So it’s already impressive that Clarke has radioed Bellamy for 2,199 days straight, BUT...
Look at the last shot of communication we get between Clarke and her friends before it cuts to the time jump:
The screen goes dark before it’s ever confirmed that the signal was sent. Clarke has no idea if it went through. She has no idea if there will be power on the Ark when her friends get up there. She has no idea if Raven will be able to get the hangar door open. When Praimfaya hits, Clarke has no idea if her mission was successful.
After the time jump, Clarke can’t get through on the radio. If that’s true, then communication between the ship and Becca’s lab probably isn’t happening either, so there’s no way she would have confirmation that the Ark has power. We hear Clarke say, “Bellamy, if you can hear me, if you’re alive…” Clarke isn’t saying ‘if you’re still alive.’ She’s saying, ‘if you’re alive, if you even made it up there to begin with.’
She doesn’t even know if they even made it to the Ark. She has no idea if he’s alive or if he’s been dead for 6 years. But every day she goes to that same spot and tries like hell to talk to him.
Clarke has been radioing Bellamy for 2,199 days without even knowing if they got on the Ark.