Phytoplankton and foraminiferal frequencies in northern Indian Ocean and Red Sea surface waters

1989 ◽  
Vol 24 (4) ◽  
pp. 531-539 ◽  
Author(s):  
Annelies Kleijne ◽  
Dick Kroon ◽  
Wanda Zevenboom
Keyword(s):  
Indian Ocean ◽  
Red Sea ◽  
Surface Waters ◽  
Sea Surface ◽  
Northern Indian Ocean

Surface radiocarbon record from the northern Indian Ocean: understanding surface ocean processes

2021 ◽  
Author(s):  
Harsh Raj ◽  
Ravi Bhushan
Keyword(s):  
Exchange Rate ◽  
Indian Ocean ◽  
Surface Waters ◽  
Northern Indian Ocean ◽  
Natural Processes ◽  
Surface Ocean ◽  
Nuclear Bomb ◽  
Decline Rate ◽  
Bomb Radiocarbon ◽  
Enormous Amount

<p>Due to nuclear bomb tests during mid 1950s and 1960s, enormous amount of bomb radiocarbon was introduced into the atmosphere and subsequently to the ocean. Corals growing in shallow oceanic region record the radiocarbon variations in ocean surface waters. The bomb radiocarbon signature embedded in coral can be useful in providing information about natural processes affecting the surface waters of the region. In this regard, coral based radiocarbon records from the Lakshadweep Islands and the Andaman Islands from the northern Indian Ocean has been analysed. The analysed coral ∆<sup>14</sup>C values of recent period show comparable or even higher than the atmospheric ∆<sup>14</sup>C values, suggesting that major fraction of bomb radiocarbon have transferred in to the ocean. The northern Andaman region show ∆<sup>14</sup>C decline rate of about 3.1 ‰ yr<sup>-1</sup> between 1978 to 2014. Whereas, the southern Bay of Bengal and the Lakshadweep records show relatively lower decline rate of 2.5 ‰ yr<sup>-1</sup> for the same period. Based on the coral and atmospheric radiocarbon values, air-sea CO<sub>2</sub> exchange rate over the Lakshadweep and Andaman region has been estimated. The bomb radiocarbon based estimate of air-sea CO<sub>2</sub> exchange rate over Lakshadweep is 13.4 ± 2.1 mol m<sup>-2</sup> yr<sup>-1</sup> and over northern Andaman is 8.8 ± 1.3 mol m<sup>-2</sup> yr<sup>-1</sup>. The Lakshadweep region show net regional CO<sub>2</sub> flux of 2.5 ± 0.4 Tg C yr<sup>-1</sup>, while the northern Andaman region shows value of -0.3 ± 0.04 Tg C yr<sup>-1</sup>. This study discusses the spatial and temporal radiocarbon changes in the northern Indian Ocean and has implications to constraining the carbon flux over the region.</p>

Glacial to Holocene changes in sea surface temperature and seawater δ18O in the northern Indian Ocean

2017 ◽  
Vol 485 ◽  
pp. 697-705 ◽  
Author(s):  
Tabish Raza ◽  
Syed Masood Ahmad ◽  
Stephan Steinke ◽  
Waseem Raza ◽  
Mahjoor Ahmad Lone ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Northern Indian Ocean

scholarly journals Marine Reservoir Correction for the Cocos (Keeling) Islands, Indian Ocean

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 603-610 ◽  
Author(s):  
Quan Hua ◽  
Colin D Woodroffe ◽  
Mike Barbetti ◽  
Scott G Smithers ◽  
Ugo Zoppi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Indian Ocean ◽  
Red Sea ◽  
Surface Waters ◽  
Accelerator Mass Spectrometry ◽  
Arabian Sea ◽  
Indonesian Throughflow ◽  
Gulf Of Aden ◽  
The Indian Ocean ◽  
Reservoir Age

Known-age corals from the Cocos (Keeling) Islands, Indian Ocean, have been analyzed by accelerator mass spectrometry (AMS) for radiocarbon to determine marine reservoir age corrections. The ΔR value for the Cocos (Keeling) Islands is 66 ± 12 yr based on the analyses undertaken for this study. When our AMS and previously published dates for Cocos are averaged, they yield a ΔR of 64 ± 15 yr. This is a significant revision of an earlier estimate of the ΔR value for the Cocos (Keeling) Islands of 186 ± 66 yr (Toggweiler et al. 1991). The (revised) lower ΔR for the Cocos (Keeling) Islands is consistent with GEOSECS 14C data for the Indian Ocean, and previously published bomb 14C data for the Red Sea, Gulf of Aden, and Cocos Islands. The revised ΔR is also close to values for the eastern Indian Ocean and adjacent seas. These suggest surface waters that reach the Cocos Islands might be partly derived from the far western Pacific, via the Indonesian throughflow, and might not be influenced by the southeast flow from the Arabian Sea.

Examination of interannual variability of sea surface temperature in the Indian Ocean using the physical decomposition dethod

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Xingrong Chen ◽  
Yi Cai ◽  
Fangli Qiao
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Interannual Variability ◽  
Surface Waters ◽  
Indian Ocean Dipole ◽  
Sea Surface ◽  
The Third ◽  
Fourth Term ◽  
The Indian Ocean ◽  
Spatially Varying

 The physical decomposition method suggested by Qian (2012) is used to examine the interannual variability of sea surface temperature (SST) and anomaly (SSTA) in the Indian Ocean (IO) for the period 1945.2003. The monthly mean SSTs taken from the global ocean reanalysis produced by the Simple Ocean Data Assimilation (SODA) are decomposed into four terms. The first term is the zonally averaged monthly climatological SST ([Tt(ϕ)]), which features relatively warm surface waters in the tropical IO and relatively colder surface waters over the southern IO. This term also has a relatively low SST pool between the Equator and 20°N. The SST at the center of the pool in summer is about 1-2°C lower than in spring and autumn. The second term is the spatially-varying monthly climatological SSTA (Tt*(λ,ϕ)), due mainly to the topographic effect and seasonal variation in wind forcing. The values of Tt*(λ,ϕ) are negative over the western coastal waters and positive over the eastern coastal and shelf waters in the tropical and northern IO. The third term is the zonally-averaged transient SSTA([T(ϕ,t)']Y). The largest values of [T(ϕ,t)']Y occur over the subtropical and mid-latitudes of the IO, which differs from the SSTA in the tropical waters of the Pacific Ocean. Time series of zonally and meridionally averaged T(ϕ,t)'Y in the tropical-subtropical IO is strongly correlated with the Indian Ocean basin-wide (IOBW) mode. The fourth term is the spatially-varying transient SSTA (T(λ,ϕ,t)*Y']. The REOF analysis of the fourth term demonstrates that the first REOF is correlated strongly with the South Indian Ocean Dipole (SIOD) mode. The second REOF is correlated strongly with the equatorial Indian Ocean dipole (IOD) mode. The third REOF is highly correlated with the tropical IOBW mode.

Descriptions of four new species of Thysanophrys (Scorpaeniformes: Platycephalidae) from the Western Indian Ocean

Zootaxa ◽  
2013 ◽  
Vol 3608 (2) ◽  
pp. 127-136 ◽  
Author(s):  
LESLIE W. KNAPP
Keyword(s):  
New Species ◽  
Indian Ocean ◽  
Red Sea ◽  
Western Indian Ocean ◽  
Maximum Size ◽  
Color Pattern ◽  
Northern Indian Ocean ◽  
Dorsal Fin ◽  
Spine Structure ◽  
Pacific Species

Four new species of Thysanophrys are described from the Western Indian Ocean (WIO). T. rarita, known from a single specimen taken off Somalia, is provisionally placed in Thysanophrys and is distinguished by its color pattern and number of preocular and suborbital spines. T. tricaudata is described from three specimens taken at SCUBA stations off southwestern Sri Lanka. They differ from other western Indian Ocean (WIO) Thysanophrys in color pattern, lack of ocular flaps, number of dorsal fin spines and scale counts.  The remaining two new species are somewhat similar to the widespread Indo-Pacific species, T. chiltonae Schultz (1966). T. randalli is described from specimens taken at the Amirante Islands and Mauritius. It may also be widespread in the Indo-Pacific, but differs from T. chiltonae in nasal spine structure, color pattern, type of iris lappet margin, and in having a much shorter maximum size. T. springeri also appears to be a smaller species than T. chiltonae and, aside from one record off Djibouti, is restricted to Red Sea. It also differs from T. chiltonae in color pattern, in having fewer pectoral rays and fewer scale rows between the second dorsal-fin insertion and the lateral line. Although T. chiltonae is relatively common in the northern Indian Ocean, it does not appear to have entered the Red Sea.

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