Question

The alignment of the moon, the sun and earth to cause a spring tide

Answer 1

Spring tides occur when the Earth, sun and moon are aligned. Despite its name spring tides have nothing to do with the Spring season. It was derived from the concept of "springing-forth" . They occur at twice each lunar month, bringing higher tides during high tide and lower tides during low tide. 

Answer 2

When the sun, moon, and Earth are in alignment (at the time of the new or fullmoon), the solar tide has an additive effect on the lunar tide, creating extra-high hightides, and very low, low tides — both commonly called spring tides.