Monitoring of ocean surface algal blooms in coastal and oceanic waters around India

Autor: T. Suresh, Palanisamy Shanmugam, Muniyandi Tholkapiyan
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Oceans and Seas
Climate change
India
Wind
Management
Monitoring
Policy and Law
Monsoon
Algal bloom
Arid regions
Meteorological problems
Mixing
NASA
Radiometers
Remote sensing
Spatial distribution
Surface waters
Time series
Algal blooms
Atmospheric depositions
Climate change scenarios
Hydrographic changes
Meteorological condition
MODIS-Aqua
Sea-surface height anomalies
Strong seasonal pattern
Nutrients
algal bloom
Aqua (satellite)
biomonitoring
climate change
coastal current
coastal water
growth
MODIS
nutrient cycling
remote sensing
sea surface
sea surface height
spatial distribution
vertical mixing
algal growth
article
atmospheric deposition
coastal waters
cooling
environmental monitoring
environmental parameters
meteorological phenomena
nonhuman
Oman
physical phenomena
precipitation
sea
seasonal variation
Sri Lanka
summer
time series analysis
wind
winter
Arabian Sea
Bay of Bengal
Indian Ocean
algae
Ecosystem
Environmental Monitoring
Eutrophication
Microalgae
Seasons
United States
Convective mixing
General Environmental Science
General Medicine
Sea-surface height
Pollution
Oceanography
Climatology
Environmental science
Upwelling
Indian Ocean Dipole
Zdroj: IndraStra Global.
ISSN: 2381-3652
Popis: The National Aeronautics and Space Administration's (NASA) sensor MODIS-Aqua provides an important tool for reliable observations of the changing ocean surface algal bloom paradigms in coastal and oceanic waters around India. A time series of the MODIS-Aqua-derived OSABI (ocean surface algal bloom index) and its seasonal composite images report new information and comprehensive pictures of these blooms and their evolution stages in a wide variety of events occurred at different times of the years from 2003 to 2011, providing the first large area survey of such phenomena around India. For most of the years, the results show a strong seasonal pattern of surface algal blooms elucidated by certain physical and meteorological conditions. The extent of these blooms reaches a maximum in winter (November-February) and a minimum in summer (June-September), especially in the northern Arabian Sea. Their spatial distribution and retention period are also significantly increased in the recent years. The increased spatial distribution and intensity of these blooms in the northern Arabian Sea in winter are likely caused by enhanced cooling, increased convective mixing, favorable winds, and atmospheric deposition of the mineral aerosols (from surrounding deserts) of the post-southwest monsoon period. The southward Oman coastal current and southwestward winds become apparently responsible for their extension up to the central Arabian Sea. Strong upwelling along this coast further triggers their initiation and growth. Though there is a warming condition associated with increased sea surface height anomalies along the coasts of India and Sri Lanka in winter, surface algal bloom patches are still persistent along these coasts due to northeast monsoonal winds, enhanced precipitation, and subsequent nutrient enrichment in these areas. The occurrence of the surface algal blooms in the northern Bay of Bengal coincides with a region of the well-known Ganges-Brahmaputra Estuarine Frontal (GBEF) system, which increases supply of nutrients in addition to the land-derived inputs triggering surface algal blooms in this region. Low density (initiation stage) of such blooms observed in clear oceanic waters southeast and northeast of Sri Lanka may be caused by the vertical mixing processes (strong monsoonal winds) and the occurrence of Indian Ocean Dipole events. Findings based on the analyses of time series satellite data indicate that the new information on surface algal blooms will have important bearing on regional fisheries, ecosystem and environmental studies, and implications of climate change scenarios. � 2014 Springer International Publishing.
Databáze: OpenAIRE
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