scholarly journals Global chemical model analysis of biomass burning and lightning influences over the South Pacific in austral spring

2002 ◽  
Vol 107 (D14) ◽  
Author(s):  
Amanda C. Staudt
Keyword(s):  
Biomass Burning ◽  
South Pacific ◽  
Model Analysis ◽  
Chemical Model ◽  
The South ◽  
Austral Spring

scholarly journals Circulation Regimes and Low-Frequency Oscillations in the South Pacific Sector

2003 ◽  
Vol 131 (8) ◽  
pp. 1566-1576 ◽  
Author(s):  
Andrew W. Robertson ◽  
Carlos R. Mechoso
Keyword(s):  
Singular Spectrum Analysis ◽  
Low Frequency ◽  
South Pacific ◽  
Stationary Wave ◽  
Gaussian Mixture ◽  
Reanalysis Data ◽  
Oscillatory Behavior ◽  
South American ◽  
The South ◽  
Austral Spring

Abstract The characteristics of subseasonal circulation variability over the South Pacific are examined using 10-day lowpass-filtered 700-hPa geopotential height NCEP–NCAR reanalysis data. The extent to which the variability in each season is characterized by recurrent geographically fixed circulation regimes and/or oscillatory behavior is determined. Two methods of analysis (a K-means cluster analysis and a cross-validated Gaussian mixture model) both indicate three to four geographically fixed circulation regimes in austral fall, winter, and (to some extent) spring. The spatial regime structures are found to be quite similar in each season; they resemble the so-called Pacific–South American (PSA) patterns discussed in previous studies and often referred to as PSA 1 and PSA 2. Oscillatory behavior is investigated using singular spectrum analysis. This identifies a predominantly stationary wave with a period of about 40 days and a spatial structure similar to PSA 1; it is most pronounced in winter and spring and exhibits a noticeable eastward drift as it decays. The power spectrum of variability is otherwise well approximated by a red spectrum, together with enhanced broader-band 15–30-day variability. The results presented herein indicate that low-frequency variability over the South Pacific is not dominated by a propagating wave whose quadrature phases are PSA 1 and PSA 2, as hitherto described. Rather, it is found that the variability is well described by the occurrence of three to four geographically fixed circulation regimes, with a (near) 40-day oscillation that is predominantly stationary in space. The potential subseasonal predictability implied by this duality is discussed. Only during austral spring is a strong correlation found between El Niño and the frequency of occurrence of the circulation regimes.

scholarly journals South Pacific Ocean Dipole: A Predictable Mode on Multiseasonal Time Scales

2014 ◽  
Vol 27 (4) ◽  
pp. 1648-1658 ◽  
Author(s):  
Yuanhong Guan ◽  
Jieshun Zhu ◽  
Bohua Huang ◽  
Zeng-Zhen Hu ◽  
James L. Kinter III
Keyword(s):  
Pacific Ocean ◽  
Time Scales ◽  
Southern Oscillation ◽  
Austral Summer ◽  
South Pacific ◽  
The South ◽  
Active Centers ◽  
Austral Spring ◽  
South Pacific Ocean ◽  
South Indian

Abstract Evaluating the climate hindcasts for 1982–2009 from the NCEP CFS Reanalysis and Reforecast (CFSRR) project using the Climate Forecast System, version 2 (CFSv2), this study identifies substantial areas of high prediction skill of the sea surface temperature (SST) in the South Pacific. The skill is the highest in the extratropical oceans on seasonal-to-interannual time scales, and it is only slightly lower than that for the El Niño–Southern Oscillation (ENSO). Two regions with the highest prediction skills in the South Pacific in both the CFSv2 and persistence hindcasts coincide with the active centers of opposite signs in the South Pacific Ocean dipole (SPOD) mode, a seesaw between the subtropical and extratropical SST in the South Pacific with a strong phase locking to austral summer. Interestingly, the CFSv2 prediction exhibits skillful predictions made three seasons ahead, more superior to the persistence forecast, suggesting significant dynamical predictability of the SPOD. An austral “spring predictability barrier” is noted in both the dynamical and persistence hindcasts. An analysis of the observational and model data suggests that the SPOD mode is significantly associated with ENSO, as an oceanic response to the atmospheric planetary wave trains forced by the anomalous atmospheric heating in the western Pacific. Although previous studies have demonstrated that the pattern of subtropical SST dipole is ubiquitous in the Southern Ocean, the SPOD has been least known and studied, compared with its counterparts in the south Indian and Atlantic Oceans. Since the SPOD is the most predictable oceanic mode in the whole Southern Hemisphere, its climate effects for local and remote regions should be further studied.

scholarly journals Austral Spring Southern Hemisphere Circulation and Temperature Changes and Links to the SPCZ

2015 ◽  
Vol 28 (18) ◽  
pp. 7371-7384 ◽  
Author(s):  
Kyle R. Clem ◽  
James A. Renwick
Keyword(s):  
Surface Temperature ◽  
Antarctic Peninsula ◽  
South Pacific ◽  
South Atlantic ◽  
South Pacific Convergence Zone ◽  
Positive Pressure ◽  
West Antarctica ◽  
The South ◽  
Austral Spring ◽  
Sea Ice Concentration

Abstract Significant austral spring trends have previously been observed in West Antarctica and Antarctic Peninsula temperatures and in atmospheric circulation across the southern Pacific and Atlantic. Here, physical mechanisms for the observed trends are investigated through analysis of monthly circulation and temperatures from the ERA-Interim dataset and outgoing longwave radiation (OLR) data. The negative pressure trend over the South Pacific during spring is strongest in September, while the positive pressure trend over the South Atlantic is strongest in October. Pressure trends in November are generally nonsignificant. The authors demonstrate that a significant September trend toward increased convection (reduced OLR) in the poleward portion of the South Pacific convergence zone (SPCZ) is statistically related to Rossby wave–like circulation changes across the southern oceans. The wave response is strongest over the South Pacific in September and propagates eastward to the South Atlantic in October. OLR-related changes are linearly congruent with around half of the observed total changes in circulation during September and October and are consistent with observed trends in South Pacific sea ice concentration and surface temperature over western West Antarctica and the western Antarctic Peninsula. These results suggest SPCZ variability in early spring, especially on the poleward side of the SPCZ, is an important contributor to circulation and surface temperature trends across the South Pacific/Atlantic and West Antarctica.

Mechanism of Interannual Variability of Ocean Bottom Pressure in the South Pacific

2021 ◽  
Author(s):  
Jianhuang Qin ◽  
Xuhua Cheng ◽  
Chengcheng Yang ◽  
Niansen Ou ◽  
Xiaoqin Xiong
Keyword(s):  
Sea Level ◽  
Southern Oscillation ◽  
South Pacific ◽  
Ekman Transport ◽  
Ocean Bottom ◽  
Bottom Pressure ◽  
The South ◽  
Austral Spring ◽  
Ocean Bottom Pressure ◽  
Southeastern Pacific

Abstract The study of ocean bottom pressure (OBP) is useful for understanding the barotropic processes variability that contribute to sea level rise. Previous studies have reported the strong OBP anomalies in the Southern Ocean on different time scales. In this study, the characteristic and mechanisms of the energetic interannual OBP variability in the southeastern Pacific are examined using 14 years of GRACE data. It is found that the OBP anomalies are positive (negative) related to the convergence (divergence) of Ekman transport forced by local winds variability. The sea level pressure (SLP) anomalies shows a wavenumber-3 structure in the high latitude of the South Pacific, which benefits a strong and persistent anticyclone over the southeastern Pacific, leading to the positive OBP anomalies there. Such SLP anomalies are similar to the second Pacific-South American (PSA2). Moreover, El Niño–Southern Oscillation (ENSO) plays an important role in the austral spring (August-November) OBP variability and leads the austral autumn (March-June) OBP variability by 1 season. These results highlight the influence of atmospheric variability on OBP anomalies and are validated by a mass conservation (non-Boussinesq) ocean model, which is expected to not only better understanding of OBP mechanisms in a longer time, but also predict OBP variation in the global scale.

scholarly journals Seasonal Variability in Precipitation in Central and Southern Chile: Modulation by the South Pacific High

2017 ◽  
Vol 30 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Bradford S. Barrett ◽  
Sultan Hameed
Keyword(s):  
Goodness Of Fit ◽  
Southern Oscillation ◽  
Austral Summer ◽  
South Pacific ◽  
Monthly Precipitation ◽  
Southern Chile ◽  
The South ◽  
Spring Precipitation ◽  
Austral Spring ◽  
South Central

Monthly precipitation in Chile (30°–55°S) was found to vary by intensity, latitude, and longitude of the South Pacific high (SPH). In austral winter, precipitation was higher when the SPH was weaker and when it was centered farther west. In austral spring, precipitation was higher when the SPH was weaker, similar to winter. However, spring precipitation was not found to be related to SPH longitude, and higher precipitation was found when the SPH was centered farther north. In austral summer, no relationship was found between precipitation and either SPH intensity or longitude, but positive correlations were found between precipitation and latitude of the SPH. In austral autumn, correlation patterns between precipitation and all three SPH metrics more closely resembled those seen in winter. The results of a multiple linear regression confirmed the importance of two SPH metrics (intensity and longitude) and the unimportance of a third SPH metric (latitude) in understanding variability in winter, summer, and autumn precipitation in central and southern Chile. In spring, regression results confirmed a relationship between precipitation and SPH intensity and latitude. Furthermore, the SPH intensity and longitude in winter combined to hindcast monthly precipitation with a better goodness of fit than five El Niño–Southern Oscillation metrics traditionally related to Chilean precipitation. Anomalies of lower-tropospheric circulation and vertical velocities were found to support the observed relationships between SPH and precipitation. Based on these results, a physical mechanism is proposed that employs the SPH as a metric to aid in understanding variability in precipitation in central and south-central Chile in all seasons.

scholarly journals Uncovering the Composition and Diversity of Pelagic Copepods in the Oligotrophic Blue Water of the South Pacific Subtropical Gyre

2021 ◽  
Vol 8 ◽  
Author(s):  
Johanna Medellín-Mora ◽  
Rubén Escribano ◽  
Andrea Corredor-Acosta ◽  
Pamela Hidalgo ◽  
Wolfgang Schneider
Keyword(s):  
Coastal Upwelling ◽  
Mesoscale Eddies ◽  
South Pacific ◽  
Subtropical Gyre ◽  
The South ◽  
Austral Spring ◽  
Near Surface ◽  
Shallow Habitat ◽  
Basin Scale ◽  
Pelagic Copepods

The subtropical gyres occupy approximately 40% of the surface of the Earth and are widely recognized as oligotrophic zones. Among them, the South Pacific subtropical gyre (SPSG) shows the lowest chlorophyll-a levels (0.02–0.04 μgL–1), the deepest nutricline (>200 m) and euphotic zone (∼160 m), and the lowest rates of nitrogen fixation. The zooplankton community is poorly known in the SPSG. We report a study focused on the composition and distribution of pelagic copepods within the gyre so as to uncover the diversity and habitat conditions of this special community. Therefore, during the austral spring of 2015, an oceanographic cruise was conducted across the eastern side of the SPSG. Physical and chemical variables were measured in the upper 1000 m, while zooplankton samples were collected by means of vertically stratified hauls using a multiple net sampler for five layers (0–800 m). Satellite data were also used to assess near-surface phytoplankton biomass (Chl-a) and physical-dynamics conditions during the cruise, and 121 species of copepods were identified, which belonged to five taxonomic orders, 24 families, and 50 genera. Calanoida and Cyclopoida were the most frequent orders, containing 57% and 38% of species, respectively, whereas Harpacticoida and Mormonilloida contained 2% of species each, and Siphonostomatoida contained 1% of species. The vertical distribution of copepods revealed an ecological zonation linked to a strongly stratified water column, such that three different vertical habitats were defined: shallow (0–200 m), intermediate (200–400 m), and deep (400–800 m). Both the abundance and diversity of copepods were greater in the shallow habitat and were strongly associated with water temperature, whereas copepods in the subsurface layers subsisted with relatively low oxygen waters (2–3 mL O2 L–1) and presumably originated at the Chilean upwelling zone, being transported offshore by mesoscale eddies. Furthermore, the analysis of species composition revealed a marked dominance of small-sized copepods, which may play a key role in nutrient recycling under an oligotrophic condition, as inferred from their mostly omnivorous feeding behavior. Our findings also suggested a potentially high endemism within the gyre, although basin-scale circulation and mesoscale eddies, traveling from the coastal upwelling zone and transporting plankton, can also influence the epipelagic fauna.

Culture and leadership: Project GLOBE in the South Pacific

2009 ◽  
Author(s):  
Anthony R. Paquin ◽  
Reinout E. de Vries ◽  
Raghuvar D. Pathak ◽  
Rafia Naz
Keyword(s):  
South Pacific ◽  
The South

Tourism Development in the South Pacific: The Cases of Nauru and Tuvalu

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Nick Towner ◽  
Semisi Taumoepeau
Keyword(s):  
Swot Analysis ◽  
Tourism Development ◽  
Geographic Location ◽  
South Pacific ◽  
The South ◽  
South Pacific Ocean ◽  
Economic Survival ◽  
Processing Centre ◽  
Remote Island ◽  
The Impact

Abstract Tuvalu and Nauru are isolated developing island nations located in the South Pacific Ocean. In contrast to the established larger Pacific destinations such as Fiji and Tahiti, the tourism industries on both Tuvalu and Nauru are in their infancy. Tourism development in these remote island nations faces a myriad of challenges which include a lack of infrastructure, environmental susceptibility, economic vulnerability, difficulties with access and considerable distances from major tourist markets. This paper reviews tourism on Tuvalu and Nauru and evaluates their current situation regarding potential tourism development through workshops with relevant stakeholders, surveys and subsequent SWOT analysis. The results of the paper outlined a large number of challenges faced by Tuvalu and Nauru due to their geographic location but also highlighted that both Islands possess fascinating and unique features that have the potential to attract niche tourism markets. A key finding of this paper is that the tourism stimulus or potential attraction can also be the chief threat to the islands’ economic survival hence the two edges of the sword. Further research is required to assess the effect of the withdrawal of the Refugee Processing Centre on Nauru’s economy and to evaluate the impact of climate change on Tuvalu’s society and potential adaption strategies.

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