On the Variations in Precipitable Water over Some West African Stations during the Special Observation Period of WAMEX

Balogun, E. E.; Adedokun, J. A.

doi:10.1175/1520-0493(1986)114<0772:otvipw>2.0.co;2

Cited by 10 publications

(6 citation statements)

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“…They concluded that the precipitation climatologies of the northern and southern parts of West Africa differ appreciably (Hamilton and Archbold 1945;Obasi 1965;Ilesanmi 1971;Adedokun 1978Adedokun , 1986Balogun 1981;Garbutt et al 1981). The differences in precipitation climatologies between the stations have made it impossible to have a single model that can adequately satisfy the stations altogether.…”

Section: Discussionmentioning

confidence: 99%

Empirical Modeling of Layered Integrated Water Vapor Using Surface Mixing Ratio in Nigeria

Adeyemi

2009

Journal of Applied Meteorology and Climatology

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Using the available upper-air data for three stations in Nigeria (Lagos, a coastal station; Minna, an inland station; and Kano, a sub-Sahelian station), an intensive examination has been carried out on the linkage between surface mixing ratio r s and layered integrated water vapor W (g cm 22 ) over Nigeria. The goal was to identify the seasonal distribution of the parameter and to develop models that can best be used to estimate W from surface mixing ratio. To achieve these objectives, integrated water vapor at the low level (W L ), midlevel (W m ), and upper level (W u ) and total column integrated water W T have been calculated using daily values of upper-air data spanning over a decade from the above three radiosonde stations. A relationship of the form W 5 ar s 1 b (where a and b are constants) has been established between W and r s using the analysis-of-variance (ANOVA) technique. Tests carried out on the models, using daily soundings made in 1990 for Lagos, 1983 for Minna, and 1991 for Kano, respectively, gave encouraging results as established by the use of Kolmogorov-Smirnov tests. Owing to the difference in the climatological patterns of precipitation among the different regions in Nigeria (i.e., southern, midland, and northern regions) as represented by the three stations, no single relationship was found to be suitable for the entire country of Nigeria. Earlier models, generally of the form W 5 aq b (where a and b are constants and q is specific humidity), were found to be less adequate over the stations.

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Section: Discussionmentioning

confidence: 99%

Empirical Modeling of Layered Integrated Water Vapor Using Surface Mixing Ratio in Nigeria

Adeyemi

2009

Journal of Applied Meteorology and Climatology

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“…These are referred to as N L (low-level refractivity), N u (upper-level refractivity), N Total (total columnar refractivity), respectively. The atmospheric column considered here is the surface to 300 mb pressure level because it is assumed here that humidity decreases rapidly to zero above this level (Aro, 1972(Aro, , 1975Balogun and Adedokun, 1986). The radiosonde observations for 1200GMT and for the years 1975-1990 were used for the computations.…”

Section: Surface Water Vapour Density (Swvd) Calculationsmentioning

confidence: 99%

“…During this July/August drought, water vapour pressure at the surface is lowest, thereby causing the SWVD to fall (Balogun and Adedokun, 1986). The duration of this drought is usually of the order of three weeks and it is prominent only in southern parts of Nigeria (Kolawole, 1983).…”

Section: Annual Distribution Of Tropospheric Radio Refractivity In Nimentioning

confidence: 99%

Surface water vapour density and tropospheric radio refractivity linkage over three stations in Nigeria

Adeyemi

2006

Journal of Atmospheric and Solar-Terrestrial Physics

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“…For instance, Peixoto and Oort (1996), who studied the climatology of relative humidity in the atmosphere based on global radiosonde data, have observed these differences. Also, Balogun and Adedokun (1986) and Olaniran and Sumner (1989) have confirmed such differences over West Africa. Four seasons: NEM, pre-monsoon, SWM, and early NEM have been identified for Peninsular Malaysia (Varikoden et al 2011).…”

Section: Comparison Between Satellite and Radiosonde Datamentioning

confidence: 62%

Characteristics of precipitable water over Peninsular Malaysia from satellite and in situ data

Makama¹,

San²

2017

Terr. Atmos. Ocean. Sci.

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Variations as well as distribution patterns of total precipitable water vapour (WST) and layered precipitable water vapour (W) over Peninsular Malaysia using data retrieved and archived by the Satellite Application Facilities on Climate Monitoring (CM SAF), Deutscher Wetterdienst, Germany, for the period 2001 -2011 are analysed using simple regression method. The lower and middle layers of W are observed to exhibit bimodal annual oscillations, which are in phase with WST at all the climatic regions, with a pair of minima and maxima in each case. The primary and secondary minima occur in February and August, while their maxima counterparts are noticed around November and May/June respectively. These oscillations are synchronous to the movement of the prevailing monsoons. The satellite and radiosonde products are compared at the seasonal scale and the results show good agreement, with correlation coefficients between 0.60 -0.98 and mean bias range of -0.60 -0.59 kg m -2 throughout the study area. Also at the seasonal scale WST and W exhibit significant agreement at all the stations for which radiosonde records were available. The difference between W, from the two sources of measurements are relatively uniform, irrespective of the satellite value, at all the layers and to a large extend, throughout the period of the year. While the satellite precipitable water is greater than its radiosonde counterpart at the middle and upper layers, the reverse is, however, the case for the lower layer in all the climatic regions. These differences are more as a result of instrumentation than the variability of the atmosphere.

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On the Variations in Precipitable Water over Some West African Stations during the Special Observation Period of WAMEX

Cited by 10 publications

References 0 publications

Empirical Modeling of Layered Integrated Water Vapor Using Surface Mixing Ratio in Nigeria

Empirical Modeling of Layered Integrated Water Vapor Using Surface Mixing Ratio in Nigeria

Surface water vapour density and tropospheric radio refractivity linkage over three stations in Nigeria

Characteristics of precipitable water over Peninsular Malaysia from satellite and in situ data

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