Wyniki wyszukiwania - Biblioteka Nauki

1

Ambient noise induced by large-amplitude internal waves in the ocean

100%

Serebryany A. , Aredov A. , Okhrimenko N.

Hydroacoustics

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2009

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tom Vol. 12

209-216

EN

Experimental data on the ambient noise generated by large-amplitude internal waves in the ocean are considered. The data are obtained by us during oceanic expeditions in the Indian Ocean and South China Sea. In both cases the generation of noise was caused by solitary internal waves with 50-m amplitudes. The internal waves were accompanied by strong orbital currents (up to 1.5 m/s) which created intense convergence with choppy surface waves at the sea surface. Simultaneous observations of internal waves and parameters of the ambient noise were carried out from a drifting vessel during calm weather. In both cases, the increase in the level of the ambient noise coincided with the passages of internal waves. The analysis of experimental data and the data of numerically modeling are presented.

2

A study on loops and eddies identified from the trajectories of drifters in the North Indian Ocean

88%

Dora S. , Aparna S. G.

Oceanologia

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2021

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tom 63

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nr 4

3

Indian Ocean wind speed variability and global teleconnection patterns

88%

Sinha M. , Jha S. , Chakraborty P.

Oceanologia

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2020

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tom 62

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nr 2

4

Response of eastern Indian Ocean (ODP Site 762B) benthic foraminiferal assemblages to the closure of the Indonesian seaway

88%

Rai A. K. , Singh W. B.

Oceanologia

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2012

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tom No. 54 (3)

449-472

EN

Pliocene-Pleistocene deep sea benthic foraminifera from ODP Site 762B in the eastern Indian Ocean were examined to understand the tectonically/climatically induced palaeoceanographic changes. In addition to already published data on this site by Rai & Singh (2001), some more faunal parameters were considered in the present work. Characteristic benthic foraminiferal assemblages as well as more diverse fauna during the early Pliocene (before 3.5 Ma) reflected relatively oligotrophic and warm bottom water conditions. At the beginning of the late Pliocene (i.e. ~3 š 0.5 Ma) relative abundances of Uvigerina proboscidea, infaunal taxa and high productivity taxa increased, whereas faunal diversity showed a distinct decline, suggesting the development of pronounced upwelling resulting in higher surface water productivity. The strongly reduced inflow of warm and oligotrophic water masses as the South Equatorial Current (SEC) from the South Pacific to the eastern Indian Ocean due to the effective closure of the Indonesian seaway increased the surface water productivity. The closing of the Indonesian seaway during the late Pliocene was also responsible for the cessation of the warm, southward-flowing Leeuwin Current (LC) and the greater influence of the cold, deep and northward-flowing Western Australian Current (WAC) in the eastern Indian Ocean.

5

Rules for Maldi vian Trading Ships Tra velling Abroad (1925) and a Sojourn in Southern Ceylon

88%

Romero‑Frias X.

Politeja : Pismo Wydziału Studiów Miedzynarodowych i Politycznych Uniwersytetu Jagiellońskiego

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2016

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nr 40

67-84

EN

‘Rules for Maldivian Trading Ships,’ the translated document that forms the first part of the paper is a twelve‑page manual published by the Royal House on the rules that were to be followed by Maldivian oceangoing ships while on their yearly trading trip to “the continent” (kara). Kara referred primarily to the island of Ceylon (Sri Lanka), the foreign place that Maldivian traders found most convenient to reach. This trade originated in most major islands of the archipelago in the past, including Minicoy (Maliku), but was vital for the communities living in the atolls located at the southern end of the chain. The second part of the paper includes the translation of a personal account by an old Maldivian trader about his experiences in and around Gali (Galle, Sri Lanka), the description of conditions in the harbour and an inland town in Ceylon, as well as the friendships he established there with local people.

6

Book review: Bimal N. Patel, Aruna K. Malik and William Nunes (eds.), Indian Ocean and Maritime Security: Competition, Cooperation and Treat, Routledge, London and new York: 2017

88%

Kałduński M.

Polish Yearbook of International Law

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2017

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tom 37

308-311

EN

Review of a book: Bimal N. Patel, Aruna K. Malik and William Nunes (eds.), Indian Ocean and Maritime Security: Competition, Cooperation and Treat, Routledge, London and new York: 2017

7

Distribution and biogeochemical perspectives of nutrients in the Eastern Equatorial Indian Ocean

88%

Paul M. , Sanyal P. , Mukherjee R. , Gupta V. K. , Bakshi S. , Acharya A. , Bhattacharya T. , Chakraborty K. , Mukhopadhyay S. K.

Oceanologia

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2024

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tom Vol. 66 (2)

381--393

EN

The seasonal reversal of ocean circulation associated with seasonal change in the direction of prevailing winds and the occurrence of several anomalous events in the Eastern Equatorial Indian Ocean (EEIO) make this region dynamic and complex in terms of its biogeochemical characteristics. Two multidisciplinary cruises were conducted to measure nutrients and associated physicochemical parameters across the water column (up to 1000 m) of the EEIO during boreal summer and winter monsoons to understand the distribution of nutrients and their spatio-temporal variability from a biogeochemical perspective. The seasonality in the thermohaline structure of the region is indistinct except for surface salinity drop during summer monsoon due to more precipitation on-site and in adjoining areas. Low concentrations of chlorophyll at the surface and in the deep chlorophyll maxima represent the oligotrophic nature of this region. Surface water was found nutrient-depleted (0.03–0.4 µM Nitrate, 0.02–0.13 µM Phosphate). The maxima of vertical profiles of nitrate and phosphate were recorded at a shallower depth (150–200 m) when compared to its maxima in usual oceanic conditions, but a silicate maximum was recorded in deeper water. In the surface and upper mixed layer paucity of nutrients resulted in low N:P and N:Si ratios. Therefore, nitrogen limitation is evident. The overall ratio of N:P yielded a mean value of 15.33 and matched with the representative literature value for the Indian Ocean. The minimum oxygen values (<50 µM) in the deep water (150–200 m) indicated a hypoxic condition. No signature of denitrification and a moderate nitrate deficit were observed in deep waters. The negative values of Nitrate anomaly (N-tracer) at 50–100 m depth were attributed to a Watermass influenced by denitrification. The prevailing oligotrophic condition caused limited synthesis of organic matter and subsequently little decomposition in deep water. The maxima in the apparent oxygen utilization (AOU) profile are confined to 150 to 200 m depth and represent the most active zone for regeneration that is limited to shallow depth. Regenerated nutrients reached maxima at shallower depth and primarily control material cycling in this region. Supply of nitrate to the surface water based on the preformed values of prevailing water mass was primarily by Bay of Bengal water. According to the findings of this study, preformed nitrate concentrations between 100 and 200 metres below the surface were found very low, indicating that Indonesian Through Flow (ITF) has little impact on the distribution of nutrients in this area.

8

Digenetic trematodes of marine teleost fishes from the Seychelles, Indian Ocean. III

88%

Toman G.

Acta Parasitologica

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1992

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tom 37

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nr 3

EN

Several new and known Digenea are measured and described; Zoogonidae: Zoogonoides kamegaii sp. n., Zoogonoides anampsi sp. n., Deretrema ludwicki sp. n. and Lecithostaphylus pomacentri sp. n.; Monorchiidae: Lasiotocus himezi Yamaguti, 1951; Opecoelidae: Paradactylostomum saipanensis g. n. sp. n., Pseudopecoeloides capucini sp. n., Pseudopecoeloides wekeula Yamaguti, 1970, Pseudopecoeloides sp., Apertile overstreeti sp. n., Plagioporus (Caudotestis) seychellensis sp. n. and Podocotyloides stenometra Pritchard, 1966; Callodistomidae: Guptatrema papillonae sp. n.; and Opistholebetidae: Maculifer subaequiporus Nicoll, 1915.

9

Digenetic trematodes of marine teleost fishes from the Seychelles, Indian Ocean. IV

88%

Toman G.

Acta Parasitologica

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1992

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tom 37

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nr 3

EN

New and known trematodes are discussed, immature worms are not taken under consideration. Trematodes mentioned are: Apocreadiidae: Apocreadium balistis Manter, 1947; Acanthocolpidae: Stephanostomum casum (Linton, 1910) McFarlane, 1934; Hemiuridae: Tubulovesicula lycodontis sp. n.; Lecithocladium chingi Manter et Pritchard, 1960.

10

Trade and 'treasure': the role of Suakin in the movement of valuables (15th–19th centuries)

75%

Smith L. , Taha S. , Philips J. , Mallinson M.

Polish Archaeology in the Mediterranean

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2020

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tom 29(1)

EN

This paper focuses historical and archaeological evidence for the ‘valuables’ passing through Suakin, as part of the Red Sea-Indian Ocean trade. The main locations on Suakin Island Town investigated 2002-2013 are briefly described. Interviews show that at Suakin, in the later 19th century/early 20th century, imported valuables included fabrics from Europe, perfume oils, cloths and wooden chests from India; porcelain from China and Turkey; rugs from Persia/Iran and glass from Italy. Interviews and early modern European accounts indicate the range of products from the hinterland, such as cotton, gold, ivory, ostrich feathers, slaves, horses, gum arabic, ebony, musk, tobacco, rubber and coffee. Local fishermen supplied fish, shells, pearls and mother-of-pearl. The archaeological evidence indicates pottery and porcelain from the Arabian Peninsula, south-west Asia, south Asia, China and south-east Asia, while identifications of wood samples indicates teak from south and south-east Asia. A combination of archaeological, historical and ethnographic evidence is needed to build up a picture of the trade in valuables.

11

Precursory Study on South Asian Security and Geopolitics

75%

Ramachandra B.

Acta Asiatica Varsoviensia

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2018

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nr 31

82-96

XX

Security issues in South Asia could be the key to world peace. Understanding the particular dynamics of security creation and its provision in the region has therefore become extremely important. That said, there are major hurdles to a proper comprehension of the underlying complexities. Most of the home-grown security studies and analyses are sponsored or directly provided by the security establishment, focusing mainly on the tactical capacities of the military apparatus. The outside academic community, mainly the Singapore-Australia-USA triangle, tend to concentrate on the global perspectives with predominance given to the India-China aspect of the security configuration. For these reasons, vital and insightful concepts are missing for the proper and realistic understanding of the security policies and configuration of South Asia. The purpose of this essay will be to introduce some of these analytical concepts and give a deeper understanding of the issues at work, in short to provide a historic background to the conflict and security configuration of South Asia

12

Analysis of labile aluminium form in grain size fractions of tsunami deposits in Thailand

75%

Ziola-Frankowska A. , Frankowski M. , Szczucinski W. , Siepak J.

Polish Journal of Environmental Studies

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2009

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tom 18

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nr 1

77-85

EN

Our study presents the results of determining labile aluminium form in samples from the 2004 tsunamiaffected coastal zone of Thailand. The samples were collected from tsunami deposits, beach sediments, sediments underlying the tsunami deposits (pre 2004 tsunami soil), as well as from soils from areas, that were not flooded. The extraction of the labile form of aluminium was performed using 3 mol L⁻¹ HCl in twelve grain size fractions. In the surface layer samples the highest concentrations were determined in the tsunami deposits in fractions <0.063 mm (5850 mg kg⁻¹). The highest determined concentration in the whole set of investigated samples occurred in soil sample in fractions 0.09-0.125 mm (19770 mg kg⁻¹). An increase in concentration of labile aluminium form, along with decreasing grain diameter, was observed in samples from all the studied settings. In general, concentrations were higher in soil samples not affected by the tsunami. This is probably due to steady weathering of minerals during soil forming processes and removal of sediment grain surface coatings potentially enriched in labile Al during high energy transport by tsunami.

13

The shoemaker spinefoot Siganus sutor (Valenciennes, 1835) in the marine waters of Iraq: second appearance and the northernmost record in the northern Indian Ocean

75%

Jawad L. , Abed J. , Resen A. K. , Al-Yassein R. , Kulw A. M.

Oceanological and Hydrobiological Studies

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2023

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tom Vol. 52, No. 2

166--171

EN

A new record of Siganus sutor from inland artificial marine extension Shatt al-Basrah canal, south of Iraq, is reported.Two specimens were collected during an ichthyologic survey on 2 November 2021. The specimens are 127 and 129 mm in total length. This record from Iraqi waters represents the species’ second and northernmost appearance in thenorthern Indian Ocean.

14

Remotely induced storm effects on the coastal flooding along the southwest coast of India

75%

Swathy Krishna P. S. , Aboobacker V. M. , Ramesh M. , Nair L. S.

Oceanologia

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2023

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tom Vol. 65 (3)

503--516

EN

The southwest coast of India is exposed to long-period swells propagated from the South Indian Ocean during pre- and post-monsoon seasons. Although swells from the Southern Ocean and Atlantic Ocean were identified in the North Indian Ocean, their existence and impact along the southwest coast of India were not well investigated. On 19 March 2019, the Valiyathura-Shangumukham coastal stretch along the southwest coast of India experienced an unexpected coastal inundation without having a prompt forecast/warning, and not induced by a storm/cyclone in its vicinity. The present study investigates the causative forces of this inundation and estimates the wave runup and inundation. The study reveals that an unusual swell system was developed in the Indian-Atlantic-Southern Oceans (IASO) interface during 10–12 March and propagated towards the southwest coast of India. The measured wave spectra off Varkala clearly depicts the presence of long-period swells (Tp>18 s), which dominantly occurred as single-peaked. Wave modelling has been carried out to characterize the wave transformation associated with the “IASO interface swells” along the southern Kerala coast. A wave runup of up to 0.93 m height and a coastal inundation of up to 83 m onshore have been estimated during this event.

15

Indian Ocean wind speed variability and global teleconnection patterns

75%

Sinha M. , Jha S. , Chakraborty P.

Oceanologia

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2020

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tom No. 62 (2)

126--138

EN

The influence of the local sea surface temperature (SST) and remote ENSO (El Niño-Southern Oscillation) indices on the wind speed (WS) data were explored for the Indian Ocean region. Relationships among the parameters were studied using spatial correlation plots and significant correlation ranges. Two months (July and January) representing opposite monsoon phases were selected for analysis for the period 1950-2016. There was a significant negative correlation between WS and SST over the Bay of Bengal (BOB) during July. Although different ENSO indices correlated differently in different areas of the Indian Ocean, the region off the coast of Sri Lanka was most significantly teleconnected. The southwest monsoon locally impacted the WS and SST relationship and the WS parameter was remotely teleconnected in both the monsoon seasons. Further empirical orthogonal function (EOF) analysis was applied on the 67 years WS data of the BOB region to extract the dominant mode representing maximum variability of the total variance. The temporal pattern of the first principal component (PC1) of WS data was linked to the North Atlantic Oscillations in January and the Atlantic Multidecadal Oscillation in July respectively. The continuous wavelet power spectra of the PC1 of WS showed significant regions in the 2-4-year band resembling the ENSO variability. Wavelet coherence applied between PC1 of WS and the ENSO indices showed greatest values for January in the 8-16-year band and for July in the 0-4-year band. A close relationship was established between the WS variability in BOB and the ENSO indices.

16

Generation and Assessment of ARGO Sea Surface Temperature Climatology for the Indian Ocean Region

75%

Jha R. K. , Bhaskar T. V. S. U.

Oceanologia

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2023

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tom Vol. 65 (2)

343--357

EN

ARGO program was conceived with an aim to generate near real-time ocean observations as the primary in-situ sources for use in operational oceanography studies. Two decades-long ARGO near-surface temperature data set was used for generating monthly gridded ARGO sea surface temperature (ASST) product on a climatological scale. Data interpolating variational analysis (DIVA) method was employed for generating the product with a spatial resolution of 0.25° x 0.25° for the Tropical Indian Ocean. This monthly ASST product was evaluated using five different climatological SST products derived from in-situ and satellite measurements. Various statistics such as BIAS, RMSE, coefficient of correlation, and skill scores were generated to evaluate the reliability of the ASST product. Further, the ASST product was validated with climatological in-situ SST obtained from RAMA and OMNI moorings deployed in the Indian Ocean. Statistical comparisons showed low BIAS and RMSE, and high correlation and skill scores with most of the buoys locations and the gridded SST products. Results concluded that the near-surface temperature data from ARGO can be used along with other SST data sets in the generation of high-resolution blended SST products.

17

The geomorphology of the Makran Trench in the context of the geological and geophysical settings of the Arabian Sea

75%

Lemenkova P.

Geology, Geophysics and Environment

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2020

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tom Vol. 46, no. 3

205--222

EN

The study focuses on the Makran Trench in the Arabian Sea basin, in the north Indian Ocean. The area is tectonically active, with a system of ridges and fracture zones morphologically separating the Arabian Sea. The study examined the relationships between the topographic structure of the Makran Trench and the regional settings of the Arabian Sea: geomorphology, sediment thickness, geophysical fields, geology and tectonic lineaments. The methodology is based on the GMT scripting toolset. The spatial analysis includes high-resolution datasets GEBCO, EGM2008, GlobSed and data on tectonics, geology, geophysics, sediment thickness and topographic terrain model visualized by GMT. The paper also defined a way in which the proprietary ESRI data format can be transformed into the freely available GMT geospatial data of the geoid EGM2008 model. The geomorphological modeling included the automatic digitization of 300-km width cross-section profiles of the trench demonstrating its submarine relief. The analysis showed a correlation between the geological and tectonic structures, asymmetric geomorphology and geophysical anomaly fields. Gravity data indicate a crustal structure with anomalies generated by the bending of the lithosphere into the Makran subduction zone and density variations in the mantle reflected on the gravity maps. The gravity correlates with lineaments of the geomorphic structures. Bathymetric analysis revealed the most frequent depth (448 samples) at −3,250 to −3,500 m, followed by intervals: −3,000 to −3,250 m, −2,750 to −3,000 m. The declining continental slope correlates with gradually decreasing depths as equally distributed bins: 124 samples (−2,500 to −2,750 m), 96 (−2,250 to −2,500 m), 86 (−2,000 to −2,250 m). The trench is an asymmetric form with a high steepness on the continental slope of Pakistan and low steepness with a flat valley on the oceanward side. The multi-source data integration is important for seafloor mapping and the geomorphological analysis of oceanic trenches hidden to direct observations. The machine learning methods of GMT and cartographic modeling provide possibilities for the effective visualization of the trench. The comparison of the geomorphology with gravity anomalies, tectonic lineation, geological structures and topographical variations provides more detail to studies of the seafloor in the Arabian Sea.

18

Characterictics of turbulent horizontal heat exchange in subsurface layers of the Southern Ocean. Part II. Indian Ocean and Pacific

75%

Druet C. , Siwecki R.

Oceanologia

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1986

|

tom 24

19

Indian and Australian Maritime Security Doctrines in the Indian Ocean Region in the 21st Century. Christian Bueger’s Matrix of Maritime Security Approach

75%

Łukaszuk T.

Polish Political Science Yearbook

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2020

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nr 4 (49)

105-127

EN

The article’s purpose is the multidimensional analysis of the evolution of Australia and India’s maritime policies and their impact on the endeavors to develop their maritime cooperation in the 21st century. Two research questions are to be answered in that connection: what changes and why India and Australia introduced to enhance their maritime security doctrines in the 21st century and why those changes contributed to the more in-depth cooperation in the second decade of the 21st century. The hypothesis based on those questions argues that not only the rise of China but also global processes in maritime affairs - such as the growing number of state and non-state actors, as well as the interdependence between the fields of human activities at sea - pushed the littorals like India and Australia to turn their maritime strength from coastal to oceanic and convinced them too to cooperate. That process was accompanied by the convergence of the security perceptions by both countries (India and Australia) and the mutual understanding of common interests in all the elements of modern maritime security. The Christian Bueger’s matrix serves as an explanatory framework to highlight the dynamics and broader context of the changes in India and Australia’s maritime security doctrines in the 21st century. It provides the conceptual framework for explaining closer cooperation between these two countries. The article analyzes India and Australia’s maritime strategies, focusing on four variables from Bueger’s matrix: national security, economic development, marine environment, and human security. In those dependent variables, particular elements of their activities serving as sub-variables are highlighted: in national security - shaping the seapower; in economic development - Illegal, Unreported, and Unregulated (IUU) fishing; in the marine environment - climate change mitigation; in human security - the fight against piracy and human trafficking. The choice of the mentioned elements is justified by their role in Australia and India’s activities within maritime strategies and their influence on other elements of the maritime security matrix. The article starts with a description of Bueger’s matrix in the context of the evolution of the maritime security concept in international relations. The second part outlines the centrality of the Indian Ocean in Indian and Australian modern military and economic security. The third part explores and explains the roots of Indian maritime security thinking, and the fourth investigates the evolution in Australia’s attitude toward maritime affairs. The final part presents the developments in Indo-Australian bilateral cooperation in the 21st century.

20

The Effect of ENSO on the Upwelling Intensity in the Seas along the Northern Coast of Papua: A Case Study of the 2015-2016 El Niño and the 2010-2011 La Niña Events

75%

Lesmana P. S. O. P. , Wirasatriya A. , Setiyono H. , Suryoputro A. A. D. , Wijaya Y. J. , Ismunarti D. H. , Haryanti D. , Abdillah M. R.

Ecological Engineering & Environmental Technology

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2024

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tom Vol. 25, iss. 2

243--253

EN

The seas along the Northern Coast of Papua constitute a region with complex oceanographic conditions as they are situated within the Indo-Pacific warm pool (IPWP). The geographical location in the southern hemisphere induces upwelling during the west monsoon season (December-January-February). Additionally, interannual phenomena such as the El Niño Southern Oscillation (ENSO) can impact the intensity of upwelling in these waters. This study aimed to compare the upwelling intensity in the seas along the Northern Coast of Papua during neutral phases and ENSO phases. The main indicators of upwelling are sea surface temperature (SST) and Ekman mass transport (EMT). The data utilized in this study include SST from GHRSST and surface wind from ASCAT. The data processing employed the monthly composite method with spatiotemporal analysis based on anomaly results derived from monthly climatology. The analysis results reveal that El Niño 2015–2016 led to an increase in upwelling intensity ranging from 1.82 to 4.00 m/s2, while La Niña 2010–2011 resulted in a weakening of upwelling intensity ranging from 4.95 to 6.56 m/s2 in the seas along the Northern Coast of Papua. On the basis of correlation and regression analysis, it can be concluded that offshore EMT significantly influences upwelling anomalies in the southeastern waters, whereas the northwestern waters are more influenced by the shifting IPWP during ENSO.