scholarly journals SEA SURFACE TEMPERATURE DAN CHLOROPHYLL-A CONCENTRATION VARIABILITIES OF JAKARTA BAY AND ITS SURROUNDING WATERS

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Bisman Nababan

<p>Variability of sea surface temperature (SST) and the concentration of chlorophyll-a (Chla) in Jakarta Bay and its surrounding waters were analyzed based on the time series data of monthly mean SST and Chla estimated by NOAA AVHRR, SeaWiFS, and MODIS satellites for 17 years (1997 to 2014). Generally, the monthly mean SST values fluctuated seasonally with the semi-annual pattern with the maximum value occurred in the second transitional season (Oct-Nov) and relatively high in the first transitional season (Mar). In contrast, the minimum of monthly mean SST values was found during the east season (Jul) and relatively low during the west season (Des-Jan). SST variabilities were generally associated with the sun position, sea water circulation, and rainfall. Based on MODIS data, the minimum-maximum of monthly mean SST ranged of 28.39°C-32.58°C. Seasonal fluctuations with the semi-annual pattern also occurred in the monthly mean Chla values with the maximum value occurred during the west season (Des-Jan) and relatively high values occurred during the east season (Jun). In contrast, the minimum of the monthly mean Chla was found during the second transition season (Sep-Oct) and relatively low during the first transitional season (March-Apr). The minimum-maximum of monthly mean Chla ranged of 0.09 mg/m<sup>3</sup>-2.50 mg/m<sup>3</sup>. Chla fluctuations were generally associated with the variabilities of rainfall, river water discharge, and sea water circulation of the Java Sea. Anomalous climatic factors such as El Nino Southern Oscillation (ENSO) and La Nina produced a significant impact on the SST and Chla interannual variability. Generally, the ENSO phenomenon lo-wers the value SST and Chla, while La Nina events tended to increase Chla values.</p><p><strong><em>Keywords: </em></strong><em>sea surface temperature, chlorophyll-a, fluctuation, NOAA AVHRR, SeaWiFS, MODIS</em></p>

2016 ◽  
Vol 8 (1) ◽  
pp. 385-402
Author(s):  
Bisman Nababan

Variability of sea surface temperature (SST) and the concentration of chlorophyll-a (Chla) in Jakarta Bay and its surrounding waters were analyzed based on the time series data of monthly mean SST and Chla estimated by NOAA AVHRR, SeaWiFS, and MODIS satellites for 17 years (1997 to 2014). Generally, the monthly mean SST values fluctuated seasonally with the semi-annual pattern with the maximum value occurred in the second transitional season (Oct-Nov) and relatively high in the first transitional season (Mar). In contrast, the minimum of monthly mean SST values was found during the east season (Jul) and relatively low during the west season (Des-Jan). SST variabilities were generally associated with the sun position, sea water circulation, and rainfall. Based on MODIS data, the minimum-maximum of monthly mean SST ranged of 28.39°C-32.58°C. Seasonal fluctuations with the semi-annual pattern also occurred in the monthly mean Chla values with the maximum value occurred during the west season (Des-Jan) and relatively high values occurred during the east season (Jun). In contrast, the minimum of the monthly mean Chla was found during the second transition season (Sep-Oct) and relatively low during the first transitional season (March-Apr). The minimum-maximum of monthly mean Chla ranged of 0.09 mg/m3-2.50 mg/m3. Chla fluctuations were generally associated with the variabilities of rainfall, river water discharge, and sea water circulation of the Java Sea. Anomalous climatic factors such as El Nino Southern Oscillation (ENSO) and La Nina produced a significant impact on the SST and Chla interannual variability. Generally, the ENSO phenomenon lo-wers the value SST and Chla, while La Nina events tended to increase Chla values.Keywords: sea surface temperature, chlorophyll-a, fluctuation, NOAA AVHRR, SeaWiFS, MODIS


2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Bisman Nababan ◽  
Kristina Simamora

Variability of chlorophyll-a concentration and sea surface temperature (SST) in Natuna waters were analyzed using satellite data Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR). SeaWiFS data with a resolution of 9×9 km2 and AVHRR with a resolution of 4×4 km2 were the monthly average data downloaded from NASA website. Chlorophyll-a concentrations and SST were estimated using OC4v4 and MCSST algorithms. In general, the concentration of chlorophyll-a in Natuna waters ranged between 0.11-4.92 mg/m3 with an average of 0.56 mg/m3 during the west season and 0.09-2.93 mg/m3 with an average of 0.66 mg/m3 during the east season. Chlorophyll-a concentrations were relatively high seen in coastal areas, especially around the mouth of the Kapuas, Musi, and Batang Hari rivers allegedly caused by the high nutrient intake from the mainland. SST variability in Natuna waters ranged from 23.46-30.88 °C during the west season and tended to be lower than that the east season (27.91-31.95 °C). In addition, the SST values tended to be lower in the offshore than that inshore. During the west season (Nov-Feb) and the transitional season (Apr) in the years of Elnino Southern Oscillation (ENSO), the concentration of chlorophyll-a and the SST in Natuna waters was generally higher than that in non-ENSO years. The results of wind analyses showed that ENSO caused the change of direction and speed of wind from its normal conditions.Keywords: Sea surface temperature, chlorophyll-a, Natuna waters, ENSO, SeaWiFS, AVHRR


Author(s):  
Bisman Nababan ◽  
Kristina Simamora

<p>Variability of chlorophyll-a concentration and sea surface temperature (SST) in Natuna waters were analyzed using satellite data Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR). SeaWiFS data with a resolution of 9×9 km2 and AVHRR with a resolution of 4×4 km2 were the monthly average data downloaded from NASA website. Chlorophyll-a concentrations and SST were estimated using OC4v4 and MCSST algorithms. In general, the concentration of chlorophyll-a in Natuna waters ranged between 0.11-4.92 mg/m3 with an average of 0.56 mg/m3 during the west season and 0.09-2.93 mg/m3 with an average of 0.66 mg/m3 during the east season. Chlorophyll-a concentrations were relatively high seen in coastal areas, especially around the mouth of the Kapuas, Musi, and Batang Hari rivers allegedly caused by the high nutrient intake from the mainland. SST variability in Natuna waters ranged from 23.46-30.88 °C during the west season and tended to be lower than that the east season (27.91-31.95 °C). In addition, the SST values tended to be lower in the offshore than that inshore. During the west season (Nov-Feb) and the transitional season (Apr) in the years of Elnino Southern Oscillation (ENSO), the concentration of chlorophyll-a and the SST in Natuna waters was generally higher than that in non-ENSO years. The results of wind analyses showed that ENSO caused the change of direction and speed of wind from its normal conditions.</p><p>Keywords: Sea surface temperature, chlorophyll-a, Natuna waters, ENSO, SeaWiFS, AVHRR</p>


Author(s):  
Hasan Sitorus ◽  
Zulham Apandy Harahap ◽  
Tifani Zianida

The east coast of North Sumatra is part of the Malacca Strait, a highly utilized fishing area. One of the commodities that can be harvested is the Yellowstripe Scad (Selaroides leptolepis). Through oceanography parameters, specifically temperature and chlorophyll-aconcentrations, it is possible to determine optimal fishing grounds which can be used as guidelines. One of the satellites that can detect sea surface temperature (SST) and chlorophyll-a concentrations is Aqua (EOS PM),which is equipped with a Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Data on the Yellowstripe Scad (Selaroide sleptolepis) were obtained from the Belawan Ocean Fishing Port (OFP). Based on the analysis of MODIS images from the Aqua satellite, the sea surface temperature of theeast coastal waters of North Sumatra in 2012 - 2016 ranged from 29oC – 32oC with chlorophyll-a concentrations ranging from 0.19 - 5.26 mg/m³. The largest harvest occurred during the west monsoon with a value of 143.46 tons and the lowest was during the east monsoon with a value of 139.87 tons. Yellowstripe Scad harvest has a negative correlation with the sea surface temperature with a correlation value of -0.365. Chlorophyll-a concentrations and harvest amount have a positive correlation value of 0.660. Yellowstripe Scad is predicted to yield the largest harvest during the west monsoon (December-February) between the Asahan and Labuhanbatu Regencies at coordinates 2.68oN - 2.74oN and 100.37oE - 100.44oE.


Author(s):  
Dendy Mahabror ◽  
Abdul Rohman Zaky

<p class="ColorfulList-Accent11CxSpFirst"><em>Perairan selatan Aru merupakan daerah penangkapan  ikan yang potensial dengan sumberdaya ikannya yang berlimpah. Kapal-kapal ikan melakukan penangkapan ikan dengan mempertimbangkan kondisi kesuburan perairan yaitu fenomena upwelling melalui parameter suhu permukaan laut dan kelimpahan konsentrasi klorofil-a. Penggunaan citra MODIS secara periodik dapat menggambarkan waktu dan lokasi upwelling. Variabilitas suhu permukaan laut dan konsentrasi klorofil-a di lintang 7 LS dan 7.5 LS, bujur 133.1 – 136 BT menunjukkan fenomena upwelling pada musim Timur dimana suhu permukaan laut menurun hingga 24 <sup>o</sup>C sedangkan konsentrasi klorofil-a rata-rata meningkat hingga 3.61 mg/m<sup>3</sup>. Fenomena downwelling terjadi di musim Barat dimana suhu permukaan laut di lintang yang sama menjadi hangat berkisar 30<sup> o</sup>C dengan konsentrasi rata-rata klorofil-a &lt;1 mg/m<sup>3</sup>. Jumlah kapal ikan yang beroperasi di daerah penangkapan diketahui dengan menggunakan citra Radarsat-2 dan data VMS yang disesuaikan dengan waktu pengambilan citra di setiap bulannya dengan lokasi yang sama. Analisis spasial dan temporal dilakukan untuk mengetahui sebaran kapal ikan pada musim timur saat kesuburan perairan tinggi dimana konsentrasi klorofil-a di titik penangkapan mencapai 5.01 mg/m<sup>3</sup> dan jumlah kapal ikan yang beroperasi &gt;150 unit/hari. Pada musim Barat kesuburan perairan rendah dimana konsentrasi klorofil-a di titik penangkapan &lt;1 mg/m<sup>3 </sup>dan jumlah kapal ikan yang beroperasi &lt;40 unit/hari.</em></p><p class="ColorfulList-Accent11CxSpMiddle"> </p><p class="ColorfulList-Accent11CxSpMiddle"><strong>KATA KUNCI</strong></p><p class="ColorfulList-Accent11CxSpLast">klorofil-a, Modis, perairan selatan Aru, Radarsat-2, suhu permukaan laut.</p><p class="ColorfulList-Accent11CxSpLast"> </p><p align="center"><strong><em>SPATIAL AND TEMPORAL ANALYSIS OF WATER PRODUCTIVITY AFFECTING ACTIVITIES IN FISHING VESSEL AT SOUTH ARU FISHING GROUND USING MODIS IMAGE AND RADARSAT-2</em></strong><strong><em></em></strong></p><p class="ColorfulList-Accent11CxSpFirst"><em>Southern Aru waters is a potential fishing areas with abundant fish resources. Fishing boats catch fish by considering the condition of the waters productivity such as upwelling phenomenon through the parameters of sea surface temperatures and an abundance of chlorophyll-a concentration. The use of MODIS imagery can periodically describe the timing and location of upwelling. Variability of sea surface temperature and chlorophyll-a concentration in latitude 7 LS and 7.5 LS, longitude 133.1 - 136 BT showed the phenomenon of upwelling in the east season where sea surface temperature decreased from 30° C to 24° C while the chlorophyll-a concentration increased by an average of 0,3 mg/m<sup>3</sup> to 3.61 mg/m<sup>3</sup>. Downwelling phenomenon took place in the west season where the sea surface temperature in the same latitude range 30° C to be warm with an average concentration of chlorophyll-a &lt;1 mg/m<sup>3</sup>. The number of fishing vessels operating in the fishing area known using RADARSAT-2 imagery and data VMS were later adapted to capture images of each month at the same location. Based on the spatial and temporal analysis was conducted to determine the distribution of fishing vessels in the eastern summer time high waters productivity where the concentration of chlorophyll-a at the point reached 5:01 mg m<sup>3</sup>, the number of fishing vessels in operation increased to 150 units/ ay. While in the West season low waters productivity where the concentration of chlorophyll-a at the point of &lt;1 mg/m<sup>3</sup> and the number of ships in operation decreased to below 40 units/day. This suggests that the increase in the number of fishing fleets affected by the level of waters productivity or fishing season in the East to Transition II at the southern Aru Islands waters.</em></p><p class="ColorfulList-Accent11CxSpMiddle"><em> </em></p><p class="ColorfulList-Accent11CxSpLast"><strong>Keywords: </strong><em>Chlorophyll-a, Modis, the south of Aru, RADARSAT-2, Sea surface temperature.</em></p>


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