Seasonal and inter-annual variability in sea surface temperature and chlorophyll-a concentration along the West Florida Shelf: analyzing 5 years of satellite data

Author(s):  
Erica T. Krueger ◽  
Felix Jose
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>


2003 ◽  
Vol 30 (15) ◽  
Author(s):  
Ruoying He ◽  
Robert H. Weisberg ◽  
Haiying Zhang ◽  
Frank E. Muller-Karger ◽  
Robert W. Helber

2006 ◽  
Vol 23 (2) ◽  
pp. 325-338 ◽  
Author(s):  
Yonggang Liu ◽  
Robert H. Weisberg ◽  
Ruoying He

Abstract Neural network analyses based on the self-organizing map (SOM) and the growing hierarchical self-organizing map (GHSOM) are used to examine patterns of the sea surface temperature (SST) variability on the West Florida Shelf from time series of daily SST maps from 1998 to 2002. Four characteristic SST patterns are extracted in the first-layer GHSOM array: winter and summer season patterns, and two transitional patterns. Three of them are further expanded in the second layer, yielding more detailed structures in these seasons. The winter pattern is one of low SST, with isotherms aligned approximately along isobaths. The summer pattern is one of high SST distributed in a horizontally uniform manner. The spring transition includes a midshelf cold tongue. Similar analyses performed on SST anomaly data provide further details of these seasonally varying patterns. It is demonstrated that the GHSOM analysis is more effective in extracting the inherent SST patterns than the widely used EOF method. The underlying patterns in a dataset can be visualized in the SOM array in the same form as the original data, while they can only be expressed in anomaly form in the EOF analysis. Some important features, such as asymmetric SST anomaly patterns of winter/summer and cold/warm tongues, can be revealed by the SOM array but cannot be identified in the lowest mode EOF patterns. Also, unlike the EOF or SOM techniques, the hierarchical structure in the input data can be extracted by the GHSOM analysis.


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>


2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Nabil Balbeid ◽  
Agus Saleh Atmadipoera ◽  
Alan Frendy Koropitan

<p class="Paragraf"><em>Madden-Julian Oscillation (MJO) is a large-scale phenomenon that occurs in equatorial area, parti-cularly Indonesia. This research aimed to investigate the MJO propagation process and studied the correlation between MJO and sea surface temperature (SST) and chlorophyll-a. Sea variables (SST and chlorophyll-a) and atmosphere variables (</em><em>outgoing longwave radiation</em><em>/OLR, 1,5 km wind,</em><em> and</em><em> surface wind) were band-pass filtered for 20-100 days period. Spectral density from OLR and 1,5 km wind (2003-2012) shows that the MJO period was dominantly occurred for </em><em>40–50</em><em> days. </em><em>Average </em><em>pro-pagation</em><em> of</em><em> </em><em> MJO</em><em> </em><em>velocity </em><em>resulted from the atmospheric variable analysis by </em><em>Hovmöller</em><em> diagram was 4,7 m/s. Cross correlation between SST and OLR in South Java and Banda Sea result</em><em>s</em><em> a strong corre-lation during MJO active phase, where </em><em>MJO too</em><em>k </em><em> place first and was then followed by</em><em> the </em><em>decreasing </em><em>SST </em><em>along the equatorial region</em><em>.</em><em> Increasing chlorophyll-a concentration occured at some areas du</em><em>-</em><em>ring MJO active phase with relatively short phase delay. </em><em>During the MJO active phase, fluctuation of wind velocity generates variation over mixed layer depth and triggers upwelling /entrainment. Nutri-ent was upwelled to the water surface and hence increase phytoplankton production and chlorophyll-a concentration.</em></p><p><em> </em><strong><em>Keywords</em></strong><em>:</em><em> Madden Julian Oscillation, OLR, </em><em>sea surface temperature, surface chlorophyll-a</em></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.


Sign in / Sign up

Export Citation Format

Share Document