Coherent intraseasonal oceanic variations in the eastern equatorial Indian Ocean and in the Lombok and Ombai Straits from observations and a high‐resolution OGCM

Iskandar, Iskhaq; Masumoto, Yukio; Mizuno, Keisuke; Sasaki, Hideharu; Affandi, Azhar; Setiabudidaya, Dedi; Syamsuddin, Fadli

doi:10.1002/2013jc009592

Cited by 23 publications

(19 citation statements)

References 36 publications

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“…The Indonesian Throughflow cools and freshens the eastern Indian Ocean [Gordon, 2005]. Indian Ocean Kelvin waves forced by westerly wind bursts (section 3.3.4) are partially transformed to coastal Kelvin waves, where they can modulate the Throughflow [Gordon, 2005;Sprintall et al, 2009;Gordon et al, 2010;Drushka et al, 2010;Sprintall et al, 2010;Iskandar et al, 2014] and tidal mixing [e.g., Schiller et al, 2010]. From the perspective of MJO convection, the Maritime Continent presents reduced ocean area, steep island terrain, and strongly forced diurnal convection, all of which may interfere with the intraseasonal convection and associated air-sea interactions.…”

Section: Air-sea Interactions In Other Tropical Regions and Seasonsmentioning

confidence: 99%

Atmosphere‐ocean coupled processes in the Madden‐Julian oscillation

DeMott

Klingaman

Woolnough

2015

Reviews of Geophysics

230

210

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The Madden-Julian oscillation (MJO) is a convectively coupled 30-70 day (intraseasonal) tropical atmospheric mode that drives variations in global weather but which is poorly simulated in most atmospheric general circulation models. Over the past two decades, field campaigns and modeling experiments have suggested that tropical atmosphere-ocean interactions may sustain or amplify the pattern of enhanced and suppressed atmospheric convection that defines the MJO and encourage its eastward propagation through the Indian and Pacific Oceans. New observations collected during the past decade have advanced our understanding of the ocean response to atmospheric MJO forcing and the resulting intraseasonal sea surface temperature fluctuations. Numerous modeling studies have revealed a considerable impact of the mean state on MJO ocean-atmosphere coupled processes, as well as the importance of resolving the diurnal cycle of atmosphere-upper ocean interactions. New diagnostic methods provide insight to atmospheric variability and physical processes associated with the MJO but offer limited insight on the role of ocean feedbacks. Consequently, uncertainty remains concerning the role of the ocean in MJO theory. Our understanding of how atmosphere-ocean coupled processes affect the MJO can be improved by collecting observations in poorly sampled regions of MJO activity, assessing oceanic and atmospheric drivers of surface fluxes, improving the representation of upper ocean mixing in coupled model simulations, designing model experiments that minimize mean state differences, and developing diagnostic tools to evaluate the nature and role of coupled ocean-atmosphere processes over the MJO cycle.

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Section: Air-sea Interactions In Other Tropical Regions and Seasonsmentioning

confidence: 99%

Atmosphere‐ocean coupled processes in the Madden‐Julian oscillation

DeMott

Klingaman

Woolnough

2015

Reviews of Geophysics

230

210

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“…High-resolution modelling studies have suggested that the intra-seasonal variability has a time scale of 30-60 days (e.g. Iskandar et al (2006Iskandar et al ( , 2014) and the only known mooring data in this region shows deep fluctuations in this current to last at least a couple of weeks (see Figs. 2b-d of Sprintall et al (1999)).…”

Section: Crossover Analysis and Cross-calibrationmentioning

confidence: 99%

Cross-calibrating ALES Envisat and CryoSat-2 Delay–Doppler: A coastal altimetry study in the Indonesian Seas

Passaro

Dinardo

Quartly

et al. 2016

Advances in Space Research

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A regional cross-calibration between the first Delay-Doppler altimetry dataset from Cryosat-2 and a retracked Envisat dataset is here presented, in order to test the benefits of the Delay-Doppler processing and to expand the Envisat time series in the coastal ocean. The Indonesian Seas are chosen for the calibration, since the availability of altimetry data in this region is particularly beneficial due to the lack of in-situ measurements and its importance for global ocean circulation. The Envisat data in the region are retracked with the Adaptive Leading Edge Subwaveform (ALES) Retracker, which has been previously validated and applied successfully to coastal sea level research.The study demonstrates that CryoSat-2 is able to decrease the 1-Hz noise of sea level estimations by 0.3 cm within 50 km of the coast, when compared to the ALES-reprocessed Envisat dataset. It also shows that Envisat can be confidently used for detailed oceanographic research after the orbit change of October 2010. Cross-calibration at the crossover points indicates that in the region of study a sea state bias correction equal to 5% of the significant wave height is an acceptable approximation for Delay-Doppler altimetry.The analysis of the joint sea level time series reveals the geographic extent of the semiannual signal caused by Kelvin waves during the monsoon transitions, the larger amplitudes of the annual signal due to the Java Coastal Current and the impact of the strong La Niña event of 2010 on rising sea level trends.

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“…The significant correlations and respective time lags (Table ) suggested that the signals were propagated along the coasts by coastal Kelvin waves, as discussed by Iskandar et al . [].…”

Section: Data and Processingmentioning

confidence: 99%

“…Each correlation was statistically significant at the 99% level and the correlation coefficient of two adjacent stations was high (>0.7), which suggested that the observational data were reliable. The significant correlations and respective time lags (Table 1) suggested that the signals were propagated along the coasts by coastal Kelvin waves, as discussed by Iskandar et al [2014].…”

Section: Sea Level Datamentioning

confidence: 99%

Intraseasonal coastal upwelling signal along the southern coast of Java observed using Indonesian tidal station data

Horii

Ueki

Syamsudin³

et al. 2016

JGR Oceans

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Sea level variations along the coasts of Sumatra and Java were investigated to determine the coastal upwelling signal that is linked to local sea surface temperature (SST) variability. We used Indonesian tidal station data together with satellite SST data and atmospheric reanalysis data. The sea level variations along the southern coast of Java have a significant coherence with remote wind, local wind, and local SST variations, with an intraseasonal time scale of 20–50 days. Assuming that a coastal upwelling signal would appear as a sea level drop (SLD), we focused on intraseasonal‐scale SLD events in the data. Significant upwelling signals are frequently observed during both the boreal summer and winter. To evaluate the impact of the coastal upwelling on local SST, we examined statistical relationships between sea level and SST variations. The results demonstrated that events that occurred during April–August were associated with local SST cooling. The horizontal distribution of the SST cooling was analogous with annual mean SST, suggesting the importance of intraseasonal‐scale coastal upwelling in forming the climatic conditions of the southeastern tropical Indian Ocean.

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Coherent intraseasonal oceanic variations in the eastern equatorial Indian Ocean and in the Lombok and Ombai Straits from observations and a high‐resolution OGCM

Cited by 23 publications

References 36 publications

Atmosphere‐ocean coupled processes in the Madden‐Julian oscillation

Atmosphere‐ocean coupled processes in the Madden‐Julian oscillation

Cross-calibrating ALES Envisat and CryoSat-2 Delay–Doppler: A coastal altimetry study in the Indonesian Seas

Intraseasonal coastal upwelling signal along the southern coast of Java observed using Indonesian tidal station data

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