1. the sun is at an altitude of 30° to the horizontal. what is the corresponding air mass?

Maritime tropical and continental tropical as they develop over the lower latitudes.

Explanation:

When the sun rays lie on in the place of 30-degree latitude in both the hemisphere the air mass acquires the characteristics of both maritime and continental. As the continental air masses are dry in nature and hence cover mostly the continental parts of the country as compared to the wet maritime air masses. These continental air masses are hot and humid nature and travel polewards. Normally monsoonal air masses reside over the ocean is and thus are cools and thus form what is called the trade winds. Other known popular places that produce these air masses are the Arabian peninsula and western landmasses. Sometimes their modification leads to the front formation and cyclone formations.