| Name | Type | Country | Components |
|---|---|---|---|
| Pallas Atmosphere-Ecosystem Supersite | Observational platform | Finland | 4 |
| Payerne | Observational platform | Switzerland | 3 |
| Pyrenean Platform for Observation of the Atmosphere (P2OA) | Observational platform | France | 2 |
| Quartz Glass Reactor (QUAREC) | Atmospheric simulation chamber | Germany | 2 |
| Racibórz | Observational platform | Poland | 2 |
| RADO-Bucharest | Observational platform | Romania | 3 |
| RADO-Cluj | Observational platform | Romania | 2 |
| RADO-Galati | Observational platform | Romania | 1 |
| RADO-Iasi | Observational platform | Romania | 1 |
| Risoe Research Station | Observational platform | Denmark | 1 |
