Analysis of Weather Conditions for Aerial Security and Optimization in Maroua-Salak

In this study, the weather conditions of the accident at Maroua-Salak airport on 02 August 2020 are analyzed. This C130 aircraft accident took place under bad weather conditions. This bad weather is diagnosed using the models as CFS, GFS and GEFS that reanalyze outputs of the results. At the end of this re-analysis, the result obtained shows that the event which took place at the Maroua-Salak airport was predictable. However, the analysis of these results has made it possible to present the rainfall cumul between 05 and 10 mm for this day. In addition, a comparative study of the rainfall cumul obtained by the CFS, GFS and GEFS models and that estimated by the satellites has been carried out. These models can significantly improve the prevention of such disasters in the region.


Study Area
Our study area is located in the Diamaré Division, Far North region of Cameroon. This Division is one of six (6) Divisions that make up the Far North region and is bounded to the north by Logone and Chari Division, north-west by the Mayo Sava Division, west by the Mayo Tsanaga Division, east by Mayo-Danay Division, and south by Mayo-Kani Division (see Figure 1). IL is located in the   [4]. Its floors are very diverse.

Data and Methods
The  For that day, in addition to the waves that have been observing, we notice that there has been the appearance of a Kelvin wave.

Analysis of Synoptic Weather Parameters 1) Pressure field
The model has provided a low-pressure being in the Sahel-Saharan area ( Figure 4). From 12 UTC onwards, the center of action which is north of Chad amplify while that of the DRC weakens.

2) Wind flow
The wind flow distribution provided at 850 hPa by the model reveals the cyclonic configurations for the four days in advance of the day of 02 August 2020.
In Figure 5(a), at 00 UTC, one identifies theses configurations in western Sudan with strong penetration of the southern trade winds as the days approach. In addition, we also note the birth vortex cyclone in the center of Niger. At 06 UTC, the confluence line in the center of Chad intensifies and the disturbance is growing ( Figure 5(b)). At 12 UTC, the system multiplies and the confluence line intensifies southern Chad (Figure 5(c)). At 18 UTC, the new system comes into play and the former ends ( Figure 5(d)).
The model has provided a displacement of the wind flow from 700HPA to 00 UTC and 06 UTC (Figure 6(a) and Figure 6(b)). In Figure 6(a) and Figure   6(b), we note that at this level the flow is not laminar; it is which marks the presence of an east wave and the Talweg along with South Chad. This wave defines the trajectory of the East-West system. At 12 UTC to 18 UTC, the confluence line at this level is strengthened (Figure 6(c) and Figure 6(d)).
3) Moisture   Figure 7(a) shows that the moisture provided by the model in the layer 850_500 to 00 UTC is 70% to 80% which can maintain the system, and the maximum of the humidity is found in eastern Chad more precisely in the area where we have been located our disturbance (80%). It is noted that moisture in the 850_500 HPA layer at 06 UTC has undergone an increase in the layer ( Figure 7(b)). The model also shows that an increase in humidity in the layer at 12 UTC of which a large amount of humidity is at least 80% (Figure 7(c)) and a decrease to 18 UTC in some areas (Figure 7(d)).

Rainfall Vigilance Map for the Day of August 2, 2020 in the Far North Region (Maroua-Salak) of Cameroon
The results from the re-analyzes of model outputs are presented on the rainfall

Comparative Study of the Cumul Rainfall Obtained by the CFS, GFS and GEFS Models and by the Satellites
In addition to their assimilation into the models, satellite data is used in the form of images. Figure 15 shows the rainfall data observed for the day of August 2, According to Figure 15, Satellite IMERG estimated the amount of precipitation to vary between 10 and 25 mm; Satellite ARC2 in turn saw a cumul rainfall of between 05 and 20 mm; Satellite ERA5 records a cumul rainfall of 05 to 10 mm and in the TAMSAT Satellite, the observed cumul amount is 05 to 10 mm of precipitation with a resolution of 0.03˚ × 0.03˚ including about 03 km on the side.
As for the analysis of the outputs of CFS, GFS and GEFS models, the cumul rainfall provided is 05 and 10 mm ( Figure 14).
In view of all the above, it can be seen that the result obtained by the re-analysis of the GFS and GEFS models gives an cumul rainfall which is in the interval between 10 and 25 mm excluded.

Conclusion
The work focused on the plane crash that occurred at Maroua-Salak airport on August 2, 2020. To do this, it was a question of analyzing the weather conditions of the day using the outputs of the models (CFS, GFS and GEFS) to see if the event was foreseeable. However, the evaluation of today's weather forecast bulle-