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Solar insolation driven periodicities in southwest monsoon and its impact on NE Arabian Sea paleoceanography

Geoscience Frontiers 2019年第6期10卷 2251-2263页

作者： Syed Azharuddin Pawan Govil Arun Deo Singh Ravi Mishra Mayank Shekhar Birbal Sahni Institute of Palaeosciences LucknowU.P.226007India Department of Geology Banaras Hindu UniversityVaranasi221005India National Centre for Antarctic and Ocean Research Vasco-da-GamaGoa403804India

In the northeastern(NE) Arabian Sea,the fluctuation in terrestrial and freshwater runoff directly depends on southwest monsoon(SWM) precipitation as well as the meltwater flux provided by Indus River.Therefore,analysis of multi-proxy spectral signatures was carried out to trace the high-resolution SWM periodicities and their influence on the productivity,regional sea level fluctuations and depositional processes in the NE Arabian Sea.The time series data of stable isotopes of oxygen(δ^18 O(G.ruber)).carbon(δ^13 C(G.ruber) and δ^13 C(org)) and nitrogen(δ^15 N).Total Organic Carbon(TOC),planktic-benthic foraminiferal ratio(P/B ratio) and>63 μm coarse fraction(CF) were used from two coastal sedimentary cores located offshore Saurashtra,NE Arabian Sea(Core SK-240/485 having 88 m water depth;Core GC/SK-240/496 having 174 m water depth).The REDFIT based spectral analysis recorded significant periodicities(>90% significance) in δ^18 0 time series centered at^1609,~667,~525,~296,~290 and^256 years.Further,the significant periodicities recorded in carbon isotopes time series(δ^13 C(G.ruber) and δ^13 C(org))centered at^681,~512,~471,~452,~438,~360,~292,~275,~269,~245 and^209 years.The significant periodicities in TOC include^471 and-322 years whereas δ^15 N time series recorded significant periodicity centered at-360 years.The significant periodicities in P/B ratio time series centered at^512,~388,~304,~250,~235,~217,~152,~139 and^135 years while CF recorded^268,~216,~209,~198,~188,~173 and^140 years significant periodicities.The observed periodicities in the multi-proxy record consist of similar cycles(within the radiocarbon dating error) which also natch with previously reported solar insolation influenced SWM and other global and regional cycles.Further,the stationarity of the data has been verified using wavelet analysis and shows similar periodicities as observed in REDFIT analysis.Thereafter,the depositional behaviour was studied using correlation analysis of the common periods of δ^18 0 time series of both the cores

关键词： Southwest monsoon Periodicities Arabian sea Spectral analysis Foraminifera

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Upper ocean high resolution regional modeling of the Arabian Sea and Bay of Bengal

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Acta Oceanologica Sinica 2019年第5期38卷 32-50页

作者： Dwivedi Suneet Mishra Alok Kumar Srivastava Atul K Banerjee Centre of Atmospheric and Ocean Studies and M N Saha Centre of Space Studies University of Allahabad

In this paper, effort is made to demonstrate the quality of high-resolution regional ocean circulation model in realistically simulating the circulation and variability properties of the northern Indian Ocean(10°S–25°N,45°–100°E) covering the Arabian Sea(AS) and Bay of Bengal(BoB). The model run using the open boundary conditions is carried out at 10 km horizontal resolution and highest vertical resolution of 2 m in the upper ocean.The surface and sub-surface structure of hydrographic variables(temperature and salinity) and currents is compared against the observations during 1998–2014(17 years). In particular, the seasonal variability of the sea surface temperature, sea surface salinity, and surface currents over the model domain is studied. The highresolution model's ability in correct estimation of the spatio-temporal mixed layer depth(MLD) variability of the AS and BoB is also shown. The lowest MLD values are observed during spring(March-April-May) and highest during winter(December-January-February) seasons. The maximum MLD in the AS(BoB) during December to February reaches 150 m (67 m). On the other hand, the minimum MLD in these regions during March-April-May becomes as low as 11–12 m. The influence of wind stress, net heat flux and freshwater flux on the seasonal variability of the MLD is discussed. The physical processes controlling the seasonal cycle of sea surface temperature are investigated by carrying out mixed layer heat budget analysis. It is found that air-sea fluxes play a dominant role in the seasonal evolution of sea surface temperature of the northern Indian Ocean and the contribution of horizontal advection, vertical entrainment and diffusion processes is small. The upper ocean zonal and meridional volume transport across different sections in the AS and BoB is also computed. The seasonal variability of the transports is studied in the context of monsoonal currents.

关键词： Indian Ocean modeling Arabian Sea and Bay of Bengal mixed layer depth transport

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Arabian Peninsula-North Pacific Oscillation and its association with the Asian summer monsoon

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Science China Earth Sciences 2008年第7期51卷 1001-1012页

作者： SUN JianQi1, YUAN Wei2 & GAO YuZhong3 1 Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 2 China Meteorological Administration Training Centre, Beijing 100081, China 3 Heilongjiang Meteorological Observatory, Harbin 150030, China Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China China Meteorological Administration Training Centre Beijing China Heilongjiang Meteorological Observatory Harbin China

Using correlation and EOF analyses on sea level pressure from 57-year NCEP-NCAR reanalysis data, the Arabian Peninsula-North Pacific Oscillation (APNPO) is identified. The APNPO reflects the co-variability between the North Pacific high and South Asian summer monsoon low. This teleconnec- tion pattern is closely related to the Asian summer monsoon. On interannual timescale, it co-varies with both the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM); on decadal timescale, it co-varies with the EASM: both exhibit two abrupt climate changes in the middle 1960s and the late 1970s respectively. The possible physical process for the connections between the APNPO and Asian summer monsoon is then explored by analyzing the APNPO-related atmospheric circulations. The results show that with a strong APNPO, the Somali Jet, SASM flow, EASM flow, and South Asian high are all enhanced, and an anomalous anticyclone is produced at the upper level over northeast China via a zonal wave train. Meanwhile, the moisture transportation to the Asian monsoon regions is also strengthened in a strong APNPO year, leading to a strong moisture convergence over India and northern China. All these changes of circulations and moisture conditions finally result in an anoma- lous Asian summer monsoon and monsoon rainfall over India and northern China. In addition, the APNPO has a good persistence from spring to summer. The spring APNPO is also significantly corre- lated with Asian summer monsoon variability. The spring APNPO might therefore provide valuable in- formation for the prediction of Asian summer monsoon.

关键词： Arabian Peninsula-North Pacific Oscillation East Asian summer monsoon South Asian summer monsoon wave train abrupt climate change

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Late Neoproterozoic adakitic magmatism of the eastern Arabian Nubian Shield

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Geoscience Frontiers 2019年第6期10卷 1981-1992页

作者： Grant M.Cox John Foden Alan S.Collins Centre for Tectonics Resources and Exploration(TRaX) Dept of Earth SciencesThe University of Adelaide

Late Neoproterozoic adakitic magmatism within the Eastern Arabian Nubian Shield has been dated at633.2±9.0 Ma(2σ).These magnas intrude the forearc Ad Dawadimi Basin,which is composed of metapelitic schists and greywacke along with ophiolitic melanges of boninitic affinity which underwent inversion and deformation by^620 Ma.This adakitic magmatism,while intruding parts of the Ad Dawadimi Basin,predates this deformation,but is possibly coincident with basin closure.As adakitic magmatism requires melting of an amphibolite or eclogitic source,empirical and experimental constraints require anomalously hot supra-subduction zone mantle.Considering that this magmatism immediately predates basin inversion,these magmas possibly pinpoint the timing of the slab breaking,marking the terminal stages of arc magmatism,terrane accretion and the influx of hot oceanic asthenospheric mantle.This influx of hot asthenospheric mantle may also be responsible for postcolltsional A-type magmatism.

关键词： Arabian Nubian Shield Adakites A-type magmatism

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Time of foaling in Arabian mares raised in Tiaret, Algeria

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Asian Pacific Journal of Tropical Biomedicine 2013年第7期3卷 587-588页

作者： Samia Meliani Bouabdellah Benallou Miloud Halbouche Zohra Haddouche Master of Reproduction Sciences Veterinary Institute University of Tiaret14000 Algeria Biology of Reproduction Veterinary Institute University of Tiaret14000 Algeria Professor of Agronomic Sciences Mostaganem UniversityAlgeria Reproduction Manager of the National Haras of Chaouchaoua Tiaret Algeria

Objective:To enhance effectiveness of reproduction management in Arabian mares,factorsinfluencing the time of foaling were investigated in this study.Methods:Data were collectedat the National Haras of Tiaret in Algeria from 2003 to 2010.The foaling time of 255 Arabian purebred mares,aged from 3 to 20 years were used for this study.Results:A total of 78.07%of foalinghappens between 7 pm and 6 am.Conclusions:The influence of the month of foaling and the sexof the foal,on the time of foaling was statically significant.

关键词： Arabian mare Time of foaling Reproduction Foal heat

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Endoscopic monitoring the estrous phase of Arabian mares with assaying its biopsy

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Asian pacific Journal of Reproduction 2017年第3期6卷 140-143页

作者： Mohamed Fathi Haithem AMFarghali Nagla AAbdelkader Khattab MA El Karmoty AF Department of Theriogenoloy Faculty of Veterinary MedicineCairo UniversityEgypt Department of Surgery Anesthesiology and RadiologyFaculty of Veterinary MedicineCairo UniversityEgypt Department of Cytology and Histology Faculty of Veterinary MedicineCairo UniversityEgypt Department of Anatomy and Embryology Faculty of Veterinary MedicineCairo UniversityEgypt

Objective:To evaluate the changes occur in the vagina, cervix and endometrium during the pre- ovulatory period in Arabian mares by using endoscope as a diagnostic tool as well as the availability of taking an endoscopic biopsy during this stage.Methods:Ten cyclic and healthy Arabian mares were subjected to ultrasound scanning of their ovaries to estimate the diameter of the preovulatory follicles, collection of blood samples for estimating the hormonal levels (Estradiol-17β and progestrone) for confirming the estrous phase, endoscopic monitoring their vagina, cervix and endometrium, the availability of taking biopsical samples and histological examination of the obtained samples.Results:The obtained data revealed that, the mean diameter of the preovulatory follicles was (3.95±0.34) cm, the plasma estradiol and progestrone levels were (85.98±5.26) pg/mL and (0.73±0.23) ng/mL, respectively, endoscopic monitoring the vagina, cervix and endometrium revealed hyperemic vaginal mucous membrane, soft and opened cervical ostium with abundant estrous mucous and folding, hyperemic and edematous appearance of the endometrium, respectively and the histological features of the biopsical endometrial samples revealed that, The lamina propria-sub mucosa was packed with simple or branched tubular glands lined with simple columnar epithelium showing oval or rounded dark nuclei with different degrees of secretory activities of the glands.Conclusions: The endoscope proved to be a reliable tool for confirming the estrous phase in mares and monitoring the gross features of the vagina, the cervix and the endometrium, in addition to the availability of taking biopsical smears.

关键词： Arabian mares Endoscope Estrous

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Measurements of Natural Radioactivity of Industrial Raw Materials from the West of Saudi Arabia (Arabian Shield)

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Journal of Modern Physics 2015年第4期6卷 510-520页

作者： Safia H. Q. Hamidalddin Physics Department Girls Faculty of Science King Abdulaziz University Jeddah Saudi Arabia

Rock samples of industrial raw materials that are used in the building, from the West of Saudi Arabia (Arabian Shield), have been investigated using X-ray diffraction to identify the mineral chemical composition. The concentrations of Al%, Bi, Pb, Th, U, and K in ppm were measured by atomic absorption analysis. The activity concentrations in Bq/kg dry weight of 226Ra, 232Th and 40K were measured using gamma-ray spectrometry where the range and average were found to be (03.04 - 10.91) 07.90, (03.19 - 13.31) 09.14 and (95.59 - 361.52) 234.81 in Basalt, for Granite (33.81 - 89.13) 80.85, (28.42 - 112.77) 68.50 and (1260.13 - 1629.21) 1376.69, for Gold (00.78 - 11.84) 04.73, (01.48 - 4.69) 02.69 and (13.76 - 445.09) 197.58, for Andesite 05.72, 03.73 and 471.93, and for Marble 01.56, 01.38 and 10.15 respectively. Most results existing within the given values in building materials by UNSCEAR 1993 included Raeq (Bq/kg), D (nGy/h), Deff (mSv/y), Hex and Hin, which meant that it was safe for humans.

关键词： Arabian Shield Industrial Raw Materials Harrat

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Coral Assemblages in the Southeastern Arabian Gulf (Qatar and Abu Dhabi, UAE): Various Stages of <i>Acropora</i>Recovery a Decade after Recurrent Elevated Temperature Anomalies

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Open Journal of Marine Science 2013年第2期3卷 28-39页

作者： Kristi A. Foster Greg Foster Suaad Al-Harthi Environment Agency-Abu Dhabi Abu Dhabi United Arab Emirates Nova Southeastern University Oceanographic Center Dania Beach USA

This study describes the coral communities near Qatarand Abu Dhabi (UAE) ten years after the recurrent elevated temperature anomalies of 1996, 1998 and 2002 which resulted in the mass mortality of Acropora spp. Data derived from photo transects taken over a four-year period were analyzed to characterize the existing coral communities, to compare these to the pre- and post-disturbance communities in the adjacent waters near Dubai, and to project the time-frames required for the communities to return to pre-disturbance levels. The massive corals, dominated by Porites spp. and faviids, showed no long-terms affects associated with exposures to the three thermal anomalies;whereas acroporids, comprising 0% - 8% of the live coral cover, were in various stages of recovery. Projections indicated that acroporid regeneration will require 15 - 32 years to achieve the ≥40% pre-disturbance area cover. The existing communities are too small in size and number to be self-seeding;thus, they are dependent upon the recruitment of larvae from remote refuges of colonies that survived the thermal anomalies. Efforts to identify these refuges and to establish appropriate multi-national conservation programs shall become critical to the future survival of acroporids throughout the southeasternArabian Gulfas the projected regeneration times exceed the periods between disturbances, which are expected to occur more frequently as a result of global climate change.

关键词： Coral Community Elevated Temperature Anomaly Mass Mortality Acropora Arabian Gulf Recovery

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Morphometric Analysis of Drainage Basins in the Western Arabian Peninsula Using Multivariate Statistics

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International Journal of Geosciences 2014年第5期5卷 527-539页

作者： Ali P. Yunus Takashi Oguchi Yuichi S. Hayakawa Center for Spatial Information Science The University of Tokyo Kashiwanoha Kashiwa Japan Department of Natural Environmental Studies Graduate School of Frontier Sciences The University of Tokyo Kashiwanoha Kashiwa Japan

The uplift of the Arabian Shield and the opening of the Red Sea led to the development of steep drainage systems in the Western Arabian Peninsula. Although the Peninsula has been studied from a geological perspective, in relation to oil production, plate tectonics and eolian systems such as sand dunes, the steep mountainous drainage basins have received much less attention. This paper aims to assess the characteristics and development of 36 drainage basins in the Western Arabian Peninsula, using a digital elevation model (DEM), principal component analysis (PCA), and hierarchical cluster analysis (CA). Three major principal components (PC1 to PC3) are found to explain 73% of total variance. CA divided the basins into two or four groups. The division by CA strongly reflects PC1, showing that the two analyses give comparable results. PC1 strongly reflects basin dimensions and drainage texture, and their positive correlations indicate the significant effect of basin relief and slope on mass wasting and limited stream incision in small basins under an arid climate. PC2 mainly reflects the effect of bedrock geology, suggesting that volcanic rocks tend to produce more elongated and less eroded immature basins than crystalline rocks do. PC3 mainly reflects the basin relief and slope and the length of each stream segment, which may also reflect the effect of mass wasting on stream development.

关键词： Arabian Peninsula Drainage Basin Digital Elevation Model Morphometry Principal Component Analysis Cluster Analysis

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Watershed Characterization of Wadi Aurnah, Western Arabian Peninsula

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Journal of Water Resource and Protection 2009年第5期1卷 316-324页

作者： Mashael AL SAUD 不详

The Western part of Arabian Peninsula constitutes a shield-like mega-structure, in which mountain chains are oriented in the NW-SE direction. Along this mountainous region, surface runoff is almost diverted to-wards the Red Sea in the west. Thus, several catchment topographic units exist to capture rainfall water among them. Even tough, the precipitation rate in the Western part of Arabian Peninsula is low (i.e. Arabian Peninsula are still rare and sometimes they show erroneous morphological characterization, notably in the catchments delineation. This is attributed mainly to the complicated drainage pattern, which is structurally-controlled. Thus, related morphological and hydrological studied obtained on these drainage systems reveal discreditable results and measures. This study aims to characterize Wadi Aurnah Watershed (~3113 km2), which comprises a typical catchment in the Western part of Arabian Peninsula. In addition to topographic maps, remotely sensed data (ASTER and IKONOS satellite images) were utilized to delineate water divides with the most precision. Consequently, relevant morphological and hydrological characteristics of Aurnah watershed were obtained.

关键词： Watershed Topographic Maps ASTER Arabian Peninsula

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