scholarly journals Observation of current variations off the New Guinea coast including the 1997–1998 El Niño period and their relationship with Sverdrup transport

2003 ◽  
Vol 108 (C7) ◽  
Author(s):  
Iwao Ueki
Keyword(s):  
El Niño ◽  
El Nino ◽  
New Guinea ◽  
Guinea Coast ◽  
Sverdrup Transport

Anomalous Upper-Ocean Circulation of the Western Equatorial Pacific following El Niño Events

2020 ◽  
Vol 50 (11) ◽  
pp. 3353-3373
Author(s):  
Yilong Lyu ◽  
Yuanlong Li ◽  
Jianing Wang ◽  
Jing Duan ◽  
Xiaohui Tang ◽  
...  
Keyword(s):  
El Niño ◽  
Rossby Waves ◽  
El Nino ◽  
New Guinea ◽  
Equatorial Pacific ◽  
Eastern Pacific ◽  
Western Boundary ◽  
Western Equatorial Pacific ◽  
Anomalous Circulation ◽  
El Niño Events

AbstractMooring measurements at ~140°E in the western equatorial Pacific Ocean documented greatly intensified eastward subsurface currents, which largely represent the nascent Equatorial Undercurrent, to ~67 cm s−1 in boreal summer of 2016. The eastward currents occupied the entire upper 500 m while the westward surface currents nearly disappeared. Historical in situ data observed similar variations after most El Niño events. Further analysis combining satellite and reanalysis data reveals that the eastward currents observed at ~140°E are a component of an anomalous counterclockwise circulation straddling the equator, with westward current anomalies retroflecting near the western boundary and feeding southeastward current anomalies along the New Guinea coast. A 1.5-layer reduced-gravity ocean model is able to crudely reproduce these variations, and a hierarchy of sensitivity experiments is performed to understand the underlying dynamics. The anomalous circulation is largely the delayed ocean response to equatorial wind anomalies over the central-to-eastern Pacific basin emerging in the mature stage of El Niño. Downwelling Rossby waves are generated by the reflection of equatorial Kelvin waves and easterly winds in the eastern Pacific. Upon reaching the western Pacific, the southern lobes of Rossby waves encounter the slanted New Guinea island and deflect to the equator, establishing a local sea surface height maximum and leading to the detour of westward currents flowing from the Pacific interior. Additional experiments with edited western boundary geometry confirm the importance of topography in regulating the structure of this cross-equatorial anomalous circulation.

Coastal upwelling along the north coast of Papua New Guinea and El Niño events during 1981–2005

2010 ◽  
Vol 60 (5) ◽  
pp. 1255-1269 ◽  
Author(s):  
Takuya Hasegawa ◽  
Kentaro Ando ◽  
Keisuke Mizuno ◽  
Roger Lukas ◽  
Bunmei Taguchi ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
El Niño ◽  
Coastal Upwelling ◽  
El Nino ◽  
New Guinea ◽  
North Coast ◽  
The North ◽  
El Niño Events ◽  
El Nino Events

scholarly journals Landslide inventory development in a data sparse region: spatial and temporal characteristics of landslides in Papua New Guinea

2015 ◽  
Vol 3 (8) ◽  
pp. 4871-4917 ◽  
Author(s):  
J. C. Robbins ◽  
M. G. Petterson
Keyword(s):  
Papua New Guinea ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rapid Development ◽  
New Guinea ◽  
Landslide Hazard ◽  
Landslide Inventory ◽  
Triggering Events ◽  
Landslide Triggering

Abstract. In Papua New Guinea (PNG) earthquakes and rainfall events form the dominant trigger mechanisms capable of generating many landslides. Large volume and high density landsliding can result in significant socio-economic impacts, which are felt particularly strongly in the largely subsistence-orientated communities which reside in the most susceptible areas of the country. As PNG has undergone rapid development and increased external investment from mining and other companies, population and settled areas have increased, hence the potential for damage from landslides has also increased. Information on the spatial and temporal distribution of landslides, at a regional-scale, is critical for developing landslide hazard maps and for planning, sustainable development and decision making. This study describes the methods used to produce the first, country-wide landslide inventory for PNG and analyses of landslide events which occurred between 1970 and 2013. The findings illustrate that there is a strong climatic control on landslide-triggering events and that the majority (~ 61 %) of landslides in the PNG landslide inventory are initiated by rainfall related triggers. There is also large year to year variability in the annual occurrence of landslide events and this is related to the phase of El Niño Southern Oscillation (ENSO) and mesoscale rainfall variability. Landslide-triggering events occur during the north-westerly monsoon season during all phases of ENSO, but less landslide-triggering events are observed during drier season months (May to October) during El Niño phases, than either La Niña or ENSO neutral periods. This analysis has identified landslide hazard hotspots and relationships between landslide occurrence and rainfall climatology and this information can prove to be very valuable in the assessment of trends and future behaviour, which can be useful for policy makers and planners.

scholarly journals Drought Detection over Papua New Guinea Using Satellite-Derived Products

2020 ◽  
Vol 12 (23) ◽  
pp. 3859
Author(s):  
Zhi-Weng Chua ◽  
Yuriy Kuleshov ◽  
Andrew B. Watkins
Keyword(s):  
Papua New Guinea ◽  
El Niño ◽  
El Nino ◽  
Standardized Precipitation Index ◽  
Longwave Radiation ◽  
New Guinea ◽  
False Alarms ◽  
Vegetation Health ◽  
The Impact

This study evaluates the World Meteorological Organization’s (WMO) Space-based Weather and Climate Extremes Monitoring (SWCEM) Demonstration Project precipitation products over Papua New Guinea (PNG). The products evaluated were based on remotely-sensed precipitation, vegetation health, soil moisture, and outgoing longwave radiation (OLR) data. The satellite precipitation estimates of the Climate Prediction Center/National Oceanic and Atmospheric Administration’s (CPC/NOAA) morphing technique (CMORPH) and Japan Aerospace Exploration Agency’s (JAXA) Global Satellite Mapping of Precipitation (GSMaP) were assessed on a monthly timescale over an 18-year period from 2001 to 2018. Station data along with the ERA5 reanalysis were used as the reference datasets for assessment purposes. In addition, a case study was performed to investigate how well the SWCEM precipitation products characterised drought in PNG associated with the 2015–2016 El Niño. Overall statistics from the validation study suggest that although there remains significant variability between satellite and ERA5 rainfall data in remote areas, this difference is much less at locations where rain gauges exist. The case study illustrated that the Vegetation Health Index (VHI), OLR anomaly and the Standardized Precipitation Index (SPI) were able to reliably capture the spatial and temporal aspects of the severe 2015–2016 El Niño-induced drought in PNG. Of the three, VHI appeared to be the most effective, in part due to its reduced incidence of false alarms. This study is novel as modern-day satellite-derived products have not been evaluated over PNG before. A focus on their value in monitoring drought can bring great value in mitigating the impact of future droughts. It is concluded that these satellite-derived precipitation products could be recommended for operational use for drought detection and monitoring in PNG, and that even a modest increase in ground-based observations will increase the accuracy of satellite-derived observations remotely.

Aboveground Forest Carbon Dynamics in Papua New Guinea: Isolating the Influence of Selective-Harvesting and El Niño

Ecosystems ◽  
2011 ◽  
Vol 14 (8) ◽  
pp. 1276-1288 ◽  
Author(s):  
Julian C. Fox ◽  
Ghislain Vieilledent ◽  
Cossey K. Yosi ◽  
Joe N. Pokana ◽  
Rodney J. Keenan
Keyword(s):  
Papua New Guinea ◽  
El Niño ◽  
El Nino ◽  
New Guinea ◽  
Carbon Dynamics ◽  
Forest Carbon ◽  
Selective Harvesting

Correlations Among Charcoal Records of Fires from the Past 16,000 Years in Indonesia, Papua New Guinea, and Central and South America

2001 ◽  
Vol 55 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Simon G. Haberle ◽  
Marie-Pierre Ledru
Keyword(s):  
South America ◽  
Papua New Guinea ◽  
Biomass Burning ◽  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Inverse Correlation ◽  
New Guinea ◽  
Atmospheric Transmission ◽  
Climate Signal

AbstractMicroscopic charcoal preserved in lake and swamp sediments from 10 sites in Indonesia and Papua New Guinea and from 5 sites in Central and South America have been used to reconstruct long-term fire histories for these two regions. Comparison of these records demonstrates that fire is promoted during periods of rapid climate change and high climate variability, regardless of the presence or absence of humans. Broad synchrony of changes in corrected charcoal values in each region supports an atmospheric transmission of the climate signal via the dominant large-scale atmospheric circulation systems (Walker Circulation) that appears to have persisted since 16,000 cal yr B.P. Altered climate boundary conditions under the influence of changing El Niño-related variability, insolation, sea level, and sea surface temperature all influenced the strength of this connection. Correlation of biomass burning records between the regions tends to increase in the Holocene. The main period of inverse correlation occurs during the Younger Dryas Stade, when extratropical climate most affected the tropics. The strongest correlation between the two regions postdates 5000 cal yr B.P., when El Niño-related variability intensified. Fluctuations in tropical biomass burning are at least partly controlled by orbital forcing (precession), although extratropical climate influences and human activity are also important.

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