EFFECT OF ALTITUDE AND WOUNDING ON BLOOD DISEASE PROGRESS OF PLANTAIN

Effect of Altitude and Wounding on Blood Disease Progress of Plantain. In the latest decade, the blood disease of banana has spread in almost all provinces in Indonesia and caused wilting of millions banana clusters in several provinces. It is very difficult to control the disease due to the base data about ecology and epidemiology of the pathogen are still poorly understood. This research aimed to evaluate the effect of wounding of inoculation site on blood disease progress of plantain. The experiment was arranged using randomized completely block design It was conducted at three locations with altitude of 100, 1000, and 1600 m above sea levels as replication block. The treatments were wounding, unwounding inoculation site, inoculation, and uninoculation of plantain cv. Kepok Kuning Wounding was applied by stabbing with an injection pin around the corm of 15 stabs/seedling. The seedlings were planted singly in one liter of non sterile soil in plastic bag. Each treatment consisted of 5 seedlings which was replicated 3 times. Inoculation was done by soil drenching of 20 ml bacterial suspension at concentration of 108 cfu/ml two week after planting. The pathogen used for inoculation originated from low land area (about 100 m above sea level). Observation was done weekly for 5 weeks. The variables observed were wilt intensity and area under disease progress (AUDPC). The results showed that blood disease was able to establish at altitude of 1600 m above sea level. The disease progress however was slower that those at 100 and 1000 m above sea level. On wounded seedling, the disease progress was more aggressive than those on unwounded one.

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Anthropogenic sediment starvation forces tidal dominance in a mega-delta

10.21203/rs.3.rs-81555/v1 ◽

2020 ◽

Author(s):

Grigorios Vasilopoulos ◽

Quan Quan ◽

Daniel Parsons ◽

Stephen Darby ◽

Van Tri ◽

...

Keyword(s):

Sea Level ◽

Mekong Delta ◽

Driving Factors ◽

Climate Change Scenarios ◽

Recent Past ◽

Sea Levels ◽

River Deltas ◽

Major River ◽

Rising Sea Levels ◽

Almost All

Abstract The world’s major river deltas provide bountiful ecosystem services to hundreds of millions of people1,2, but there are widespread concerns that their ability to support these critical functions is being threatened by increases in salinity and the extent of tidal zones3, forced by sea-level rise4. Changes in the position of the fluvial-marine interface are governed not only by climate-driven sea-level rise, but by other factors including variations in river discharge and channel geometry5,6. However, the relative contributions of different driving factors to shifting tidal extent remains unconstrained. Here we use new field data and hydrodynamic modelling to quantify the influence of these different driving factors on accelerating tidal extension in the Mekong delta, both for the recent past and projected into the future under a range of policy, regulation and climate change scenarios. Our results indicate that, within the next two decades, tidal extension into the delta will increase by up to 56 km due to channel deepening, primarily driven by anthropogenic sediment starvation, which accounts for almost all (92%) of this incursion. Eustatically rising sea-levels are found to contribute only modestly. These findings will be transferable to other large sediment starved deltas that are facing similar challenges.

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Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change

Nature Communications ◽

10.1038/s41467-021-22838-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Benjamin H. Strauss ◽

Philip M. Orton ◽

Klaus Bittermann ◽

Maya K. Buchanan ◽

Daniel M. Gilford ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

East Coast ◽

The United States ◽

Hurricane Sandy ◽

Water Levels ◽

Anthropogenic Climate Change ◽

Economic Damage ◽

Sea Levels

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.

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Records of sea-level highstand over the Meghalayan age/late Holocene from uranium-series ages of beachrock in Weizhou Island, northern South China Sea

The Holocene ◽

10.1177/09596836211033215 ◽

2021 ◽

pp. 095968362110332

Author(s):

Tingli Yan ◽

Kefu Yu ◽

Rui Wang ◽

Wenhui Liu ◽

Leilei Jiang

Keyword(s):

South China Sea ◽

Sea Level ◽

South China ◽

Intertidal Zone ◽

Meteoric Water ◽

Northern South China Sea ◽

Water Environment ◽

Sea Levels ◽

China Sea ◽

Micro Structures

Beachrock is considered a good archive for past sea-levels because of its unique formation position (intertidal zone). To evaluate sea-level history in the northern South China Sea, three well-preserved beachrock outcrops (Beigang, Gongshanbei, and Hengling) at Weizhou Island, northern South China Sea were selected to examine their relative elevation, sedimentological, mineralogical, and geochemical characteristics. Acropora branches with well-preserved surface micro-structures were selected from the beachrocks and used to determine the ages of these beachrocks via U-series dating. The results show that the beachrocks are composed of coral reef sediments, terrigenous clastics, volcanic clastics, and various calcite cements. These sediments accumulated in the intertidal zone of Weizhou Island were then cemented in a meteoric water environment. The U-series ages of beachrocks from Beigang, Gongshanbei, and Hengling are 1712–768 ca. BP, 1766–1070 ca. BP, and 1493–604 ca. BP (before 1950 AD) respectively. Their elevations are 0.91–1.16 m, 0.95–1.24 m, and 0.82–1.17 m higher than the modern homologous sedimentary zones, respectively. Therefore, we concluded that the sea-level in the Meghalayan age (1766–604 ca. BP) was 0.82–1.24 m higher than the present, and that the sea-level over this period showed a declining trend.

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Flooding Conditions at Aveiro Port (Portugal) within the Framework of Projected Climate Change

Journal of Marine Science and Engineering ◽

10.3390/jmse9060595 ◽

2021 ◽

Vol 9 (6) ◽

pp. 595

Author(s):

Américo Soares Ribeiro ◽

Carina Lurdes Lopes ◽

Magda Catarina Sousa ◽

Moncho Gomez-Gesteira ◽

João Miguel Dias

Keyword(s):

Climate Change ◽

Sea Level ◽

Climate Change Impacts ◽

Storm Surges ◽

Historical Period ◽

Return Periods ◽

Wave Regime ◽

Mean Sea Level ◽

Sea Levels ◽

Far Future

Ports constitute a significant influence in the economic activity in coastal areas through operations and infrastructures to facilitate land and maritime transport of cargo. Ports are located in a multi-dimensional environment facing ocean and river hazards. Higher warming scenarios indicate Europe’s ports will be exposed to higher risk due to the increase in extreme sea levels (ESL), a combination of the mean sea level, tide, and storm surge. Located on the west Iberia Peninsula, the Aveiro Port is located in a coastal lagoon exposed to ocean and river flows, contributing to higher flood risk. This study aims to assess the flood extent for Aveiro Port for historical (1979–2005), near future (2026–2045), and far future (2081–2099) periods scenarios considering different return periods (10, 25, and 100-year) for the flood drivers, through numerical simulations of the ESL, wave regime, and riverine flows simultaneously. Spatial maps considering the flood extent and calculated area show that most of the port infrastructures' resilience to flooding is found under the historical period, with some marginal floods. Under climate change impacts, the port flood extent gradually increases for higher return periods, where most of the terminals are at high risk of being flooded for the far-future period, whose contribution is primarily due to mean sea-level rise and storm surges.

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Twenty-first century response of Petermann Glacier, northwest Greenland to ice shelf loss

Journal of Glaciology ◽

10.1017/jog.2020.97 ◽

2020 ◽

pp. 1-11

Author(s):

Emily A. Hill ◽

G. Hilmar Gudmundsson ◽

J. Rachel Carr ◽

Chris R. Stokes ◽

Helen M. King

Keyword(s):

Sea Level ◽

First Century ◽

Ice Shelf ◽

Ice Shelves ◽

Sea Levels ◽

Grounding Line ◽

Global Mean Sea Level ◽

Near Future ◽

Global Mean ◽

Large Sections

Abstract Ice shelves restrain flow from the Greenland and Antarctic ice sheets. Climate-ocean warming could force thinning or collapse of floating ice shelves and subsequently accelerate flow, increase ice discharge and raise global mean sea levels. Petermann Glacier (PG), northwest Greenland, recently lost large sections of its ice shelf, but its response to total ice shelf loss in the future remains uncertain. Here, we use the ice flow model Úa to assess the sensitivity of PG to changes in ice shelf extent, and to estimate the resultant loss of grounded ice and contribution to sea level rise. Our results have shown that under several scenarios of ice shelf thinning and retreat, removal of the shelf will not contribute substantially to global mean sea level (<1 mm). We hypothesize that grounded ice loss was limited by the stabilization of the grounding line at a topographic high ~12 km inland of its current grounding line position. Further inland, the likelihood of a narrow fjord that slopes seawards suggests that PG is likely to remain insensitive to terminus changes in the near future.

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Mean Sea Level as a Reference for Geodetic Leveling

The Canadian Surveyor ◽

10.1139/tcs-1974-0095 ◽

1974 ◽

Vol 28 (5) ◽

pp. 524-530 ◽

Cited By ~ 3

Author(s):

G. W. Lennon

Keyword(s):

Sea Level ◽

World Ocean ◽

Equipotential Surface ◽

Scientific Discipline ◽

Mean Sea Level ◽

Sea Levels ◽

Coastal Sea ◽

Long Time ◽

Marine System

The use of mean sea level as a surface of reference that might provide an independent control for geodetic leveling has been a long term goal arising from the classical analogy between the geoid as an equipotential surface and the surface assumed by a hypothetical undisturbed world ocean. The problems associated with this aim are now known to be vast, and are associated with the dynamics of the marine system, notably its response to meteorological forces, to variations in density and to the effects of basic circulation patterns. In consequence the mean sea level surface varies rapidly in both time and space. This identifies in fact a distinctive scientific discipline, coastal geodesy, in which contributions are required by both geodesists and oceanographers. It has come to be recognized that the coastal zone is a hazardous environment for all observational techniques concerned. On the one hand, the difficulties of measurement of coastal sea levels have only recently been understood; on the other hand, precise leveling procedures are now known to be influenced by the attraction of marine tides and by crustal deformation of tidal loading. Much of the data available for study are therefore inadequate and, moreover, it should be noted that long-time series are required. It is now possible to lay plans for both geodetic and oceanographic procedures to remedy these deficiencies in the long-term interests of the study.

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Revising key parameters for long-term carbon cycle models

10.5194/egusphere-egu21-2794 ◽

2021 ◽

Author(s):

Chloé M. Marcilly ◽

Trond H. Torsvik ◽

Mathew Domeier ◽

Dana L. Royer

Keyword(s):

Sea Level ◽

Age Distribution ◽

Silicate Weathering ◽

Geological Time ◽

Sea Levels ◽

Climate Fluctuations ◽

Climate Gradients ◽

Sea Level Fluctuations ◽

Temperature And Precipitation

CO2 is the most important greenhouse gas in the Earth&#8217;s atmosphere and has fluctuated considerably over geological time. However, proxies for past CO2 concentrations have large uncertainties and are mostly limited to Devonian and younger times. Consequently, CO2 modelling plays a key role in reconstructing past climate fluctuations. Facing the limitations with the current CO2 models, we aim to refine two important forcings for CO2 levels over the Phanerozoic, namely carbon degassing and silicate weathering.Silicate weathering and carbonate deposition is widely recognized as a primary sink of carbon on geological timescales and is largely influenced by changes in climate, which in turn is linked to changes in paleogeography. The role of paleogeography on silicate weathering fluxes has been the focus of several studies in recent years. Their aims were mostly to constrain climatic parameters such as temperature and precipitation affecting weathering rates through time. However, constraining the availability of exposed land is crucial in assessing the theoretical amount of weathering on geological time scales. Associated with changes in climatic zones, the fluctuation of sea-level is critical for defining the amount of land exposed to weathering. The current reconstructions used inmodels tend to overestimate the amount of exposed land to weathering at periods with high sea levels. Through the construction of continental flooding maps, we constrain the effective land area undergoing silicate weathering for the past 520 million years. Our maps not only reflect sea-level fluctuations but also contain climate-sensitive indicators such as coal (since the Early Devonian) and evaporites to evaluate climate gradients and potential weatherablity through time. This is particularly important after the Pangea supercontinent formed but also for some time after its break-up.Whilst silicate weathering is an important CO2 sink, volcanic carbon degassing is a major source but one of the least constrained climate forcing parameters. There is no clear consensus on the history of degassing through geological time as there are no direct proxies for reconstructing carbon degassing, but various proxy methods have been postulated. We propose new estimates of plate tectonic degassing for the Phanerozoic using both subduction flux from full-plate models and zircon age distribution from arcs (arc-activity) as proxies.The effect of revised modelling parameters for weathering and degassing was tested in the well-known long-term models GEOCARBSULF and COPSE. They revealed the high influence of degassing on CO2 levels using those models, highlighting the need for enhanced research in this direction. The use of arc-activity as a proxy for carbon degassing leads to interesting responses in the Mesozoic and brings model estimates closer to CO2 &#160;proxy values. However, from simulations using simultaneously the revised input parameters (i.e weathering and degassing) large model-proxy discrepancies remain and notably for the Triassic and Jurassic.&#160;

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The Impact of Climate Change on States

International Community Law Review ◽

10.1163/18719732-12341465 ◽

2021 ◽

Vol 23 (2-3) ◽

pp. 115-132

Author(s):

Łukasz Kułaga

Keyword(s):

Climate Change ◽

International Law ◽

Sea Level Rise ◽

Sea Level ◽

The State ◽

Fundamental Change ◽

Sea Levels ◽

Impact Of Climate Change ◽

Potential Impact ◽

The Impact

Abstract The increase in sea levels, as a result of climate change in territorial aspect will have a potential impact on two major issues – maritime zones and land territory. The latter goes into the heart of the theory of the state in international law as it requires us to confront the problem of complete and permanent disappearance of a State territory. When studying these processes, one should take into account the fundamental lack of appropriate precedents and analogies in international law, especially in the context of the extinction of the state, which could be used for guidance in this respect. The article analyses sea level rise impact on baselines and agreed maritime boundaries (in particular taking into account fundamental change of circumstances rule). Furthermore, the issue of submergence of the entire territory of a State is discussed taking into account the presumption of statehood, past examples of extinction of states and the importance of recognition in this respect.

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Estimating contribution of high-frequency sea-level oscillations to the extreme sea levels in the Adriatic Sea

10.5194/egusphere-egu21-4602 ◽

2021 ◽

Author(s):

Krešimir Ruić ◽

Jadranka Šepić ◽

Maja Karlović ◽

Iva Međugorac

Keyword(s):

Time Series ◽

Sea Level ◽

High Frequency ◽

Adriatic Sea ◽

Tide Gauge ◽

Data Series ◽

Sea Levels ◽

Short Period ◽

Extreme Sea Levels ◽

Sea Level Oscillations

Extreme sea levels are known to hit the Adriatic Sea and to occasionally cause floods that produce severe material damage. Whereas the contribution of longer-period (T > 2 h) sea-level oscillations to the phenomena has been well researched, the contribution of the shorter period (T <&#160;2 h) oscillations is yet to be determined. With this aim, data of 1-min sampling resolution were collected for 20 tide gauges, 10 located at the Italian (north and west) and 10 at the Croatian (east) Adriatic coast. Analyses were done on time series of 3 to 15 years length, with the latest data coming from 2020, and with longer data series available for the Croatian coast. Sea level data were thoroughly checked, and spurious data were removed.&#160;For each station, extreme sea levels were defined as events during which sea level surpasses its 99.9 percentile value. The contribution of short-period oscillations to extremes was then estimated from corresponding high-frequency (T < 2 h) series. Additionally, for four Croatian tide gauge stations (Rovinj, Bakar, Split, and Dubrovnik), for period of 1956-2004, extreme sea levels were also determined from the hourly sea level time series, with the contribution of short-period oscillations visually estimated from the original tide gauge charts.&#160;&#160;Spatial and temporal distribution of contribution of short-period sea-level oscillations to the extreme sea level in the Adriatic were estimated. It was shown that short-period sea-level oscillation can significantly contribute to the overall extremes and should be considered when estimating flooding levels.&#160;

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What can idealized storm surge simulations tell us about worst case scenarios?

10.5194/egusphere-egu21-12284 ◽

2021 ◽

Author(s):

Elin Andrée ◽

Jian Su ◽

Martin Drews ◽

Morten Andreas Dahl Larsen ◽

Asger Bendix Hansen ◽

...

Keyword(s):

Wind Speed ◽

Sea Level ◽

North Sea ◽

Wind Direction ◽

Water Levels ◽

Sea Levels ◽

The North ◽

The North Sea ◽

Sea Coast ◽

North Sea Coast

The potential impacts of extreme sea level events are becoming more apparent to the public and policy makers alike. As the magnitude of these events are expected to increase due to climate change, and increased coastal urbanization results in ever increasing stakes in the coastal zones, the need for risk assessments is growing too.The physical conditions that generate extreme sea levels are highly dependent on site specific conditions, such as bathymetry, tidal regime, wind fetch and the shape of the coastline. For a low-lying country like Denmark, which consists of a peninsula and islands that partition off the semi-enclosed Baltic Sea from the North Sea, a better understanding of how the local sea level responds to wind forcing is urgently called for.We here present a map for Denmark that shows the most efficient wind directions for generating extreme sea levels, for a total of 70 locations distributed all over the country&#8217;s coastlines. The maps are produced by conducting simulations with a high resolution, 3D-ocean model, which is used for operational storm surge modelling at the Danish Meteorological Institute. We force the model with idealized wind fields that maintain a fixed wind speed and wind direction over the entire model domain. Simulations are conducted for one wind speed and one wind direction at a time, generating ensembles of a set of wind directions for a fixed wind speed, as well as a set of wind speeds for a fixed wind direction, respectively.For each wind direction, we find that the maximum water level at a given location increases linearly with the wind speed, and the slope values show clear spatial patterns, for example distinguishing the Danish southern North Sea coast from the central or northern North Sea Coast. The slope values are highest along the southwestern North Sea coast, where the passage of North Atlantic low pressure systems over the shallow North Sea, as well as the large tidal range, result in a much larger range of variability than in the more sheltered Inner Danish Waters. However, in our simulations the large fetch of the Baltic Sea, in combination with the funneling effect of the Danish Straits, result in almost as high water levels as along the North Sea coast.Although the wind forcing is completely synthetic with no spatial and temporal structure of a real storm, this idealized approach allows us to systematically investigate the sea level response at the boundaries of what is physically plausible. We evaluate the results from these simulations by comparison to peak water levels from a 58 year long, high resolution ocean hindcast, with promising agreement.

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