The Transfer of the North Polar Standards to the Southern Hemisphere.

1953 ◽  
Vol 117 ◽  
pp. 83 ◽  
Author(s):  
Arthur N. Cox
Keyword(s):  
Southern Hemisphere ◽  
The North ◽  
North Polar

Evidence for a Rapid Global Climate Shift across the Late 1960s

2007 ◽  
Vol 20 (12) ◽  
pp. 2721-2744 ◽  
Author(s):  
Peter G. Baines ◽  
Chris K. Folland
Keyword(s):  
Southern Hemisphere ◽  
North Atlantic ◽  
Amazon Basin ◽  
Storm Track ◽  
Central Pacific ◽  
Atlantic Sector ◽  
The North ◽  
The North Atlantic ◽  
The 1950S ◽  
African Sahel

Abstract It is shown that a number of important characteristics of the global atmospheric circulation and climate changed in a near-monotonic fashion over the decade, or less, centered on the late 1960s. These changes were largest or commonest in tropical regions, the Southern Hemisphere, and the Atlantic sector of the Northern Hemisphere. Some, such as the decrease in rainfall in the African Sahel, are well known. Others appear to be new, but their combined extent is global and dynamical linkages between them are evident. The list of affected variables includes patterns of SST; tropical rainfall in the African Sahel and Sudan, the Amazon basin, and northeast Brazil; pressure and SST in the tropical North Atlantic and the west and central Pacific; various branches of the southern Hadley circulation and the southern subtropical jet stream; the summer North Atlantic Oscillation; south Greenland temperature; the Southern Hemisphere storm track; and, quite likely, the Antarctic sea ice boundary. These changes are often strongest in the June–August season; changes are also seen in December–February but are generally smaller. In Greenland, annual mean temperature seems to be affected strongly, reflecting similar changes in SST throughout the year in the higher latitudes of the North Atlantic. Possible causes for these coordinated changes are briefly evaluated. The most likely candidates appear to be a likely reduction in the northward oceanic heat flux associated with the North Atlantic thermohaline circulation in the 1950s to 1970s, which was nearly in phase with a rapid increase in anthropogenic aerosol emissions during the 1950s and 1960s, particularly over Europe and North America.

scholarly journals Occurrence of suicide and seasonal variation

1998 ◽  
Vol 32 (5) ◽  
pp. 408-412 ◽  
Author(s):  
Pedro Retamal C. ◽  
Derek Humphreys
Keyword(s):  
Seasonal Variation ◽  
Statistical Analysis ◽  
Southern Hemisphere ◽  
Suicide Rate ◽  
Seasonal Pattern ◽  
Suicide Rates ◽  
The North ◽  
Political Center

OBJECTIVE: To review the estimated suicide rates for the Region Metropolitan, the main socio-political center in Chile, for the period 1979-1994, and to determine whether they follow a seasonal pattern. METHOD: Data available for the period 1979-94 at the Forensic Services in Chile was analyzed using ANOVA. RESULTS: It was register 5.386 suicides. While the "warm" months (October, November, December & January) concentrated 39.0% of cases, the so called "cold" months reported 28,7%. This contrast is made even clearer by the month-to-month analysis, showing the highest suicide rate in December (10.9%) against the lowest rate in June (7.0%). Further statistical analysis revealed these differences to be significant. CONCLUSION: The study shows that in Chile, representing as it does the Southern Hemisphere, the suicide rates tend to present a seasonal variation as has elsewhere been determined for in the North Hemisphere.

scholarly journals Avalanches of the martian north polar cap

2020 ◽  
Author(s):  
Patricio Becerra ◽  
Susan Conway ◽  
Nicholas Thomas ◽  
Keyword(s):  
Polar Regions ◽  
Martian Surface ◽  
Polar Cap ◽  
Water Ice ◽  
The North ◽  
Imaging Science ◽  
Resolution Imaging ◽  
North Polar ◽  
Gas Expansion ◽  
Trigger Mechanisms

<p>In 2008, the High Resolution Imaging Science Experiment (HiRISE) on board NASA’s MRO fortuitously captured several discrete clouds of material in the process of cascading down a steep scarp of the water-ice-rich north polar layered deposits (NPLD). The events were only seen during a period of ~4 weeks, near the onset of martian northern spring in 2008, when the seasonal cover of CO2 is beginning to sublimate from the north polar regions. Russell et al. [1] analyzed the morphology of the clouds, inferring that the particles involved were mechanically analogous to terrestrial “dry, loose snow or dust”, so that the events were similar to terrestrial “powder avalanches” [2]. HiRISE confirmed the seasonality of avalanche occurrence the following spring, and continued to capture between 30 and 50 avalanches per season (fig. 1b,c) between 2008 and 2019, for a total of 7 Mars Years (MY29–MY35) of continuous scarp monitoring.</p><p>In this work we will present statistics on these events, in an attempt to quantify their effect on the mass balance of the NPLD, and with respect to competing processes such as viscous deformation and stress-induced block falls that do not trigger avalanches [3,4]. We also use a 1D thermal model [5] to investigate the sources and trigger mechanisms of these events. The model tracks the accumulation and ablation of seasonal CO2 frost on a martian surface. Russell et al. [1] support an initiation through gas-expansion related to the presence of CO2 frost on the scarp. Therefore the amount of frost that lingers on different sections of the model scarp at the observed time of the avalanches will provide evidence either for or against this particular mechanism. We will present preliminary results and discuss their implications.</p><p>References: [1] P. Russell et al. (2008) Geophys. Res. Lett. 35, L23204. [2] D. McClung, P.A. Schaerer (2006), Mountaineers, Seattle Wash. [3] Sori, M. M., et al., Geophys. Res. Lett., 43. [4] Byrne et al. (2016), 6th Int. Conf. Mars Polar Sci. Exploration [4] C. M. Dundas and S. Byrne (2010) Icarus 206, 716.</p>

scholarly journals Widespread Megaripple Activity Across the North Polar Ergs of Mars

2021 ◽  
Author(s):  
Matthew Chojnacki ◽  
David A. Vaz ◽  
Simone Silvestro ◽  
David C.A. Silva
Keyword(s):  
The North ◽  
North Polar

scholarly journals Contrasting Phylogeographic Patterns Among Northern and Southern Hemisphere Fin Whale Populations With New Data From the Southern Pacific

2021 ◽  
Vol 8 ◽  
Author(s):  
MJosé Pérez-Alvarez ◽  
Sebastián Kraft ◽  
Nicolás I. Segovia ◽  
Carlos Olavarría ◽  
Sergio Nigenda-Morales ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Phylogenetic Analyses ◽  
Morphological Data ◽  
Phylogeographic Structure ◽  
Fin Whale ◽  
Middle Latitudes ◽  
The North ◽  
Southeastern Pacific ◽  
Fin Whales ◽  
Dispersal Events

Four fin whale sub-species are currently considered valid: Balaenoptera physalus physalus in the North Atlantic, B. p. velifera in the North Pacific, B. p. quoyi and B. p. patachonica in the Southern Hemisphere. The last, not genetically validated, was described as a pygmy-type sub-species, found in low to mid latitudes of the Southern Hemisphere. Genetic analyses across hemispheres show strong phylogeographic structure, yet low geographic coverage in middle latitudes of the Southern Hemisphere impeded an assessment within the area, as well as evaluating the validity of B. p. patachonica. New mtDNA sequences from the Southeastern Pacific allowed an improved coverage of the species’ distribution. Our phylogenetic analyses showed three main lineages and contrasting phylogeographic patterns between Northern and Southern Hemispheres. Absence of recurrent female mediated gene flow between hemispheres was found; however, rare dispersal events revealing old migrations were noted. The absence of genetic structure suggests the existence of one single taxa within the Southern Hemisphere. Thus, until further evidence supporting this subspecies can be produced, such as genetic, ecological, behavioral, or morphological data, we propose that all fin whales from the Southern Hemisphere, including those from middle latitudes of the Southeastern Pacific belong to B. p. quoyi subspecies. This information is important for the current assessment of fin whales, contributing to the evaluation of the taxonomic classification and the conservation of the species.

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