Synergistic Use of Remote Sensing and Modeling for Estimating Net Primary Productivity in the Red Sea With VGPM, Eppley-VGPM, and CbPM Models Intercomparison

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models--the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)--produced over the Red Sea domain for the 1998-2018 time period. A detailed investigation is conducted using multilinear regression analysis, multivariate visualization, and moving averages correlative analysis to uncover the models\u27 responses to various climate factors. Here, we use the models\u27 eight-day composite and monthly averages compared with satellite-based variables, including chlorophyll-a (Chla), mixed layer depth (MLD), and sea-surface temperature (SST). Seasonal anomalies of NPP are analyzed against different climate indices, namely, the North Pacific Gyre Oscillation (NPGO), the multivariate ENSO Index (MEI), the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (NAO), and the Dipole Mode Index (DMI). In our study, only the CbPM showed significant correlations with NPGO, MEI, and PDO, with disagreements relative to the other two NPP models. This can be attributed to the models\u27 connection to oceanographic and atmospheric parameters, as well as the trends in the southern Red Sea, thus calling for further validation efforts

Analisis ENSO terhadap Variabilitas Kedalaman Mixed Layer di Laut Maluku

Kondisi oseanografi di perairan Maluku dipengaruhi oleh variabilitas iklim ENSO salah satunya adalah kedalaman mixed layer. Menggunakan data satelit observasi dan data model untuk mengetahui kondisi angin, suhu permukaan laut dan kedalaman mixed layer tebal jangka waktu 10 tahun, penelitian ini bertujuan untuk mengetahui pengaruh ENSO terhadap ketebaln mixed layer di perairan Maluku. Dengan mengginakan data kedalaman mixed layer dari Marine Copernicus, kami menemukan bahwa saat periode El-Niño (2015/2016) pada wilayah upwelling mengalami penipisan sebesar 2 meter sedangkan pada wilayah yang tidak terjadi upwelling mengalami penebalan sebesar 1- 2 meter. Saat periode La-Niña (2010/2011) tidak mengalami upwelling sehingga perairan ini mengalami penipisan hingga 7 meter pada seluruh perairan Maluku. Fenomena ini sangat berkaitan dengan kondisi angin di perairan Maluku.Kata kunci: ENSO, Suhu Permukaan Laut, Angin, Kedalaman Mixed Layer dan Perairan Maluku Oceanographic conditions in Maluku Seas are influenced by ENSO climate variability, one of which is the mixed layer depth. Using satellite observation and model data to determine wind, sea surface temperature and mixed layer depth condition in a period 10 years, this study aims to determine the influence of ENSO on the mixed layer depth in Maluku Seas. Using mixed layer depth data from Marine Copernicus, we found that during the El-Niño (2015/2016) the upwelling area experienced a shallower 2 meters while in the area that did not occur upwelling experienced a deeper 1-2 meters. During the La-Niña  (2010/2011) there was no upwelling so that these seas experienced shallower up to 7 meters in Maluku Seas. This phenomenon is clearly related to wind conditions in the  Maluku Seas.Keywords: ENSO, Sea Surface Temperature, Mixed Layer Depth, Winds, and Maluku Sea

The role of the Sunda Strait in the glacial to Holocene development of the eastern tropical Indian Ocean hydrography

The eastern tropical Indian Ocean (ETIO) off southern Indonesia is a very important region for the global thermohaline circulation as it hosts the exit pathway of the Indonesian Throughflow (ITF). From this region cool and fresh ITF waters are advected by the South Equatorial Current (SEC) to the Indian Ocean. Consequently, the ITF water freshens the Indian Ocean. Nevertheless, the hydrology condition was different during the Last Glacial Maximum (LGM). During this period the sea level was low and the Sunda Shelf was an exposed land. Marine records and simulation study suggest that the exposure of the Sunda Shelf caused a significant reduction in convection over the Indonesian region, resulting arid condition and saltier sea surface condition off south Java. Armed with two sedimentary archives collected from the ETIO off the Sunda Strait, this dissertation investigates the evolution of hydrological changes in the ETIO during the past ~40 kyr B.P. with respect to the flooding of the Sunda Shelf. Furthermore, this dissertation examines the applicability of planktic foraminifera Ba/Ca ratio as a tracer for freshwater discharge. New results of Mg/Ca-based sea surface temperature (SST), seawater à ´18O (à ´18Osw), and XRF-Ti/Ca ratio of GeoB 10042-1 and GeoB 10043-3 collected from off the Sunda Strait revealed that the region has experienced prominent hydrological changes during the past ~40 kyr B.P. The results show that sea surface conditions off the Sunda Strait were cooler and saltier conditions during the last glacial compared to the Holocene, and support previous finding that suggests slowdowns of the Atlantic meridional overturning circulation (AMOC) during the Heinrich stadials 1-3 and the Younger Dryas have caused dry conditions in the ETIO region. Whereas during the Holocene sea surface conditions off the Sunda Strait exhibit warmer and fresher conditions, particularly after the opening of the Sunda Strait at ~10 kyr B.P. This fresher sea surface condition is maintained until today as a consequence of persistent transport of low salinity Java Sea water into the ETIO via the Sunda Strait. Novel millennial-scale reconstruction of past bottom water conditions (foraminifera à µNd) show distinct modifications of the bottom water (2171 m) off the Sunda Strait during the past 19 kyr. Modifications of the bottom water during the last deglaciation and the Holocene correspond to a strong- and a weak thermocline ITF flow, respectively. Furthermore, the results imply that the variability of the detrital à µNd data off the Sunda Strait is susceptible to the ITF flow and large terrigenous material supply from the Sunda Strait. Planktic foraminifera Ba/Ca ratio has been recently used to reconstruct modern and past freshwater discharge. The application of this proxy is based on the observation that suggests that the Ba/Ca ratio of seawater is directly incorporated into foraminifera calcite, and river water has a distinctly higher Ba/Ca ratio than seawater. However, cleaning experiments results on planktic foraminifera G. sacculifer collected from the ETIO revealed that the Ba/Ca ratio of G. sacculifer cannot be used as a tracer for modern and past salinity changes due to the appearance of seasonal upwelling complicates the interpretation of the proxy

11th International Coral Reef Symposium Proceedings

A defining theme of the 11th International Coral Reef Symposium was that the news for coral reef ecosystems are far from encouraging. Climate change happens now much faster than in an ice-age transition, and coral reefs continue to suffer fever-high temperatures as well as sour ocean conditions. Corals may be falling behind, and there appears to be no special silver bullet remedy. Nevertheless, there are hopeful signs that we should not despair. Reef ecosystems respond vigorously to protective measures and alleviation of stress. For concerned scientists, managers, conservationists, stakeholders, students, and citizens, there is a great role to play in continuing to report on the extreme threat that climate change represents to earth’s natural systems. Urgent action is needed to reduce CO2 emissions. In the interim, we can and must buy time for coral reefs through increased protection from sewage, sediment, pollutants, overfishing, development, and other stressors, all of which we know can damage coral health. The time to act is now. The canary in the coral-coal mine is dead, but we still have time to save the miners. We need effective management rooted in solid interdisciplinary science and coupled with stakeholder buy in, working at local, regional, and international scales alongside global efforts to give reefs a chance.https://nsuworks.nova.edu/occ_icrs/1000/thumbnail.jp

11th International Coral Reef Symposium Abstracts

https://nsuworks.nova.edu/occ_icrs/1001/thumbnail.jp