Acknowledging the support of NCAR and CISL computing when you publish research results helps ensure continued support from the National Science Foundation and other sources of funding for future high-performance computing systems. It is also one of the requirements of receiving an allocation, as was noted in your award letter.
The reporting requirements and recommended wording of acknowledgments can be found here on the Advanced Research Computing portal
. The content of citations and acknowledgments varies depending on the type of allocation that was awarded.