Northwest monsoon upwelling within the Indonesian seas

Wirasatriya, Anindya; Susanto, R. Dwi; Kunarso, Kunarso; Jalil, Abdul Rasyid; Ramdani, Fatwa; Puryajati, Ardiansyah Desmont

doi:10.1080/01431161.2021.1918790

Cited by 27 publications

(14 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The seasonal cycle peaks earlier in the year (January-February) near the island of Borneo, in the Sulu Sea, and further eastward in the Pacific. The relationship between monsoonal and low-frequency variability of Chl a is described in detail in Mandal et al (2021), Wirasatriya et al (2021), and Mandal et al (2022).…”

Section: Methodsmentioning

confidence: 99%

“…It is a challenge to disentangle the variability connected with long-term trends and monsoonal and seasonal processes, which are each heteroge-E. D. Zaron et al: Fortnightly variability of Chl a in the Indonesian seas neous across the domain (Susanto and Ray, 2022). Recent joint analysis of chlorophyll a (Chl a), winds, ocean currents, and active tracers (Mandal et al, 2022); Chl a, winds, sea surface temperature, and sea level (Wirasatriya et al, 2021); Chl a, climate indices, precipitation, and river runoff (Siswanto et al, 2020); and sea level, winds, and stratification (Devlin et al, 2018) are all examples of multi-variable approaches to understanding the low-frequency dynamics of this complex region.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fortnightly variability of Chl a in the Indonesian seas

2023

View full text Add to dashboard Cite

Abstract. Twenty years of daily MODIS-Aqua ocean color observations (2002–2022) are used to identify periodic variability of near-surface chlorophyll (Chl a) in the Indonesian seas. The frequency spectrum of Chl a is dominated by the mean and low-frequency monsoonal variability; however, a prominent peak around the fortnightly tidal period, MSf, is present. Harmonic analysis is used to quantify and map the fortnightly Chl a signal, which is discovered to be significant along the continental shelves of NW Australia and at several sites associated with narrow passages between the Lesser Sunda Islands, within the Sulu Archipelago, and at a few other sites in the Philippines Archipelago. Fortnightly variability at the shallow coastal sites is attributed to the spring–neap cycle of barotropic ocean currents, while we hypothesize that the variability in deeper water near the island passages is due to the modulation of vertical nutrient fluxes by baroclinic tidal mixing. The results document the significance of tidal mixing and highlight the heterogeneous character of biophysical processes within the Indonesian seas.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fortnightly variability of Chl a in the Indonesian seas

2023

View full text Add to dashboard Cite

show abstract

“…The monsoon variation plays an important role in influencing the rainfall intensities across the Indonesian area and further affects many ocean parameters. For instance, the variability of seawater salinity (e.g., Chen et al, 2019), upwelling (e.g., Wirasatriya et al, 2021), and downstream flooding (e.g., Narulita and Ningrum 2018) depend on the monsoonal cycle, potentially affecting the sustainability of seagrass ecosystems. A study on seagrass physical characteristics showed the decrease of carbohydrates within seagrass shoots due to the increase of seawater salinity affecting the elasticity of the shoots (Touchette 2007).…”

Section: Ecological Process Across Indonesian Seagrass Ecosystemsmentioning

confidence: 99%

Hydrodynamics across seagrass meadows and its impacts on Indonesian coastal ecosystems: A review

Risandi¹,

Rifai²,

Lukman³

et al. 2023

Front. Earth Sci.

View full text Add to dashboard Cite

Seagrass canopies are important components of the world’s coastal environments providing critical ecological services. Nearshore hydrodynamics, i.e., waves and currents, are essential in controlling the ecological processes across coastal environments. Seagrass meadows can impose more complex hydrodynamics processes by attenuating sea-swell waves and decreasing the impact of nearshore mean water level rise due to wave setup and Infragravity (IG) waves. Consequently, the seagrasses dissipate waves and reduce flows allowing sediments to settle and accrete the shorelines. However, despite their significant roles, knowledge of hydrodynamics in the Indonesian seagrass ecosystems is relatively limited compared to other coastal ecosystems such as sandy beaches, mangroves, and coral reefs. This review highlights the dynamics of waves and currents, and their interaction with sediment transport and ecological processes, including biogeochemical and dispersal processes on the seagrass ecosystem contributing to the existing seagrass research in Indonesia. The associated literature is collected from scientific databases such as Scopus and Google Scholar that range between 1965 and 2021. The result showed that most of the research on hydrodynamic in seagrass ecosystems was carried out in temperate zones. Until recently, there have been limited publications discussing the interaction between the Indonesian (tropical) seagrass ecosystem and hydrodynamics parameters, even though the region has abundant seagrass species. Moreover, Indonesia is strongly influenced by various atmospheric-oceanic forcing, including the Asian monsoon affecting the dynamic of the coastal area with seagrass ecosystems. At a canopy scale, the correlation between the nearshore (tropical) hydrodynamics and ecological processes in the system is yet to be explored. Considering the potential benefit of seagrasses to coastal ecosystems, developing future research in hydrodynamics across the ecosystem is critical to overcoming the knowledge gaps in Indonesia. The knowledge gained could support the Indonesian seagrass ecosystem services and their resilience to potential hazards and climate change.

show abstract

“…Upwelling areas-where cold, nutrientrich waters are brought to the sea surface-have been well documented within the Indonesian Seas (Susanto et al, 2001;Wirasatriya et al, 2021). They are mainly generated by the persistence of the alongshore monsoon wind, which induces offshore Ekman mass transport and pushes the surface water mass away from the coastline to be replaced by deeper, upwelling water (e.g., Ningsih et al, 2013;Kämpf, 2015;Utama et al, 2017;Setiawan et al, 2019Setiawan et al, , 2020Wirasatriya et al, 2020Wirasatriya et al, , 2021. This type of upwelling is known as monsooninduced coastal upwelling.…”

Section: Introductionmentioning

confidence: 99%

Extreme Upwelling Events in the Seas of the Alor Kecil, Alor Island, Indonesia

Wirasatriya¹,

Susanto²,

Setiawan³

et al. 2023

Oceanog

View full text Add to dashboard Cite

Upwelling is a process by which deep, colder, higher-nutrient waters are brought to the sea surface. In the tropics, an indicator that an upwelling event has occurred is lowering of sea surface temperatures (SSTs) to 25°–27°C from a mean of ~28°C. Based on more than one year of in situ data, we observed an unusual extreme upwelling event (EUE) when the near-surface temperature (NST) dropped by 10°C within one hour during the spring tide in Mulut Kumbang Strait of Alor Kecil. The extreme minimum NST during this EUE was ~12°C, and the upward displacement speed of the cold water was ~0.012 m s–1. The increase in salinity from ~30‰ to 34‰–36 ‰ during the decrease in NST indicates a deep source for the cold water mass . From bathymetry and CTD data, the source of the cold water mass was a deep basin (>300 m) located at the southern part of Pantar Strait. In this basin, the temperature at 270 m depth can be as low as 8°C. We suggest that tidal sloshing (i.e., the back-and-forth movement of water) brings the cold water mass through a channel that connects this deep basin to Mulut Kumbang Strait. Interactions between semi-diurnal (M2, S2, and N2) tidal components strongly modulate the tidal signal with a period of nearly one month. That EUEs only occur from August to November also suggests a strong monsoonal influence. Because tides are predictable, we suggest that future EUEs are predictable.

show abstract

Northwest monsoon upwelling within the Indonesian seas

Cited by 27 publications

References 58 publications

Fortnightly variability of Chl a in the Indonesian seas

Fortnightly variability of Chl a in the Indonesian seas

Hydrodynamics across seagrass meadows and its impacts on Indonesian coastal ecosystems: A review

Extreme Upwelling Events in the Seas of the Alor Kecil, Alor Island, Indonesia

Contact Info

Product

Resources

About