Which air mass is recognized for dry, cold characteristics over Canada?

The Continental Arctic air mass, classified as cA, is indeed recognized for its dry and cold characteristics, particularly over Canada. This air mass originates from the Arctic regions and typically forms during winter months when cold, dense air descends from higher latitudes. As it moves southward, it maintains its coldness due to its origin over ice and snow-covered areas. This results in lower humidity, making it relatively dry compared to other types of air masses.

In contrast, Maritime Tropical air masses are warm and humid, originating from tropical oceans, which do not fit the characteristics described in the question. The Maritime Polar air mass also carries cool and moist air from polar sea regions but is not primarily recognized for the very cold temperatures and dry conditions that the Continental Arctic provides. Lastly, the Continental Tropical air mass is warm and dry, typical of regions that experience high temperatures, such as deserts, and is not associated with cold conditions at all. Thus, the characteristics of being dry and cold are distinctly aligned with the Continental Arctic air mass.