scholarly journals Validation and Quality Assessment of Sea Levels from SARAL/ AltiKa Satellite Altimetry over the Marginal Seas at the Southeast Asia

Author(s):  
Noor Nabilah Abdullah ◽  
Nurul Hazrina Idris
2018 ◽  
Vol 39 (1) ◽  
pp. 99-111
Author(s):  
Gordon Draškić ◽  
Sansareeya Wangkulangkul ◽  
Iñigo Martínez-Solano ◽  
Judit Vörös

Many biodiversity hotspots are located in areas with a complex geological history, like Southeast Asia, where species diversity may still be far underestimated, especially in morphologically conservative groups like amphibians. Recent phylogenetic studies on the frog genusLeptobrachiumfrom Southeast Asia revealed the presence of deeply divergent mitochondrial clades inLeptobrachium hendricksonifrom Malaysia and Sumatra but populations from Thailand have not been studied so far. In this study, we re-evaluate patterns of intraspecific genetic diversity inL. hendricksonibased on the analysis of combined sequences of mitochondrial 12S and 16S genes (1310 base pairs) including for the first time samples from southern Thailand. Thai populations ofL. hendricksoniformed a distinct clade with respect to populations from central and southern Malaysia and Sumatra. High sequence divergence between lineages from Thailand, Malaysia and Sumatra suggests the possible presence of cryptic species inL. hendricksoni. Divergence withinL. hendricksonidates back to the late Miocene, around 6 Mya, when lineages from Thailand, north Malaysia and Sumatra split from a lineage in south Malaysia, at about the same time as rising sea levels isolated the Thai-Malay peninsula. Subsequent splits took place later in the Pliocene, around 4.5 and 2.6 Mya. Our results highlight the role of geological history in promoting population divergence and speciation.


2020 ◽  
Vol 8 (6) ◽  
pp. 425 ◽  
Author(s):  
MyeongHee Han ◽  
Yang-Ki Cho ◽  
Hyoun-Woo Kang ◽  
SungHyun Nam ◽  
Do-Seong Byun ◽  
...  

Monthly mean sea-levels have annual maxima in August in the northeast Asian marginal seas (NEAMS). Based on satellite altimetry data, the rising rate of the August NEAMS sea-level (ANS, 4.2 mm∙yr−1) is greater than those of the NEAMS (3.6 mm∙yr−1) and global (3.4 mm∙yr−1) annual mean sea-levels. Thus, the interannual variations of ANS are classified as relatively high (period H) and low (period L) years and have been analysed because of the high risk of sea-level fluctuation to the coastal regions in August. In period H, there are large atmospheric pressure gradients between the high pressure zone in the Kuroshio Extension (KE) and the low pressure zone in the west of Taiwan (WT). In period L, the atmospheric pressure gradients are small between the above-mentioned zones. Large atmospheric pressure gradients induce strong west-northwestward wind stresses and more Ekman transport from the northwest Pacific Ocean into the NEAMS. The correlation coefficient between August NEAMS sea-level index (ANSI), which is the difference of atmospheric pressure anomalies between the KE and the WT, and the August NEAMS sea-level anomaly (ANSA) is 0.73. Although there is a significant correlation (coefficient: 0.64) between ANSA and the East Asian summer monsoon index (EASMI), ANSI might be more useful in estimating the variability of ANSA.


Survey Review ◽  
2012 ◽  
Vol 44 (326) ◽  
pp. 215-222 ◽  
Author(s):  
K Miller ◽  
B Hart ◽  
P Sydney

The Holocene ◽  
2005 ◽  
Vol 15 (8) ◽  
pp. 1199-1213 ◽  
Author(s):  
B. P. Horton ◽  
P. L. Gibbard ◽  
G. M. Mine ◽  
R. J. Morley ◽  
C. Purintavaragul ◽  
...  
Keyword(s):  

Author(s):  
Amelius Andi Mansawan ◽  
Jonson Lumban Gaol ◽  
James P. Panjaitan

Observation of sea levels continuously is very important in order to adapt the disasters in the coastal areas. Conventionally observations of sea level using tide gauge, but the number of tide gauge installed along the coast of Indonesia is still limited. Altimetry satellite data is one solution; therefore it is necessary to assess the potential and accuracy of altimetry satellite data to complement the sea level data from tide gauges. The study was conducted in the coastal waters of Cilacap and Bali by analysis data Envisat satellite altimetry for period 2003 to 2010 and data compiled from a variety of satellite altimetry from 2006 to 2014. Data tidal was used as a comparison of altimetry satellite data. The altimetry satellite data in Cilacap and Benoa waters more than 90% could be used to assess the variation and the sea level rise during the period 2003-2010. The rate of sea level rise both the data of tidal and satellite altimetry data indicates the same rate was 3.5 mm/year in Cilacap. in Benoa are 4.7 mm/year and 5.60 mm/year respectively.


Sign in / Sign up

Export Citation Format

Share Document