chandanlal parida | BERHAMPUR UNIVERSITY ,BHANJABIHAR.ODISHA (original) (raw)

Papers by chandanlal parida

Research Square (Research Square), Dec 31, 2023

During the summer monsoon, the local wind forcings around Sri Lanka causes the formation of a col... more During the summer monsoon, the local wind forcings around Sri Lanka causes the formation of a cold dome called the Sri Lanka Dome (SLD), which upwells subsurface waters. To the east of SLD, the summer monsoon current (SMC) ows into the Bay of Bengal (BoB), transporting high-salinity water from the Arabian Sea. We show that the SMC and the upwelled waters of the SLD are ventilated episodically during summer monsoon in the southern BoB, leading to a net exchange of low oxygen subsurface waters with saturated mixed layers. We observed presence of hypoxic boundary < 63 µmol kg − 1 very close to the surface. Within the SLD, it shoaled between 35 to 40 m, with oxygen values reaching as low as 6 µmol kg − 1 at the bottom of the thermocline. Negative uxes showing the ingassing rates ranged between − 0.33 and − 9.43 µmol m − 2 sec − 1 within the SLD and SMC. We propose that the episodic ventilation seen during this investigation may lead to disequilibrium between mixed layer and below thereby contributing to mid-depth oxygen enrichment. This study possibly illustrates a pathway through which the oxygen minimum zone in BoB may be gaining oxygen, thereby preventing from becoming denitrifying.

Progress in Oceanography, Nov 1, 2022

Deep-sea Research Part Ii-topical Studies in Oceanography, Feb 1, 2022

Ocean Science Journal, 2018

The present paper reports on the phenomenon of pinkish-red discoloration of the nearshore water o... more The present paper reports on the phenomenon of pinkish-red discoloration of the nearshore water of Puri, Odisha on 12 th May 2016. Many local newspapers covered this event, as Puri city is a major tourist and pilgrimage place on the east coast of India. Field observations were carried out in order to provide a scientific basis to the event and to elicit possible causes of this discoloration. Taxonomic analysis of the phytoplankton samples revealed the dominance of red colored dinoflagellate species Gonyaulax polygramma, contributing 90% to total phytoplankton population. The localized concentration of G. polygramma was responsible for the pinkish-red discoloration of nearshore water. The exact factor that lay behind the genesis of this bloom could not be delineated due to the short period of its persistence. But two factors-upwelling and anthropogenic nutrient influx-can be viewed as the main cause for this ephemeral bloom. Non-hypoxic conditions in the coastal water following the ephemeral bloom event indicated no significant risk of ecological deterioration to the ambient medium.

Environmental Science and Pollution Research, 2019

Seasonal distribution of phytoplankton community and size structure was assessed in three differe... more Seasonal distribution of phytoplankton community and size structure was assessed in three different tropical ecosystems of the western Bay of Bengal viz. estuary (Mahanadi), lagoon (Chilika), and coastal waters (off Gopalpur) in response to ambient hydrobiology. Salinity regimes differentiated the study regions as contrasting ecosystems irrespective of seasons (pre-monsoon, monsoon, post-monsoon). Taxonomic account revealed a total no of 175, 65, and 101 phytoplankton species in the estuary, lagoon, and coastal waters, respectively. Prevalence of marine, brackish, and fresh water types in the coastal waters, lagoon, and estuary, respectively, characterized the contrasting nature of the study regions in hosting the phytoplankton community. In general, phytoplankton abundance was observed in increasing order of coastal waters > estuary > lagoon during postmonsoon and pre-monsoon, while lagoon > coastal waters > estuary during monsoon. Bacillariophyta dominated the phytoplankton community in the estuary and coastal waters during all the seasons. In contrast, the lagoon exhibited a diverse array of phytoplankton group such as cyanophyta, dinophyta, and bacillariophyta during monsoon, post-monsoon, and pre-monsoon, respectively. Over the seasons, microphytoplankton emerged as the dominant phytoplankton size class in the coastal waters. Diversely, nanophytoplankton contributed to major fraction of chlorophyll-a concentration in the estuary and lagoon. Interestingly, pre-monsoon dinophyta bloom (causative species: Noctiluca scintillans with cell density 9 × 10 4 cells•l −1) and monsoon bacillariophyta bloom (causative species: Asterionellopsis glacialis 5.02 × 10 4 cells•l −1) resulted decline in species diversity. Multivariate statistical analysis deciphered salinity as a major environmental player in determining the distribution, diversity, and composition of phytoplankton communities in the three contrasting environments. Trophic state indices signified the lagoon and estuary as hypereutrophic during all season. The coastal water was marked as highly eutrophic through trophic state index during monsoon and pre-monsoon.

Ocean Science Journal, 2017

Clear thermal inversion was observed with cold surface waters (< 24°C) overlying the warm (> 26°C... more Clear thermal inversion was observed with cold surface waters (< 24°C) overlying the warm (> 26°C) subsurface water in the coastal waters of the northwestern Bay of Bengal during winter (January 2015). Simultaneously, preponderance of the cyanobacteria Trichodesmium erythraeum was observed dominating the phytoplankton community with > 90% of total population, reaching maximum density of 9.8 × 10 5 filaments/L. Further, the Trichodesmium predominance was associated with low water temperature (< 24°C).

Marine pollution bulletin, Jan 19, 2016

An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region a... more An intense bloom of red Noctiluca scintillans (NS) occurred off the Rushikulya estuarine region along the east coast of India, an important site for mass nesting events of the vulnerable Olive Ridley sea turtle. At its peak, densities of NS were 3.3×10(5) cells-l(-1), with low relative abundance of other phytoplankton. The peak bloom coincided with high abundance of gelatinous planktivores which may have facilitated bloom development by their grazing on other zooplankton, particularly copepods. Ammonium concentrations increased by approximately 4-fold in the later stages of bloom, coincident with stable NS abundance and chlorophyll concentrations in the nano- and microplankton. This increase likely was attributable to release of intracellular ammonium accumulated through NS grazing. Dissolved oxygen concentrations decreased in sub-surface waters to near hypoxia. Micro-phytoplankton increasingly dominated chlorophyll-a biomass as the bloom declined, with diminishing picoplankton abun...

SPIE Proceedings, 2016

Asia's largest brackish water ecosystem, Chilika lagoon, supports livelihood of millions of i... more Asia's largest brackish water ecosystem, Chilika lagoon, supports livelihood of millions of inhabitants and also known to be bio-geo-chemically dynamic. This demands continuous monitoring of lagoon for which optical remote sensing may be crucial. The in situ bio-optical parameters were analyzed in two sectors (Outer Channel: OC and Southern Sector: SS) of Asia's largest brackish water ecosystem, Chilika lagoon. The spectral Remote Sensing Reflectance (Rrs) ranged from 0.003 to 0.02sr-1 in OC whereas in SS it was between 0.003 and 0.028sr-1. The minimum Rrs was at 400nm that gradually increased with a peak at 580nm and subsequently decreased towards longer wavelength. Rrs exhibited similar pattern in both the sectors from 400 to 600nm. Beyond this wavelength, Rrs was relatively higher in SS. The shifting of peak towards longer wavelength could be attributed to high absorption due to chlorophyll-a (chl-a) and chromophoric dissolved organic matter (CDOM) that varied largely between sectors with relatively higher concentration of chl-a in OC and CDOM in SS. Further, we modelled chl-a by seven ocean colour algorithms (OC4, OC4E, OC4O, OC3M, OC3V, OC3C and OCMO2) using in situ Rrs. The modelled chl-a was overestimating in situ at all stations due to high concentration of CDOM contaminating chl-a signals. However in OC, in situ and modelled chl-a followed the same trend (R2=0.88 to 0.90) probably due to strong co-variance of chl-a with CDOM. The analysis of this study points out towards the requirement for sector specific bio-optical algorithm for accurate chl-a retrieval for synoptic monitoring of lagoon health.

Bulletin of the American Meteorological Society, 2018

The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up ... more The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up the South Asian summer monsoon system. In particular, the southern BoB has cooler sea surface temperatures (SST) that influence ocean–atmosphere interaction and impact the monsoon. Compared to the southeastern BoB, the southwestern BoB is cooler, more saline, receives much less rain, and is influenced by the summer monsoon current (SMC). To examine the impact of these features on the monsoon, the BoB Boundary Layer Experiment (BoBBLE) was jointly undertaken by India and the United Kingdom during June–July 2016. Physical and biogeochemical observations were made using a conductivity–temperature–depth (CTD) profiler, five ocean gliders, an Oceanscience Underway CTD (uCTD), a vertical microstructure profiler (VMP), two acoustic Doppler current profilers (ADCPs), Argo floats, drifting buoys, meteorological sensors, and upper-air radiosonde balloons. The observations were made along a zonal s...

Journal of Threatened Taxa, 2017

This article gives a description about the seasonal occurrence of Whale Shark in the southern Odi... more This article gives a description about the seasonal occurrence of Whale Shark in the southern Odisha coast by taking into account of the current observed data and published literatures. The present report claims the sighting of whale sharks during offshore surveys on 13th March 2016 and 15th March 2016, 8 km (19° 15’ 38” N, 85° 01’32” E) and 4.5 km (19º 15’ 69” N, 85° 00’ 58” E) off the coast of Gopalpur Port, Odisha respectively. Most of the earlier reports of whale shark sightings along Odisha coast are from the coastal waters off Rushikulya river mouth or Gopalpur during the month of February-March. Continuous records of whale sharks along southern Odisha coast during February and March suggest the probability of seasonal migration of this giant fish during the period.

Deep Sea Research Part II: Topical Studies in Oceanography

Current Science, 2016

During the regular environmental monitoring exercise, discrete red-coloured patches were observed... more During the regular environmental monitoring exercise, discrete red-coloured patches were observed in coastal waters of the Bay of Bengal, off Gopalpur Port on 24 April 2014. Water samples from the discoloured zone were collected and transferred into two separate containers. One sample (1 litre) was preserved with acidic Lugol's iodine-formalin solution and the other sample (1 litre) was left as such without any treatment.

Marine Pollution Bulletin

Ecohydrology & Hydrobiology

SN Applied Sciences

Optically active substances (OAS) such as chlorophyll-a (chl-a), chromophoric dissolved organic m... more Optically active substances (OAS) such as chlorophyll-a (chl-a), chromophoric dissolved organic matter (CDOM) and total suspended matter (TSM) play significant role in health assessment of aquatic ecosystem. Temporal variability in OAS plays important role in modulating coastal water ecology. This demand for continuous monitoring of OAS in coastal waters. The present study highlights on temporal variability of OAS off Gopalpur, a coastal site along the northwestern Bay of Bengal. The OAS were found to be having strong seasonal influence apart from large variability in concentration. Chl-a concentration showed fourfold variability (0.03-12.29 mg m −3) with seasonal trend of pre-monsoon > post-monsoon > monsoon. Absorption due to CDOM at 440 nm (a CDOM 440) varied between 0.02 and 4.48 m −1 following seasonal trend of pre-monsoon > monsoon > post-monsoon. TSM concentration was ranged within 0.1-28.21 mg l −1 showing maximum during monsoon and minimum during post-monsoon season. The higher concentration of chl-a and a CDOM 440, during pre-monsoon season, was predominantly due to ecosystem disrupting red tide event of Noctiluca bloom during pre-monsoon season of 2014. The high load of TSM during monsoon was due to increased river influx attributed to upstream precipitation. There was no significant relation observed among the OAS indicating that multiple sources of OAS in optically complex waters of the northwestern Bay of Bengal. The study provides understanding on long-term variations in OAS which is essential for development or tuning of bio-optical algorithms for accurate remote estimation of geophysical products. Keywords Chlorophyll-a • Total suspended matter • a CDOM 440 • Southwest monsoon • Bay of Bengal

SN Applied Sciences, Sep 13, 2019