Abstract
Deep convective systems during active periods of the West African monsoon season have not been properly investigated over better temporal and spatial resolution in West Africa. Deep convective systems are investigated over seven climatic zones of the West African sub-region, which are as follows: west-coast rainforest, dry rainforest, Nigeria-Cameroon rainforest, Nigeria savannah, Central African and South Sudan (CASS) savannah, Sudano-Sahel, and Sahel, using data from Tropical Rainfall Measurement Mission (TRMM) Precipitation Feature (PF) database. The vertical structure of the convective systems indicated by the presence of at least one 40 dBZ and reaching (attaining) at least 1 km in the atmosphere showed strong core (highest frequency (%)) of reflectivity values around 2 km which is below the freezing level (4–5 km) for all the zones. Echoes are detected above the 15-km altitude much more frequently in the rainforest and Savannah zones than the Sudano and Sahel zones during active periods in March–May (MAM), whereas during active periods in June–September (JJAS), the savannahs, Sudano, and Sahel zone convections tend to reach higher altitude more frequently than the rainforest zones. The frequencies of deep convection defined by the presence of at least one 40 dBZ, reaching (attaining) at least 1 km in the atmosphere, with sizes greater than 2000 square, and having at least one convective pixels indicate that these systems are within the range of 2.3–2.8% in frequency averaged over the 16-year period of study in both March–May (MAM) and June–September (JJAS) active periods in the rainforest and savannah zones. These were found to be less than 2% in the Sudano and Sahel zones, except for the active JJAS period in Sudano zone.
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Data were extracted from the database of Texas A & M University Corpus Christi United States. Many thanks to Dr. Chuntao Liu for granting access to the data.
References
Abhilash S, Mohankumar K, Das SS, Kumar KK (2010) Vertical structure of tropical mesoscale convective systems: observations using VHF radar and cloud resolving model simulations. Meteorog Atmos Phys 109:73–90. https://doi.org/10.1007/s00703-010-0087-7
Bharti V, Singh C (2015) Evaluation of error in TRMM 3B42V7 precipitation estimates over the Himalayan region. J Geophys Res Atmos 120:12,458–12,473. https://doi.org/10.1002/2015JD023779
DeMott CA, Rutledge SA (1998) The vertical structure of TOGA COARE convection. Part I: radar echo distributions. J Atmos Sci 55:2730–2747
Fontaine B, Louvet S (2006) Sudan-Sahel rainfall onset: definition of an objective index, types of years, and experimental hindcasts. J Geophys Res 111:D20103. https://doi.org/10.1029/2005JD007019
Fu YF, Pan X, Liu GS, Li R, Zhong L (2016) Characteristics of precipitation based on cloud brightness temperatures and storm tops in summer Tibetan Plateau. Chinese J Atmos Sci 40:102–120. https://doi.org/10.3878/j.issn.1006-9895.1507.15165
Fuentes JD, Geerts B, Dejene T, D’Odorico P, Joseph E (2008) Vertical attributes of precipitation systems in West Africa and adjacent Atlantic Ocean. Theor Appl Climatol 92:181–193. https://doi.org/10.1007/s00704-007-0318-0
Futyan J, Del Genio A (2007) Deep convective system evolution over Africa and the tropical Atlantic. J Clim 20:5041–5060. https://doi.org/10.1175/JCLI4297.1
Geerts B, Dejene T (2005) Regional and diurnal variability of the vertical structure of precipitation systems in Africa based on spaceborne radar data. J Clim 18:893–916. https://doi.org/10.1175/JCLI-3316.1
Gremillion MS, Orville RE (1999) Thunderstorm characteristics of cloud-to-ground lightning at the Kennedy Space Center, Florida: a study of lightning initiation signatures as indicated by the WSR-88D. Weather Forecast 14:640–649. https://doi.org/10.1175/15200434(1999)014<0640:TCOCTG>2.0.CO;2
Guy N, Rutledge SA (2012) Regional comparison of West African convective characteristics: a TRMM-based climatology. Quart J Roy Meteor Soc 138:1179–1195. https://doi.org/10.1002/qj.1865
Inoue T, Vila D, Rajendran K, Hamada A, Wu X (2009) Life cycle of deep convective systems over the eastern tropical Pacific observed by TRMM and GOES-W. J Meteorol Soc Japan 1–32. https://doi.org/10.2151/jmsp.87A.381
Janiga MA, Thorncroft CD (2014) Convection over tropical Africa and the east Atlantic during the West African monsoon: regional and diurnal variability. J Clim 27:4159–4188. https://doi.org/10.1175/JCLI-D-13-00449.1
Kamsu-Tamo PH, Janicot S, Monkam D, Lenouo A (2014) Convection activity over the Guinean coast and Central Africa during northern spring from synoptic to intra-seasonal timescales. Clim Dyn, Springer Verlag 43(12):3377–3401
Kummerow C, Barnes W, Kozu T, Shiue J, Simpson J (1998) The tropical rainfall measuring mission (TRMM) sensor package. J Atmos Ocean Technol 15:809–817. https://doi.org/10.1175/1520-0426(1998)015,0809:TTRMMT.2.0.CO;2
Li Y, Guo B, Wang K, Wu G, Shi C (2020) Performance of TRMM product in quantifying frequency and intensity of precipitation during daytime and nighttime across China. Remote Sens 12:740. https://doi.org/10.3390/rs12040740
Liu C, Zipser EJ (2005) Global distribution of convection penetrating the tropical tropopause. J Geophys Res 110:D23104. https://doi.org/10.1029/2005JD006063
Liu CT, Zipser EJ, Cecil DJ, Nesbitt SW, Sherwood S (2008) A cloud and precipitation feature database from nine years of TRMM observations. J Appl Meteorol . 47:2712–2728
Liu M, Xu X, Sun AY, Wang K, Yue Y, Tong X, Liu W (2015) Evaluation of high-resolution satellite rainfall products using rain gauge data over complex terrain in southwest China. Theor Appl Climatol 119:203–219
Liu J, Duan Z, Jiang J, Zhu A-X (2015) Evaluation of three satellite precipitation products TRMM 3B42, CMORPH, and PERSIANN over a subtropical watershed in China. Adv Meteorol 2015:1–13
Melo DCD, Xavier AC, Bianchi T, Oliveira PTS, Scanlon BR, Lucas MC, Wendland E (2015) Performance evaluation of rainfall estimates by TRMM multi-satellite precipitation analysis 3B42V6 and V7 over Brazil. J Geophys Res Atmos 120:9426–9436. https://doi.org/10.1002/2015JD023797
Nguyen H, Thorncroft C, Zhang C (2011) Guinean coastal rainfall of the West African monsoon. Q J R Meteorol Soc 137:1828–1840. https://doi.org/10.1002/qj.867
Pan X, Fu YF (2015) Analysis on climatological characteristics of deep and shallow precipitation cloud in summer over Qinghai–Tibet Plateau. Plateau Meteor 34:1191–1203. https://doi.org/10.7522/j.issn.1000-0534.2014.00112
Petersen WA, Rutledge SA, Orville RE (1996) Cloud-to-ground lightning observations from TOGA COARE: selected results and lightning location algorithms. Mon Weather Rev 124:602–620. https://doi.org/10.1175/1520-0493(1996)124<0602:CTGLOF>2.0.CO;2
Schumacher C, Houze RA (2003) Stratiform rain in the tropics as seen by the TRMM precipitation radar. J Clim 16:1739–1756. https://doi.org/10.1175/1520-0442(2003)016,1739:SRITTA.2.0.CO;2
Schumacher C, Houze RA (2006) Stratiform precipitation production over sub-Saharan Africa and the tropical East Atlantic as observed by TRMM. Q J R Meteorol Soc 132:2235–2255. https://doi.org/10.1256/qj.05.121
Tian Y, Peters-Lidard CD, Choudhury BJ, Garcia M (2007) Multitemporal analysis of TRMM-based satellite precipitation products for land data assimilation applications. J Hydrometeorol 8:1165–1183
Wang H, Guo XL (2019) Comparative analyses of vertical structure of deep convective clouds retrieved from satellites and ground-based radars at Naqu over the Tibetan Plateau. J Meteorol Res 33(3):446–462. https://doi.org/10.1007/s13351-019-8612-1
Wu X, Yuan T, Jiang R, Li J (2018) Evolutionary characteristics of lightning and radar echo structure in thunderstorms based on the TRMM satellite. Atmos Chem Phys Discuss 1–45. https://doi.org/10.5194/acp-2018-778
Xu WX, Zipser EJ, Liu CT (2009) Rainfall characteristics and convective properties of Mei-Yu precipitation systems over South China, Taiwan, and the South China Sea. Part I: TRMM observations. Mon Weather Rev 137:4261–4275
Yuter SE, Houze RA Jr (2003) Microphysical modes of precipitation growth determined by vertically pointing radar in orographic precipitation during MAP. Q J R Meteorol Soc 129:455–476
Zipser EJ, Liu C, Cecil DJ, Nesbitt SW, Yorty DP (2006) Where are the most intense thunderstorms on Earth? Bull Am Meteorol Soc 87:1057–1071. https://doi.org/10.1175/BAMS-87-8-1057
Funding
This research was supported by Tertiary Education Trust Fund (TETFund) grant of the Nigerian government under the academic staff development program of the Federal University of Technology Akure for a split site research program with the Texas A & M University Corpus Christi United States.
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Balogun, R.A., Adeyewa, Z.D., Adefisan, E.A. et al. Vertical structure and frequencies of deep convection during active periods of the West and Central African monsoon season. Theor Appl Climatol 141, 615–626 (2020). https://doi.org/10.1007/s00704-020-03203-6
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DOI: https://doi.org/10.1007/s00704-020-03203-6