scholarly journals Climatic and seasonal variations of effective-earth-radius factor and scale height in three metereological stations in West Africa

2009 ◽  
Vol 20 (1) ◽  
Author(s):  
OD Oyedum
Keyword(s):  
West Africa ◽  
Seasonal Variations ◽  
Scale Height ◽  
Earth Radius

Seasonal variations and distribution of diatom flora of Lake Ahémé (Benin, West Africa)

2019 ◽  
Vol 167 (1) ◽  
pp. 160-173 ◽  
Author(s):  
Isabella Yasmine Olodo ◽  
Christine Cocquyt ◽  
Youssouf Abou ◽  
Kouami Kokou
Keyword(s):  
West Africa ◽  
Seasonal Variations ◽  
Diatom Flora

A numerical study of the seasonal variations for tracer redistribution by clouds over West Africa

1995 ◽  
Vol 20 (3) ◽  
pp. 237-258 ◽  
Author(s):  
M. Renard ◽  
N. Chaumerliac ◽  
S. Cautenet ◽  
N. Audiffren ◽  
E. C. Nickerson
Keyword(s):  
West Africa ◽  
Seasonal Variations ◽  
Numerical Study

scholarly journals Diurnal, seasonal, annual, and semi-annual variations of ionospheric parameters at different latitudes in East Asian sector during ascending phase of solar activity

2017 ◽  
Vol 3 (2) ◽  
pp. 45-53
Author(s):  
Чжэн Ван ◽  
Zheng Wang ◽  
Цзянькуй Ши ◽  
Jiankui Shi ◽  
Гоцзюнь Ван ◽  
...  
Keyword(s):  
Solar Activity ◽  
East Asia ◽  
Seasonal Variations ◽  
Critical Frequency ◽  
East Asian ◽  
Peak Height ◽  
Scale Height ◽  
High Latitudes ◽  
Ionospheric Parameter ◽  
Annual Variations

We analyzed ionospheric parameters including the critical frequency of the F2 layer (foF2), the peak height of the F2 layer (hmF2), and the scale height at hmF2 (HT) from 2006 to 2012 (ascending phase of solar activity) at Hainan (19.5° N, 109.1° E, MLat. 9.7° N), Irkutsk (52.4° N, 104.3° E, MLat. 42.5° N), and Norilsk (69.2° N, 88.0° E, MLat. 59.8° N) stations (low, middle and high latitudes). We have used manual scaled digisonde ionogram data. Studies of foF2 and hmF2 di-urnal-seasonal variations continue those made earlier for East Asia. Features peculiar for the ascending phase of solar activity are mostly consistent to those for de-scending phase, except for the features of sunset and nighttime hmF2 variations. Features of annual and semi-annual variations recorded by a digisonde agree with those obtained by a satellite occultation and TEC map. We also obtained seasonal, diurnal, annual, and semi-annual variations of the ionospheric parameter HT (scale height at hmF2) from digisonde data, which differ from foF2 variations and hmF2 features.

Observations on Nematode Infections of Goats and Sheep in West Africa

1958 ◽  
Vol 32 (4) ◽  
pp. 195-210 ◽  
Author(s):  
E. E. Edwards ◽  
A. S. B. Wilson
Keyword(s):  
West Africa ◽  
Seasonal Variations ◽  
Worm Burden ◽  
Egg Production ◽  
High Peak ◽  
Forest Belt ◽  
Nematode Eggs ◽  
Moniezia Expansa ◽  
High Level

An account is given of the results of preliminary studies of the worm-burden of goats and sheep in Ghana, West Africa, based on fortnightly counts of nematode eggs in their faeces over a period of three years, 1954 to 1956, inclusive. Only eggs of nematodes and Moniezia expansa were encountered apart from an occasional egg of Schistosoma sp., probably S. bovis, in two sheep. Four centres were involved in these investigations differing appreciably in regard to the amount and distribution of the rainfall. It would seem from the results obtained that:—There are in the drier regions two distinct periods in the year when worm-egg production in goats and sheep reaches a high level compared with that at other times of the year, a high peak of production in June, sometimes a month either earlier or later, and a slight peak in November or December.There are seasonal variations in the forest belt regions but here the peaks of egg-production are less evident and more irregular in respect to the time of their occurrences in different years.

scholarly journals Diurnal, seasonal, annual, and semi-annual variations of ionospheric parameters at different latitudes in East Asian sector during ascending phase of solar activity

2017 ◽  
Vol 3 (2) ◽  
pp. 43-50
Author(s):  
Чжэн Ван ◽  
Zheng Wang ◽  
Цзянькуй Ши ◽  
Jiankui Shi ◽  
Гоцзюнь Ван ◽  
...  
Keyword(s):  
Solar Activity ◽  
East Asia ◽  
Seasonal Variations ◽  
Critical Frequency ◽  
East Asian ◽  
Peak Height ◽  
Scale Height ◽  
High Latitudes ◽  
Ionospheric Parameter ◽  
Annual Variations

We analyzed ionospheric parameters including the critical frequency of the F2 layer (foF2), the peak height of the F2 layer (hmF2), and the scale height at hmF2 (HT) from 2006 to 2012 (ascending phase of solar activity) at Hainan (19.5° N, 109.1° E, MLat. 9.7° N), Irkutsk (52.4° N, 104.3° E, MLat. 42.5° N), and Norilsk (69.2° N, 88.0° E, MLat. 59.8° N) stations (low, middle and high latitudes). We have used manual scaled digisonde ionogram data. Studies of foF2 and hmF2 di-urnal-seasonal variations continue those made earlier for East Asia. Features peculiar for the ascending phase of solar activity are mostly consistent to those for de-scending phase, except for the features of sunset and nighttime hmF2 variations. Features of annual and semi-annual variations recorded by a digisonde agree with those obtained by a satellite occultation and TEC map. We also obtained seasonal, diurnal, annual, and semi-annual variations of the ionospheric parameter HT (scale height at hmF2) from digisonde data, which differ from foF2 variations and hmF2 features.

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