The phrase "an additional explanation why" is correct and usable in written English.
It can be used when you want to provide further clarification or reasoning for a particular point or statement.
Example: "I would like to offer an additional explanation why the project was delayed due to unforeseen circumstances."
Alternatives: "a further explanation for" or "an extra reason why".
In addition, our data provide an additional explanation why B cells are mainly involved in the recall response; Salmonella-infected B cells do not prime naïve CD8+ T cells, but are very efficient in reactivation of cytotoxic CD8+ memory T cells.
This may provide an additional explanation why the IL-13-treated cells did not show any significant drug effect.
This could be an additional explanation why sunitinib exposure is not influenced by gastrectomy whereas imatinib and nilotinib exposure are.
This may represent an additional explanation why studies on the effects of CYP2D6 polymorphisms on outcome in tamoxifen-treated breast cancer patients have been inconsistent.
It provides an additional explanation of why Apple should make a transition from iPod to an iPhone.
Nonetheless, biological processes that play a role in vivo may provide an additional explanation for why undersized stems are so successful, while in this study they were inferior to canal-filling stems.
This study reveals how biotic noise in the form of cicada choruses is a factor that likely shapes the frequency and timing of bird vocalizations in tropical forests and provides an additional explanation for why birds are most vocal early in the day.
Evolutionary science offers an additional explanation as to why women don't help other women.
The authors do provide evidence that each of the quantitative phenotypes chosen for study add information and that their screen and analytical methods capture previously established functional relationships, but additional explanation of why many of the seemingly esoteric measurements should be informative at a biological level is needed.
