The Meteorological Contributing Factors To Aerosol Variability And Modelling In Nigeria

• Main Author: Balarabe, Mukhtar Abubakar
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: QC1 Physics (General)
• Online Access: http://eprints.usm.my/32224/1/MUKHTAR_ABUBAKAR_BALARABE_24%28NN%29.pdf; http://eprints.usm.my/32224/

Satu kajian aerosol jangka panjang adalah satu tugas yang sukar kerana stesen pemerhatian aerosol yang terhad dan musim (yang menyebabkan kehilangan data dan pencemaran awan). Bagi menangani masalah ini, kajian ini pertamanya bertujuan untuk menganalisis ciri-ciri dan jenis aerosol menggunakan rekod jangka panjang (1998-2013) kedalaman optik aerosol (AOD) dan eksponen angstrom α, dari Aerosol Robotic Network darat (AERONET). Kajian ini menunjukkan bahawa atmosfera Nigeria sangat tercemar yang mengandungi kebanyakannya zarah kasar sebagaimana yang ditunjukkan oleh frekuensi tinggi pada berlakunya eksponen angstrom di bawah 1 (78 dan jenis 81%) semasa Harmattan (November-Mac) dan musim panas (April-Oktober). Analisis selanjutnya menunjukkan bahawa zarah-zarah tersebut adalah kebanyakanya aerosol debu semasa Harmattan dan musim panas ( 82% dan 79%). Kedua, kebolehubahan ruang dan masa bagi indeks aerosol min bulanan (AI) (penunjuk kualitatif bagi kehadiran aerosol debu dan asap) dan parameter meteorologi (kelajuan angin, penglihatan, suhu dan kelembapan relatif) yang diperolehi daripada Total Ozone Mapping Spectrometer (TOMS) dan Ozone Monitoring Instrument (OMI) dalam tempoh 1984-2013 bagi Nigeria telah dianalisis. Data meteorologi diperolehi daripada pusat data iklim National Oceanic and Atmospheric Administration-National Climate Data Center (NOAA-NCDC). A long-term aerosol study is a difficult task due to limited aerosol observation stations and seasons (resulting in missing data and cloud contamination). To address these problems, this study first aimed at analyzing the characteristics and type of aerosols using long-term (1998-2013) record of aerosol optical depth (AOD) and angstrom exponent α, from ground-based Aerosol Robotic Network (AERONET). The study showed that Nigeria atmosphere is highly polluted containing mostly coarse particles as indicated by high frequency of occurrence of angstrom exponent below 1 (78 and 81%) during Harmattan (November-March) and summer (April-October). Further analysis revealed that these particles are mostly dust aerosol (DA) for both Harmattan and summer seasons (82% and 79%). Secondly, the temporal and spatial variability of the monthly mean aerosol index (AI) (qualitative indicator of the presence of dust and smoke aerosols) and meteorological parameter (wind speed, visibility, temperature and relative humidity) obtained from the Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) during the period of 1984-2013 for Nigeria were analyzed. The meteorological data were obtained from the National Oceanic and Atmospheric administration-National climate data center (NOAA-NCDC).