Table of Content forward introduction
Fig. 11: 2012 Cold Season Minimum Temperature Anomaly
Download 236.98 Kb.
|
- Navigate this page:
- Fig. 12: 2012 Mean Temperature Anomaly 5.0 SOLAR RADIATION
- Fig. 13: Incident Solar Radiation in February 2012 6.0 RAINFALL 6.1 CUMULATIVE ANNUAL RAINFALL
- Fig. 14: 2012 Cumulative Annual Rainfall 6.2 RAINFALL ANOMALY
- Fig. 15a: 2012 Rainfall Anomaly
- Fig. 15b: 2012 Rainfall in percentage of 2011 Rainfall 6.3 AUGUST RAINFALL ANOMALY
- Fig. 16: 2012 August Rainfall Anomaly (%) 6.4 RAINFALL MONTHS ANOMALY
- Fig. 17: 2012 Rainfall months’ Anomaly 6.5 LITTLE DRY SEASON (LDS)
- Table 1: Little Dry Season in the Southwest: 2009 - 2012
- Fig. 19: Monthly Rainfall in the Southwest (area averaged) 7.0 DUST HAZE
- Table 2: Summary of Dust Haze Spells and Effects 8.0 EXTREME METEOROLOGICAL PARAMETERS 8.1 WIND SPEED
- Table 3: Daily wind speed of 40knots and higher in 2012 8.2 TEMPERATURES
Fig. 11: 2012 Cold Season Minimum Temperature Anomaly 4.5 ANNUAL MEAN TEMPERATURE ANOMALY Mean temperature departure analysis for 2012 showed that most places in the country experienced normal mean temperatures compared to 1971-2000 long term values (Fig. 12). Owerri in the southeast and Makurdi in the northcentral were 1.1°C colder than normal. On the other hand, Bauchi and Gusau in the north were 1.0°C and 1.1°C respectively warmer than normal. Slightly warmer than long term temperatures (0.6°C) were however experienced in places such as Maiduguri, Yola and Yelwa in the north, and Warri and Ondo in the south. On the average, mean temperature anomalies in 2012 were lower than 2010 and 2009 but the spatial pattern was identical to 2011 mean temperature anomalies. 
Fig. 12: 2012 Mean Temperature Anomaly 5.0 SOLAR RADIATION The northern states of Katsina, Kano, Jigawa, Gombe, Yobe and Borno states received the greatest amount of incident solar radiation ranging from 26.0 – 28.0 Wm-2 day-1 during the hot season in the country (Fig. 13). The incident solar radiation was between 24.0 - 26.0Wm-2day-1 over Sokoto, Kebbi, Zamfara, Kaduna, Bauchi, Plateau, Taraba and Adamawa states, while states in the central region received 22.0 - 24.0 Wm-2 day-1 of solar radiation. The inland states of the south and the coastal areas recorded 20.0 - 22.0Wm-2day-1 and from 18.0 - 20.0 Wm-2 day-1 of incident solar radiation respectively. Lowest incident solar radiation of 18.0Wm-2 day-1 was recorded over Eket and Calabar while Katsina had the highest value of 27.3 Wm-2 day-1. 
Fig. 13: Incident Solar Radiation in February 2012 6.0 RAINFALL 6.1 CUMULATIVE ANNUAL RAINFALL Cumulative rainfall in the year was between 1000.0 – 2000.0mm over a vast portion of the country, stretching from Nguru in the extreme north to the central states and most parts of the south (Fig. 14). Maiduguri, Nguru and Yola in the northeast, Sokoto and Yelwa in northwest, and Shaki in the southwest recorded rainfall amounts ranging from 500.0 -1000.0mm. Rainfall values of 3000.0 - 4000.0mm were recorded over the extreme southeast portion of the country. The highest rainfall of 4627.2mm occurred at Uyo, while Sokoto recorded the least rainfall amount of 613.4mm. Generally rainfall amount in 2012 was more than 2011 and 2010. 
Fig. 14: 2012 Cumulative Annual Rainfall 6.2 RAINFALL ANOMALY The rainfall anomaly showed that wetter than normal rainfall conditions were experienced over most parts of the country in the year; especially over the eastern halve (Fig. 15a). For the first time in recent years, the extreme northeast corner of the country had wetter than normal rainfall. The other parts of the country located over the western sector recorded normal rainfall except for isolated cases of drier than normal rainfall experienced over Gusau in the extreme northwest and Shaki in the inland of the southwest. 
Fig. 15a: 2012 Rainfall Anomaly Further analysis of the 2012 rainfall shows that it was much higher than the 2011 values over a greater portion of the country (Fig.15b). The northeast and areas around Minna and Abuja recorded more than 160% 0f 2011 rainfall. However, rainfall in the year was less than the preceding years’ over Yelwa, Ilorin, and Southwest except for Abeokuta, Owerri, and parts of Edo and Delta states. 
Fig. 15b: 2012 Rainfall in percentage of 2011 Rainfall 6.3 AUGUST RAINFALL ANOMALY The climatology of August rainfall in the country exhibits rainfall maxima in the north due to the northernmost influence of moisture from the South Atlantic Ocean while the south, and in particular the southwest, experiences rainfall minima in the month. The 2012 August rainfall anomaly (Fig. 16) depicts a drier than normal rainfall condition in the western half of the country, stretching from Sokoto and Gusau in the far north to Bida and Ilorin in the central region. Also, Jos, Ibi and Makurdi, the southwest and the western half of the Niger delta recorded drier than normal August rainfall. Wetter than normal rainfall in the month occurred in the eastern half of the north and the southeast while other places in the country experienced normal August rainfall. Coastal areas in the southeast (Eket, Calabar, Uyo, Ogoja) and Kano, Nguru and Potiskum in the north had 350.0 – 500.00 mm and 123.0 – 333.0mm surplus rainfall in the month respectively. 
Fig. 16: 2012 August Rainfall Anomaly (%) 6.4 RAINFALL MONTHS ANOMALY Rainfall month, for purposes of this bulletin, is regarded as the month in which the total amount of rainfall is equal to or greater than 50.0mm. In the year under review, a considerable portion of the country had normal rainfall months (Fig. 17). Places in the extreme north, Jos and Zaria in the central region, and Ijebu-Ode, Enugu, Benin, Eket and Calabar in the southern part of the country had 1 -2 months of rainfall higher than normal. On the other hand, rainfall months in other parts of the country were 1 -2 months shorter than normal. These places include Bauchi, Bida, Minna and Ilorin in the north, and Shaki, Iseyin, Lagos and Ikom in the south. The generally normal rainfall months in the year coupled with the good rainfall, especially over the eastern half of the country, was partly responsible for the extensive flooding experienced in the year. 
Fig. 17: 2012 Rainfall months’ Anomaly 6.5 LITTLE DRY SEASON (LDS) Little Dry Season (LDS) is a period of significantly reduced rainfall in terms of amount and frequency during the rainy season in the southern part of the country which normally occurs between the last week in July and the first two weeks in August. In the year under review, the LDS signal was first felt over the inland of the southwest (Akure, Ibadan and Ijebu-Ode) in the 3rd of July and then intensified to influence the amount of rainfall in other parts of the region. The season lasted till the first week in September. In 2012, the Little Dry Season (LDS) lasted from two weeks (Ibadan) to five weeks (Ikeja) with the exception of Iseyin where the season lasted for about a week. Following the pattern of the previous years, the Little Dry Season lasted longer in Lagos (37 days) than in any other place in the southwest. A summary of the intensity of the Little Dry Season in the southwest during the past four consecutive years (2009 – 2012) is shown in Table 1 below.
Table 1: Little Dry Season in the Southwest: 2009 - 2012 The LDS in 2012 was more pronounced than in any of the three preceding years in the southwest except at Abeokuta and Iseyin where the season lasted for a shorter period compared with 2011 (Fig. 18). Fig. 18: Comparison of Little Dry Season severity: 2012, 2011 and 2010 The monthly distribution of rainfall in the region depicts the pronounced impact of the 2012 LDS in the southwest (Fig. 19). The rainfall in August 2012 was below the 1971-2000 average August rainfall in the region. Fig. 19: Monthly Rainfall in the Southwest (area averaged) 7.0 DUST HAZE The first major dust haze spell of the year occurred from January 1st – 21st (Table 2). Surface horizontal visibility was reduced to less than 1000m in most parts of the country during the period. Thick dust haze was experienced between 2nd – 7th February in the northeastern part of the country. It became widespread during February 11 – 18th when places such as Maiduguri, Nguru and Ikeja reported horizontal visibilities of 300m, 600m, and 800m respectively. The extreme northern part of the country was again engulfed in another dust haze spell between 25 – 29th which reduced horizontal visibility to between 700m (Sokoto) and 300m (Maiduguri). Generally, hazy weather conditions prevailed during the second and fourth weeks of March. But thick dust haze was experienced between 2nd and 8th of March over Maiduguri, Gombe, Yola, Kano and Sokoto. Kano had the poorest horizontal visibility of 500m. Another dust haze spell was experienced between 16th – 21st when the horizontal visibility was reduced to 200 – 800m over Maiduguri, Yola, Gombe and the central states. Dry weather conditions returned after the rainy season (April and October), bringing dust particles into the country. One dust spell was recorded from November 23rd – 25th which reduced horizontal visibility to 800m in the extreme north. The second dust haze spell of the month was recorded from December 14th – 19th which reduced horizontal visibility to between 800 – 1500m in the extreme north and central region of the country.
Table 2: Summary of Dust Haze Spells and Effects 8.0 EXTREME METEOROLOGICAL PARAMETERS 8.1 WIND SPEED Destructive winds with speeds of the order of 35knots and higher (Squall) are usually experienced during the beginning and cessation of the rainy season in the country. In the current year, these winds (60-70knots) were experienced between February in the south and June in the north (Table 3).
Table 3: Daily wind speed of 40knots and higher in 2012 8.2 TEMPERATURES Daily maximum temperatures of 40.0oC and higher were experienced in the northern part of the country, which lasted for upwards of ten days except for Gombe, Minna and Makurdi (Table 4). As in previous years, the extreme north experienced highest daily maximum temperatures of 42.0 - 44.7oC between February and May 2012 and over a period of forty to sixty (non-consecutive) days. Yola had the highest frequency of sixty days while the least frequency of occurrence (4 days) was at Makurdi.
Directory: sites -> default -> files -> publications publications -> Theology beacon dictionary of theology publications -> Rehabilitation Engineering Research Center for Wireless Technologies Georgia Institute of Technology publications -> Housing Counseling Research in Chicago publications -> Communicating with Aboriginal and Torres Strait Islander Audiences publications -> New Brunswick Info Sheet on First Nations Child Welfare publications -> Paap’s Electronic Newsletter 14 November 2008 Volume 11 Number 22 towards ‘smart’ subsidies in agriculture: lessons from recent experience in malawi publications -> Information support of pedagogical process for the children experiencing difficulties with acquisition of preschool educational programs publications -> Asus’ ZenFone ar has Google’s augmentted and virtual reality baked in — but not combined publications -> School Readiness and Early Grade Success Consultation Memo Atlanta, ga Download 236.98 Kb. Share with your friends:
|