scholarly journals Sea level changes in the Pacific region and impacts of the 2009 El Niño in Fiji waters [assessment from 18 years land-based data]

2011 ◽  
Vol 29 (1) ◽  
pp. 26 ◽  
Author(s):  
Than Aung ◽  
Awnesh Singh ◽  
Dayang Siti Maryam
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
South Pacific ◽  
Pacific Region ◽  
Pacific Island ◽  
Sea Level Changes ◽  
Level Data ◽  
The Pacific

The sea level rise issue is one of the major topics that has gained increasing global attention. In particular, its impacts on many Pacific island countries and other low lying countries have been more prevalent over the last two decades. Sea level data from the AusAID funded South Pacific Sea Level and Climate Monitoring Project will be focused in this study despite the fact that the length of data is not sufficiently long. The project was set up in response to concerns raised by Pacific island countries over the potential impacts of an enhanced greenhouse effect on climate and sea levels in the South Pacific initially for 20 years and probably more. Based upon 18 years of sea level data from the project, the range of sea level rise rate in the Pacific region is between 3.1 mm y–1 (Kiribati) and 8.4 mm y–1 (Tonga) as of June 2011. This is 3–4 times higher than the global average of 1–2 mm y–1. Although the data length is for the last 18 years, the sea level trend values do not fluctuate significantly since 2002. It simply indicates that the rate of sea level rise in the Pacific region is not accelerating as anticipated by the local community. Interestingly, the profound effects of El Niño on sea level changes are quite unpredictable even during the 2009 mild El Niño. In two particular spots in the Pacific and their vicinities (at latitude 12°S & longitude 180°E and latitude 14°S & longitude 157°E) sea level drop in these areas is ~40 cm during March 2010. Although the present effect of El Niño on sea level changes is isolated and not Pacific wide like in 1997–98 El Niño, it simply indicates the complexity of sea level issue and danger of projecting future sea level trends at a particular area.

scholarly journals Technical Note: Mean sea level variation in the Singapore Strait from long-term tide data

2012 ◽  
Vol 9 (3) ◽  
pp. 2255-2271
Author(s):  
P. Tkalich ◽  
M. T. Babu ◽  
P. Vethamony
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Level Variation ◽  
Sea Level Changes ◽  
Mean Sea Level ◽  
Sea Level Variation ◽  
Singapore Strait

Abstract. Winds over the South China Sea (SCS) are primarily responsible for the observed variability in sea level anomalies (SLAs) in the Singapore Strait (SS). The present study focuses on remote forcing contributing to local mean sea level changes in the SS in seasonal and inter-annual scales, and relating the long term mean sea level variation to El Niño/ENSO. As Tanjong Pagar (TP) tide station in the SS has nearly 23.5 yr (1984–2007) of time series data with less data gaps, this data was subject to harmonic and sea level analyses. The mean sea level changes suggest that the fluctuations are quasi-periodic. Rising and falling of sea level is noticed atleast 7 times in a period of 15 yr, with 3 distinct sharp falls (1984–1987, 1989–1992 and 1995–1996) and 4 sharp rises (1987–1988, 1992–1993, 1994–1995 and 1997–1999). These sea level falls are related to El Niño events. When we segregated the results into 2 time spans, we find that from 1984 to 1999 the sea level was on the rising trend in spite of sharp falls, and from 1999 to 2007 on gradual falling trend. More or less similar trend was observed by other researchers for the SCS with altimetry data. During the El Niño periods of 1987 and 1992, the inter-annual MSL variability is the highest, of the order of 7 cm. In one of the events, sea level recovered from a fall of 60 mm (in 1987) to a rise of 40 mm (in 1988). During 1992 to 1999, sea level was continuously on rising trend (from −50 mm to +60 mm), except in one year (1995–1996). The analysis shows a MSL rise rate of 15.7 mm yr−1, which is very closer to MSL in the SCS. The average rate of sea level rise around Singapore as shown by the Tanjong Pagar tidal station is 1.6 mm yr−1, and this matches with the global sea level rise.

THE REGULARITIES OF THE SEA LEVEL VARIATION OF THE BLACK AND AZOV SEAS IN THE LAST 100 YEARS

2018 ◽  
Author(s):  
О. Андрианова ◽  
O. Andrianova
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Linear Trend ◽  
Annual Data ◽  
Sea Level Variation ◽  
The Pacific ◽  
Short Period ◽  
Global Nature

The trends in variability of the sea level on the coastal stations on the Black and Azov seas during the last 100 years were determined; their comparison from station to station was done with the trends in the levels for the last 10 years. The estimates were made by filtering of the monthly and annual data by the 5-year run ning average. The rate of the sea level rise was calculated from absolute extremes in the annual and filtered data and on the linear trend: the amplitude of level increased from the lowest values occurring on the Batumi (30 cm – for the annual and 23 cm – for the filtered) and Berdyansk (39 and 27 cm, respectively) to the biggest on the Odessa (respectively 67 and 44 cm), Sulina (65 and 40 cm) and Poti (54 and 49 cm). The explanation of the differences in the trend’s maximums based on the fact that stations Odessa and Poti are situated in tectonic areas (close to geological rifts), the stations Sulina and Primorskoe are located near the Danube delta, which has an impact also. The comparing of the trends in the sea level in periods 2000–2010 years and 2000–2009 years shows the global nature of the El Niño impact phenomenon (El Niño in the Pacific was observed during the winters of 2009– 2010 years). The evaluation of periods and amplitudes in the oscillations of sea level shows that in the short-period terms there are 3–4 year waves and in long-period terms there are 10–14 year waves; the amplitudes of short and long waves are on average equal to 11–12 cm. The exceptions are the same stations, which differed in the sea level rise; the average amplitude of the wave oscillations at these stations is bigger in 1,5 times: Sulina (14,5 cm – for short and 11,8 cm – for long), Poti (16,9 and 16,2 cm, respectively) and Berdyansk station which located in the Azov Sea (13,1 and 10,8 cm, respectively); the periods are the same as at all other stations.

scholarly journals Rise and fall of sea level in Nauru area over a nodal cycle

2010 ◽  
Vol 28 (1) ◽  
pp. 63
Author(s):  
Muhammad Ali S. Hussein ◽  
Awnesh Singh ◽  
Than Aung
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
South Pacific ◽  
Pacific Island ◽  
Sea Levels ◽  
Level Data ◽  
Rise Rate ◽  
Pacific Island Countries ◽  
Set Up ◽  
Data Length

The sea level rise issue is one of the major topics that have gained global attention. In particular, its impacts on many Pacific island countries have been more prevalent over the last two decades. The tiny island of Nauru, once a wealthy nation, is no exception to the effect of climate change. With its highest point ~61 m above sea level, and the threat of sea level rise evident, Nauru is under pressure to save itself from sea level rise problem. Sea level data from the AusAID funded South Pacific Sea Level and Climate Monitoring Project will be focussed on despite the fact that the length of data is not sufficiently long. The project was set up in response to concerns raised by Pacific island countries over the potential impacts of an enhanced greenhouse effect on climate and sea levels in the South Pacific for 20 years initially. Based upon 17 years of sea level data from the project, the sea level rise rate in Nauru as at July 2010 was 4.4 mm yr–1. This is at least 2–3 times higher than the global average of 1–2 mm yr–1. Sea level in the Nauru area has risen approximately 7.5 cm since the inception of the project 17 years ago (July 1993). Although there is no significant impact on the sea level trends, it is to be noted that the land is quite stable and the rate of land rising is 0.01 mm yr–1. Although the data length is for the last 17 years, the sea level trend values do not fluctuate significantly since 2002. It simply indicates that the rate of sea level rise in the Nauru region is not accelerating as anticipated by the community.

scholarly journals Water level changes, subsidence, and sea level rise in the Ganges–Brahmaputra–Meghna delta

2020 ◽  
Vol 117 (4) ◽  
pp. 1867-1876 ◽  
Author(s):  
Mélanie Becker ◽  
Fabrice Papa ◽  
Mikhail Karpytchev ◽  
Caroline Delebecque ◽  
Yann Krien ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Water Level ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Climate Mitigation ◽  
Vertical Land Motion ◽  
The Ganges ◽  
And Sea Level

Being one of the most vulnerable regions in the world, the Ganges–Brahmaputra–Meghna delta presents a major challenge for climate change adaptation of nearly 200 million inhabitants. It is often considered as a delta mostly exposed to sea-level rise and exacerbated by land subsidence, even if the local vertical land movement rates remain uncertain. Here, we reconstruct the water-level (WL) changes over 1968 to 2012, using an unprecedented set of 101 water-level gauges across the delta. Over the last 45 y, WL in the delta increased slightly faster (∼3 mm/y), than global mean sea level (∼2 mm/y). However, from 2005 onward, we observe an acceleration in the WL rise in the west of the delta. The interannual WL fluctuations are strongly modulated by El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) variability, with WL lower than average by 30 to 60 cm during co-occurrent El Niño and positive IOD events and higher-than-average WL, by 16 to 35 cm, during La Niña years. Using satellite altimetry and WL reconstructions, we estimate that the maximum expected rates of delta subsidence during 1993 to 2012 range from 1 to 7 mm/y. By 2100, even under a greenhouse gas emission mitigation scenario (Representative Concentration Pathway [RCP] 4.5), the subsidence could double the projected sea-level rise, making it reach 85 to 140 cm across the delta. This study provides a robust regional estimate of contemporary relative WL changes in the delta induced by continental freshwater dynamics, vertical land motion, and sea-level rise, giving a basis for developing climate mitigation strategies.

scholarly journals Future extreme sea level seesaws in the tropical Pacific

2015 ◽  
Vol 1 (8) ◽  
pp. e1500560 ◽  
Author(s):  
Matthew J. Widlansky ◽  
Axel Timmermann ◽  
Wenju Cai
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Mean Sea Level ◽  
Global Mean Sea Level ◽  
Global Mean ◽  
The Tropical Pacific

Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño–Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño–related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise.

scholarly journals Putting WASH in the water cycle: climate change, water resources and the future of water, sanitation and hygiene challenges in Pacific Island Countries

2015 ◽  
Vol 5 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Wade L. Hadwen ◽  
Bronwyn Powell ◽  
Morgan C. MacDonald ◽  
Mark Elliott ◽  
Terence Chan ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Water Resource Management ◽  
Water Cycle ◽  
Pacific Island ◽  
Water And Sanitation ◽  
Sanitation And Hygiene ◽  
The Pacific ◽  
Pacific Island Countries

The Pacific region presents some of the lowest water and sanitation coverage figures globally, with some countries showing stagnating or even declining access to improved water and sanitation. In addition, Pacific Island Countries (PICs) are among the most vulnerable countries on the globe to extreme and variable climatic events and sea-level rise caused by climate change. By exploring the state of water and sanitation coverage in PICs and projected climatic variations, we add to the growing case for conserving water, sanitation and hygiene (WASH) interventions within a holistic integrated water resource management (IWRM) framework. PICs face unique challenges of increasing variability in rainfall (leading to drought and flooding), increasing temperatures, and likely higher than average sea-level rise, all of which impact on freshwater security. Add to this geographic and economic isolation, and limited human and physical resources, and the challenge of WASH provision increases dramatically. In this setting, there is a stronger case than ever for adopting a holistic systems understanding, as promoted by IWRM frameworks, to WASH interventions so that they consider past and current challenges as well as future scenarios.

scholarly journals Imprint of the El Niño Modoki on decadal sea level changes

2010 ◽  
Vol 37 (23) ◽  
pp. n/a-n/a ◽  
Author(s):  
Swadhin Behera ◽  
Toshio Yamagata
Keyword(s):  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Sea Level Changes ◽  
El Niño Modoki

scholarly journals El Niño, La Niña, and the global sea level budget

Ocean Science ◽  
2016 ◽  
Vol 12 (6) ◽  
pp. 1165-1177 ◽  
Author(s):  
Christopher G. Piecuch ◽  
Katherine J. Quinn
Keyword(s):  
Sea Level ◽  
El Niño ◽  
Hydrological Cycle ◽  
El Nino ◽  
Southern Oscillation ◽  
Heat Content ◽  
Global Ocean ◽  
Surface Warming ◽  
Enso Events ◽  
The Pacific

Abstract. Previous studies show that nonseasonal variations in global-mean sea level (GMSL) are significantly correlated with El Niño–Southern Oscillation (ENSO). However, it has remained unclear to what extent these ENSO-related GMSL fluctuations correspond to steric (i.e., density) or barystatic (mass) effects. Here we diagnose the GMSL budget for ENSO events observationally using data from profiling floats, satellite gravimetry, and radar altimetry during 2005–2015. Steric and barystatic effects make comparable contributions to the GMSL budget during ENSO, in contrast to previous interpretations based largely on hydrological models, which emphasize the barystatic component. The steric contributions reflect changes in global ocean heat content, centered on the Pacific. Distributions of ocean heat storage in the Pacific arise from a mix of diabatic and adiabatic effects. Results have implications for understanding the surface warming slowdown and demonstrate the usefulness of the Global Ocean Observing System for constraining Earth's hydrological cycle and radiation imbalance.

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