Global Synoptic Maps *

1952 ◽  
Vol 33 (10) ◽  
pp. 435-437 ◽  
Author(s):  
Leo Alpert
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
North Pole ◽  
Weather Bureau ◽  
The North ◽  
The Earth ◽  
Antarctic Continent ◽  
Map Analysis ◽  
The Antarctic

Synoptic map analysis of the Earth from the North Pole to the shores of the Antarctic Continent is now attained by combining the Southern Hemisphere map analysis of the U. S. Weather Bureau-M.I.T. Southern Hemisphere Map Analysis Project, and the Northern Hemisphere map analysis of the published Daily Historical Weather Maps. Sample synoptic maps of the Earth for 19 and 20 March 1949 are presented.

Polar Maps

1949 ◽  
Vol 42 (5) ◽  
pp. 219-226
Author(s):  
John Kinsella ◽  
A. Day Bradley
Keyword(s):  
Northern Hemisphere ◽  
Relative Size ◽  
North Pole ◽  
Focused Attention ◽  
Polar Regions ◽  
The North ◽  
The Earth ◽  
The World ◽  
North Polar

It is time for us to get better acquainted with the top and bottom of the earth. The strategic importance of the North Polar Regions is becoming increasingly evident and recent explorations in Antarctica have focused attention on that part of the world. We are accustomed to looking at maps which either exclude the polar regions or which distort excessively the distances, directions and relative size of areas in these parts of the globe. Many maps in common usage do not indicate clearly that the great circles between many important cities in the Northern Hemisphere pass near the North Pole.

7. To the ends of the earth

2015 ◽  
pp. 100-113
Author(s):  
Stewart A. Weaver
Keyword(s):  
North Pole ◽  
The Arctic ◽  
South Pole ◽  
The South ◽  
Mount Everest ◽  
Large Space ◽  
The North ◽  
The Earth ◽  
High Asia ◽  
The Antarctic

With the filling of the large space on the map that was Tibet and High Asia, explorers turned to smaller spaces or else they turned to those untouched extremities where there was no map—the Arctic and the Antarctic. ‘To the ends of the earth ’ first describes the search for the North Pole in the Arctic. It was Americans Frederick Cook and Robert Peary who laid their competing claims to 90° north, but the race to the South Pole was between Robert Scott and Roald Amundsen. It was Amundsen who succeeded. The two next terrestrial prizes were the world's highest mountain, Mount Everest, and Rub' al Khali, the “Empty Quarter” of southeastern Arabia.

scholarly journals In situ observations of aerosol particles remaining from evaporated cirrus crystals: Comparing clean and polluted air masses

2002 ◽  
Vol 2 (5) ◽  
pp. 1599-1633 ◽  
Author(s):  
M. Seifert ◽  
J. Ström ◽  
R. Krejci ◽  
A. Minikin ◽  
A. Petzold ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Aerosol Particles ◽  
Pollution Level ◽  
Size Distributions ◽  
Number Density ◽  
Particle Volume ◽  
The North ◽  
In Situ Observations

Abstract. In situ observations of aerosol particles contained in cirrus crystals are presented and compared to interstitial aerosol size distributions (non-activated particles in between the cirrus crystals). The observations were conducted in cirrus clouds in the Southern and Northern Hemisphere mid-latitudes during the INCA project. The first campaign in March and April 2000 was performed from Punta Arenas, Chile (54° S) in pristine air. The second campaign in September and October 2000 was performed from Prestwick, Scotland (53° N) in the vicinity of the North Atlantic flight corridor. Size distribution measurements of crystal residuals (particles remaining after evaporation of the crystals) show that small aerosol particles (Dp < 0.1µm) dominate the number density of residuals. The crystal residual size distributions were significantly different in the two campaigns. On average the residual size distributions were shifted towards larger sizes in the Southern Hemisphere. For a given integral residual number density, the calculated particle volume was on average three times larger in the Southern Hemisphere. This may be of significance to the vertical redistribution of aerosol mass by clouds in the tropopause region. In both campaigns the mean residual size increased with increasing crystal number density. The observations of ambient aerosol particles were consistent with the expected higher pollution level in the Northern Hemisphere. The fraction of residual particles only contributes to approximately a percent or less of the total number of particles, which is the sum of the residual and interstitial particles.

Climate Response to External Sources of Freshwater: North Atlantic versus the Southern Ocean

2007 ◽  
Vol 20 (3) ◽  
pp. 436-448 ◽  
Author(s):  
Ronald J. Stouffer ◽  
Dan Seidov ◽  
Bernd J. Haupt
Keyword(s):  
Southern Ocean ◽  
Southern Hemisphere ◽  
North Atlantic ◽  
Surface Waters ◽  
Real World ◽  
The Other ◽  
Sea Surface ◽  
The North ◽  
The North Atlantic ◽  
The Antarctic

Abstract The response of an atmosphere–ocean general circulation model (AOGCM) to perturbations of freshwater fluxes across the sea surface in the North Atlantic and Southern Ocean is investigated. The purpose of this study is to investigate aspects of the so-called bipolar seesaw where one hemisphere warms and the other cools and vice versa due to changes in the ocean meridional overturning. The experimental design is idealized where 1 Sv (1 Sv ≡ 106 m3 s−1) of freshwater is added to the ocean surface for 100 model years and then removed. In one case, the freshwater perturbation is located in the Atlantic Ocean from 50° to 70°N. In the second case, it is located south of 60°S in the Southern Ocean. In the case where the North Atlantic surface waters are freshened, the Atlantic thermohaline circulation (THC) and associated northward oceanic heat transport weaken. In the Antarctic surface freshening case, the Atlantic THC is mainly unchanged with a slight weakening toward the end of the integration. This weakening is associated with the spreading of the fresh sea surface anomaly from the Southern Ocean into the rest of the World Ocean. There are two mechanisms that may be responsible for such weakening of the Atlantic THC. First is that the sea surface salinity (SSS) contrast between the North Atlantic and North Pacific is reduced. And, second, when freshwater from the Southern Ocean reaches the high latitudes of the North Atlantic Ocean, it hinders the sinking of the surface waters, leading to the weakening of the THC. The spreading of the fresh SSS anomaly from the Southern Ocean into the surface waters worldwide was not seen in earlier experiments. Given the geography and climatology of the Southern Hemisphere where the climatological surface winds push the surface waters northward away from the Antarctic continent, it seems likely that the spreading of the fresh surface water anomaly could occur in the real world. A remarkable symmetry between the two freshwater perturbation experiments in the surface air temperature (SAT) response can be seen. In both cases, the hemisphere with the freshwater perturbation cools, while the opposite hemisphere warms slightly. In the zonally averaged SAT figures, both the magnitude and the pattern of the anomalies look similar between the two cases. The oceanic response, on the other hand, is very different for the two freshwater cases, as noted above for the spreading of the SSS anomaly and the associated THC response. If the differences between the atmospheric and oceanic responses apply to the real world, then the interpretation of paleodata may need to be revisited. To arrive at a correct interpretation, it matters whether or not the evidence is mainly of atmospheric or oceanic origin. Also, given the sensitivity of the results to the exact details of the freshwater perturbation locations, especially in the Southern Hemisphere, a more realistic scenario must be constructed to explore these questions.

The Early Earth: An Ocean with Volcanoes

2019 ◽  
Author(s):  
David W. Deamer
Keyword(s):  
Graduate Student ◽  
North Pole ◽  
Equal Probability ◽  
Early Earth ◽  
Planetary Evolution ◽  
The North ◽  
Tectonic Processes ◽  
The Earth ◽  
Life On Mars ◽  
Geophysical Processes

Malcolm Walter was talking about the Pilbara region of Western Australia where some of the oldest known biosignatures of ancient life, in the form of extensive fossilized stromatolites, are preserved. The first potential stromatolite was discovered by graduate student John Dunlop, who was studying barite deposits at the North Pole Dome. Roger Buick went on to investigate the biogenicity of the stromatolites for his PhD (Buick, 1985) and Dunlop, Buick, and Walter published their results (Walter et al., 1980). In a prescient paper, Walter and Des Marais (1993) proposed that the ancient stromatolite fossils could guide the search for life on Mars. I have walked with Malcolm Walter through the Dresser formation where the fossils were found. It is humbling to realize that if time passed at a thousand years per second, it would take 41 days to go back in time to the first signs of life on our planet. In any description of events that occurred some 4 billion years ago, certain assumptions must be made. I will try to make assumptions explicit throughout this book, beginning here with the geochemical and geophysical conditions prevailing on the early Earth and Mars. I am including Mars not as an afterthought but because both planets had liquid water 4 billion years ago. Most of our understanding of planetary evolution comes from observations of our own planet, but it is now clear that the Earth and Mars were undergoing similar geophysical processes during the first billion years of the solar system’s existence, with an equal probability that life could begin on either planet. In a sense, the surface of Mars is a geological fossil that has preserved evidence of what was happening there at the same time that life began on the Earth. For instance, Martian volcanoes offer direct, observable evidence that volcanism was occurring nearly 4 billion years ago; making it plausible that similar volcanism was common on Earth even though the evidence has been completely erased by geological and tectonic processes.

scholarly journals Bifurcation of potential vorticity gradients across the Southern Hemisphere stratospheric polar vortex

2018 ◽  
Vol 18 (11) ◽  
pp. 8065-8077 ◽  
Author(s):  
Jonathan Conway ◽  
Greg Bodeker ◽  
Chris Cameron
Keyword(s):  
Southern Hemisphere ◽  
Potential Vorticity ◽  
Polar Vortex ◽  
Trace Gas ◽  
Stratospheric Polar Vortex ◽  
Distinct Structure ◽  
Barrier Region ◽  
Westerly Winds ◽  
Antarctic Continent ◽  
The Antarctic

Abstract. The wintertime stratospheric westerly winds circling the Antarctic continent, also known as the Southern Hemisphere polar vortex, create a barrier to mixing of air between middle and high latitudes. This dynamical isolation has important consequences for export of ozone-depleted air from the Antarctic stratosphere to lower latitudes. The prevailing view of this dynamical barrier has been an annulus compromising steep gradients of potential vorticity (PV) that create a single semi-permeable barrier to mixing. Analyses presented here show that this barrier often displays a bifurcated structure where a double-walled barrier exists. The bifurcated structure manifests as enhanced gradients of PV at two distinct latitudes – usually on the inside and outside flanks of the region of highest wind speed. Metrics that quantify the bifurcated nature of the vortex have been developed and their variation in space and time has been analysed. At most isentropic levels between 395 and 850 K, bifurcation is strongest in mid-winter and decreases dramatically during spring. From August onwards a distinct structure emerges, where elevated bifurcation remains between 475 and 600 K, and a mostly single-walled barrier occurs at other levels. While bifurcation at a given level evolves from month to month, and does not always persist through a season, interannual variations in the strength of bifurcation display coherence across multiple levels in any given month. Accounting for bifurcation allows the region of reduced mixing to be better characterised. These results suggest that improved understanding of cross-vortex mixing requires consideration of the polar vortex not as a single mixing barrier but as a barrier with internal structure that is likely to manifest as more complex gradients in trace gas concentrations across the vortex barrier region.

scholarly journals Global marine plankton functional type biomass distributions: coccolithophores

2012 ◽  
Vol 5 (2) ◽  
pp. 491-520 ◽  
Author(s):  
C. J. O'Brien ◽  
J. A. Peloquin ◽  
M. Vogt ◽  
M. Heinle ◽  
N. Gruber ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Seasonal Cycle ◽  
Marine Phytoplankton ◽  
The North ◽  
Carbon Biomass ◽  
Time Period ◽  
The Pacific ◽  
Individual Contributions ◽  
June July

Abstract. Coccolithophores are calcifying marine phytoplankton of the class Prymnesiophyceae. They are considered to play an import role in the global carbon cycle through the production and export of organic carbon and calcite. We have compiled observations of global coccolithophore abundance from several existing databases as well as individual contributions of published and unpublished datasets. We estimate carbon biomass using standardised conversion methods and provide estimates of uncertainty associated with these values. The database contains 58 384 individual observations at various taxonomic levels. This corresponds to 12 391 observations of total coccolithophore abundance and biomass. The data span a time period of 1929–2008, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 500 m. Highest biomass values are reported in the North Atlantic, with a maximum of 501.7 μg C l−1. Lower values are reported for the Pacific (maximum of 79.4 μg C l−1) and Indian Ocean (up to 178.3 μg C l−1). Coccolithophores are reported across all latitudes in the Northern Hemisphere, from the Equator to 89° N, although biomass values fall below 3 μg C l−1 north of 70° N. In the Southern Hemisphere, biomass values fall rapidly south of 50° S, with only a single non-zero observation south of 60° S. Biomass values show a clear seasonal cycle in the Northern Hemisphere, reaching a maximum in the summer months (June–July). In the Southern Hemisphere the seasonal cycle is less evident, possibly due to a greater proportion of low-latitude data. The original and gridded datasets can be downloaded from Pangaea (http://doi.pangaea.de/10.1594/PANGAEA.785092).

Bellingshausen and the discovery of Antarctica

Polar Record ◽  
1971 ◽  
Vol 15 (99) ◽  
pp. 887-889 ◽  
Author(s):  
Terence Armstrong
Keyword(s):  
Antarctic Peninsula ◽  
West Coast ◽  
North West ◽  
The North ◽  
Antarctic Continent ◽  
The Antarctic

For the last twenty years there has been considerable Soviet interest in the circumnavigation of Antarctica by the Russian naval expedition of 1819–21, led by Captain T. T. Bellingshausen, with Lieut M. P. Lazarev as his second in command, in the sloops Vostok and Mirnyy. It is now reasonably certain that Bellingshausen sighted the Antarctic continent several times, notably on 27 January 1820 (New Style) at a point about lat 69°21′S, long 2°14′W, and was thus the first to see it (Edward Bransfield sighted the north-west coast of the Antarctic Peninsula at about lat 63°50′S, long 60°30′W on 30 January 1820, three days later). Bellingshausen did not claim to have done so however, but his descriptions of what he saw tally very well with what the edge of the continent here is now known to look like. There is one relatively new point. Bellingshausen's first sighting has been moved forward one day, from the 28th to the 27th, because it has been shown that he was keeping ship's time, from mid-day to mid-day, and therefore that what his log called the 28th (his sighting being in the second half of the day) was what the civil calendar would call the 27th (Belov, 1963, p 19–29). All this much is well documented and unlikely to be disputed. The question is, how much importance did he, and his contemporaries, attach to this discovery? And did he realize that he had seen the edge of a continent? Recent Soviet studies have sought to show that he had a very good idea of the importance of what he had seen, and that this idea did get through to his contemporaries. It is here that there is room for argument with the Soviet scholars.

scholarly journals Bifurcation of potential vorticity gradients across the Southern Hemisphere stratospheric polar vortex

2017 ◽  
Author(s):  
Jonathan Conway ◽  
Greg Bodeker ◽  
Chris Cameron
Keyword(s):  
Southern Hemisphere ◽  
Potential Vorticity ◽  
Polar Vortex ◽  
Stratospheric Polar Vortex ◽  
Annual Variations ◽  
Distinct Structure ◽  
Barrier Region ◽  
Antarctic Continent ◽  
Winter Time ◽  
The Antarctic

Abstract. The winter-time stratospheric westerly winds circling the Antarctic continent, also known as the Southern Hemisphere polar vortex, create a barrier to mixing of air between middle and high latitudes. This dynamical isolation has important consequences for export of ozone-depleted air from the Antarctic stratosphere to lower latitudes. The prevailing view of this dynamical barrier has been an annulus compromising steep gradients of potential vorticity (PV) that create a single semi-permeable barrier to mixing. Analyses presented here show that this barrier often displays a bifurcated structure where a doubled-walled barrier exists. The bifurcated structure manifests as enhanced gradients of PV at two distinct latitudes – usually on the inside and outside flanks of the region of highest wind speed. Metrics that quantify the bifurcated nature of the vortex have been developed and their variation in space and time has been analysed. At most isentropic levels between 370 K and 850 K, bifurcation is strongest in winter and reduces dramatically during spring. From August onwards a distinct structure emerges, where elevated bifurcation remains between 475 K and 600 K, and a mostly single walled barrier occurs at other levels. While bifurcation at a given level evolves from month to month, and does not always persist through a season, inter-annual variations in the strength of bifurcation display coherence across multiple levels in any given month. Accounting for bifurcation allows the region of reduced mixing to be better characterized. These results suggest that improved understanding of cross-vortex mixing requires consideration of the polar vortex not as a single mixing barrier, but as a barrier with internal structure that is likely to manifest as more complex gradients in trace gas concentrations across the vortex barrier region.

Remarks on the plant geography of the southern cold temperate zone

1960 ◽  
Vol 152 (949) ◽  
pp. 447-457 ◽  
Keyword(s):  
New Zealand ◽  
Temperate Zone ◽  
Tierra Del Fuego ◽  
Plant Geography ◽  
The North ◽  
Antarctic Continent ◽  
The Difference ◽  
The Antarctic ◽  
Northern And Southern Hemispheres ◽  
Joseph Hooker

The difference between the northern and southern hemispheres in the distribution of land and sea fundamentally affects the problems of the origin, dispersal and distribution of the biota. Whereas a circumpolar distribution seems to be quite natural in the north, it is much more difficult to explain when we get to the south. Although the naturalists of James Cook’s first and second voyages visited both New Zealand and Tierra del Fuego, the purport of the existence of closely related but geographically widely disjunct organisms did not dawn upon them; Terra Australis, a vision of the old cosmographers to counterbalance the solid North, but searched for in vain by Cook, had disappeared from the map. It fell to Joseph Hooker to discover a circumpolar Flora Antarctica at a time when the Antarctic Continent, thus named by Ross, had become a reality. What Hooker found on truly antarctic shores was not very promising, but the discovery of fossilized gymnosperm wood on Kerguelen made him speculate on former antarctic forests and on the possibility of greater land areas where only small, scattered islands are found now. In a letter to Darwin in November 1851 (Huxley 1918, p. 445) he wrote: ‘... recent discoveries rather tend to ally the N. Zeald. Flora with the Australian—though there is enough affinity with extratropical S. America to be

Sign in / Sign up

Export Citation Format

Share Document