Impact of oceanic upwelling on morphometric and molecular indices of an intertidal fishScartichthys viridis(Blenniidae)

2011 ◽  
Vol 44 (1) ◽  
pp. 33-42 ◽  
Author(s):  
J. Pulgar ◽  
M. Alvarez ◽  
J. Morales ◽  
M. Garcia-Huidobro ◽  
M. Aldana ◽  
...  
Keyword(s):  
Oceanic Upwelling

Guadalupian cool versus warm water deposits in central Iran: a record of the Capitanian Kamura event

2017 ◽  
Vol 156 (3) ◽  
pp. 430-446 ◽  
Author(s):  
SAKINEH AREFIFARD
Keyword(s):  
Primary Productivity ◽  
Association Studies ◽  
Central Iran ◽  
Warm Water ◽  
Middle Permian ◽  
Warm Climate ◽  
Diagenetic Alteration ◽  
Lime Mud ◽  
Jamal Formation ◽  
Oceanic Upwelling

AbstractAn integration of geochemical and grain association studies were carried out on Middle Permian deposits in central Iran where both cool and warm water carbonates are found. The recrystallization of most bioclasts, lime-mud matrix and ooids along with high Sr contents suggests a probable original aragonite mineralogy for carbonates of the Middle Permian Jamal Formation at the Shotori section. Low bulk carbonate δ18O values imply pervasive diagenetic alteration in this section. Conversely, Middle Permian deposits at the correlative Bagh-e Vang section have a probable calcite precursor supported by low Sr contents and no evidence of recrystallization. This mineralogical variation in these coeval carbonates is considered to be due to the change in depth and temperature of the depositional palaeoenvironment. δ13C values started to rise over 2 ‰ PDB and reached a maximum of 4.3 ‰ PDB at the Wordian–Capitanian boundary at the Bagh-e Vang section. This δ13C rise is attributed to high primary productivity as previously reported in the Capitanian Abadeh Formation in central Iran. The positive δ13C excursion in these sections is correlated with the Capitanian ‘Kamura event’ identified from the mid-Panthalassian sections in Japan. No noticeable positive excursion occurs in the δ13C plot at the Shotori section making the interpretation of palaeo-productivity difficult. It is suggested that an active oceanic upwelling was the probable driver of the Middle Permian oceanic productivity in central Iran. Remarkable negative δ13C excursions around 3.7 and 4.2 ‰ PDB in Capitanian carbonates close to the Guadalupian–Lopingian boundary at the Bagh-e Vang and Abadeh sections, respectively are recorded, which are a proxy for low palaeo-productivity and a transition from a cool to warm climate, consistent with an early Lopingian sea level rise.

Chemical weathering and erosion responses to changing monsoon climate in the Late Miocene of Southwest Asia

2019 ◽  
Vol 157 (6) ◽  
pp. 939-955 ◽  
Author(s):  
Peter D Clift ◽  
Denise K Kulhanek ◽  
Peng Zhou ◽  
Melanie G Bowen ◽  
Sophie M Vincent ◽  
...  
Keyword(s):  
Late Miocene ◽  
Chemical Weathering ◽  
Southern China ◽  
Drainage Basins ◽  
Flood Plains ◽  
Dry Conditions ◽  
Climatic Transition ◽  
Oceanic Upwelling ◽  
The Pearl River ◽  
International Ocean Discovery Program

AbstractThe late Miocene is a time of strong environmental change in SW Asia. Himalayan foreland stable isotope data show a shift in the dominant vegetation of the flood plains away from trees and shrubs towards more C4 grasslands at a time when oceanic upwelling increased along the Oman margin. We present integrated geochemical and colour spectral records from International Ocean Discovery Program Site U1456 in the eastern Arabian Sea to reconstruct changing chemical weathering and erosion, as well as relative humidity during this climatic transition. Increasing hematite/goethite ratios derived from spectral data are consistent with long-term drying after c. 7.7 Ma. Times of dry conditions are largely associated with weaker chemical alteration measured by K/Rb and reduced coarse clastic flux, constrained by Si/Al and Zr/Al. A temporary phase of increased humidity from 6.3 to 5.95 Ma shows a reversal to stronger weathering and erosion. Wetter conditions can result in both more and less alteration due to the nonlinear relationship between weathering rates, precipitation and sediment transport times. Trends in relative aridity do not follow existing palaeoceanographic records and are not apparently linked to changes in Tibetan or Himalayan elevation, but more closely correlate with global cooling. An apparent opposing trend in the humidity evolution in the Indus compared to southern China, as tracked by spectrally estimated hematite/goethite, likely reflects differences in the topography in the Indus compared to the Pearl River drainage basins, as well as the generally wetter climate in southern China.

Effects of Streamflow and Upwelling on Yield of Wild Coho Salmon (Oncorhynchus kisutch) in Oregon

1981 ◽  
Vol 38 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Dennis L. Scarnecchia
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Positive Relation ◽  
Significant Relation ◽  
Oregon Coast ◽  
Growth And Survival ◽  
Coastal Rivers ◽  
High Flows ◽  
Oceanic Upwelling

To investigate the dependence of coho salmon (Oncorhynchus kisutch) yield on streamflow and oceanic upwelling, I regressed catch by the Oregon commercial troll fishery from 1942 to 1962 against indices of offshore upwelling the previous spring and measurements of streamflow from five Oregon coastal rivers during the freshwater rearing phase. A highly significant positive relation was found between total streamflows during the freshwater residency of the fish for the five rivers combined and the weight of the annual catch of coho salmon from 1942 to 1962. There was also a significant positive relation between total combined annual (January–December) flows for these rivers and the catch 2 yr later. Conversely, I found no significant relation between the 60 consecutive days of lowest flow during summer and catch 2 yr later. High flows during freshwater rearing probably provide more habitat and better conditions for growth and survival. I also found a significant positive relation between April through June upwelling at two stations and catch of coho salmon the following year from 1947 to 1962. Fifty-six percent of the variation in catch from 1947 to 1962 was explained by the total flows during freshwater residency, 60 consecutive days of lowest flow, plus combined April through June upwelling at both stations. It is suggested that some stocks of coho salmon smolts may move southward or remain in local offshore waters after they enter the ocean to take advantage of the production of invertebrates resulting from upwelling.Key words: streamflow, upwelling, coho salmon, Oregon coast

scholarly journals Radiocarbon/Tree-Ring Calibration, Solar Activity, and Upwelling of Ocean Water

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 987-995 ◽  
Author(s):  
F B Knox ◽  
B G McFadgen
Keyword(s):  
Solar Activity ◽  
Tree Ring ◽  
North Atlantic ◽  
Little Ice Age ◽  
Ice Age ◽  
Calibration Data ◽  
Ocean Water ◽  
Smooth Curves ◽  
The North ◽  
Oceanic Upwelling

Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot numbers over the period AD 1670 to 1950.Calibration curves from different parts of the globe are not identical, and appear to be determined by a combination of variable solar activity and variable oceanic upwelling of 14C-depleted water, with the variable upwelling itself partly determined by solar activity.

Oceanic upwelling and downwelling processes in waters off the west coast of India

2008 ◽  
Vol 58 (3-4) ◽  
pp. 213-226 ◽  
Author(s):  
A. D. Rao ◽  
Madhu Joshi ◽  
M. Ravichandran
Keyword(s):  
West Coast ◽  
The West ◽  
West Coast Of India ◽  
Oceanic Upwelling ◽  
Upwelling And Downwelling

scholarly journals Oceanic upwelling and productivity in the eastern tropical Pacific

1991 ◽  
Vol 36 (8) ◽  
pp. 1834-1850 ◽  
Author(s):  
Paul C. Fiedler ◽  
Valerie Philbrick ◽  
Francisco P. Chavez
Keyword(s):  
Tropical Pacific ◽  
Eastern Tropical Pacific ◽  
Oceanic Upwelling

scholarly journals Interactive Feedback between ENSO and the Indian Ocean in an Interactive Ensemble Coupled Model

2006 ◽  
Vol 19 (24) ◽  
pp. 6371-6381 ◽  
Author(s):  
Jong-Seong Kug ◽  
Ben P. Kirtman ◽  
In-Sik Kang
Keyword(s):  
Indian Ocean ◽  
El Niño ◽  
El Nino ◽  
Coupled Model ◽  
Walker Circulation ◽  
Western Pacific ◽  
The Indian Ocean ◽  
Oceanic Upwelling ◽  
Interactive Feedback ◽  
The Western Pacific

Abstract An interactive feedback between ENSO and the Indian Ocean is investigated using a Center for Ocean–Land–Atmosphere Studies (COLA) interactive ensemble coupled model. From a long-term simulation of the coupled GCM, it is shown that El Niño events terminate relatively rapidly when the Indian Ocean SST is anomalously warm. The anomalous Indian Ocean warming induces the anomalous easterlies over the western Pacific by modulating the Walker circulation. In turn, the anomalous easterlies generate oceanic-upwelling Kelvin waves over the western Pacific, which propagate eastward and accelerate the decay of the warm SST in the eastern Pacific. As a result, El Niño terminates relatively quickly, and the phase transition from El Niño to La Niña progresses rapidly. These interactive processes are consistent with those derived from the previous observational analyses.

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