The relationship between the decline of Southeastern Australian rainfall and the strengthening of the subtropical ridge

2012 ◽  
Vol 33 (4) ◽  
pp. 1021-1034 ◽  
Author(s):  
B. Timbal ◽  
W. Drosdowsky
Keyword(s):  
The Relationship ◽  
Subtropical Ridge ◽  
Australian Rainfall

scholarly journals The relationship between the subtropical ridge and Australian temperatures

2018 ◽  
Vol 68 (1) ◽  
pp. 201
Author(s):  
Acacia Pepler ◽  
Linden Ashcroft ◽  
Blair Trewin
Keyword(s):  
Strong Influence ◽  
Southeast Australia ◽  
Eastern Australia ◽  
Autumn And Winter ◽  
The Relationship ◽  
Subtropical Ridge ◽  
Australian Rainfall

The intensity and latitude of the subtropical ridge over eastern Australia is strongly associated with southeast Australian rainfall, particularly during the cool months of the year. We show that the subtropical ridge also exerts a strong influence on temperatures across much of Australia, with warmer daytime temperatures and more warm extremes across southern Australia when the subtropical ridge is stronger than average, which is largely independent of the relationship between the subtropical ridge and rainfall. A strong subtropical ridge is also linked to warmer than average minimum temperatures over southern Australia throughout much of the year, except from May to August when a strong ridge is associated with cooler mean minimum temperatures and an increased frequency of cool nights. This relationship, and the observed strengthening of the subtropical ridge during autumn and winter in recent decades, can partially explain the weaker warming trends in minimum temperatures in southeast Australia compared to elsewhere in the country over the period 1960-2016.

Fluctuations of the relationship between ENSO and northeast Australian rainfall

2001 ◽  
Vol 17 (5-6) ◽  
pp. 421-432 ◽  
Author(s):  
W. Cai ◽  
P. H. Whetton ◽  
A. B. Pittock
Keyword(s):  
The Relationship ◽  
Australian Rainfall

scholarly journals Midlatitude Fronts and Variability in the Southern Hemisphere Tropical Width

2019 ◽  
Vol 32 (23) ◽  
pp. 8243-8260 ◽  
Author(s):  
Irina Rudeva ◽  
Ian Simmonds ◽  
David Crock ◽  
Ghyslaine Boschat
Keyword(s):  
Southern Hemisphere ◽  
Regional Differences ◽  
Southern Annular Mode ◽  
Sea Level Pressure ◽  
Cold Fronts ◽  
Atmospheric Fronts ◽  
Zonal Asymmetry ◽  
The Tropics ◽  
The Relationship ◽  
Subtropical Ridge

Abstract This study examines the relationship between midlatitude synoptic activity and variations in the width of the tropics in the Southern Hemisphere for the period 1979–2016. The edge of the tropical belt is defined here in terms of the latitude of the subtropical ridge (STR) of sea level pressure, and eddy activity in the midlatitudes is characterized by the behavior of atmospheric fronts. It is shown that the location and intensity of the STR are significantly correlated with the number of cold fronts between 20° and 40°S and that these relationships exhibit seasonal and zonal asymmetry. The link between the STR and the number of fronts is analyzed in five sectors of the Southern Hemisphere to reveal regional differences in their behavior and relationship with the southern annular mode. Some earlier studies on the widening of the tropics suggest that such changes may be caused by a shift in the location of midlatitude eddies. Our analysis explores the connection between these on a synoptic time scale. It shows that the variability of the width of the tropics is indeed strongly influenced by changes in the midlatitude synoptic activity, and that changes in synoptic activity lead those in the edge of the tropical belt by approximately one day.

scholarly journals The Southern Annular Mode: a comparison of indices

2012 ◽  
Vol 16 (3) ◽  
pp. 967-982 ◽  
Author(s):  
M. Ho ◽  
A. S. Kiem ◽  
D. C. Verdon-Kidd
Keyword(s):  
Southern Annular Mode ◽  
Data Sets ◽  
Data Set ◽  
Annular Mode ◽  
Time Periods ◽  
Development Approach ◽  
The Impact ◽  
The Relationship ◽  
Mode A ◽  
Australian Rainfall

Abstract. The Southern Annular Mode (SAM) has been identified as a climate mechanism with potentially significant impacts on the Australian hydroclimate. However, despite the identification of relationships between SAM and Australia's hydroclimate using certain data sets, and focussed on certain time periods, the association has not been extensively explored and significant uncertainties remain. One reason for this is the existence of numerous indices, methods and data sets by which SAM has been approximated. In this paper, the various SAM definitions and indices are reviewed and the similarities and discrepancies are discussed, along with the strengths and weaknesses of each index development approach. Further, the sensitivity of the relationship between SAM and Australian rainfall to choice of SAM index is quantified and recommendations are given as to the most appropriate index to use when assessing the impacts of the SAM on Australia's hydroclimate. Importantly this study highlights the need to consider the impact that the choice of SAM index, and data set used to calculate the index, has on the outcomes of any SAM attribution study.

scholarly journals The Southern Annular Mode: a comparison of indices

2011 ◽  
Vol 8 (4) ◽  
pp. 7461-7498 ◽  
Author(s):  
M. Ho ◽  
A. S. Kiem ◽  
D. C. Verdon-Kidd
Keyword(s):  
Southern Annular Mode ◽  
Annular Mode ◽  
Index Development ◽  
Development Approach ◽  
The Relationship ◽  
Mode A ◽  
Australian Rainfall

Abstract. The Southern Annular Mode (SAM) has been identified as a climate mechanism with potentially significant impacts on the Australian hydroclimate. However, despite the identification of some relationships between SAM and Australia's hydroclimate, the association has not been extensively explored or robustly quantified. Further complicating the situation is the existence of numerous indices (or methods) by which SAM has been approximated. In this paper, the various SAM definitions and indices are reviewed and the similarities and discrepancies are discussed, along with the strengths and weaknesses of each index development approach. Further, the sensitivity of the relationship between SAM and Australian rainfall on choice of SAM index is quantified and recommendations are given as to the most appropriate index to use when assessing the impacts of the SAM on Australia's hydroclimate.

scholarly journals The relationship between the subtropical ridge and Australian temperatures

2018 ◽  
Vol 68 (1) ◽  
pp. 201-214 ◽  
Author(s):  
Acacia Pepler ◽  
Linden Ashcroft ◽  
Blair Trewin
Keyword(s):  
The Relationship ◽  
Subtropical Ridge

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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