Northern Indian Ocean Salt Transport (NIOST): Estimation of Fresh and Salt Water Transports in the Indian Ocean using Remote Sensing, Hydrographic Observations and HYCOM Simulations

2013 ◽  
Author(s):  
Subrahmanyam Bulusu
Keyword(s):  
Remote Sensing ◽  
Indian Ocean ◽  
Salt Water ◽  
Salt Transport ◽  
Northern Indian Ocean ◽  
The Indian Ocean

scholarly journals Impact of Monsoon-Transported Anthropogenic Aerosols and Sun-Glint on the Satellite-Derived Spectral Remote Sensing Reflectance in the Indian Ocean

2021 ◽  
Vol 13 (2) ◽  
pp. 184
Author(s):  
Rongjie Liu ◽  
Jie Zhang ◽  
Tingwei Cui ◽  
Haocheng Yu
Keyword(s):  
Remote Sensing ◽  
Indian Ocean ◽  
Infrared Imaging ◽  
Atmospheric Correction ◽  
Spatiotemporal Pattern ◽  
Anthropogenic Aerosols ◽  
Remote Sensing Reflectance ◽  
The Indian Ocean ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Terra Modis

Spectral remote sensing reflectance (Rrs(λ), sr−1) is one of the most important products of ocean color satellite missions, where accuracy is essential for retrieval of in-water, bio-optical, and biogeochemical properties. For the Indian Ocean (IO), where Rrs(λ) accuracy has not been well documented, the quality of Rrs(λ) products from Moderate Resolution Imaging Spectroradiometer onboard both Terra (MODIS-Terra) and Aqua (MODIS-Aqua), and Visible Infrared Imaging Radiometer Suite onboard the Suomi National Polar-Orbiting Partnership spacecraft (VIIRS-NPP), is evaluated and inter-compared based on a quality assurance (QA) system, which can objectively grade each individual Rrs(λ) spectrum, with 1 for a perfect spectrum and 0 for an unusable spectrum. Taking the whole year of 2016 as an example, spatiotemporal pattern of Rrs(λ) quality in the Indian Ocean is characterized for the first time, and the underlying factors are elucidated. Specifically, QA analysis of the monthly Rrs(λ) over the IO indicates good quality with the average scores of 0.93 ± 0.02, 0.92 ± 0.02 and 0.92 ± 0.02 for VIIRS-NPP, MODIS-Aqua, and MODIS-Terra, respectively. Low-quality (~0.7) data are mainly found in the Bengal Bay (BB) from January to March, which can be attributed to the imperfect atmospheric correction due to anthropogenic absorptive aerosols transported by the northeasterly winter monsoon. Moreover, low-quality (~0.74) data are also found in the clear oligotrophic gyre zone (OZ) of the south IO in the second half of the year, possibly due to residual sun-glint contributions. These findings highlight the effects of monsoon-transported anthropogenic aerosols, and imperfect sun-glint removal on the Rrs(λ) quality. Further studies are advocated to improve the sun-glint correction in the oligotrophic gyre zone and aerosol correction in the complex ocean–atmosphere environment.

First occurrence of the moray eel Gymnothorax prolatus Sasaki & Amaoka, 1991 (Teleostei: Anguilliformes: Muraenidae) from the northern Indian Ocean

2015 ◽  
Vol 8 ◽  
Author(s):  
Anil Mohapatra ◽  
Dipanjan Ray ◽  
David G. Smith
Keyword(s):  
Indian Ocean ◽  
Arabian Sea ◽  
Western Indian Ocean ◽  
Northern Indian Ocean ◽  
The North ◽  
First Occurrence ◽  
The Indian Ocean ◽  
First Time ◽  
North Western ◽  
Moray Eel

Gymnothorax prolatusis recorded for the first time from the Indian Ocean on the basis of four specimens collected in the Bay of Bengal off India and one from the Arabian Sea off Pakistan. These records extend the range of the species from Taiwan to the north-western Indian Ocean.

Observed Seasonal and Interannual Controls on Coastal Oxygen and Dead Zones in the Indian Ocean

2021 ◽  
Author(s):  
Jenna Pearson ◽  
Laure Resplandy ◽  
Mathieu Poupon
Keyword(s):  
Indian Ocean ◽  
World Ocean ◽  
Low Oxygen ◽  
Northern Indian Ocean ◽  
Dead Zones ◽  
Oxygen Minimum Zones ◽  
Coastal Waves ◽  
The Indian Ocean ◽  
Repeat Hydrography ◽  
Seasonal Signal

<p>A major concern is that global de-oxygenation will expand Oxygen minimum zones (OMZs) and favor coastal dead zones (DZs) where already low oxygen levels threaten ecosystems and adjacent coastal economies. The northern Indian ocean is home to both intense OMZs and DZs, and is surrounded by many kilometers of biodiverse and commercially valuable coastline. Exchanges between OMZs and shelf waters that contribute to coastal DZs are subject to the strong monsoonal seasonal cycle and the interannual variability of the Indian Ocean Dipole (IOD).  There is, however, no observational constraints on how these exchanges influence coastal DZs at the scale of the entire northern Indian Ocean.</p><p>In this work, we examine the timing and processes that favor low-oxygen concentrations along the coasts of the Bay of Bengal (BoB) and Arabian Sea (AS) using multi-decadal time series of oxygen profiles (Bio-Argo, World Ocean Database and repeat hydrography) combined with a suite of satellite data. Seasonally, we show that coastal oxygen is lowest during winter/spring in the BoB and summer/fall in the AS, closely following the seasonal propagation of coastal waves and wind-driven upwelling. Interannually, observations indicate that positive IODs increase coastal O2 in summer/fall in the AS, partly offsetting the seasonal signal; a result in agreement with prior modeling work (Vallivattathillam et al 2017). Observations reveal, however, that positive IODs favor low coastal O2 conditions and increase the risk of coastal DZs year-round in the BoB and in winter/spring in the AS, whereas negative IODs favor low O2 in summer/fall in the AS.</p><div> <div> <div> </div> </div> </div>

scholarly journals Seasonal variability of salt transport during the Indian Ocean monsoons

2011 ◽  
Vol 116 (C8) ◽  
Author(s):  
Ebenezer S. Nyadjro ◽  
Bulusu Subrahmanyam ◽  
Jay F. Shriver
Keyword(s):  
Indian Ocean ◽  
Seasonal Variability ◽  
Salt Transport ◽  
The Indian Ocean

Redescription of Deltamysis holmquistae Bowman & Orsi, 1992 (Crustacea: Mysida: Mysidae), a mysid species new to the Atlantic Ocean with observations on the taxonomic status of Kochimysis Panampunnayil & Biju, 2007

Zootaxa ◽  
2020 ◽  
Vol 4729 (4) ◽  
pp. 501-518
Author(s):  
MATTHEW J. SCRIPTER ◽  
W. WAYNE PRICE ◽  
RICHARD W. HEARD
Keyword(s):  
Indian Ocean ◽  
Atlantic Ocean ◽  
Morphological Variability ◽  
Geographical Location ◽  
Taxonomic Status ◽  
Northwest Pacific ◽  
Monotypic Genus ◽  
Northern Indian Ocean ◽  
The Indian Ocean ◽  
Source Populations

The first occurrences of the estuarine mysid Deltamysis holmquistae Bowman & Orsi from the Atlantic Ocean are documented from sites on the eastern Florida and northwest Gulf of Mexico (Texas) coasts of North America. Based on examination of type material and specimens from Florida and Texas, considerable morphological variability and additional characters were observed necessitating a rediagnosis of the monotypic genus Deltamysis and a redescription of D. holmquistae. As a result of these new taxonomic criteria, the Indian Ocean species, Kochimysis pillaii Panampunnayil & Biju, described from southwest coastal India, is subsumed as a junior synonym of D. holmquistae. The current distribution of this apparently invasive species is probably due to maritime commerce. The geographical location of the endemic or source populations of D. holmquistae remains undetermined; however, its co-occurrence in California with three introduced Asian mysids suggests a northern Indian Ocean or northwest Pacific origin. 

Seasonal Variability of Salinity and Salt Transport in the Northern Indian Ocean

2015 ◽  
Vol 45 (7) ◽  
pp. 1947-1966 ◽  
Author(s):  
Joseph M. D’Addezio ◽  
Bulusu Subrahmanyam ◽  
Ebenezer S. Nyadjro ◽  
V. S. N. Murty
Keyword(s):  
Indian Ocean ◽  
Seasonal Variability ◽  
Ocean Model ◽  
Salt Transport ◽  
Sea Surface Salinity ◽  
Northern Indian Ocean ◽  
Surface Salinity ◽  
Ocean Reanalysis ◽  
Model Simulations ◽  
Ocean Data Assimilation

AbstractAnalyses using a suite of observational datasets (Aquarius and Argo) and model simulations are carried out to examine the seasonal variability of salinity in the northern Indian Ocean (NIO). The model simulations include Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2), the European Centre for Medium-Range Weather Forecasts–Ocean Reanalysis System 4 (ECMWF–ORAS4), Simple Ocean Data Assimilation (SODA) reanalysis, and the Hybrid Coordinate Ocean Model (HYCOM). The analyses of salinity at the surface and at depths up to 200 m, surface salt transport in the top 5-m layer, and depth-integrated salt transports revealed different salinity processes in the NIO that are dominantly related to the semiannual monsoons. Aquarius proves a useful tool for observing this dynamic region and reveals some aspects of sea surface salinity (SSS) variability that Argo cannot resolve. The study revealed large disagreement between surface salt transports derived from observed- and analysis-derived salinity fields. Although differences in SSS between the observations and the model solutions are small, model simulations provide much greater spatial variability of surface salt transports due to finer detailed current structure. Meridional depth-integrated salt transports along 6°N revealed dominant advective processes from the surface toward near-bottom depths. In the Arabian Sea (Bay of Bengal), the net monthly mean maximum northward (southward) salt transport of ~50 × 106 kg s −1 occurs in July, and annual-mean salt transports across this section are about −2.5 × 106 kg s −1 (3 × 106 kg s −1).

scholarly journals Out of the Pacific: A New Alvinellid Worm (Annelida: Terebellida) From the Northern Indian Ocean Hydrothermal Vents

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuru Han ◽  
Dongsheng Zhang ◽  
Chunsheng Wang ◽  
Yadong Zhou
Keyword(s):  
Indian Ocean ◽  
Hydrothermal Vents ◽  
Southwest Indian Ridge ◽  
Rrna Genes ◽  
Northwest Pacific ◽  
Northern Indian Ocean ◽  
West Pacific ◽  
The Pacific ◽  
The Indian Ocean ◽  
Indian Ridge

Alvinellids have long been considered to be endemic to Pacific vents until recent discovery of their presence in the Indian Ocean. Here, a new alvinellid is characterized and formally named from recently discovered vents, Wocan, and Daxi, in the northern Indian Ocean. Both morphological and molecular evidences support its placement in the genus Paralvinella, representing the first characterized alvinellid species out of the Pacific. The new species, formally described as Paralvinella mira n. sp. herein, is morphologically most similar to Paralvinella hessleri from the northwest Pacific, but the two species differ in three aspects: (1), the first three chaetigers are not fused in P. mira n. sp., whereas fused in P. hessleri; (2), paired buccal tentacles short and pointed in P. mira but large and strongly pointed in P. hessleri; (3), numerous slender oral tentacles ungrouped in P. mira but two groups in P. hessleri. Phylogenetic inference using the concatenated alignments of the cytochrome c oxidase I (COI), 16S rRNA and 18S rRNA genes strongly supports the clustering of P. mira with two West Pacific congeners, P. hessleri and an undescribed species (Paralvinella sp. ZMBN). The resulting Indian/West Pacific lineage suggests a possible invasion into the Indian Ocean from the West Pacific. This is the third polychaete reported from Wocan hydrothermal field. Among the three species, two including P. mira and Hesiolyra heteropoda (Annelida:Hesionidae) are present in high abundance, forming an alvinellids/hesionids-dominated polychaete assemblage distinct from that at all other Central Indian Ridge and Southwest Indian Ridge vents. Thus, this study expands our understanding of alvinellid biogeography beyond the Pacific, and adds to the unique biodiversity of the northern Indian Ocean vents, with implications for biogeographic subdivision across the Indian Ocean ridges.

scholarly journals Plastics in the Indian Ocean – sources, fate, distribution and impacts

2021 ◽  
Author(s):  
Charitha Pattiaratchi ◽  
Mirjam van der Mheen ◽  
Cathleen Schlundt ◽  
Bhavani E. Narayanaswamy ◽  
Appalanaidu Sura ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Plastic Material ◽  
Northern Indian Ocean ◽  
Plastic Debris ◽  
Sources And Sinks ◽  
Topographic Features ◽  
The Pacific ◽  
Tremendous Amount ◽  
The Indian Ocean ◽  
The Subject

Abstract. Plastic debris are the most common and exponentially increasing human pollutant in the world's oceans. The distribution and impact of plastics in the Pacific and Atlantic Oceans have been the subject of many studies but not so for the Indian Ocean (IO). Some of the IO rim countries have the highest population densities in the world and mis-management of plastic waste is of concern in many of these IO rim states. Some of the highest plastic-polluted rivers end up in the IO with all this suggesting that the IO receives a tremendous amount of plastic debris each year. However, the concentration, distribution and impacts of plastics in the IO are poorly understood as the region is under-sampled compared to other oceans. In this review, we discuss sources and sinks, which are specific for the IO as well as unique atmospheric, oceanographic and topographic features of the IO such as reversing wind directions due to the monsoon, fronts and upwelling regions that control plastic distribution. We identified hotspots of possible plastic accumulation in the IO, which were different in the two hemispheres. In the northern Indian Ocean, the majority of the plastic material will most likely end up being beached due to the absence of a sub-tropical gyre, whereas in the southern Indian Ocean, the garbage patch is not well defined and there may be leakage of plastics into the southern Atlantic Ocean. Hotspots of predicted plastic accumulations are identified here as well as the vast knowledge gaps about the plastic issue of the IO and point to the most striking future investigation topics.

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