THE SOUTHERN OSCILLATION INDEX AND CLIMATIC PARAMETERS, AND THEIR RELATIONSHIP TO SNOW AND SKI CONDITIONS AT MT. RUAPEHU, NEW ZEALAND

1993 ◽  
Vol 13 (2) ◽  
pp. 22 ◽  
Author(s):  
West ◽  
Healy
1994 ◽  
Vol 30 (10) ◽  
pp. 2717-2723 ◽  
Author(s):  
M. E. Moss ◽  
C. P. Pearson ◽  
A. I. McKerchar

2006 ◽  
Vol 43 ◽  
pp. 14-22 ◽  
Author(s):  
David Bolius ◽  
Margit Schwikowski ◽  
Theo Jenk ◽  
Heinz W. Gäggeler ◽  
Gino Casassa ◽  
...  

AbstractIn January 2003, shallow firn cores were recovered from Glaciar Esmeralda on Cerro del Plomo (33°14’S, 70°13’W; 5300 ma.s.l.), central Chile, and from Glaciar La Ollada on Cerro Mercedario (31°58’S, 70°07’W; 6070 ma.s.l.), Argentina, in order to find a suitable archive for paleoclimate reconstruction in a region strongly influenced by the El Nino-Southern Oscillation. In the area between 28°S and 35°S, the amount of winter precipitation is significantly correlated to the Southern Oscillation Index, with higher values during El Nino years. Glaciochemical analysis indicates that the paleo-record at Glaciar La Ollada is well preserved, whereas at Glaciar Esmeralda the record is strongly influenced by meltwater formation and percolation. A preliminary dating of the Mercedario core by annual-layer counting results in a time-span of 17 years (1986-2002), yielding an average annual net accumulation of 0.45 m w.e.


2016 ◽  
Vol 5 (2) ◽  
pp. 132 ◽  
Author(s):  
Tatiana A. Arivelo ◽  
Yuh-Lang Lin

Variability of and generation mechanisms for Madagascar rainfall are studied by conducting climatological, synoptic and mesoscale analyses. It is found the rainfall variability is highly sensitive to seasons with high variability in summer (Nov-Apr). The rainfall in summer is controlled by the Intertropical Convergence Zone (ITCZ) and orographic rainfall associated with tropical cyclones (TCs), while the rainfall in winter (May-Oct) is controlled by trade winds and local orographic rainfall along the eastern coast. Synoptic analysis reveals that major climate variations in summer are associated with ITCZ position, which is closely related to TC genesis locations and quasi-biennial oscillation (QBO). Linkages between El-Niño Southern Oscillation Index (ENSO) and Southern Oscillation Index (SOI) are identified as the cause of inconsistent dry or wet summers. Mesoscale analysis depicts the importance of the orographic effects on prevailing wind, which are controlled by the orography in both seasons. In winter, the prevailing trade winds over the Southwest Indian Ocean are from the east and are split to the north and south when it impinges on Malagasy Mountains. On the other hand, in summer the prevailing easterlies are weaker leading to the production of lee vortices, in addition to the flow splitting upstream of the mountain. Thus, the flow is classified into two regimes: (a) flow-over regime with no lee vortices under high Froude number (Fr=1.2-1.8) flow, and (b) flow-around regime with lee vortices under low Fr (=0.88-1.16) flow. A case study of TC Domoina (1984) indicates that the long-lasting heavy rainfall was induced by the strong orographic blocking of Madagascar. The shorter-term (e.g., 2 days) heavy orographic precipitation is characterized by large VH ∙Ñh which is composed by two common ingredients, namely a strong low-level wind normal to the mountain (VH) and a steep mountain slope (∇h).


2017 ◽  
Author(s):  
Imogen M. Browne ◽  
Christopher M. Moy ◽  
Christina R. Riesselman ◽  
Helen L. Neil ◽  
Lorelei G. Curtin ◽  
...  

Abstract. The Southern Hemisphere westerly winds (SHWW) play a major role in controlling wind-driven upwelling of Circumpolar Deep Water (CDW) and outgassing of CO2 in the Southern Ocean on interannual to glacial-interglacial timescales. Despite their significance in the global carbon cycle, our understanding of millennial-scale changes in the strength and latitudinal position of the westerlies during the Holocene (especially since 5000 yr BP) is limited by a scarcity of paleoclimate records from comparable latitudes. Here, we reconstruct middle to late Holocene variability in the SHWW using a fjord sediment core collected from the subantarctic Auckland Islands (51° S, 166° E), located in the modern centre of the westerly wind belt. Drainage basin response to variability in the strength of the SHWW at this latitude is reconstructed from downcore variations in magnetic susceptibility (MS) and bulk organic δ13C and atomic C/N, which monitor influxes of lithogenous and terrestrial vs marine organic matter, respectively. The hydrographic response to SHWW variability is reconstructed using benthic foraminifer δ18O and δ13C, both of which are influenced by the isotopic composition of shelf water masses entering the fjord. Using these data, we provide marine and terrestrial-based evidence for increased wind strength from ~ 1600–900 yr BP at subantarctic latitudes that is broadly consistent with previous studies of vegetation response to climate at the Auckland Islands. Comparison with a SHWW reconstruction using similar proxies from Fiordland suggests a northward migration of the SHWW over New Zealand at the beginning of the Little Ice Age (LIA). Comparison with paleoclimate and paleoceanographic records from southern South America and the western Antarctic Peninsula indicates a late Holocene strengthening of the SHWW after ~ 1600 yr BP that appears to be broadly symmetrical across the Pacific basin, although our reconstruction suggests that this symmetry breaks down during the LIA. Contemporaneous increases in SHWW at localities either side of the Pacific in the late Holocene are likely controlled atmospheric teleconnections between the low and high latitudes and by variability in the Southern Annular Mode (SAM) and El Niño Southern Oscillation (ENSO).


2019 ◽  
Vol 11 (3) ◽  
pp. 683-695 ◽  
Author(s):  
Taufik R. Syachputra ◽  
Ivonne M. Radjawane ◽  
Rina Zuraida

Variabilitas iklim dapat mempengaruhi sifat sedimen yang terendapkan di dasar laut. Salah satu sifat sedimen yang dipengaruhi oleh iklim adalah besar butir. Penelitian ini bertujuan untuk menguji hubungan antara besar butir dengan variabilitas iklim menggunakan sampel core GM01-2010-TJ22 dari Muara Gembong, Teluk Jakarta, muara sungai Citarum. Sampel core diambil pada tahun 2010 dengan menggunakan Kapal Riset Geomarin I oleh Pusat Penelitian dan Pengembangan Geologi Kelautan (P3GL). Pengukuran besar butir dilakukan dengan menggunakan Mastersizer 2000. Hasil pengukuran ditampilkan dalam seri waktu dari tahun 2001 sampai 2010. Hasil analisis besar butir sampel sedimen dikorelasikan secara statistik dengan fenomena musiman (monsun), tahunan dan antar tahun (El Niño/La Niña dan Dipole Mode). Verifikasi data dilakukan dengan menggunakan data sekunder temperatur permukaan laut dari citra satelit di sekitar lokasi sampel dan data curah hujan di Bekasi. Hasil verifikasi menunjukkan bahwa peningkatan curah hujan di sekitar daerah hilir Sungai Citarum diikuti dengan penurunan temperatur permukaan laut dan peningkatan ukuran rata-rata besar butir. Hasil yang didapat dalam uji statistika menunjukkan bahwa perubahan ukuran besar butir sampel sedimen di Muara Gembong memiliki korelasi signifikan dengan Multivariate ENSO (El Niño Southern Oscillation) Index (MEI), Ocean Niño Index (ONI), Dipole Mode Index (DMI) dan Australian Monsoon Index (AUSMI). Hasil tersebut menunjukkan bahwa besar butir sedimen dasar laut potensial digunakan untuk mengetahui variabilitas iklim di sekitar Teluk Jakarta.


MAUSAM ◽  
2021 ◽  
Vol 58 (3) ◽  
pp. 345-350
Author(s):  
O. P. SINGH

In this paper the relationships between the Arabian Sea warm pool intensity, Southern Oscillation (SO) and the monsoon onset have been discussed. The results show that the peak intensity of the warm pool in the Lakshadweep Sea is significantly correlated with the monsoon onset date over Kerala. Warmer Sea Surface Temperature (SST) anomalies in the warm pool region during April-May are associated with delayed monsoon onset over Kerala though the cause-and-effect relationship is not known. The Southern Oscillation Index (SOI) of March can provide predictive indications of the peak intensity of the warm pool which, normally occurs during April.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243794
Author(s):  
Sam McKechnie ◽  
David Fletcher ◽  
Jamie Newman ◽  
Corey Bragg ◽  
Peter W. Dillingham ◽  
...  

A suite of factors may have contributed to declines in the tītī (sooty shearwater; Ardenna grisea) population in the New Zealand region since at least the 1960s. Recent estimation of the magnitude of most sources of non-natural mortality has presented the opportunity to quantitatively assess the relative importance of these factors. We fit a range of population dynamics models to a time-series of relative abundance data from 1976 until 2005, with the various sources of mortality being modelled at the appropriate part of the life-cycle. We present estimates of effects obtained from the best-fitting model and using model averaging. The best-fitting models explained much of the variation in the abundance index when survival and fecundity were linked to the Southern Oscillation Index, with strong decreases in adult survival, juvenile survival and fecundity being related to El Niño-Southern Oscillation (ENSO) events. Predation by introduced animals, harvesting by humans, and bycatch in fisheries also appear to have contributed to the population decline. It is envisioned that the best-fitting models will form the basis for quantitative assessments of competing management strategies. Our analysis suggests that sustainability of the New Zealand tītī population will be most influenced by climate, in particular by how climate change will affect the frequency and intensity of ENSO events in the future. Removal of the effects of both depredation by introduced predators and harvesting by humans is likely to have fewer benefits for the population than alleviating climate effects.


2021 ◽  
Author(s):  
◽  
Aitana Forcén-Vázquez

<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>


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