scholarly journals Weather systems and extreme rainfall generation in the 2019 north Queensland floods compared with historical north Queensland record floods

2021 ◽  
Vol 71 (1) ◽  
pp. 123
Author(s):  
Jeff Callaghan
Keyword(s):  
Large Scale ◽  
Vertical Structure ◽  
Extreme Rainfall ◽  
Monsoon Circulation ◽  
The South ◽  
Total Rainfall ◽  
The North ◽  
Flooding Disaster ◽  
Climate Influences ◽  
Using Data

Earlier papers have addressed floods from warm-air advection (WAA) in southeast Australia and around the globe, and extreme rainfall in US hurricanes and Australian tropical cyclones (TCs). This is the first paper to address the WAA phenomena in causing monsoon and TC floods and in TC-like systems which develop over the interior of northern Australia. The inland events help explain Australia’s worst tropical flooding disaster in 1916. A disastrous series of floods during late January and early February 2019 caused widespread damage in tropical north Queensland both in inland regions and along the coast. This occurred when some large-scale climate influences, including the sea surface temperatures suggested conditions would not lead to major flooding. Therefore, it is important to focus on the weather systems to understand the processes that resulted in the extreme rainfall responsible for the flooding. The structure of weather systems in most areas involved a pattern in which the winds turned in an anticyclonic sense as they ascended from the low to middle levels of the atmosphere (often referred to as WAA) which was maintained over large areas for 11 days. HYSPLIT air parcel trajectory observations were employed to confirm these ascent analyses. Examination of a period during which the heaviest rain was reported and compared with climatology showed a much stronger monsoon circulation, widespread WAA through tropical Queensland where normally its descending equivalent of cold-air advection is found, and higher mean sea level pressures along the south Queensland coast. The monsoon low was located between strong deep monsoon westerlies to the north and strong deep easterlies to the south which ensured its slow movement. This non-TC event produced heavy inland rainfall. Extreme inland rainfall is rare in this region. Dare et al. (2012), using data from 1969/70 to 2009/10, showed that over north Queensland non-TC events produced a large percentage of the total rainfall. The vertical structure associated with one of the earlier events that occurred in 2008 had sufficient data to detect strong and widespread WAA overlying an onshore moist tropical airstream. This appears to have played a crucial role in such extreme rainfall extending well inland and perhaps gives insight to the cause of a 1916 flooding disaster at Clermont which claimed around 70 lives. Several other events over the inland Tropics with strong WAA also help explain the 1916 disaster.

scholarly journals Upper-Tropospheric Forcing on Late July Monsoon Transition in East Asia and the Western North Pacific

2012 ◽  
Vol 25 (11) ◽  
pp. 3929-3941 ◽  
Author(s):  
Chi-Hua Wu ◽  
Ming-Dah Chou
Keyword(s):  
East Asia ◽  
South Asian ◽  
North Pacific ◽  
Western North Pacific ◽  
Large Scale ◽  
Asian Monsoon ◽  
Monsoon Circulation ◽  
South Asian Monsoon ◽  
The South ◽  
The North

By investigating the large-scale circulation in the upper troposphere, it is demonstrated that the rapid late July summer monsoon transition in the East Asia and western North Pacific (EA-WNP) is associated with a weakened westerly at the exit of the East Asian jet stream (EAJS). Even in a normally stable atmosphere under the influence of the North Pacific (NP) high in late July, convection rapidly develops over the midoceanic region of the western NP (15°–25°N, 150°–170°E). Prior to the rapid transition, the EAJS weakens and shifts northward, which induces a series of changes in downstream regions; the northeastern stretch of the Asian high weakens, upper-tropospheric divergence in the region southwest of the mid-NP trough increases, and convection is enhanced. At the monsoon transition, upper-level high potential vorticity intrudes southward and westward, convection expand from the mid NP westward to cover the entire subtropical western NP, the lower-tropospheric monsoon trough deepens, surface southwesterly flow strengthens, and the western stretch of the NP high shifts northward ~10° latitude to the south of Japan. This series of changes indicates that the EA-WNP late July monsoon transition is initiated from changes in the upper-tropospheric circulation via the weakening of the EAJS south of ~45°N. The weakening of the EAJS south of ~45°N is related to a reduced gradient of the geopotential height on the northern flank of the Asian high, which is related to the massive inland heating and weakening of the South Asian monsoon circulation. The exact timing of the monsoon onset might be tied to the hypothesized “Silk Road pattern” and/or a strong weakening of the South Asian monsoon circulation.

Evidence of 8.2-ka event in Southeast Asia inferred from marginal marine sediments off Kallang River Basin, Singapore

2021 ◽  
Author(s):  
Yama Dixit ◽  
Stephen Chua ◽  
Yu Ting Yan ◽  
Adam Switzer
Keyword(s):  
River Basin ◽  
Marine Sediments ◽  
Large Scale ◽  
Southern Oscillation ◽  
Signal Propagation ◽  
Warm Pool ◽  
Seasonal Migration ◽  
Monsoon Circulation ◽  
Tropical Regions ◽  
The North

<p>The Maritime Continent (MC) is located within the Indo-Pacific Warm Pool, which is known as the largest area of warm sea surface temperatures with the highest rainfall on Earth that drives the global atmospheric and hydrologic circulation. The complex climatic system of the MC is controlled by large-scale phenomena such as the seasonal migration of the Intertropical Convergence Zone which causes the northwest and southeast monsoon circulation in the region as well as tropical Indo-Pacific climate phenomena, the Indian Ocean Dipole in the west and the El Niño-Southern Oscillation operating to the east of the MC. In addition to interactions of these climate phenomena, their influence varies across the region due to island topography and ocean–atmosphere fluxes. Despite dedicated efforts, a comprehensive picture of the impacts of abrupt climate events such as the ‘8.2 ka event’ during the Holocene on the MC has proved elusive. Here we use sedimentology and stable isotopes of benthic foraminifera collected from the marginal marine sediments off the Kallang River Basin, Singapore to reconstruct paleoenvironmental history of the early-mid Holocene. Owing to the high sedimentation rate (~4.4 mm/yr), the timing and nature of the ‘8.2 ka event’ was examined in detail in this region making this an invaluable and unique archive to study up to sub-centennial changes. Comparison of the Kallang record with other high-resolution marine and absolutely dated terrestrial archives speleothems revealed that the timing of the onset of ‘8.2 ka event’ in the western IPWP region lags the cooling in the North Atlantic and that of Asian and Indian monsoon failure, by ~100years possibly implying a north-south signal propagation. The termination of the ‘8.2 ka event’, however may have occurred near synchronously between high and low tropical regions at ~7.96ka BP possibly linked via both atmospheric and oceanic processes.</p><p> </p>

scholarly journals Large-Scale Flow Patterns Associated with Extreme Precipitation and Atmospheric Rivers over Norway

2019 ◽  
Vol 147 (4) ◽  
pp. 1415-1428 ◽  
Author(s):  
Imme Benedict ◽  
Karianne Ødemark ◽  
Thomas Nipen ◽  
Richard Moore
Keyword(s):  
Extreme Precipitation ◽  
Large Scale ◽  
Moisture Flux ◽  
Cold Season ◽  
Fuzzy Cluster ◽  
The South ◽  
Atmospheric Rivers ◽  
The North ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract A climatology of extreme cold season precipitation events in Norway from 1979 to 2014 is presented, based on the 99th percentile of the 24-h accumulated precipitation. Three regions, termed north, west, and south are identified, each exhibiting a unique seasonal distribution. There is a proclivity for events to occur during the positive phase of the NAO. The result is statistically significant at the 95th percentile for the north and west regions. An overarching hypothesis of this work is that anomalous moisture flux, or so-called atmospheric rivers (ARs), are integral to extreme precipitation events during the Norwegian cold season. An objective analysis of the integrated vapor transport illustrates that more than 85% of the events are associated with ARs. An empirical orthogonal function and fuzzy cluster technique is used to identify the large-scale weather patterns conducive to the moisture flux and extreme precipitation. Five days before the event and for each of the three regions, two patterns are found. The first represents an intense, southward-shifted jet with a southwest–northeast orientation. The second identifies a weak, northward-shifted, zonal jet. As the event approaches, regional differences become more apparent. The distinctive flow pattern conducive to orographically enhanced precipitation emerges in the two clusters for each region. For the north and west regions, this entails primarily zonal flow impinging upon the south–north-orientated topography, the difference being the latitude of the strong flow. In contrast, the south region exhibits a significant southerly component to the flow.

scholarly journals Characteristics of shallow thermally driven flow in the complex topography of the south-eastern Adriatic

2010 ◽  
Vol 28 (10) ◽  
pp. 1905-1922 ◽  
Author(s):  
M. T. Prtenjak ◽  
I. Tomažić ◽  
I. Kavčič ◽  
S. Đivanović
Keyword(s):  
Large Scale ◽  
Sea Breeze ◽  
Small Scale ◽  
The South ◽  
Fine Grid ◽  
Easterly Wind ◽  
Sodar Data ◽  
South Eastern ◽  
The North ◽  
Convergence Zones

Abstract. Characteristics of thermally induced flow, namely the sea breeze, are investigated along the south-eastern Adriatic. The chosen period 24–25 April 2006 favoured sea breeze development and simultaneously allowed a comparison of the large-scale wind influence (north-westerly wind versus south-easterly wind) and the complex terrain on the local circulations. Particular attention is paid to the small-scale formation of the wind field, convergence zones (CZs), channelling flows and small scale eddies, especially in the vicinity of two airports in the central part of south-eastern Adriatic. The results are based on wind measurements (from meteorological surface stations, radiosoundings, satellite data and sodar data) and further supplemented by model data at fine grid spacing. This study shows the formation of numerous irregular daytime and nighttime CZs, which occurred along the coastline in the lee of mountains and over the larger, elongated islands. The results show that the above mentioned airports are surrounded by daytime CZ formations within the lowermost 1000 m and associated updrafts of 1 m s−1, especially if CZs are maintained by the north-westerly large-scale winds. Whereas the daytime CZ was generated due to merged sea breezes, the weaker and shallower nighttime CZs were formed by wind convergence of the seaward breezes, and significantly modified by the large-scale flow of the topography (e.g., accelerated flow in the sea channels and substantial swirled flows around the islands). The passes between the coastal mountain peaks changed the inflow penetration, provoking the increase in wind speed of the channelled flow. The strongest sea breeze channelling was observed above the valley of the Neretva River, where the onshore flow reached 40 km inland with a strength of 8 m s−1, and the highly asymmetric offshore part was confined within the sea channel.

The Mudu Archaic City Site of the Spring-and-Autumn Period in Suzhou City, Jiangsu

2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Joint Archaeological Team Of Instit ◽  
Suzhou Municipal Institute Of Archa
Keyword(s):  
Cultural History ◽  
Large Scale ◽  
The South ◽  
Autumn Period ◽  
The North ◽  
Regional Center ◽  
Water Gate ◽  
Spring And Autumn Period ◽  
History Of ◽  
Eastern Zhou

AbstractIn 2009 and 2010, a series of archaeological investigations were conducted in and around the Mudu archaic city site located in the southwestern highland of Greater Suzhou, Jiangsu. The excavations revealed sections of the north circumference wall at Wufeng and the water gate of the south circumference wall at Xinfeng. The surveys identified the possible locations of the east and the west circumference walls. Diagnostic proto-porcelain and stamped potsherds were recovered. It is tentatively argued that both the north and the south walls were built and in use during the late Spring-and-Autumn Period. The Mudu Site, therefore, was a large-scale walled settlement functioned as a regional center of its time. These findings are instrumental in the search for the lost capital of Wu State of the Spring-and-Autumn Period, the understanding of the relationship among the various contemporary settlement sites, cairns, earthen mounds, and caches distributed in the region, and the reconstruction of the local cultural history of Eastern Zhou.

scholarly journals Dipole Anisotropy in the Lick galaxy catalogue

1988 ◽  
Vol 130 ◽  
pp. 510-511
Author(s):  
Manolis Plionis
Keyword(s):  
Large Scale ◽  
The South ◽  
Microwave Background ◽  
Cluster Sample ◽  
Cosmological Principle ◽  
The North ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Apparent Reason

The Shane & Wirtanen (SW) galaxy catalog, as reduced by Seldner et al (SSGP), is used to calculate the dipole vector of the galaxy distribution. The catalogue covers 86% of the North and 53% of the South Galactic cap (totally 8.8 steradians) and contains about 810,000 galaxies binned in 10′ × 10′ cells with magnitude limit mB ∼ 18.8. Dipoles have been found in the IRAS and in an optical catalogue based on the ESO, UGC and MCG catalogues, with average depths of ∼ 100 h−1 and ∼ 50 h−1 Mpc respectively. The direction of these dipoles is consistent with that of the microwave background dipole which means that the structures responsible for the dipole are present within the limits of the shallower catalogue and dominate the large-scale morpology of the galaxy distribution in both catalogues. It can therefore be expected that these structures will be ‘washed out’ by more distant structures dominating the deeper SW catalogue. The characteristic depth of the SW catalogue is 360 h−1 and the median depth of a cluster sample, identified from the SW catalogue by an objective proccedure, is ∼ 180 h−1 Mpc. Even if a dipole is found there is no apparent reason for it to point towards the MWB dipole direction since other galaxy fluctuations, comparable in size with those responsible for the MWB dipole, should be present in the SW catalogue if the Cosmological Principle is relevant on scales traced by the catalogue.

Third report on Glossina investigations in Nyasaland

1916 ◽  
Vol 7 (1) ◽  
pp. 29-50 ◽  
Author(s):  
W. A. Lamborn
Keyword(s):  
Large Scale ◽  
Dry Season ◽  
The South ◽  
Glossina Morsitans ◽  
Lake Shore ◽  
The North ◽  
Sandy Ground ◽  
Artificial Breeding

I remained in the proclaimed area till 6th August 1915, then returning to the vicinity of Monkey Bay for the purpose of endeavouring to establish artificial breeding places on a large scale.While in the proclaimed area I took the opportunity of completing my survey of the distribution of Glossina morsitans, especially in the neighbourhood of Rifu and Kuti described by Dr. Shircore (Bull. Ent. Res., v, p. 87) as “primary centres 1 and 2,” which I had been unable to examine last season before the advent of the rains. As in the case of “ centres 3 and 4,” at Nyansato and Lingadzi respectively, I have not been able to find that the fly is sufficiently localised, even when the dry season is far advanced, as to render feasible any attempt to control it by prophylactic clearing of the bush. In the Rifu district there is a range of rocky hills and high ground running more or less parallel to the lake, with corresponding modification of the soil, so that a zone of scrub has sprung up, from half a mile to two miles in width, consisting very largely of thorn bush, among which are a few big trees. Towards the north this gradually dwindles, to be replaced by the borassus palms usually growing in the sandy ground along the Lake shore, and towards the south it gradually widens out and becomes continuous with the Kuti bush some five miles distant. Throughout its whole extent the fly was plentiful.

scholarly journals The South Atlantic Subtropical High: Climatology and Interannual Variability

2017 ◽  
Vol 30 (9) ◽  
pp. 3279-3296 ◽  
Author(s):  
Xiaoming Sun ◽  
Kerry H. Cook ◽  
Edward K. Vizy
Keyword(s):  
Interannual Variability ◽  
Annual Cycle ◽  
Large Scale ◽  
Austral Summer ◽  
Southern Annular Mode ◽  
South Atlantic ◽  
Subtropical High ◽  
Interannual Variations ◽  
The South ◽  
The North

ERA-Interim and JRA-55 reanalysis products are analyzed to document the annual cycle of the South Atlantic subtropical high (SASH) and examine how its interannual variability relates to regional and large-scale climate variability. The annual cycle of the SASH is found to have two peaks in both intensity and size. The SASH is strongest and largest during the solstitial months when its center is either closest to the equator and on the western side of the South Atlantic basin during austral winter or farthest poleward and in the center of the basin in late austral summer. Although interannual variations in the SASH’s position are larger in the zonal direction, the intensity of the high decreases when it is positioned to the north. This relationship is statistically significant in every month. Seasonal composites and EOF analysis indicate that meridional changes in the position of the SASH dominate interannual variations in austral summer. In particular, the anticyclone tends to be displaced poleward in La Niña years when the southern annular mode (SAM) is in its positive phase and vice versa. Wave activity flux vectors suggest that ENSO-related convective anomalies located in the central-eastern tropical Pacific act as a remote forcing for the meridional variability of the summertime SASH. In southern winter, multiple processes operate in concert to induce interannual variability, and none of them appears to dominate like ENSO does during the summer.

scholarly journals Population biology of monkfish Lophius americanus

2008 ◽  
Vol 65 (7) ◽  
pp. 1291-1305 ◽  
Author(s):  
R. Anne Richards ◽  
Paul C. Nitschke ◽  
Katherine A. Sosebee
Keyword(s):  
Atlantic Ocean ◽  
Shallow Water ◽  
Population Biology ◽  
Sex Ratios ◽  
Marine Science ◽  
The South ◽  
Northwest Atlantic ◽  
The North ◽  
Using Data

Abstract Richards, R. A., Nitschke, P. C., and Sosebee, K. A. 2008. Population biology of monkfish Lophius americanus. – ICES Journal of Marine Science, 65: 1291–1305. This paper provides an overview of the biology of monkfish in US waters of the Northwest Atlantic Ocean using data from resource surveys spanning the period 1948–2007. Monkfish exhibited seasonal onshore–offshore shifts in distribution, migrated out of the southern Mid-Atlantic Bight (MAB) in mid-spring, and re-appeared there in autumn. Sex ratios at length for fish 40–65-cm long were skewed towards males in the southern MAB, but approximated unity elsewhere, suggesting that a portion of the population resides outside sampled areas. Growth was linear at 9.9 cm year−1 and did not differ by region or sex. Maximum observed size was 138 cm for females and 85 cm for males. Length at 50% maturity for males was 35.6 cm (4.1 years old) in the north and 37.9 cm (4.3 years old) in the south; for females 38.8 cm (4.6 years old) in the north and 43.8 cm (4.9 years old) in the south. Ripe females were found in shallow (<50 m) and deep (>200 m) water in the south, and in shallow water (<50 m) in the north.

Strain partitioning around an indenter during oroclinal bending: kinematics of the Circum-Moesian fault system of the Carpatho-Balkanides

2021 ◽  
Author(s):  
Nemanja Krstekanic ◽  
Liviu Matenco ◽  
Uros Stojadinovic ◽  
Ernst Willingshofer ◽  
Marinko Toljić ◽  
...  
Keyword(s):  
Large Scale ◽  
Strike Slip ◽  
Fault System ◽  
Normal Faults ◽  
Strain Partitioning ◽  
The South ◽  
The Carpathians ◽  
The North ◽  
Moesian Platform ◽  
Parallel Extension

&lt;p&gt;The Carpatho-Balkanides of south-eastern Europe is a double 180&amp;#176; curved orogenic system. It is comprised of a foreland-convex orocline, situated in the north and east and a backarc-convex orocline situated in the south and west. The southern orocline of the Carpatho-Balkanides orogen formed during the Cretaceous closure of the Alpine Tethys Ocean and collision of the Dacia mega-unit with the Moesian Platform. Following the main orogen-building processes, the Carpathians subduction and Miocene slab retreat in the West and East Carpathians have driven the formation of the backarc-convex oroclinal bending in the south and west. The orocline formed during clockwise rotation of the Dacia mega-unit and coeval docking against the Moesian indenter. This oroclinal bending was associated with a Paleocene-Eocene orogen-parallel extension that exhumed the Danubian nappes of the South Carpathians and with a large late Oligocene &amp;#8211; middle Miocene Circum-Moesian fault system that affected the orogenic system surrounding the Moesian Platform along its southern, western and northern margins. This fault system is composed of various segments that have different and contrasting types of kinematics, which often formed coevally, indicating a large degree of strain partitioning during oroclinal bending. It includes the curved Cerna and Timok faults that cumulate up to 100 km of dextral offset, the lower offset Sokobanja-Zvonce and Rtanj-Pirot dextral strike-slip faults, associated with orogen parallel extension that controls numerous intra-montane basins and thrusting of the western Balkans units over the Moesian Platform. We have performed a field structural study in order to understand the mechanisms of deformation transfer and strain partitioning around the Moesian indenter during oroclinal bending by focusing on kinematics and geometry of large-scale faults within the Circum-Moesian fault system.&lt;/p&gt;&lt;p&gt;Our structural analysis shows that the major strike-slip faults are composed of multi-strand geometries associated with significant strain partitioning within tens to hundreds of metres wide deformation zones. Kinematics of the Circum-Moesian fault system changes from transtensional in the north, where the formation of numerous basins is controlled by the Cerna or Timok faults, to strike-slip and transpression in the south, where transcurrent offsets are gradually transferred to thrusting in the Balkanides. The characteristic feature of the whole system is splaying of major faults to facilitate movements around the Moesian indenter. Splaying towards the east connects the Circum-Moesian fault system with deformation observed in the Getic Depression in front of the South Carpathians, while in the south-west the Sokobanja-Zvonce and Rtanj-Pirot faults splay off the Timok Fault. These two faults are connected by coeval E-W oriented normal faults that control several intra-montane basins and accommodate orogen-parallel extension. We infer that all these deformations are driven by the roll-back of the Carpathians slab that exerts a northward pull on the upper Dacia plate in the Serbian Carpathians. However, the variability in deformation styles is controlled by geometry of the Moesian indenter and the distance to Moesia, as the rotation and northward displacements increase gradually to the north and west.&lt;/p&gt;

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