scholarly journals Gryllacrididae (Orthoptera: Ensifera) in southern Africa

2018 ◽  
Vol 27 (2) ◽  
pp. 183-186
Author(s):  
Clarke Scholtz ◽  
Corinna S. Bazelet ◽  
Hennie de Klerk
Keyword(s):  
Southern Hemisphere ◽  
Southern Africa ◽  
High Quality ◽  
Insect Family

Although Gryllacrididae are a largely southern hemisphere insect family, they are relatively poorly represented in southern Africa, with three genera (Ametroides Karny, 1928, Glomeremus Karny, 1937, and Stictogryllacris Karny, 1937) and ten species and subspecies recorded from the region. All Ametroides and Glomeremus species are wingless while those of Stictogryllacris are long-winged. All species are arboreal and nocturnal, returning by day to characteristically silk-spun shelters between leaves. Here, we present a diagnosis, key to genera, and high-quality images to assist in identification of Gryllacrididae. By compiling all published information in one place, we hope to facilitate future researchers to investigate this poorly known group.

A Study for IGSO Inclination Angles in the Transmitting Satellite Navigation Constellation

2011 ◽  
Vol 64 (S1) ◽  
pp. S73-S82 ◽  
Author(s):  
Lihua Ma ◽  
Guoxiang Ai ◽  
Haifu Ji
Keyword(s):  
Southern Hemisphere ◽  
High Latitude ◽  
Navigation System ◽  
Satellite Navigation ◽  
Geosynchronous Orbit ◽  
High Quality ◽  
Satellite Navigation System ◽  
Inclination Angles ◽  
Navigation Signals ◽  
China Mainland

Unlike a direct broadcasting satellite navigation system, the transmitting satellite navigation system developed in China uses transponders onboard communication satellites to retransmit navigation signals generated at a ground master station. The transmitting navigation satellite constellation consists of a number of inclined geosynchronous orbit (IGSO) satellites. Considering China's mainland coverage in the northern hemisphere occupies some 62 degrees in longitude, the inclination of the IGSO satellites cannot be too high, or its signals would not be received by the users in the middle and high latitude areas when the IGSO satellite travels over the southern hemisphere. Meanwhile, the latitude of the most southerly station in China mainland that can uplink navigation signals is about 18°N when the IGSO satellite travels to the southern hemisphere. Therefore, there is a need to consider the IGSO inclination to achieve balance between uplinking high-quality navigation signals and covering the high-latitude area. In this work, the navigation performance and availability of the IGSO satellite are examined when navigation signals are uplinked from the stations Lintong and Sanya.

scholarly journals The role of Southern Africa as a dust precursor to East Antarctica

2020 ◽  
Author(s):  
Stefania Gili ◽  
Aubry Vanderstraeten ◽  
Mathieu Cazaunau ◽  
Amelie Chaput ◽  
Jean-Francois Doussin ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Southern Africa ◽  
Mineral Dust ◽  
Numerical Models ◽  
Dust Emission ◽  
East Antarctica ◽  
Namib Desert ◽  
Earth Planet ◽  
Dust Sources ◽  
Dronning Maud Land

<p>Identifying the provenance of mineral dust depositions in Antarctica is crucial to reconstruct Southern Hemisphere (SH) atmospheric circulation, validate numerical models, evaluate their contribution as micronutrients in the Southern Ocean and assess their control on the climate changes. For the last few decades, it has been demonstrated Southern South America (SSA) is the main precursor of dust reaching Antarctica during both ice ages and interglacial periods (e.g. Gili et al., 2017, 2016). However, the origin of modern dust depositions on the Antarctic continent is still poorly constrained. Back in the nineties, together with SSA, Australia, New Zealand, and Southern Africa were firstly identified as dust contributors to East Antarctica (EA) (e.g. Delmonte et al., 2004a). Since then, only SSA and Australian dust sources benefited from detailed studies. While some works identified the Makgadikgadi and Etosha Pans as southern Africa's major mineral dust sources in the SH, it was not until recently the Namib Desert coastal areas were described as another important regional dust sources. Within the Namib Desert and along the coast, the Kuiseb (K), Omaruru (O) and Huab (H) dry riverbeds are the three main areas identified as the dustiest ones with the higher frequency of dust emission events (Von Holdt et al., 2017). Here we use Sr, Nd and Pb isotopes (measured on HR-MC-ICP-MS) to characterize and evaluate the influence of this region in Southern Africa as a dust source to EA. Samples collected in K, O and H desertic areas were analyzed together with snow samples collected along a ~250 km N-S transect (defined from the coast to inland) at seven different sampling sites in the surroundings of Dronning Maud Land, EA. In addition, using the bulk of the Huab region, dust aerosols were generated into an atmospheric simulation chamber (CESAM) to reproduce, mechanically the saltation and sandblasting processes responsible for the release of mineral dust in natural conditions. Our isotopic results show Namibia’s coast emerged as another possible source end-member, together with some regions in SSA, that supply dust to EA during warmer periods.</p><p>References:</p><p>Delmonte, B., Basile-Doelsch, I., Petit, J.R., Maggi, V., Revel-Rolland, M., Michard, A., Jagoutz, E., Grousset, F., 2004. Comparing the EPICA and Vostok dust records during the last 220,000 years: stratigraphical correlation and provenance in glacial periods. Earth-Sci. Rev. 66, 63–87.</p><p>Gili, S., Gaiero, D.M., Goldstein, S.L., Chemale, F. Jr., Koester, E., Jweda, J., Vallelonga, P., Kaplan, M.R., 2016. Provenance of dust to Antarctica: a lead isotopic perspective. Geophys. Res. Lett. 43. http://dx.doi.org/10.1002/2016GL068244.</p><p>Gili, S., D.M. Gaiero, S.L. Goldstein, F. Chemale, J. Jweda, M.R. Kaplan, R.A. Becchio, and E. Koester (2017). Glacial/interglacial changes of Southern Hemisphere wind circulation from the geochemistry of South American dust. Earth Planet. Sci. Lett., 469, 98-109, doi: 10.1016/j.epsl.2017.04.007.</p><p>Von Holdt, JR., Eckardt FD., and Wiggs GFS., 2017. Landsat identifies aeolian dust emission dynamics at the landform scale. Remote Sensing of Environment 198., 229–243.</p>

scholarly journals Co-creation to scale up provision of simplified high-quality comprehensive abortion care in East Central and Southern Africa

2018 ◽  
Vol 11 (1) ◽  
pp. 1490106
Author(s):  
M. Klingberg-Allvin ◽  
S. Atuhairwe ◽  
A. Cleeve ◽  
J. K. Byamugisha ◽  
E. C. Larsson ◽  
...  
Keyword(s):  
Southern Africa ◽  
Scale Up ◽  
High Quality ◽  
East Central ◽  
Abortion Care ◽  
Comprehensive Abortion Care

First record of the early Mesozoic sphenodontian Clevosaurus (Lepidosauria: Rhynchocephalia) from the Southern Hemisphere

1995 ◽  
Vol 69 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Hans-Dieter Sues ◽  
Robert R. Reisz
Keyword(s):  
Nova Scotia ◽  
Southern Hemisphere ◽  
Southern Africa ◽  
First Record ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Red Beds ◽  
Early Mesozoic

An incomplete skull of a small sphenodontian lepidosaur from the upper part of the Stormberg Group of southern Africa is referable to Clevosaurus Swinton, 1939. It is most closely related to C. bairdi from the McCoy Brook Formation (Lower Jurassic) of Nova Scotia (Canada) and C. mcgilli from the Dark Red Beds of the Lower Lufeng Formation (Lower Jurassic) of Yunnan (China). The new specimen is important because it represents the first record of Clevosaurus from the Southern Hemisphere. Like many other taxa of Early Jurassic continental tetrapods (crocodylomorph archosaurs, dinosaurs, synapsids), Clevosaurus had an apparently Pangaean distribution.

scholarly journals The Large-Scale Distribution of Galaxies in the Southern Hemisphere

1988 ◽  
Vol 130 ◽  
pp. 121-124
Author(s):  
L. N. da Costa ◽  
P. S. Pellegrini
Keyword(s):  
Southern Hemisphere ◽  
Large Scale ◽  
Radial Velocities ◽  
Space Distribution ◽  
High Quality ◽  
Redshift Survey

Here we present a first hand look at the space distribution of some 2000 galaxies from a recently completed redshift survey in the southern hemisphere. This sample extends to the southern skies the database of high-quality radial velocities of the CfA Redshift Survey, over a comparable volume of space.

scholarly journals Seasonal variability and long-term evolution of tropospheric composition in the tropics and Southern Hemisphere

2013 ◽  
Vol 13 (7) ◽  
pp. 20011-20048
Author(s):  
K. M. Wai ◽  
S. Wu
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Latin American ◽  
Biomass Burning ◽  
Southern Africa ◽  
Marine Boundary Layer ◽  
Transport Model ◽  
Nox Emissions ◽  
Chemical Transport Model ◽  
The Tropics

Abstract. Present-day and future impacts of biomass burning and other sources in the tropics and Southern Hemisphere are studied by global chemical transport model (GCTM), satellites retrievals and surface measurements. The spring CO peaks found at Mahe Island (Western Indian Ocean) are attributed to the burnings in India but not those from Northern Africa. Easter Island (Eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burnings in Southern Africa/Latin America, via the westerlies. An increasing trend for CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of Latin American/Southern Africa burnings and increase of CH4 level. Changes in water vapour and UV over Southern Atlantic Ocean (SAO) in future January have dominated effects on the O3 distribution. More than 55% of O3 concentrations over SAO in both present-day and future September are not directly affected by the emissions (including lightning) over the adjacent two continents but attributable to transport of O3 from outside due to CO and CH4 oxidation and stratospheric intrusion. High NOx emissions in both continents in future increase the PAN concentrations over remote oceans at higher southern latitudes (> 35° S) as far as those near Australia, affecting the O3 budget over there. Future changes of biomass burning and anthropogenic NOx emissions in Southern Africa lead to a new area of O3 maximum near South Africa. The resulted O3 outflow to the Indian Ocean is pronounced due to the effects of the persistent anti-cyclone. A general reduction of future OH radical concentrations is predicted over the remote marine boundary layer in the tropics and Southern Hemisphere, due to the increases in CH4 and CO emissions combined with the low-NOx environment.

Notes on Southern African Tuberales

Bothalia ◽  
1973 ◽  
Vol 11 (1/2) ◽  
pp. 139-141 ◽  
Author(s):  
W. F. O. Marasas ◽  
James M. Trappe
Keyword(s):  
West Africa ◽  
Southern Hemisphere ◽  
Southern Africa ◽  
The Other ◽  
Kalahari Desert ◽  
South West ◽  
South West Africa

Three species of Tuberales have been found in Southern Africa.  Terfezia pfeilii Henn. occurs in the Kalahari Desert and adjacent areas of the Cape Province, Botswana and South-West Africa. The other two,  Terfezia austroafricana sp. nov. and  Choiromyces echinulatus sp. nov., are known only from the Cape.  C. echinulatus is the first representative of that genus to be collected in Africa or the Southern Hemisphere.

scholarly journals Seasonal variability and long-term evolution of tropospheric composition in the tropics and Southern Hemisphere

2014 ◽  
Vol 14 (10) ◽  
pp. 4859-4874 ◽  
Author(s):  
K. M. Wai ◽  
S. Wu ◽  
A. Kumar ◽  
H. Liao
Keyword(s):  
Indian Ocean ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Southern Africa ◽  
Transport Model ◽  
Easter Island ◽  
Atmospheric Composition ◽  
Nox Emissions ◽  
Ascension Island ◽  
The Tropics

Abstract. Impacts on tropospheric composition in the tropics and the Southern Hemisphere from biomass burning and other emission sources are studied using a global chemical transport model, surface measurements and satellite retrievals. Seasonal variations in observed CO at remote island sites are examined. Easter Island (eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burning in southern Africa/South America, via the westerlies. An increasing trend in CO by 0.33 ppb yr−1 in the past decade at Ascension Island is attributed to the combined effects of South American/southern Africa burnings and the increases in CH4 level. Compared to Easter Island and Ascension Island, much less contribution from biomass burning to atmospheric CO is found at the island of Mahé (western Indian Ocean), where the total CO peaks in January–February, reflecting the contributions of anthropogenic emissions from India. We also examine the 2000–2050 changes in atmospheric composition in the tropics and the Southern Hemisphere driven by future changes in emissions and climate. Changes in solar radiation (UV) over South Atlantic Ocean (SAO) in future January have dominant effects on the O3 distribution. More than 55% of O3 concentrations over the SAO in both present-day and future September are not directly affected by the emissions (including lightning) over the adjacent two continents but are attributable to the transport of O3 from surrounding areas due to CO and CH4 oxidation and stratospheric intrusion. High NOx emissions in both continents in 2050s increase PAN concentrations over remote oceans at the higher southern latitudes (> 35° S) as far as those near Australia, affecting the O3 budget over there. Future changes in biomass burning and anthropogenic NOx emissions in southern Africa lead to a new area of high O3 concentrations near South Africa. The resulted O3 outflow to the Indian Ocean is pronounced due to the effects of the persistent anticyclone. A general reduction in future OH radical concentrations is predicted over the remote marine boundary layer in the tropics and the Southern Hemisphere, as a result of the increases in CH4 and CO emissions.

Explaining globally inhomogeneous future changes in monsoons using simple moist energy diagnostics

2021 ◽  
pp. 1-45
Author(s):  
Rodrigo J. Bombardi ◽  
William R. Boos
Keyword(s):  
North America ◽  
South America ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Southern Africa ◽  
Rainy Season ◽  
Coupled Model ◽  
Summer Precipitation ◽  
The North ◽  
The Difference

AbstractThis study examines the annual cycle of monsoon precipitation simulated by models from the Coupled Model Intercomparison Project phase 6 (CMIP6), then uses moist energy diagnostics to explain globally inhomogeneous projected future changes. Rainy season characteristics are quantified using a consistent method across the globe. Model bias is shown to include rainy season onsets tens of days later than observed in some monsoon regions (India, Australia, and North America) and overly large summer precipitation in others (North America, South America, and southern Africa). Projected next-century changes include rainy season lengthening in the two largest Northern Hemisphere monsoon regions (South Asia and central Sahel) and shortening in the two largest Southern Hemisphere regions (South America and southern Africa). Changes in the North American and Australian monsoons are less coherent across models. To understand these changes, relative moist static energy (MSE) is defined as the difference between local and tropical-mean surface air MSE. Future changes in relative MSE in each region correlate well with onset and demise date changes. Furthermore, Southern Hemisphere regions projected to undergo rainy season shortening are spanned by an increasing equator-to-pole MSE gradient, suggesting their rainfall will be increasingly inhibited by fluxes of dry extratropical air; Northern Hemisphere regions with projected lengthening of rainy seasons undergo little change in equator-to-pole MSE gradient. Thus, although model biases raise questions on the reliability of some projections, these results suggest that globally inhomogeneous future changes in monsoon timing may be understood through simple measures of surface air MSE.

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