One group of students did an experiment to study the movement of ocean water. The steps of the experiment are listed below. Fill a rectangular baking glass dish with water. Place a lighted lamp near the left edge of the dish. Place a plastic bag with ice in the water near the right edge of the dish. Put a few drops of ink in the water. Observe the ink flow from the side where the lamp is placed towards the side where the ice bag is placed. What does the students' experiment most likely demonstrate?