"existence of phenomenon" is a correct and usable phrase in written English.
You could use it to describe a fact or event that already exists or has been observed, such as in the sentence: "The existence of the phenomenon of climate change has been accepted by the scientific community."
At the beginning of electrolysis, ECI >1, this can be interpreted by the chemical existence of phenomenon associated with the electrochemical reaction; this phenomenon has measurable effects only in the first moments of electrolysis [15].
Throughout time there have always been those who insist they have seen mythical creatures, people who swear to the existence of phenomenon for which scientists say there is no tangible evidence, only hearsay, fable, legend.
Rather, the two-tiered approach to the existence of phenomena, which distinguishes between substantial and nominal existents, is meant to reject not the existence of extra mental entities proper, but rather the existence of all partite entities such as chairs, pots, and tables (cf. Kapstein 2001, 90 and passim; Siderits 2003, 33 and passim).
The link between features and facial events, as listed in Table 1, is of course dependent on the existence of phenomena and data.
It is seen as the most effective method for coursing a "middle way" between the philosophical extremes of asserting the absolute existence of phenomena on the one hand, and the non-existence of them on the other.
Numerical models reveal the existence of phenomena and effects otherwise unobserved.
The search for a mechanism of decreasing rate of macroevolution and decreasing variability of species in macroevolutionary time-scale, i.e. the third part of frozen plasticity theory, was inspired by the existence of phenomena described by Stephen J. Gould, Mark Webster and John A. Davison.
Although it is unclear whether this phenomenon occurred consequent upon a nearby insertion of transposable element, the existence of this phenomenon supports the suggestion that inserted sequence is not the only source of CpG sequences and that inserted sequence itself is not necessarily CpG-rich.
Recent work has demonstrated the existence of this phenomenon in adult HGG (termed vasculogenic mimicry) [ 39, 42, 45]; our work provides evidence that this phenomenon may also exist in pHGG.
The existence of chattering phenomenon for bi-input control affine systems is also proved in [93].
The non-bonding character of frontier molecular orbitals (FMO) of these para isomers is the main reason for the existence of this phenomenon.
