What is air mass mP?

<p style=";text-align:left;direction:ltr">Arab Weather - The mP (Maritime Polar) air mass is a marine polar air mass that forms over cold marine areas, such as the North Atlantic or North Pacific Oceans. It is characterized by being cold and humid, and usually affects coastal areas where it causes a drop in temperatures and cloudy or rainy weather.</p><p style=";text-align:left;direction:ltr"> These masses affect areas near oceans and seas in particular in winter, bringing rain and cold.</p>