Spatial distribution of microplastics around an inhabited coral island in the Maldives, Indian Ocean

Spatial distribution of the chlorophyll-a and phytoplankton community composition related to different water masses were studied during regional cruise in February-March 2006 across the Arabian/Persian Gulf and the Sea of Oman, the marginal seas of the Western Indian Ocean.Chlorophyll-a concentrations were measured using in vitro method with fluorescence detection and also were assessed as in vivo fluorescence measured by submersible fluorometer. Nearly four hundred species of phytoplankton were enumerated and identified using microscopy in the samples collected at the same stations.High phytoplankton abundance was associated with diatom-dominated phytoplankton blooms in the central and northwestern part of the Gulf, in the Strait of Hormuz and in the Sea of Oman.&#160;The average concentration of in vitro measured surface chlorophyll-a in the studied area was 2.5 mg/m3, with the maximum over 9 mg/m3. The relationships between the concentrations of satellite remotely sensed chlorophyll and in vitro measured chlorophyll-a were found to be mostly in good agreement. The highest concentrations of the surface chlorophyll (> 4 mg/m3) were observed in the areas where diatom-dominated blooms were identified. It was revealed a significant relationship between the phytoplankton composition and water masses indexed by salinity.The main significance of this study is in the first data set of in vitro measured precise chlorophyll-a concentrations that were obtained along with phytoplankton abundance and taxonomic diversity from the entire region of the Arabian/Persian Gulf and the Sea of Oman.&#160;This data set can&#160;be used for remote sensing measurements validation and as a baseline for future studies of the biological productivity changes in the Western Indian Ocean.

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Spatial distribution of the Southeast Asian smoke plume over the Indian Ocean and its radiative heating in the atmosphere during the major fire event of 2006

Geophysical Research Letters ◽

10.1029/2009gl039316 ◽

2009 ◽

Vol 36 (16) ◽

Cited By ~ 15

Author(s):

Bijoy V. Thampi ◽

K. Rajeev ◽

K. Parameswaran ◽

Manoj Kumar Mishra

Keyword(s):

Spatial Distribution ◽

Indian Ocean ◽

Southeast Asian ◽

Radiative Heating ◽

Fire Event ◽

Smoke Plume ◽

The Indian Ocean

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Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain

Journal of Climate ◽

10.1175/2009jcli2388.1 ◽

2009 ◽

Vol 22 (13) ◽

pp. 3595-3616 ◽

Cited By ~ 53

Author(s):

Neil Davis ◽

Jared Bowden ◽

Fredrick Semazzi ◽

Lian Xie ◽

Bariş Önol

Keyword(s):

Spatial Distribution ◽

Indian Ocean ◽

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Eastern Africa ◽

Massachusetts Institute Of Technology ◽

Convective Rainfall ◽

Total Rainfall ◽

Sensitivity Tests

Abstract Rainfall is a driving factor of climate in the tropics and needs to be properly represented within a climate model. This study customizes the precipitation processes over the tropical regions of eastern Africa and the Indian Ocean using the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3). The convective schemes of Grell with closures Arakawa–Schubert (Grell–AS)/Fritch–Chappel (Grell–FC) and Massachusetts Institute of Technology–Emanuel (MIT–EMAN) were compared to determine the most realistic spatial distribution of rainfall and partitioning of convective/stratiform rainfall when compared to observations from the Tropical Rainfall Measuring Mission (TRMM). Both Grell–AS and Grell–FC underpredicted convective rainfall rates over land, while over the ocean Grell–FC (Grell–AS) over- (under-) estimates convective rainfall. MIT–EMAN provides the most realistic pardoning and spatial distribution of convective rainfall despite the tendency for overestimating total rainfall. MIT–EMAN was used to further customize the subgrid explicit moisture scheme (SUBEX). Sensitivity tests were performed on the gridbox relative humidity threshold for cloudiness (RHmin) and the autoconversion scale factor (Cacs). An RHmin value of 60% (RHmin-60) reduced the amount of total rainfall over five heterogeneous rainfall regions in eastern Africa, with most of the reduction coming from the convective rainfall. Then, Cacs sensitivity tests improved upon the total rainfall amounts and convective stratiform partitioning compared to RHmin-60. Based upon all sensitivity simulations performed, the combination of the MIT–EMAN convective scheme, RHmin-60, and halving the model default value (0.4) of Cacs provided the most realistic simulation in terms of spatial distribution, convective partition, rainfall totals, and temperature bias when compared to observations.

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Consideration of various aspects in a drift study of MH370 debris

10.5194/os-2017-80 ◽

2017 ◽

Author(s):

Oleksandr Nesterov

Keyword(s):

Spatial Distribution ◽

Indian Ocean ◽

Biochemical Analysis ◽

Southern Indian Ocean ◽

La Réunion ◽

Kuala Lumpur ◽

Radar Tracking ◽

Search Operation ◽

Malaysian Airlines ◽

Made In

Abstract. On March 7, 2014, a Boeing 777-200ER aircraft operated by Malaysian Airlines on the route MH370 from Kuala Lumpur to Beijin abruptly ceased all communications and disappeared with 239 people aboard, leaving a mystery about its fate. The subsequent analysis of so-called satellite handshakes supplemented by military radar tracking has suggested that the aircraft ended up in the southern Indian Ocean. Eventual recovery of a number of fragments washed ashore in several countries has confirmed its crash. A number of drift studies were undertaken to assist in locating the crash site, mostly focusing either on the spatial distribution of the washed ashore debris or efficacy of the aerial search operation. A recent biochemical analysis of the barnacles attached to the flaperon (the first fragment found in La Réunion) has indicated that their growth likely began in the water of 24 °C, then the temperature dropped to 18 °C, and then it rose up again to 25 °C. An attempt was made in the present study to take into consideration all these aspects. The analysis was conducted by the means of numerical screening of 40 hypothetical locations of the crash site along the so-called 7th arc. Obtained results indicate the likelihood of the crash site to be located between 25.5° S and 30.5° S latitudes, with the segment from 28° S to 30° S being the most promising.

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Consideration of various aspects in a drift study of MH370 debris

Ocean Science ◽

10.5194/os-14-387-2018 ◽

2018 ◽

Vol 14 (3) ◽

pp. 387-402 ◽

Cited By ~ 10

Author(s):

Oleksandr Nesterov

Keyword(s):

Spatial Distribution ◽

Indian Ocean ◽

Biochemical Analysis ◽

Southern Indian Ocean ◽

La Réunion ◽

Kuala Lumpur ◽

Radar Tracking ◽

Search Operation ◽

Malaysian Airlines ◽

Made In

Abstract. On 7 March 2014, a Boeing 777-200ER aircraft operated by Malaysian Airlines as MH370 on the route from Kuala Lumpur to Beijing abruptly ceased all communications and disappeared with 239 people aboard, leaving its fate a mystery. The subsequent analysis of so-called satellite handshakes supplemented by military radar tracking has suggested that the aircraft ended up in the southern Indian Ocean. The eventual recovery of a number of fragments washed ashore in several countries has confirmed its crash. A number of drift studies were undertaken to assist in locating the crash site, mostly focusing either on the spatial distribution of the debris washed ashore or on the efficacy of the aerial search operation. A recent biochemical analysis of the barnacles attached to the flaperon (the first fragment found in La Réunion) has indicated that their growth likely began in water of 24 °C; then the temperature dropped to 18 °C, and then it rose up again to 25 °C. An attempt was made in the present study to take into consideration all these aspects. The analysis was conducted by means of numerical screening of 40 hypothetical locations of the crash site along the so-called seventh arc. Obtained results indicate the likelihood of the crash site to be located between 25.5 and 30.5° S, with the segment from 28 to 30° S being the most promising.

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