he equatorial ionosphere is a dynamic medium by different processes, for example due to the disturbance of ion and electron densities in the ionosphere, and brought the problem in the communication and navigation system. Therefore, based on the C/NOFS measurement collect the sampling data by using the NASA data center (http://cindispace.utdalls.edu) from each season (on 25 October 2013, 15 December 2013, 17 March 2013 and 15 May 2013). Then the given data is imported into the mathlab software and filter the available input data (data of ion temperature, ion density and time) from those bulk data by using this software to investigate and present the variability of equatorial ionospheric ion density and the effect of ion temperature on the variability of ion density on a given days at a Height of ( 400- 850)km in a latitudes (Lat) less than about ±30°. The results show that well-known negative correlation between daytime Ni and Ti when Ni is low. However, when the daytime Ni is significantly high (> 106cm-3), the correlation turns positive. The positive correlation is most clear during 12-15 local time and around the magnetic ~ 'dip~ equator (llatl < 10°) where high values of Ni with high Ti are most abundant. <, ""'"' Ti also -increases with increasing MLat in the same Ni range. Since the cooling " •\t.- \. Abstract through Coulomb collisionsincreases with the increase of Ni, the results suggest that an additional heat source(s) is involved for the positive correlation between Ni and . Ti. -The additional heat source seems to be related to the integrated Ne along the " . magnetic field lines from the ground to 500 km altitude. Note that when Ne is _r _ *sufficrn.ntly high, the high cooling that is due to column collisions, the rate of which .... is proportional to N e2 leads to a rapid energy transfer from the electrons to the ions ;:rn? from the ions t~ the neutrals. These processes result in small temperature -cliffonellces between electrons, ions, and neutrals Therefore, electron, ion, and neutral . temperatures increase with increasing solar flux because the neutral temperature (Tn)

A PROJECT SUBMITTED IN PARTIAL FULFILLMENT ,. OF THE REQUIREMENTS FOR THE DEGREE _,. ...... _ SATELLITES by of ,MASTER OF SCIENCE in PHYSICS