospheric CO<sub>2</sub> record from Baring Head, New Zealand

2013 ◽  
Vol 10 (4) ◽  
pp. 2683-2697 ◽  
Author(s):  
B. B. Stephens ◽  
G. W. Brailsford ◽  
A. J. Gomez ◽  
K. Riedel ◽  
S. E. Mikaloff Fletcher ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Seasonal Cycle ◽  
Southern Oscillation ◽  
Atmospheric Co2 ◽  
Co2 Uptake ◽  
South Pole ◽  
The South ◽  
Wide Range

Abstract. We present an analysis of a 39-year record of continuous atmospheric CO2 observations made at Baring Head, New Zealand, filtered for steady background CO2 mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO2 time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended episodes of strong southerly winds with low CO2 variability. The filtered Baring Head CO2 record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO2 fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO2 growth rate in the Baring Head record closely match the El Niño-Southern Oscillation, reflecting the global reach of CO2 mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO2 record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern Hemisphere fossil-fuel burning and Southern Ocean CO2 uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO2 uptake, as a result of increased zonal winds, is too small to be detectable as significant differences in atmospheric CO2 between mid to high latitude Southern Hemisphere observing stations.

scholarly journals Analysis of a 39-yr continuous atmospheric CO<sub>2</sub> record from Baring Head, New Zealand

2012 ◽  
Vol 9 (10) ◽  
pp. 15237-15277 ◽  
Author(s):  
B. B. Stephens ◽  
G. W. Brailsford ◽  
A. J. Gomez ◽  
K. Riedel ◽  
S. E. Mikaloff Fletcher ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Seasonal Cycle ◽  
Southern Oscillation ◽  
Atmospheric Co2 ◽  
Co2 Uptake ◽  
South Pole ◽  
The South ◽  
Wide Range

Abstract. We present an analysis of a 39-yr record of continuous atmospheric CO2 observations made at Baring Head, New Zealand, filtered for steady CO2 mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO2 time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended periods of strong southerly winds with low CO2 variability. The filtered Baring Head CO2 record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO2 fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO2 growth rate in the Baring Head record closely match the El Niño/Southern Oscillation, reflecting the global reach of CO2 mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO2 record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern-Hemisphere fossil-fuel burning and Southern Ocean CO2 uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO2 uptake as a result of increased zonal winds is too small to be detectable as significant differences in atmospheric CO2 between mid- to high-latitude Southern Hemisphere observing stations.

Surface erosion assessment in the South-Canterbury downlands, New Zealand using 137Cs distribution

Soil Research ◽  
1995 ◽  
Vol 33 (5) ◽  
pp. 787 ◽  
Author(s):  
LR Basher ◽  
KM Matthews ◽  
L Zhi
Keyword(s):  
New Zealand ◽  
Mean Value ◽  
Slope Position ◽  
Surface Erosion ◽  
The South ◽  
Erosion And Deposition ◽  
Erosion Rates ◽  
Land Use Types ◽  
Radionuclide Tracer

Redistribution of the radionuclide tracer 137Cs was used to examine the pattern of erosion and deposition at two sites with contrasting long-term land uses (pasture and cropping) in the South Canterbury downlands, New Zealand. There were clear differences between the two land use types in variation in 137Cs concentrations and areal activity, erosion rates and topsoil depth variability. Erosion and deposition have resulted in greater variability and lower mean levels of 137Cs areal activity under cropping (46.3 mBq cm-2) than pasture (55.0 mBq cm-2). At the cropping site, erosion and deposition roughly balanced with the mean value over all sampling sites, suggesting no net soil loss, but considerable redistribution of soil within paddocks. At the pasture site results suggested slight net deposition. There was evidence for both sheet/rill and wind erosion being important in soil redistribution. While there was no difference in mean topsoil depth between pasture and cropping, there were significant differences with slope position. At the pasture site, there was little variation of topsoil depth with slope position, except for swales which tended to be deeper, whereas at the cropping site there was considerable variation in topsoil depth with slope position. Topsoil depth was a poor indicator of erosion status.

scholarly journals Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand 1954–2014

2016 ◽  
Author(s):  
Jocelyn C. Turnbull ◽  
Sara E. Mikaloff Fletcher ◽  
India Ansell ◽  
Gordon Brailsford ◽  
Rowena Moss ◽  
...  
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Co2 Emissions ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Fossil Fuel ◽  
Anthropogenic Sources ◽  
Deep Waters ◽  
Cape Grim

Abstract. We present 60 years of Δ14CO2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest atmospheric Δ14CO2 record and records the rise of the 14C "bomb spike", the subsequent decline in Δ14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric Δ14CO2. The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport, and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, Northern Hemisphere clean air sites show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites show a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean. This developing Δ14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s, and suggests that upwelling of deep waters plays an important role in this change.

Oceanography of the New Zealand subantarctic region

2021 ◽  
Author(s):  
◽  
Aitana Forcén-Vázquez
Keyword(s):  
New Zealand ◽  
Interannual Variability ◽  
Water Column ◽  
Large Scale ◽  
Southern Oscillation ◽  
Complex Structure ◽  
Positive Trend ◽  
Intermediate Water ◽  
Subantarctic Region

<p>Subantarctic New Zealand is an oceanographycally dynamic region with the Subtropical Front (STF) to the north and the Subantarctic Front (SAF) to the south. This thesis investigates the ocean structure of the Campbell Plateau and the surrounding New Zealand subantarctic, including the spatial, seasonal, interannual and longer term variability over the ocean properties, and their connection to atmospheric variability using a combination of in-situ oceanographic measurements and remote sensing data.  The spatial and seasonal oceanographic structure in the New Zealand subantarctic region was investigated by analysing ten high resolution Conductivity Temperature and Depth (CTD) datasets, sampled during oceanographic cruises from May 1998 to February 2013. Position of fronts, water mass structure and changes over the seasons show a complex structure around the Campbell Plateau combining the influence of subtropical and subantarctic waters.  The spatial and interannual variability on the Campbell Plateau was described by analysing approximately 70 low resolution CTD profiles collected each year in December between 2002 and 2009. Conservative temperature and absolute salinity profiles reveal high variability in the upper 200m of the water column and a homogeneous water column from 200 to 600m depth. Temperature variability of about 0.7 °C, on occasions between consecutive years, is observed down to 900m depth. The presence of Subantarctic Mode Water (SAMW) on the Campbell Plateau is confirmed and Antarctic Intermediate Water (AAIW) reported for the first time in the deeper regions around the edges of the plateau.  Long-term trends and variability over the Campbell Plateau were investigated by analysing satellite derived Sea Level Anomalies (SLA) and Sea Surface Temperature (SST) time series. Links to large scale atmospheric processes are also explored through correlation with the Southern Oscillation Index (SOI) and Southern Annular Mode (SAM). SST shows a strong seasonality and interannual variability which is linked to local winds, but no significant trend is found. The SLA over the Campbell Plateau has increased at a rate of 5.2 cm decade⁻¹ in the last two decades. The strong positive trend in SLA appears to be a combination of the response of the ocean to wind stress curl (Ekman pumping), thermal expansion and ocean mass redistribution via advection amongst others.  These results suggest that the variability on the Campbell Plateau is influenced by the interaction of the STF and the SAF. The STF influence reaches the limit of the SAF over the western Campbell Plateau and the SAF influence extends all around the plateau. Results also suggest different connections between the plateau with the surrounding oceans, e.g., along the northern edge with the Bounty Trough and via the southwest edge with the SAF. A significant correlation with SOI and little correlation with SAM suggest a stronger response to tropically driven processes in the long-term variability on the Campbell Plateau.  The results of this thesis provide a new definitive assessment of the circulation, water masses and variability of the Campbell Plateau on mean, annual, and interannual time scales which will support research in other disciplines such as palaeoceanography, fisheries management and climate.</p>

The Southern Ocean carbon sink 1985-2018: first results of the RECCAP2 project

2021 ◽  
Author(s):  
Judith Hauck ◽  
Luke Gregor ◽  
Cara Nissen ◽  
Eric Mortenson ◽  
Seth Bushinsky ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Seasonal Cycle ◽  
Carbon Sink ◽  
Global Ocean ◽  
Biogeochemical Models ◽  
Wide Range ◽  
Data Products ◽  
First Results ◽  
Ocean Carbon ◽  
Indian Sector

&lt;p&gt;The Southern Ocean is the main gateway for anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; into the ocean owing to the upwelling of old water masses with low anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; concentration, and the transport of the newly equilibrated surface waters into the ocean interior through intermediate, deep and bottom water formation. Here we present first results of the Southern Ocean chapter of RECCAP2, which is the Global Carbon Project&amp;#8217;s second systematic study on Regional Carbon Cycle Assessment and Processes. In the Southern Ocean chapter, we aim to assess the Southern Ocean carbon sink 1985-2018 from a wide range of available models and data sets, and to identify patterns of regional and temporal variability, model limitations and future challenges.&lt;/p&gt;&lt;p&gt;We gathered global and regional estimates of the air-sea CO&lt;sub&gt;2&lt;/sub&gt; flux over the period 1985-2018 from global ocean biogeochemical models, surface pCO&lt;sub&gt;2&lt;/sub&gt;-based data products, and data-assimilated models. The analysis on the Southern Ocean quantified geographical patterns in the annual mean and seasonal amplitude of air-sea CO&lt;sub&gt;2&lt;/sub&gt; flux, with results presented here aggregated to the level of large-scale ocean biomes.&lt;/p&gt;&lt;p&gt;Considering the suite of observed and modelled estimates, we found that the subtropical seasonally stratified (STSS) biome stands out with the largest air-sea CO&lt;sub&gt;2&lt;/sub&gt; flux per area and a seasonal cycle with largest ocean uptake of CO&lt;sub&gt;2&lt;/sub&gt; in winter, whereas the ice (ICE) biome is characterized by a large ensemble spread and a pronounced seasonal cycle with the largest ocean uptake of CO&lt;sub&gt;2&lt;/sub&gt; in summer. Connecting these two, the subpolar seasonally stratified (SPSS) biome has intermediate flux densities (flux per area), and most models have difficulties simulating the seasonal cycle with strongest uptake during the summer months.&lt;/p&gt;&lt;p&gt;Our analysis also reveals distinct differences between the Atlantic, Pacific and Indian sectors of the aforementioned biomes. In the STSS, the Indian sector contributes most to the ocean carbon sink, followed by the Atlantic and then Pacific sectors. This hierarchy is less pronounced in the models than in the data-products. In the SPSS, only the Atlantic sector exhibits net CO&lt;sub&gt;2&lt;/sub&gt; uptake in all years, likely linked to strong biological production. In the ICE biome, the Atlantic and Pacific sectors take up more CO&lt;sub&gt;2&lt;/sub&gt; than the Indian sector, suggesting a potential role of the Weddell and Ross Gyres.&lt;/p&gt;&lt;p&gt;These first results confirm the global relevance of the Southern Ocean carbon sink and highlight the strong regional and interannual variability of the Southern Ocean carbon uptake in connection to physical and biogeochemical processes.&lt;/p&gt;

The long-term conservation of forest diversity in New Zealand

1995 ◽  
Vol 2 (1) ◽  
pp. 77 ◽  
Author(s):  
John Ogden
Keyword(s):  
New Zealand ◽  
Land Surface ◽  
Alpha Diversity ◽  
Forest Diversity ◽  
Forest Reserves ◽  
Introduced Plants ◽  
Wide Range ◽  
Average Loss ◽  
Endemic Flora

The largely endemic flora of New Zealand is a remnant of the Cretaceous flora of Gondwana, supplemented by later additions from Australia and the tropics. Semi-natural plant communities cover about 50% of the country, and a scheme for the protection of supposedly representative areas is in place. Existing reserves do not adequately reflect the patterns of plant species diversity. Many are modified by introduced animals and alien plants. The latter are being actively introduced into New Zealand at the rate of c. 11 species per year. Measures of diversity are discussed and the broad pattern of (gamma) diversity and endemicity in the country is described. A comparison is made between (alpha) diversity levels in Beech Nothofagus solandri var. cliffortioidesand Kauri Agathis australisforest. Within each of these two forest types there are similar levels of alpha-diversity over a wide range of latitude. Altitudinal alpha-diversity trends indicate an average loss of 3.4 species per 100 m of altitude. This can be accounted for by the reduction of land surface area with increasing altitude on conical or ridge-shaped mountains. The altitudinal data emphasize the importance of the lowlands in the conservation of bio-diversity. The Holocene history of the forests in New Zealand suggests that the concept of "representativeness" is flawed: forest varies continuously in time and space. It may be possible to create some "living museums" of the past biota of New Zealand, but unless there are radical changes in our ability to eradicate animal pests and introduced plants, the composition of mainland forest reserves in the lowlands will change dramatically over the next few centuries. Conservation effort on saving endangered birds may have been at the expense of long-term "habitat" survival on the mainland.

Long-term air quality monitoring at the South Pole by the NOAA Program Geophysical Monitoring for Climatic Change

1988 ◽  
Vol 26 (1) ◽  
pp. 63 ◽  
Author(s):  
E. Robinson ◽  
B. A. Bodhaine ◽  
W. D. Komhyr ◽  
S. J. Oltmans ◽  
L. P. Steele ◽  
...  
Keyword(s):  
Air Quality ◽  
Climatic Change ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
South Pole ◽  
The South ◽  
Geophysical Monitoring

scholarly journals Discussion to the special issue: Supporting the transition of a diversity of students: Developing the “whole student” during and beyond their time at higher education.

2021 ◽  
Vol 9 (2) ◽  
pp. 170-178
Author(s):  
Jacques Van der Meer
Keyword(s):  
Higher Education ◽  
New Zealand ◽  
20Th Century ◽  
South Pacific ◽  
Student Diversity ◽  
Special Issue ◽  
The South ◽  
Wide Range ◽  
The World ◽  
The Many

Apart from the current Covid19 context, the higher education sectors across the world have been faced with major challenges over the last few decades (Auerbach et al., 2018; Haggis, 2004), including increased numbers and diversity. Considering the many challenges in higher education, especially the rise of students’ mental health issues, I am strongly convinced that education sectors, but in particular the higher education sector, have a societal responsibility to not just focus on students as learners of knowledge and/or professional skills, but to support them in being developed as “whole students”. All these challenges also raise a need for research into the broader context to identify how we can better support the diverse student population as they transition into higher education, but also how to prepare them for a positive experience during and beyond their time in higher education. Overall, it can be said that the contributions to this special issue beneficially addressed some of the main foci to widening the perspectives on diversity related to the transition into higher education. The contribution came from different European countries, including Belgium, Germany, Italy, Sweden, Switzerland, The Netherlands and the United Kingdom. De Clercq et al. (in this special issue) indicated that environmental characteristics, such as distinctiveness of countries, is often overlooked in research. In this discussion article, therefore, some particular references will also be made to a specific country, New Zealand. This may be of interest and relevant for the particular questions raised in this special issue as focusing on student diversity in educational contexts has been considered important for some time in this country. Aoteraroa New Zealand is a country in the South Pacific colonised by Europeans in the 19th century. In the second part of the 20th century, the focus across the New Zealand education sectors, including higher education, started to develop beyond just a European perspective, and started to focus more on recognition of student diversity. Initially, the main focus was on the indigenous population, the Māori people. In the last few decades of the 20th century, the focus was extended to the Pacific Island people, many of whom migrated to New Zealand from a wide range of different islands in the South Pacific. In the 21st century, the focus on Culturally and Linguistically Diverse (CALD) groups was further extended, and over the last decade also because of the increase of refugees from the Middle East and Asia. Providing some insights from the other end of the world, in quite a different and de-colonised ex-European nation may help European (and other) countries to reflect on their own approaches.

Variation in mussel and barnacle recruitment parallels a shift in intertidal community structure in the Cook Strait region of New Zealand

2011 ◽  
Vol 62 (10) ◽  
pp. 1221 ◽  
Author(s):  
Rahul Demello ◽  
Nicole E. Phillips
Keyword(s):  
New Zealand ◽  
Intertidal Zone ◽  
Spatial Scales ◽  
South Coast ◽  
The South ◽  
Sessile Invertebrates ◽  
High Zone ◽  
Species Specific ◽  
High Intertidal Zone

Recruitment influences populations and communities of marine organisms to varying degrees and across a range of spatial scales. We hypothesised that recruitment plays a role in maintaining different intertidal invertebrate assemblages between two nearby locations in New Zealand (Wellington Harbour and the south coast), long reported to have dramatically different communities (with greater cover of sessile invertebrates in the Harbour). Sites in Wellington Harbour were hypothesised to have higher monthly recruitment rates of mussels and barnacles and greater barnacle colonisation after 1 year. Surveys were conducted to quantify community differences. In Wellington Harbour, the mid-intertidal zone was dominated by the mussel Mytilus galloprovincialis and the barnacle Chamaesipho columna and the high intertidal zone by C. columna. In contrast, on the south coast mussels were almost completely absent from both tidal heights and barnacles (predominantly Chamaesipho brunnea) were sparse. In the high zone, monthly recruitment and long term colonisation (over 1 year) of barnacles was much greater in the Harbour; in the mid-intertidal zone, mussel recruitment was up to two orders of magnitude greater in the Harbour than the south coast. Species-specific recruitment patterns differed between the locations, however and were consistent with those of adult abundance.

Sign in / Sign up

Export Citation Format

Share Document