I am pretty sure there are many ways one could go about this. One method is to use narrow ellipses filled with a gradient. These are all the same ellipse copied and pasted multiple times, some narrower and some wider, and some I edited by moving the red stop so it comes further up the ellipse. Everything is then cropped by using a clipping mask over a black filled rectangle grouped with the ellipses.
Note: the black stop in the gradient is set to a 100% M,Y, and K. and so too is the fill of the rectangle used as the background, otherwise the gradient woudn't look right against the background. The gradients could be further tweaked so that there is more bright red at the bottom.