Within the occlusion of the front , a circulation of air brings warm air upward .
Within the occlusion of the front , a circulation of air sends drafts of cold air downward , or vice versa depending on the occlusion the front is experiencing .
Within the occlusion of the front , a circulation of air brings warm air upward and sends drafts of cold air downward , or vice versa depending on the occlusion the front is experiencing .