scholarly journals COASTAL UPWELLING UNDER THE INFLUENCE OF WESTERLY WIND BURST IN THE NORTH OF PAPUA CONTINENT, WESTERN PACIFIC

Author(s):  
Harold J.D. Waas ◽  
Vincentius P Siregar ◽  
Indra Jaya ◽  
Jonson Lumban Gaol

Coastal upwelling play an important role in biological productivity and the carbon cycle in the ocean. This research aimed to examine the phenomenon of coastal upwelling that occur in the coastal waters north of Papua continent under the influence of Westerly Wind Burst(WWB) prior to the development of El Nino in the Pacific. Data consisted of sea surface temperature, vertical oceanic temperature, ocean color satellite image, wind stress and vector wind speed image, sea surface high, and Nino 3.4 index. Coastal upwelling events in the northern coastal waters of Papua continent occurred in response to westerly winds and westerly wind burst (WWBs) during December to March characterizing by low sea surface temperature (SST) (25 - 28C), negative sea surface high deviation and phytoplankton blooming, except during pre-development of the El Nino 2006/2007 where weak upwelling followed by positive sea surface high deviation. Strong coastal upwelling occurred during two WWBs in December and March1996/1997 with maximum wind speed in March produced a strong El Nino 1997/1998. Upwelling generally occurred along coastal waters of Jayapura to Papua New Guinea with more intensive in coastal waters north of Papua New Guinea indicated by Ekman transport and Ekman layer depth maximum.

Ocean Science ◽  
2014 ◽  
Vol 10 (3) ◽  
pp. 345-355 ◽  
Author(s):  
H. Herrera-Cervantes ◽  
S. E. Lluch-Cota ◽  
D. B. Lluch-Cota ◽  
G. Gutiérrez-de-Velasco

Abstract. Interannual correlation between satellite-derived sea surface temperature (SST) and surface chlorophyll a (Chl a) are examined in the coastal upwelling zone off Punta Eugenia on the west coast of the Baja California Peninsula, an area than has been identified as having intense biological productivity and oceanographic transition between midlatitude and tropical ocean conditions. We used empirical orthogonal functions (EOF) analysis separately and jointly on the two fields from 1997 through 2007, a time period dominated by different remote forcing: ENSO (El Niño–Southern Oscillation) conditions (weak, moderate and strong) and the largest intrusion of subarctic water reported in the last 50 years. Coastal upwelling index anomalies (CUI) and the multivariate ENSO index (MEI) were used to identify the influence of local (wind stress) and remote (ENSO) forcing over the interannual variability of both variables. The spatial pattern of the individual EOF1 analysis showed the greater variability of SST and Chl a offshore, their corresponding amplitude time series presented the highest peaks during the strong 1997–2000 El Niño–La Niña cycles and during the 2002–2004 period associated to the intrusion of subarctic water. The MEI is well correlated with the individual SST principal component (R &amp;approx; 0.67, P < 0.05) and poorly with the individual Chl a principal component (R = −0.13). The joint EOF1 and the SST–Chl a correlation patterns show the area where both variables covary tightly; a band near the coast where the largest correlations occurred (| R | > 0.4) mainly regulated by ENSO cycles. This was spatially revealed when we calculated the homogeneous correlations for the 1997–1999 El Niño–La Niña period and during the 2002–2004 period, the intrusion of subarctic water period. Both, SST and Chl a showed higher coupling and two distinct physical–biological responses: on average ENSO influence was observed clearly along the coast mostly in SST, while the subarctic water influence, observed offshore and in Bahía Vizcaíno, mostly in Chl a. We found coastal chlorophyll blooms off Punta Eugenia during the 2002–2003 period, an enrichment pattern similar to that observed off the coast of Oregon. These chlorophyll blooms are likely linked to high wind stress anomalies during 2002, mainly at high latitudes. This observation may provide an explanation of why Punta Eugenia is one of the most important biological action centers on the Pacific coast.


Author(s):  
Vu Van Tac ◽  
Nguyen Huu Huan ◽  
Tong Phuoc Hoang Son ◽  
Manh Manh Tien ◽  
Nguyen Hoang Thai Khang ◽  
...  

The studies on the impact of the ENSO phenomenon on climate and environment change have shown that the Bien Dong (Southeast Asia Sea) is strongly influenced by this phenomenon. This paper focuses on analyzing sea surface temperature (SST) monthly data for 16 years (7/2002–12/2017) in the coastal waters of Vietnam from MODIS satellite images of National Aeronautics and Space Administration (US NASA). The analysis results showed a clear pattern of ENSO impacts on SST in the coastal waters of Vietnam. However, the intensity of the ENSO phenomenon affecting the three studied areas is very different, and in terms of trend, the intensity gradually increases to the north. The period of impact of ENSO on SST in the coastal waters of Vietnam is often about one month later than the ONI index and the influenced duration lasts about 6 to 9 months. In addition, in the La Niña years, the values of the SST anomaly reflect quite well in terms of the intensity of the La Niña phenomenon. However, in the El Niño years, the SST anomaly index is not generally proportional to the ONI index. Specifically, in the years when El Niño phenomenon was considered to be weak, the SST anomaly index of the coastal waters of Vietnam is much higher than in the years when El Niño phenomenon was considered to be moderate or very strong. The above results are contributing to improving the understanding of the impact of the vagaries of the climate on the coastal waters of Vietnam, supporting scientists and managers in making measures to prevent and efficiently avoid, limit and mitigate the damage caused by ENSO, and to have reasonable alternatives in the protection of biodiversity and environment in the coastal waters of Vietnam. It could be considered as a “small piece” of the overall picture of the impacts of the ENSO phenomenon on global climate change.


2000 ◽  
Vol 203 (15) ◽  
pp. 2311-2322 ◽  
Author(s):  
B. Culik ◽  
J. Hennicke ◽  
T. Martin

We satellite-tracked five Humboldt penguins during the strong 1997/98 El Nino Southern Oscillation (ENSO) from their breeding island Pan de Azucar (26 degrees 09′S, 70 degrees 40′W) in Northern Chile and related their activities at sea to satellite-derived information on sea surface temperature (SST), sea surface temperature anomaly (SSTA), wind direction and speed, chlorophyll a concentrations and statistical data on fishery landings. We found that Humboldt penguins migrated by up to 895 km as marine productivity decreased. The total daily dive duration was highly correlated with SSTA, ranging from 3.1 to 12.5 h when the water was at its warmest (+4 degrees C). Birds travelled between 2 and 116 km every day, travelling further when SSTA was highest. Diving depths (maximum 54 m), however, were not increased with respect to previous years. Two penguins migrated south and, independently of each other, located an area of high chlorophyll a concentration 150 km off the coast. Humboldt penguins seem to use day length, temperature gradients, wind direction and olfaction to adapt to changing environmental conditions and to find suitable feeding grounds. This makes Humboldt penguins biological in situ detectors of highly productive marine areas, with a potential use in the verification of trends detected by remote sensors on board satellites.


2020 ◽  
Vol 33 (2) ◽  
pp. 727-747
Author(s):  
Chunxiang Li ◽  
Chunzai Wang ◽  
Tianbao Zhao

AbstractSeasonal covariability of the dryness/wetness in China and global sea surface temperature (SST) is investigated by using the monthly self-calibrated Palmer drought severity index (PDSI) data and other data from 1950 to 2014. The singular value decomposition (SVD) analysis shows two recurring PDSI–SST coupled modes. The first SVD mode of PDSI is associated with the warm phases of the eastern Pacific–type El Niño–Southern Oscillation (ENSO), the interdecadal Pacific oscillation (IPO) or Pacific decadal oscillation (PDO), the Indian Ocean basin mode (IOBM) in the autumn and winter, and the cold phase of the IOBM in the spring. Meanwhile, the Atlantic multidecadal oscillation (AMO) pattern appears in every season except the autumn. The second SVD mode of PDSI is accompanied by a central Pacific–type El Niño developing from the winter to autumn over the tropical Pacific and a positive phase of IPO or PDO from the winter to summer. Moreover, an AMO pattern is observed in all seasons except the summer, whereas the SST over the tropical Indian Ocean shows negligible variations. The further analyses suggest that AMO remote forcing may be a primary factor influencing interdecadal variability of PDSI in China, and interannual to interdecadal variability of PDSI seems to be closely associated with the ENSO-related events. Meanwhile, the IOBM may be a crucial factor in interannual variability of PDSI during its mature phase in the spring. In general, the SST-related dryness/wetness anomalies can be explained by the associated atmospheric circulation changes.


Ocean Science ◽  
2018 ◽  
Vol 14 (2) ◽  
pp. 301-320 ◽  
Author(s):  
Mei Hong ◽  
Xi Chen ◽  
Ren Zhang ◽  
Dong Wang ◽  
Shuanghe Shen ◽  
...  

Abstract. With the objective of tackling the problem of inaccurate long-term El Niño–Southern Oscillation (ENSO) forecasts, this paper develops a new dynamical–statistical forecast model of the sea surface temperature anomaly (SSTA) field. To avoid single initial prediction values, a self-memorization principle is introduced to improve the dynamical reconstruction model, thus making the model more appropriate for describing such chaotic systems as ENSO events. The improved dynamical–statistical model of the SSTA field is used to predict SSTA in the equatorial eastern Pacific and during El Niño and La Niña events. The long-term step-by-step forecast results and cross-validated retroactive hindcast results of time series T1 and T2 are found to be satisfactory, with a Pearson correlation coefficient of approximately 0.80 and a mean absolute percentage error (MAPE) of less than 15 %. The corresponding forecast SSTA field is accurate in that not only is the forecast shape similar to the actual field but also the contour lines are essentially the same. This model can also be used to forecast the ENSO index. The temporal correlation coefficient is 0.8062, and the MAPE value of 19.55 % is small. The difference between forecast results in spring and those in autumn is not high, indicating that the improved model can overcome the spring predictability barrier to some extent. Compared with six mature models published previously, the present model has an advantage in prediction precision and length, and is a novel exploration of the ENSO forecast method.


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