scholarly journals “Beyond Weather Regimes”: Descriptors Monitoring Atmospheric Centers of Action. A case study for Aotearoa New Zealand

2021 ◽  
pp. 1-50
Author(s):  
Benjamin Pohl ◽  
Andrew Lorrey ◽  
Andrew Sturman ◽  
Hervé Quénol ◽  
James Renwick ◽  
...  
Keyword(s):  
New Zealand ◽  
Climate Variability ◽  
Large Scale ◽  
Scale Effects ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Future Research ◽  
Weather Regimes ◽  
Aotearoa New Zealand

AbstractThis paper introduces a set of descriptors applied to weather regimes, that allow for a detailed monitoring of the location and intensity of their atmospheric centers of action (e.g. troughs and ridges) and the gradients between them, when applicable. Descriptors are designed to document the effect of climate variability and change in modulating the character of daily weather regimes, rather than merely their occurrence statistics.As a case study, the methodology is applied to Aotearoa New Zealand (ANZ), using ERA5 ensemble reanalysis data for the period 1979-2019. Here, we analyze teleconnections between the regimes and their descriptors, and large-scale climate variability. Results show a significant modulation of centers of action by the phase of the Southern Annular Mode, with a strong relationship identified with the latitude of atmospheric ridges. Significant associations with El Niño Southern Oscillation are also identified. Modes of large-scale variability have a stronger influence on the regimes’ intrinsic features than their occurrence. This demonstrates the usefulness of such descriptors, which help understand the relationship between mid-latitude transient perturbations and large-scale modes of climate variability.In future research, this methodological framework will be applied to analyze (i) low-frequency changes in weather regimes under climate change, in line with the southward shift of storm tracks, and (ii) regional-scale effects on the climate of ANZ, resulting from interaction with its topography.

scholarly journals Frequency Analysis of Nonidentically Distributed Hydrometeorological Extremes Associated with Large-Scale Climate Variability Applied to South Korea

2014 ◽  
Vol 53 (5) ◽  
pp. 1193-1212 ◽  
Author(s):  
Taesam Lee ◽  
Changsam Jeong
Keyword(s):  
Parameter Estimation ◽  
Climate Variability ◽  
South Korea ◽  
Simulation Study ◽  
Extreme Events ◽  
Large Scale ◽  
Southern Oscillation ◽  
Estimation Method ◽  
Parameter Estimation Method

AbstractIn the frequency analyses of extreme hydrometeorological events, the restriction of statistical independence and identical distribution (iid) from year to year ensures that all observations are from the same population. In recent decades, the iid assumption for extreme events has been shown to be invalid in many cases because long-term climate variability resulting from phenomena such as the Pacific decadal variability and El Niño–Southern Oscillation may induce varying meteorological systems such as persistent wet years and dry years. Therefore, the objective of the current study is to propose a new parameter estimation method for probability distribution models to more accurately predict the magnitude of future extreme events when the iid assumption of probability distributions for large-scale climate variability is not adequate. The proposed parameter estimation is based on a metaheuristic approach and is derived from the objective function of the rth power probability-weighted sum of observations in increasing order. The combination of two distributions, gamma and generalized extreme value (GEV), was fitted to the GEV distribution in a simulation study. In addition, a case study examining the annual hourly maximum precipitation of all stations in South Korea was performed to evaluate the performance of the proposed approach. The results of the simulation study and case study indicate that the proposed metaheuristic parameter estimation method is an effective alternative for accurately selecting the rth power when the iid assumption of extreme hydrometeorological events is not valid for large-scale climate variability. The maximum likelihood estimate is more accurate with a low mixing probability, and the probability-weighted moment method is a moderately effective option.

Large-scale tree planting initiatives as an opportunity to derive carbon and biodiversity co-benefits: a case study from Aotearoa New Zealand

New Forests ◽  
2021 ◽  
Author(s):  
Febyana Suryaningrum ◽  
Rebecca M. Jarvis ◽  
Hannah L. Buckley ◽  
David Hall ◽  
Bradley S. Case
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Tree Planting ◽  
Aotearoa New Zealand

Interannual Extremes in New Zealand Precipitation Linked to Modes of Southern Hemisphere Climate Variability

2007 ◽  
Vol 20 (21) ◽  
pp. 5418-5440 ◽  
Author(s):  
Caroline C. Ummenhofer ◽  
Matthew H. England
Keyword(s):  
New Zealand ◽  
Climate Variability ◽  
Southern Hemisphere ◽  
Large Scale ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Heat Fluxes ◽  
Ekman Transport ◽  
The South ◽  
Climate Modes

Abstract Interannual extremes in New Zealand rainfall and their modulation by modes of Southern Hemisphere climate variability are examined in observations and a coupled climate model. North Island extreme dry (wet) years are characterized by locally increased (reduced) sea level pressure (SLP), cold (warm) sea surface temperature (SST) anomalies in the southern Tasman Sea and to the north of the island, and coinciding reduced (enhanced) evaporation upstream of the mean southwesterly airflow. During extreme dry (wet) years in South Island precipitation, an enhanced (reduced) meridional SLP gradient occurs, with circumpolar strengthened (weakened) subpolar westerlies and an easterly (westerly) anomaly in zonal wind in the subtropics. As a result, via Ekman transport, anomalously cold (warm) SST appears under the subpolar westerlies, while anomalies of the opposite sign occur farther north. The phase and magnitude of the resulting SST and evaporation anomalies cannot account for the rainfall extremes over the South Island, suggesting a purely atmospheric mode of variability as the driving factor, in this case the Southern Annular Mode (SAM). New Zealand rainfall variability is predominantly modulated by two Southern Hemisphere climate modes, namely, the El Niño–Southern Oscillation (ENSO) and the SAM, with a latitudinal gradation in influence of the respective phenomena, and a notable interaction with orographic features. While this heterogeneity is apparent both latitudinally and as a result of orographic effects, climate modes can force local rainfall anomalies with considerable variations across both islands. North Island precipitation is for the most part regulated by both local air–sea heat fluxes and circulation changes associated with the tropical ENSO mode. In contrast, for the South Island the influence of the large-scale general atmospheric circulation dominates, especially via the strength and position of the subpolar westerlies, which are modulated by the extratropical SAM.

scholarly journals Application of global models and satellite data for smaller-scale groundwater recharge studies

2016 ◽  
Author(s):  
Rogier Westerhoff ◽  
Paul White ◽  
Zara Rawlinson
Keyword(s):  
New Zealand ◽  
Satellite Data ◽  
Input Data ◽  
Large Scale ◽  
Regional Scale ◽  
Global Scale ◽  
Global Models ◽  
Scale Models ◽  
Boundary Issues ◽  
Rainfall Recharge

Abstract. Large-scale models and satellite data are increasingly used to characterise groundwater and its recharge at the global scale. Although these models have the potential to fill in data gaps and solve trans-boundary issues, they are often neglected in smaller-scale studies, since data are often coarse or uncertain. Large-scale models and satellite data could play a more important role in smaller-scale (i.e., national or regional) studies, if they could be adjusted to fit that scale. In New Zealand, large-scale models and satellite data are not used for groundwater recharge estimation at the national scale, since regional councils (i.e., the water managers) have varying water policy and models are calibrated at the local scale. Also, some regions have many localised ground observations (but poor record coverage), whereas others are data-sparse. Therefore, estimation of recharge is inconsistent at the national scale. This paper presents an approach to apply large-scale, global, models and satellite data to estimate rainfall recharge at the national to regional scale across New Zealand. We present a model, NGRM, that is largely inspired by the global-scale WaterGAP recharge model, but is improved and adjusted using national data. The NGRM model uses MODIS-derived ET and vegetation satellite data, and the available nation-wide datasets on rainfall, elevation, soil and geology. A valuable addition to the recharge estimation is the model uncertainty estimate, based on variance, covariance and sensitivity of all input data components in the model environment. This research shows that, with minor model adjustments and use of improved input data, large-scale models and satellite data can be used to derive rainfall recharge estimates, including their uncertainty, at the smaller scale, i.e., national and regional scale of New Zealand. The estimated New Zealand recharge of the NGRM model compare well to most local and regional lysimeter data and recharge models. The NGRM is therefore assumed to be capable to fill in gaps in data-sparse areas and to create more consistency between datasets from different regions, i.e., to solve trans-boundary issues. This research also shows that smaller-scale recharge studies in New Zealand should include larger boundaries than only a (sub-)aquifer, and preferably the whole catchment. This research points out the need for improved collaboration on the international to national to regional levels to further merge large-scale (global) models to smaller (i.e., national or regional) scales. Future research topics should, collaboratively, focus on: improvement of rainfall-runoff and snowmelt methods; inclusion of river recharge; further improvement of input data (rainfall, evapotranspiration, soil and geology); and the impact of recharge uncertainty in mountainous and irrigated areas.

scholarly journals Another elderly lady to be knocked down: Heritage discourse and the protest to save the Missions to Seamen building, 1986

2021 ◽  
Author(s):  
◽  
Alexander Gordon
Keyword(s):  
New Zealand ◽  
City Council ◽  
Historical Case Study ◽  
Historical Case ◽  
Considerable Difficulty ◽  
Documentary Sources ◽  
Aotearoa New Zealand ◽  
History Of ◽  
Heritage Discourse

<p>Through a specific historical case study, Another Elderly Lady to be Knocked Down applies discourse theory and the Authorised Heritage Discourse (AHD) to the context of urban built heritage in Aotearoa New Zealand. Previously, only limited work had been done in this area. By examining an underexplored event this dissertation fills two gaps in present literature: the history of the event itself and identification of the heritage discourses in the country at the time. Examination of these discourses in context also allows conclusions about the use of the AHD in similar studies to be critically examined.  In 1986 the Missions to Seamen building in Wellington, New Zealand, was threatened with demolition by its government owners. In a remarkable display of popular sentiment, individuals, organisations, the Wellington City Council (WCC) and the New Zealand Historic Places Trust (NZHPT) worked together to oppose this unpopular decision. This protest was a seminal event in the history of heritage in New Zealand.  This study relies upon documentary sources, especially the archival records of the Historic Places Trust and the State Services Commission, who owned the building, to provide the history of this watershed moment in New Zealand’s preservation movement. The prevalent attitudes of different groups in Wellington are examined through the letters of protest they wrote at the time. When analysed in context, these discourses reveal the ways in which heritage was articulated and constructed.  The course of this dissertation has revealed the difficulty of identifying an AHD in this context. The level of collaboration between ‘official’ and ‘unofficial’ heritage perspectives, and the extent to which they shaped each other’s language, creates considerable difficulty in distinguishing between discreet discourses. To better explore the ways that heritage meaning is constructed and articulated, heritage must be recognised as a complex dynamic process.</p>

scholarly journals Media Digitization and Preservation Initiative: A Case Study

2018 ◽  
Vol 13 (1) ◽  
pp. 91-113
Author(s):  
Devan Ray Donaldson ◽  
Allison McClanahan ◽  
Leif Christiansen ◽  
Laura Bell ◽  
Mikala Narlock ◽  
...  
Keyword(s):  
Large Scale ◽  
Qualitative Case Study ◽  
Future Research ◽  
Indiana University ◽  
Roles And Responsibilities ◽  
Case Study Analysis ◽  
Digital Curation ◽  
Lifecycle Model ◽  
Mass Digitization

Since its creation nearly a decade ago, the Digital Curation Centre (DCC) Curation Lifecycle Model has become the quintessential framework for understanding digital curation. Organizations and consortia around the world have used the DCC Curation Lifecycle Model as a tool to ensure that all the necessary stages of digital curation are undertaken, to define roles and responsibilities, and to build a framework of standards and technologies for digital curation. Yet, research on the application of the model to large-scale digitization projects as a way of understanding their efforts at digital curation is scant. This paper reports on findings of a qualitative case study analysis of Indiana University Bloomington’s multi-million-dollar Media Digitization and Preservation Initiative (MDPI), employing the DCC Curation Lifecycle Model as a lens for examining the scope and effectiveness of its digital curation efforts. Findings underscore the success of MDPI in performing digital curation by illustrating the ways it implements each of the model’s components. Implications for the application of the DCC Curation Lifecycle Model in understanding digital curation for mass digitization projects are discussed as well as directions for future research.

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>

Experiences of Implementing a Large-Scale Blended, Flipped Learning Project

2018 ◽  
pp. 3839-3849
Author(s):  
Hazel Owen ◽  
Nicola Dunham
Keyword(s):  
New Zealand ◽  
Large Scale ◽  
Tertiary Education ◽  
Health Science ◽  
Flipped Learning ◽  
Tertiary Institution ◽  
Tertiary Institutions ◽  
Post Secondary ◽  
Aotearoa New Zealand ◽  
Personal Reflections

In the context of ongoing global adoption of all forms of technology eLearning has continued to evolve, informed by a growing body of research. Many schools, tertiary institutions, and other organisations, are implementing a variety of eLearning initiatives, although, frequently it appears the investment does not always equate to more engaged, knowledgeable, skilled learners. Tertiary education in Aotearoa, New Zealand covers all post-secondary education and is analogous to the term Higher Education in other countries. This chapter draws on the implementation of a large-scale blended, flipped learning project at a tertiary institution in Aotearoa, New Zealand. The project (within the Health Science faculty) was driven by a desire to improve student learning experiences, and develop a common semester with a suite of interdisciplinary postgraduate qualifications. The discussion is based on personal reflections, which provide different perspectives of the initial phases, from three participants in the associated study (two of whom are also the authors of this chapter). During the project two key prevalences were observed. The first was an ingrained set of beliefs, often unquestioned, that shaped overall expectations of what an eLearning experience might comprise. Interpretations and implications are discussed using the lens of mindsets to illustrate how beliefs of ‘self' fundamentally influence a person's ability to embrace - and thrive in - a period of change. The second prevalence was a familiarity with large-scale, ‘monolithic' eLearning developments, which translated into discomfort with an agile approach. The overall aim of this chapter is to provide sufficient detail to draw educators and administrators together to apply the recommendations offered, while providing support for 'change agents' - as well as those ambivalent about reform. The authors are keen to highlight how ultimately rewarding, but also emotionally and physically demanding, the implementation of reform can be for those educators on 'the front lines'.

scholarly journals Synchronous combined effects of fishing and climate within a demersal community

2012 ◽  
Vol 70 (2) ◽  
pp. 319-328 ◽  
Author(s):  
Antoni Quetglas ◽  
Francesc Ordines ◽  
Manuel Hidalgo ◽  
Sebastià Monserrat ◽  
Susana Ruiz ◽  
...  
Keyword(s):  
Climate Variability ◽  
Age Structure ◽  
Large Scale ◽  
Southern Oscillation ◽  
Climatic Variability ◽  
Early Period ◽  
Combined Effects ◽  
Population Fluctuations ◽  
Fishing Activity ◽  
The Mediterranean

Abstract Quetglas, A., Ordines, F., Hidalgo, M., Monserrat, S., Ruiz, S., Amores, Á., Moranta, J., and Massutí, E. 2013. Synchronous combined effects of fishing and climate within a demersal community. – ICES Journal of Marine Science, 70: 319–328. Accumulating evidence shows that fishing exploitation and environmental variables can synergistically affect the population dynamics of exploited populations. Here, we document an interaction between fishing impact and climate variability that triggered a synchronic response in the population fluctuations of six exploited species in the Mediterranean from 1965–2008. Throughout this period, the fishing activity experienced a sharp increase in fishing effort, which caused all stocks to shift from an early period of underexploitation to a later period of overexploitation. This change altered the population resilience of the stocks and brought about an increase in the sensitivity of its dynamics to climate variability. Landings increased exponentially when underexploited but displayed an oscillatory behaviour once overexploited. Climatic indices, related to the Mediterranean mesoscale hydrography and large-scale north Atlantic climatic variability, seemed to affect the species with broader age structure and longer lifespan, while the global-scale El Niño Southern Oscillation index (ENSO) positively influenced the population abundances of species with a narrow age structure and short lifespan. The species affected by ENSO preferentially inhabit the continental shelf, suggesting that Mediterranean shelf ecosystems are sensitive to the hydroclimatic variability linked to global climate.

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