Why did the Greek fleet withdraw from Artemisium?

During the Greco-Persian Wars, the Greek fleet at Artemisium held its position against the Persian navy for three days of fighting. However, the fleet withdrew southward after receiving news of the Greek defeat at the Battle of Thermopylae.12

At Thermopylae, the Greek land forces, led by the Spartan king Leonidas, were outflanked after a betrayal allowed the Persian army to bypass their defensive position. Once the land defense at the pass was compromised, the strategic necessity of holding the straits at Artemisium was lost, prompting the Greek naval retreat.21