In your template.css file you can look for the below:
#s5_top_row1_wrap, #s5_top_row2_wrap, #s5_top_row3_wrap, #s5_above_columns_inner, #s5_component_wrap {
padding-bottom: 100px;
padding-top: 100px;
}
and change to:
#s5_top_row2_wrap, #s5_top_row3_wrap, #s5_above_columns_inner, #s5_component_wrap {
padding-bottom: 100px;
padding-top: 100px;
}
to reduce the spacing