Opinion: The strength of long-term comprehensive observations to meet multiple grand challenges in different environments and in the atmosphere - Kulmala, M.; Lintunen, A.; Lappalainen, H.; Virtanen, A.; Yan, C.; Ezhova, E.; Nieminen, T.; Riipinen, I.; Makkonen, R.; Tamminen, J.; Sundström, A.-M.; Arola, A.; et al. (Atmos. Chem. Phys., 2023)