Southern Makassar Strait Research Articles

Influence of Marine Heatwaves on Upwelling Parameter in Indonesian Fisheries Management Area (IFMA) 713 Waters

Abstract An upwelling process linked to water productivity is likely to be affected by marine heatwaves (MHWs). The events of MHWs are distinguished by warmer sea surface temperature (SST), leading to increased stratification, causing vertical mixing limits and suppressing the upwelling process. In the Indonesian Fisheries Management Area (IFMA) 713 waters, which have enormous potential for fishery resources, five upwelling areas were identified during the southeast monsoon months (May–October) based on the Ekman pumping velocity (EPV) assessment, namely locations A (western part of West Sulawesi), B (southern Makassar), C (eastern part of Bone Bay), D (southern Banjarmasin), and E (southern Makassar Strait). Thus, this study aimed to investigate the influence of MHWs on upwelling parameter (chlorophyll-a concentration) in IFMA 713, particularly in 1998 and 2016, where prominent MHWs occurred and coincided with upwelling sessions. To accomplish this, EPV anomalies and chlorophyll-a concentrations for each MHWs event during May–October 1998 and 2016 were calculated. The analysis revealed that MHWs events co-occuring with negative (upwelling velocity is weaker than the climatological mean) and positive (upwelling velocity is stronger than the climatological average) EPV anomalies were associated with decreased chlorophyll-a concentrations.

An Evaluation of a 1/18o Resolution Regional Ocean Circulation Model of CROCO in the Southern Sunda Shelf

The Coastal and Regional Ocean Community Model (CROCO) was applied to simulate the three dimensional ocean circulation on the southern Sunda Shelf with a horizontal resolution of 1/18o and 40 vertical layers. This configuration is called as CROCO18-SSS. The initial and open boundary conditions were derived from a global reanalysis product at a resolution of 1/12o from the Copernicus Marine Environment Monitoring Service (CMEMS). The regional model was driven by atmospheric, tides, and river discharges data from a wide variety of datasets, each with a different resolution. To test the model performance and capabilities of the CROCO18-SSS model outputs including sea level anomaly, current velocity, temperature, salinity, and volume transport, we have compared in the simulation results with other reanalysis product and satellite-derived datasets. The CROCO18-SSS model outputs reproduced the regional ocean circulation well from observations and reanalysis products. For example, the reversal of the monsoonal current in the southern sunda shelf, as well as strong persistent southward Makassar throughflow and their interaction in the southern Makassar Strait, can be seen clearly. The vertical structure of the zonal current component was comparable to that of the reanalysis product reference. The seasonal shift in temperature and salinity, with the water becoming colder and saltier during the northwest monsoon and warmer and fresher during the southeast monsoon, was also accurately reproduced by the CROCO18-SSS model. Additionally, the mean volume transport calculated by the CROCO18-SSS model for the Makassar and Karimata Straits was comparable to that reported in previous studies.

Seasonal variation of mixed layer depth and thermocline thickness from the ctd argo float data in the Southern Makassar Strait

The Makassar Strait (MS) is directly connected to the Sulawesi Sea in the north and the Java Sea and the Flores Sea in the south and is the main route of Indonesia Throughflow(ITF). Hence Stratification of water mass in the MS is influenced by the dynamics of these waters. This study aims to describe seasonal variations of the mixed layer depth and the thermocline thickness, identify ITF water masses, and the occurrence of coastal upwelling in the southern part of the MS. The results show that the North Pacific water origin of North Pacific Subtropical Water (NPSW) and North Pacific Intermediate Water (NPIW) are dominant, with a maximum salinity characteristic of 34.6-34.7 psu in the thermocline layer and a minimum salinity of 34.5 psu in the intermediate layer. However, near-surface fresh Java Seawater appears to be dominant during the northwest monsoon (NWM-DJF) period. Seasonal variation of the mixed layer depth is much deeper (93m) and vertical gradient of temperature and salinity are much stronger due to the presence of fresh Java Sea water advected by the eastward Java Monsoon Current. However, during the southeast monsoon (SEM-JJA) period the mixed layer depth is much shallower and the thermocline layer is much thicker (198 m), Associated with much stronger ITF and upwelled colder water from the upwelling area. The coastal upwelling event during the SEM period in the study are is characterized by an increase of isotherm of 25 °C, isohaline of 34.0 psu, and isopycnal of 22.0 kg/m3 from about 75 m depth to the sea surface layer.

Mapping spatial-temporal skipjack tuna habitat as a reference for Fish Aggregating Devices (FADs) settings in Makassar Strait, Indonesia

Abstract. Hidayat R, Zainuddin M, Mallawa A, Mustapha MA, Putri ARS. 2021. Mapping spatial-temporal skipjack tuna habitat as a reference for Fish Aggregating Devices (FADs) settings in Makassar Strait, Indonesia. Biodiversitas 22: 3637-3647. Skipjack tuna (Katsuwonus pelamis) has a high economic value in the international market. Catching skipjack tuna using fish aggregating devices (FADs) without knowing its habitat characteristics can damage the ecosystem. This study aimed to determine suitable fishing areas for setting skipjack’s FADs. The data used included that on catch, sea surface temperature (SST), and sea surface chlorophyll-a (SSC) in the Makassar Strait obtained for 2017-2019. The generalized additive model (GAM) and empirical cumulative distribution function (ECDF) analyses were used to investigate the skipjack’s tuna habitat. A pelagic habitat index (PHI), with PHI > 75%, was applied to determine suitable FAD positions. The gravity center of the skipjack tuna habitat for ten months (January-October 2020) was calculated to validate the model’s results. The results showed that the optimum SST range was from 28.78°C to 31.25°C, while the SSC from 0.18 to 0.28 mg m-3. The best skipjack habitats in the southern Makassar Strait are criterion 4 (PHI > 90%) and criterion 3 (PHI = 85-90%), having a relatively high consistency of the average PHI values. These results can help determine the optimal positions for setting FADs to benefit the global management and sustainable development of skipjack tuna fisheries.

Mapping potential fishing zones for skipjack tuna in the southern Makassar Strait, Indonesia, using Pelagic Habitat Index (PHI)

Abstract. Putri ARS, Zainuddin M, Musbir, Mustapha MA, Hidayat R. 2021. Mapping potential fishing zones for skipjack tuna in the southern Makassar Strait, Indonesia, using Pelagic Habitat Index (PHI). Biodiversitas 22: 3037-3045. Southern Makassar Strait is one of the potential fishing grounds for skipjack tuna in the Indonesian waters. Oceanographic factors become the primary factors that limit the distribution and abundance of fish. The study aimed to identify the relationship between fish distribution with sea surface temperature (SST) and primary productivity (PP) and map out the potential fishing grounds of skipjack tuna in the southern Makassar Strait. It used pelagic habitat index (PHI) analysis, which is strengthened by the results of correlation analysis in the form of generalized additive models (GAM) and Empirical cumulative distribution function (ECDF) analysis. The results showed that the distribution of skipjack tuna was significantly associated with the preferred range of SST 29-30.5°C and PP 350-400 mg C/m2/day. The potential fishing zone is well established near the coast to offshore of Barru and Polman waters (3°-6°S and 117°-119°E), with the peak season in May and October. The spatial pattern of potential fishing grounds for skipjack fishing is associated with hotspots (oceanographic preference), leading to increased feeding opportunities. This study suggests that the spatial pattern of high potential fishing zones could improve fishing, management, and conservation strategies along the southern Makassar Strait.

Stratification and Characteristic of Water Masses in Selayar Slope-Southern Makassar Strait

Selayar slope is the confluence of the Indonesian Throughflow (ITF) from the Makassar Strait and seasonal Java-Flores current. The CTD data from Java-Makassar-Flores (JMF) Cruise where an intensive 24-h CTD “yoyo” measurement was conducted in Selayar Slope is used to determine the stratification and characteristic of water masses in the Selayar slope - southern Makassar Strait. The analyses were performed using TS Diagram processed with Matlab and Ocean Data View (ODV). The surface potential density of 24.25 s q with stratification of water masses is dominated by Makassar ITF. The water mass with higher salinity (34.6 psu) is North Pacific Subtropical water (NPSW) and lower salinity (34.44 psu) is North Pacific Intermediate Water (NPIW). However, water mass with density above 24.25 s q caused NPSW to be drastically extracted by less-saline water (34.15 psu) originated from Java Sea, where salinity profiles are more clearly observed between surface density of 22.0 s q and 23.50 s q . . Keyword: stratification and characteristic, water mass, Selayar Slope, JMF Cruise, TS Diagram

Observed Water Exchange Between the South China Sea and Java Sea Through Karimata Strait

AbstractVolume, heat and freshwater transports from the South China Sea (SCS) to the Java Sea through the Karimata Strait are estimated based on direct measurements of current, temperature, salinity, and satellite observations. Subject to strong seasonal variability, the volume, heat, freshwater transports are −1.98 ± 0.23 Sv (1 Sv = 106 m3/s), −209.68 ± 15.19 TW (1 TW = 1012 W), −99.87 ± 15.11 mSv (1 mSv = 10‐3 Sv) in boreal winter, and 0.47 ± 0.20 Sv, 61.06 ± 15.46 TW, 31.67 ± 8.76 mSv in boreal summer, respectively (negative transport defined from SCS to Java Sea). The annual mean volume, heat and freshwater transports are −0.78 ± 0.12 Sv, −77.31 ± 4.99 TW, and −30.87 ± 6.15 mSv, respectively. The freshwater transport through Karimata Strait is as large as 42% of rainfall input to the entire Indonesian seas in boreal winter, thereby modulating the Indonesian Throughflow (ITF) through the “freshwater plug” effect in the Makassar Strait. The interannual variability of the transports is not significantly correlated to the Indian Ocean Dipole and El Niño‐Southern Oscillation. There is a significant decreasing trend of volume and heat transports from the SCS to Java Sea over the period of 1997–2015, with a reduction of 0.26 Sv and 15 TW, respectively. The freshwater transport decreases 12.29 mSv by 2016 compared with that in 2009, equivalent to 33.2%–49.72% of the annual mean freshwater transport during 2009–2016. This decreasing trend would play contradictory roles in the decadal trend of ITF transport by building a “freshwater plug” in the southern Makassar Strait and a ‘buoyant plume’ in the Indo‐Australian Basin, respectively.

The spatial current structure in the Indonesian Seas in November 2014, during The Expedition of Widya Nusantara (EWIN)

The spatial current patterns in the Indonesian seas were mapped based on a wide range of snapshot observations during the Expedition of Widya Nusantara (EWIN 2014) Leg 1 in November 2014. The current profiles were measured using the Shipboard Acoustic Doppler Current Profiler (SADCP) of the RV Baruna Jaya VIII. This study is aimed to reveal the current system in the Indonesian seas from observation. Remarkable current patterns of the Indonesian throughflow (ITF) were observed penetrating via the Mindanao Strait, southern Makassar Strait, and Lifamatola Passage, including its recirculation in the northern Maluku Sea and in the Sulawesi Sea. These results suggested that during the late Southeast Monsoon (SEM), the upper layer ITF is still significantly penetrating the Indonesian seas. The indication of anticyclonic and cyclonic circulations in the upper 50 m and lower 75 m, respectively, was also observed in the western Banda Sea

The Madden‐Julian Oscillation's Impact on the Makassar Strait Surface Layer Transport

AbstractThe Indonesian Throughflow (ITF) surface layer dynamics within the Makassar Strait, responsible for ~77% of the ITF, are investigated using in situ and satellite‐derived observations from January 2004 to August 2011 and August 2013 to December 2016. Surface layer southward transport attains its minima during boreal winter in response to atmospheric and oceanic processes attributed to Australian‐Indonesian monsoon as well as the Madden‐Julian Oscillation (MJO). While the monsoon's impact on seasonal variability of the ITF transport has been well documented, the MJO's role to modulate the variability of the ITF transport is less studied. Eleven MJO events traversed from Indian Ocean to Western Pacific during boreal winter months over the course of the Makassar Strait time series. Intensified along‐strait wind stress, reduced outgoing longwave radiation, increased sea surface height in the southern Makassar Strait, and a reduction in the surface layer ITF transport by up to 4 Sv marked the impact of the active phase of the MJO. Analysis of the momentum budget in the surface layer indicates that the excess of northward momentum due to the along‐channel pressure gradient over northward momentum attributed to the vertical divergence of Reynold stress governs the northward acceleration of the surface layer during the MJO active phase.

Turbulent mixing of water masses in Selayar Slope - Southern Makassar Strait

During the Java-Makassar-Flores (JMF) Cruise in August 2015 onboard the RV GEOMARIN 3, about 56 hydrographic CTD profiles have been acquired in the JMF confluence region of Makassar Indonesian Throughflow (ITF) and seasonal Java-Flores Current, where three intensive 24-h CTD “yoyo” measurement were carried out in Dewakang sill, Selayar slope and Kangean slope. The aim of this paper is to estimates the turbulent mixing value using Thorpe analysis, particularly in the Selayar slope - southern Makassar Strait. It is found that below surface potential density of 24.25 σθ stratification of water masses is dominated by Makassar ITF with salty (34.6 psu) North Pacific thermocline water (NPSW) and less salty (34.42 psu) North Pacific lower-thermocline water (NPIW). However, above 24.25 σθ upper NPSW is drastically dominated by much fresher water (34.17 psu) from Java Sea, where inter-leavings of salinity profiles are obviously seen between surface density of 22.0 σθ and 23.50 σθ. Estimation of turbulent vertical eddy diffusivity in this upper-thermocline are found strong with the order of 10−3 m2/s. It is suggested that energetic internal tidal waves may contribute significantly to the vertical mixing in this complex topographic region.

Impact of Climate Changes on Skipjack tuna (Katsuwonus pelamis) catch during May-July in the Makassar Strait

Climate change is underway, with unexpected consequences for various fields including fisheries. Fish distribution pattern shifts are not random, but are influenced by oceanographic factors and climate variability. This study aimed to analyze the impact of changes in climate on Skipjack tuna (Katsuwonus pelamis) catch in Makassar Strait. Time series satellite data on Sea Surface Temperature (SST) and Chlorophyll-a (chl-a) concentration (MODIS-aqua) during May-July were obtained for the period from 2012 to 2016. Catch per Unit Effort (CPUE) data for Skipjack collected during May-July 2017 were used to analyze the impact of oceanographic changes on the skipjack tuna fishery. This study used the anomaly method to analyze unusual phenomena in these time series. A Generalized Additive Model (GAM) was used to analyze the effect of climatic changes on skipjack tuna catch using the R 3.1.3 software package. Spatial data were mapped using ArcGIS 10.5 software. The results indicate that climatic changes included a significant increase in SST (0.26 − 0.80°C) and chl-a concentration (0.0280 − 0.0937 mg m−3) during May-July over the period 2012 - 2016 in the southern Makassar Strait. These conditions were significantly associated with increasing skipjack tuna catch, particularly chl-a in southern part of Makassar Strait.

Variability of the Indonesian Throughflow thermal profile over the last 25-kyr: A perspective from the southern Makassar Strait

Abstract The Indonesian Throughflow (ITF), the sole conduit between the Pacific and Indian Oceans, regulates the heat and fresh water budgets between these oceans and plays a key role as the ‘warm water pathway’ in the global thermohaline circulation. In this study, we reconstructed a 25-kyr history of the ITF thermocline, based on well-dated, high-resolution (~200 yrs) records of Pulleniatina obliquiloculata δ18O and Mg/Ca from Core SO217-18515 (3.63°S, 119.54°E; water depth: 688 m), retrieved from the southern Makassar Strait. We integrated these new records with data from offshore Luzon (MD98-2188; 14.82°N, 123.49°E; water depth: 730 m), from the center of the Western Pacific Warm Pool (WPWP) (3cBX; 8.02°N, 139.6°E; water depth: 2829 m) and from the Timor Sea (MD01-2378; 13.08°S, 121.79°E; water depth: 1783 m). Both sea surface and thermocline temperatures decreased and their difference (ΔT) increased in the southern Makassar Strait and Timor Sea between 11 and 2.5 ka, corresponding to enhanced El Nino activity and dominance of East Asian winter monsoon over summer monsoon. In contrast, sea surface and thermocline temperatures increased and ΔT decreased during the last ~2.5 kyrs concomitantly with declining El Nino activity and relative weakening of the East Asian winter monsoon. Our results additionally show that ice volume corrected seawater δ18O of both sea surface and thermocline in Cores SO217-18515 and MD01-2378 co-vary with Borneo stalagmite δ18O, a proxy of regional precipitation in the WPWP, thus indicating vertical mixing of upper ocean waters along the ITF pathway. We propose that changes in the state of the El Nino-Southern Oscillation and in East Asian monsoon related to regional precipitation exerted a major influence on the ITF thermocline profile during the Holocene and largely controlled changes in ITF thermocline temperature throughout the last 25 kyrs.

The roles of mixed layer depth in affecting chemical and biological characteristics of Makassar straits, Indonesia

Mixed Layer Depth (MLD) is able to determine the amount of light and nutrients abundance for the growth of phytoplankton, its known that phytoplakton pigments are the main absorbers and light scatterers in the ocean. Location wich has deeper MLD and large seasonal variations are the most productive areas, also could have blooming or the maximum growth of large phytoplankton occurring in the existence of a limited number nutrients for several days. The aims of this study are to understand the characteristics of the MLD and it roles to the abundance of Chlorophyll and nutrient in Indonesia Through-Flow/ITF (Indonesia: “ARLINDO”), specifically the area along Makassar Strait. The Chlorophyll and oceanographic parameters were obtained based on measuring by CTD in TIMIT 2016 expedition. The MLD was deep (~43 m) in the northern part of the transect (around Central Sulawesi Island) and shoaled progressively until about 13 m in the southern transect (the Southern Makassar Strait). The Chlorophyll-a (Chl-a) concentration show a decline pattern from the north to the south transects with the maximal Chl-a is 0.37 mg/m3. Nutrient parameters in southern Makassar Strait studied were NODC (National Oceanographic Data Center) data from WOA (World Ocean Atlas), it can indicated a correlation between nutrient (Nitrate) with Chlorophyll. The mean correlation in mixing layer for whole area is 0.78, showing that Nitrate concentration is highly related proportional to Chlorophyll abundance, while below the mixing layer, correlation value is -0.52, indicating the inverse relation between Chlorophyll and nutrient. Based on those correlation, and assumption that the source of Chlorophyll is from phytoplankton, it can be concluded that phytoplankton needs Nitrate in its metabolism process as well as other productivities reason in mixing layer, while in depth below the mixing layer, growth of phytoplankton is no longer depends on concentration of Nitrate nutrient.

ON THE OCCURRENCE OF UPWELLING IN THE SOUTHERN MAKASSAR STRAIT

The possibility of upwelling occuring off the coast of Sulawesi in the Southern Makassar Strait has been discussed by earlier workers (see e.g. Veen 1953, and Wyrtki 1961). Surface salinity data show higher values in June or July along the southwest coast of Sulawesi than the rest area to the west of it. The months June and July coincide with the southeast monsoon in the area. It is believed that the presence of such high salinity could only be due to the process of upwelling. As already mentioned in these works (e.g. by Wyrtki, 1961) during the southeast monsoon, the west-going surface currents coming from the Northern Makassar Strait and the Flores Sea pass the area, and flow into the Java Sea. It is thought that part of the water masses transported by the currents originate from subsurface layer off Makassar coast.

ON THE FACTORS AFFECTING THE PRODUCTIVITY OF THE SOUTHERN MAKASSAR STRAIT

An investigation of the upwelling in the Southern Makassar Strait was conducted by LON (Lembaga Oseanologi Nasional) as part of its research program in ecology and oceanography of the Indonesian waters. It consists of observation on one monitoring station and two oceanographical cruises in the region. The result of the monitoring station indicates clearly the occurrence of upwelling and its effect on the hydrology of the region. During the southeast monsoon the upwelled water causes a decrease in temperature and dissolved oxygen and an increase in salinity, density and nitrate-nitrogen, particularly seen at the lower boundary of the homogeneous layer. During the northwest monsoon the upwelled water is replaced by the Jawa Sea water with high temperature, low oxygen, low salinity, low density, very high phosphate, and high silicate. The observation on the oceanographical cruises reveals the precence of two other types of surface waters in the region. They are the East Kalimantan Coastal Water and the South Sulawesi Coastal Water, each is formed by mixing process of sea water and land drainage along the coast of the two islands respectively. Originally they are characterized by low salinity, low oxygen, high temperature, high phosphate, low nitrate and high silicate. Their salinity and dissolved oxygen increase due to mixing with the upwelled water and the high activity of phytoplankton respectively.

Upwelling Dynamic Based on Satellite and INDESO Data in the Flores Sea

Upwelling phenomenon is crucial to be forecasted, mainly concerning the information of potential fishery areas. Utilization of calibrated model for recorded upwelling such as INDESO gives benefit for historical result up to the present time. The aim of this study is to estimate areas and seasons of upwelling occurrences in the Flores Sea using data assimilation of satellite and modeling result. This study uses sea surface temperature, chlorophyll-a data from level 3 of MODIS image and sea surface height from satellite Jason-2 monthly for three years (2014-2016) and INDESO model data for sea surface temperature, sea surface height, and chlorophyll-a daily for three years (2014-2016). The upwelling is indicated by declining of sea surface temperature, sea surface height and increasing of chlorophyll-a. Verification is conducted by comparing the model result with recorded MODIS satellite image. The result shows that the area of southern Makassar Strait having occurrences of upwelling phenomenon every year starting in June, extended to July and August. The strongest upwelling occurred in 2015 covering more or less the area of 23,000 km2. The relation of monthly data of satellite has significantly correlated with daily data of INDESO model

Nutrient and chlorophyll-a distribution in Makassar Upwelling Region: From MAJAFLOX CRUISE 2015

Upwelling is an important mechanism on productivity enhancement in the Southern Makassar Strait (MAK). Previous studies found correlation between upwelling and chlorophyll-a blooms, which is perhaps caused by nutrient regeneration from deeper water. Through a multi-disciplinary study “MAJAFLOX Cruise” in August 2015, CTD casts and seawater samples have been collected from Southern Makassar Strait. The present study aims to investigate relationship between physical processes of upwelling and nutrient usage, especially for nitrate, phosphate and silicate from regenerated processes to be used for the primary productivity (chlorophyll-a). The results show that upwelling centre is found near Dewakang Sill around station 5, associated with the highest chlorophyll-a concentration (0.438 µgL-1). Relatively high nutrient is also revealed in other station of observation. In sea surface layer, nitrate is high in station 1 to 3, phosphate high in station 2 and silicate high in station 9. This shifting of high nutrient concentration may indicate spatial variation of biogeochemical processes in the surface layer associated with nutrient fluxes.

Analysis of turbulent mixing in Dewakang Sill, Southern Makassar Strait

Dewakang Sill is located in southern Makassar Strait, conveying major path of Indonesian Throughflow (ITF), as a confluence region of different water masses, such as salty Pacific water and fresh Java Sea water. Its depth is about 680 m which blocks the ITF flow below this depth into Flores Sea. This research aimed to estimate turbulent mixing in the Dewakang Sill by applying Thorpe analysis using 24 hours “yoyo” CTD data sets, acquired from MAJAFLOX Cruise in August 2015. The results showed that stratification of water masses is dominated by Pacific water origin. Those are North Pacific Subtropical thermocline and Intermediate water masses. Mean dissipation of turbulent kinetic energy (ϵ) and turbulent vertical diffusivity (Kρ) value in the Dewakang Sill are of O(1.08 × 10−6)Wkg−1, and O(2.84 × 10−4) m2s−1 respectively. High correlation between epsilon and internal waves oscillation suggested that internal tidal waves activities are the major forcing for turbulent mixing in the study area.

Analysis of upwelling event in Southern Makassar Strait

The southeast monsoon (SEM) winds which blow in southern Makassar Strait, generate the coastal upwelling phenomenon. The wind data for one year, which is equipped with CTD data from MAJAFLOX cruise results, is used to analyze the phenomenon of upwelling in this region. During the SEM 2015 occurrence, the southeasterly winds speed were in average of 6 m/s, while the highest speed appeared in August and September. Using the Ekman theory’s analysis of upwelling during this monsoon period, we could estimate the Ekman transport was about 8.50 m2/s toward offshore (to the Southwest direction); the upwelled water, occurred from deeper layer, started from the coastal area with vertical velocity was about 6.87 x 10-5 m/s – 7.84 x 10-5 m/s; and The Ekman layer depth in the upwelling region was approximately 60 m and these were good agreement with CTD observation result.

Variations in sea surface hydrology in the southern Makassar Strait over the past 26 kyr

We present centennial-scale records of sea surface temperature and oxygen isotopes in a sediment core from Mandar Bay, offshore Sulawesi in the southern Makassar Strait, which provide new insights into the variability of Indonesian climate over the past 26 kyr. The age model for the core is constrained by 17 AMS radiocarbon ages, with a surface ocean reservoir age correction based on paired wood and foraminiferal samples. Small Holocene reservoir ages of 105 180 years point to intense surface ocean atmosphere interchange linked to increased monsoonal precipitation, whereas Last Glacial Maximum and deglacial reservoir ages are significantly higher. Mg/Ca derived sea surface temperature reconstructions based on Globigerinoides ruber (s. s., white) exhibit an extended plateau during the Antarctic Cold Reversal, suggesting an atmospheric connection to high-latitude Southern Hemisphere climate and a seasonal bias on G. ruber. This is in agreement with southern hemisphere sites along the track of the Indonesian Throughflow and in contrast to Northern Hemisphere records from the South China Sea, Sulu Sea and Western Pacific (off Mindanao), which exhibit warming during the Bolling-Allerod. Ice-volume corrected delta O-18 seawater delta O-18(sw) increased during Heinrich Stadial 1 and the Younger Dryas, whereas the Bolling-Allerod is characterized by low delta O-18(sw). We attribute delta O-18(sw) variability in the southern Makassar Strait during the Last Glacial Maximum and glacial termination to changes in provenance and seasonality of precipitation rather than to variability in the amount of local precipitation and runoff. (C) 2016 Elsevier Ltd. All rights reserved.