Published 12 issues per year
ISSN Print: 0040-2508
ISSN Online: 1943-6009
Indexed in
SPATIO-TEMPORAL VARIATION OF NONLINEARITY IN TROPOSPHERIC ZENITH WET DELAY OVER WEST AFRICA
ABSTRACT
Quantification of uncertainty in tropospheric zenith wet delay is important for planning a satellite communication link budget. The objective of this study is to determine the spatiotemporal variation of wet delay within the West African region using chaos theory. Evidence of chaos in wet delay will imply a short prediction horizon. Wet delay from January 1981 to December 2010 was computed using the Saastamoinen model. Seasonal variation was observed in wet delay over the region with high values along the coastal regions during the dry season. Using determinism and approximate entropy, the coastal regions of West Africa were found to exhibit chaos which reduces in intensity towards the north of Africa. Wet delay values in the inland region of West Africa possess short term memory while specific regions along the coast show long term memory. Our findings show that long term prediction of wet delay along the coast of West Africa will pose a great challenge for planning the communication link budget.
-
Batuo, M.E., (2015) The role of telecommunications infrastructure in the regional economic growth of Africa, The Journal of Developing Areas, 49(1), pp. 313-330.
-
D'Aleo, J. and Easterbrook, D., (2016) Relationship of multidecadal global temperatures to multidecadal oceanic oscillations, Evidence-Based Climate Science. Elsevier, pp. 191-214.
-
Neelin, J.D., Latif, M., and Jin, F.-F., (1994) Dynamics of coupled ocean-atmosphere models: The tropical problem, Annual review of fluid mechanics, 26(1), pp. 617-659.
-
Dada, J.B., Adediji, A.T., Adedayo, K.D., and Ajewole, M.O., (2019) Correlation between nao and radio refractive index over Africa, In: Patterns and Mechanisms of Climate, Paleoclimate and Paleoenvironmental Changes from Low-Latitude Regions, Springer, pp. 119-121.
-
Bohm, J., Moller, G., Schindelegger, M., Pain, G., and Weber, R., (2015) Development of an improved empirical model for slant delays in the troposphere (gpt2w), GPS Solutions, 19(3), pp. 433-441.
-
Davis, J., Herring, T., Shapiro, I., Rogers, A., and Elgered, G.,(1985) Geodesy by radio interferometry: Effects of atmospheric modeling errors on estimates of baseline length, Radio Science, 20(6), pp. 1593-1607.
-
Askne, J. and Nordius, H., (1987) Estimation of tropospheric delay for microwaves from surface weather data, Radio Science, 22(3), pp. 379-386.
-
Saastamoinen, J., (1972) Atmospheric correction for the troposphere and stratosphere in radio ranging satellites, The use of artificial satellites for geodesy, pp. 247-251.
-
Hopfield, H., (1969) Two-quartic tropospheric refractivity profile for correcting satellite data, Journal of Geophysical Research, 74(18), pp. 4487-4499.
-
Ogunjo, S.T., Dada, J.B., Oluyamo, S.S., and Fuwape, I.A., (2018) Tropospheric delay in microwave propagation in Nigeria, arXivpreprint arXiv:1811.12055.
-
Nilsson, T., Bohm, J., Wijaya, D.D., Tresch, A. et al., (2013) Path delays in the neutral atmosphere, In: Atmospheric Effects in Space Geodesy, Springer, pp. 73-136.
-
Majumder, S., Das, S., and Maitra, A., (2015) Study of tropospheric delay over Indian region from modis, NCEP/NCAR data and ground based water vapor measurements at Kolkata, Advances in Space Research, 56, pp. 1115-1124.
-
Tralli, D. and Lichten, S.M., (1990) Stochastic estimation of tropospheric path delays in global positioning system geodetic measurements, Bulletin Geodesique, 64(2), pp. 127-159.
-
Ogunjo, S.T., Adediji, A.T., and Dada, J.B., (2017) Investigating chaotic features in solar radiation over a tropical station using recurrence quantification analysis, Theoretical and Applied Climatology, 127(1-2), pp. 421-427.
-
Fuwape, I.A., Ogunjo, S.T., Oluyamo, S.S., and Rabiu, A.B., (2017) Spatial variation of deterministic chaos in mean daily temperature and rainfall over Nigeria, Theoretical and Applied Climatology, 130(1-2), pp. 119-132.
-
Fuwape, I.A. and Ogunjo, S.T., (2016) Quantification of scaling exponents and dynamical complexity of microwave refractivity in a tropical climate, Journal of Atmospheric and Solar-Terrestrial Physics, 150-151, pp. 61-68.
-
Nicholson, S., (2005) On the question of the "recovery" of the rains in the west African sahel, Journal of Arid Environments, 63(3), pp. 615-641.
-
McHugh, T.A., Morrissey, E.M., Reed, S.C., Hungate, B.A., and Schwartz, E., (2015) Water from air: an overlooked source of moisture in arid and semiarid regions, Scientific Reports, 5, p. 13767.
-
Dezfuli, A.K., Karamouz, M., and Araghinejad, S., (2010) On the relationship of regional meteorological drought with SOI and NAO over southwest Iran, Theoretical and Applied Climatology, 100(1-2), pp. 57-66.
-
Gong, C. and Eltahir, E., (1996) Sources of moisture for rainfall in West Africa, Water Resources Research, 32(10), pp. 3115-3121.
-
Cotillon, S.E. and Tappan, G.G., (2016) Landscapes of West Africa: A window on a changing world, United States Geological Survey.
-
Hulme, M., (2001) Climatic perspectives on Sahelian desiccation: 1973-1998, Global Environmental Change, 11(1), pp. 19-29.
-
Nicholson, S.E., (2018) Climate of the Sahel and West Africa, URL https:// oxfordre.com/climatescience/view/10.1093/acrefore/9780190228620.001.0001/acrefore-9780190228620-e-510.
-
Pincus, S.M., (1991) Approximate entropy as a measure of system complexity, Proc. Natl. Acad. Sci. USA, 88(March), pp. 2297-2301.
-
Sharma, R., Pachori, R.B., and Acharya, U.R., (2015) Application of entropy measures on intrinsic mode functions for the automated identification of focal electroencephalogram signals, Entropy, 17(2), pp. 669-691.
-
Fuwape, I.A., Oluyamo, S.S., Rabiu, A.B., and Ogunjo, S.T., (2018) Chaotic signature of climate extremes, Theoretical and Applied Climatology, 139(1-2), 565-570.
-
Marwan, N., Romano, M.C., Thiel, M., and Kurths, J., (2007) Recurrence plots for the analysis of complex systems, Physics Reports, 438(5), pp. 237-329.
-
Ohunakin, O.S., Adaramola, M.S., Oyewola, O.M., Matthew, J.O., and Fagbenle, R.O., (2015) The effect of climate change on solar radiation in Nigeria, Solar Energy, 116, pp. 272-286.
-
Ogunjo S.T., Dada J.B., Ajayi O.J., Forecasting tropospheric wet delay using LSTM neural network, IOP Conference Series: Earth and Environmental Science, 993, 1, 2022. Crossref