Air pressure decreases at a rate of 1 pascals per kilometer in the eastward direction. In addition, the air pressure is decreasing at a constant rate with respect to time everywhere. A ship sailing eastward at 12 km/hour past an island takes barometer readings and records a pressure drop of 30 pascals in 2 hours. Estimate the time rate of change of air pressure on the island. (A pascal is a unit of air pressure.)

Time rate of change of air pressure =
(include units)