What are the climate characteristics of American states?

The topographic structure of North America is characterized by three north-south longitudinal zones, which is of great significance to the differentiation of continental climate. The most significant influence is the Cordillera mountain system in the west, which consists of triple mountains and a series of mountain plateaus and basins. It is not only quite high, but also very wide, and the coastal areas lack bays that go deep into the mainland. Therefore, on the one hand, the Cordillera mountain system has become an important obstacle to the eastward invasion of the polar Pacific air mass, limiting the mild and humid maritime climate to the west coast north of 40 north latitude, and the intermountain plateau and intermountain basin in the leeward position become semi-arid and arid climate; On the other hand, the polar Canadian air mass and the tropical Gulf of Mexico and Atlantic air mass can only move in the central and eastern parts of the mainland because the Cordillera Mountains cannot invade the west. The Rocky Mountain in the east of Cordillera Mountains is also an important climate dividing line between the east and the west of the mainland, which not only leads to a great difference in precipitation between the east and the west, but also has a certain impact on the temperature. Generally speaking, the annual precipitation in the western part of the Rocky Mountain is below 500 mm, with little rain or drought in summer, and the temperature in winter is higher than that in the eastern part of the same latitude, except for the coastal areas and windward slopes north of 40 north latitude. Except for the northern part of high latitude and parts of the great plains near the Rocky Mountains, the annual precipitation in the east of the Rocky Mountains is above 500 mm, and the proportion of precipitation in summer increases. The climate data of Spokane and Montreal can illustrate this problem. Of course, this difference is also related to factors such as atmospheric circulation and ocean currents.

To the east of the Rocky Mountain is the central plain, which is low and flat, and there is no east-west mountain barrier. It is open to the north and south, and the Hudson Bay, the Great Lakes, the Mississippi River system and the Gulf of Mexico are interconnected. Such terrain conditions are conducive to the smooth movement of air masses with different properties in the north and south. In winter, the dry and cold polar Canadian air mass can go straight to the south, resulting in cold wave weather and a sudden drop in local temperature; In summer, the warm and humid air masses in the tropical Gulf of Mexico and the Atlantic Ocean can freely go north to the coast of Hudson Bay, bringing sultry and rainy weather. The Central Plains has become a place where cold and warm air masses meet and compete with each other, and cyclone activities are frequent, especially in winter. Therefore, the weather in the central plain is changeable, which is the area with the biggest seasonal variation of temperature and precipitation in North America and strong mainland.

The Appalachian mountains in the east are not high or wide, and the continuity of the mountains is poor, which does not constitute a significant boundary in climate, but it still has a great impact on climate in some areas. For example, on the northwest slope of the Appalachian Mountains, the polar Canadian air mass passes through the Great Lakes region, which is slightly denatured in winter and often forms heavy snow; Due to the high altitude, the tropical Gulf of Mexico and Atlantic air mass swelled in the south of the mountain, forming topographic precipitation, with annual precipitation exceeding 65,438+500mm, making it one of the rainy areas in North America.

[Problem solving process]

The basic characteristics of the climate in North America are:

First of all, temperate continental climate is dominant. North America has a wide latitude extension, but most of it is located in the north temperate zone; At the same time, the topographical structure is characterized by three longitudinal zones, and the western mountains and eastern highlands, especially the tall Cordillera Mountains, run through the north and south, forming an important obstacle to the operation of marine air masses. Therefore, the climate in North America mainly belongs to temperate zone and sub-frigid zone, especially the continental climate in sub-frigid zone is dominant. The general feature of continental climate here is cold winter, with the lowest average temperature of 1 month. Summer is warm and hot, and July is the hottest month. The annual temperature is relatively high; The annual precipitation is moderate, mainly in summer rain. However, compared with the more continental Asia, the temperate continental climate of this continent is far less extreme than that of Asia. The annual temperature is not as high as that in Asia at the same latitude, and the concentration of rain in summer and drought in winter are not as good as that in Asia.

The second is the diversity of climate types. There are many types of climate in North America, from tropical to cold zone, which are also prominent on all continents. But North America has its own characteristics, such as the distribution of polar ice sheet climate is wider than that of Asia; The west coast of Asia lacks temperate maritime climate, while the east coast of North America

It does not have the typical monsoon climate like the east coast of Asia, but is replaced by temperate continental humid climate and subtropical humid climate; In addition, this continent has no equatorial rainforest climate, tropical marine climate and tropical dry and wet season climate, and the distribution of tropical arid and semi-arid climate types is not as extensive as that of Asia.

Third, the climate type and structure are unique. Various climate types in North America also have their own characteristics in distribution and arrangement. First of all, the three distribution types in the northern part of the continent, namely, the polar ice sheet climate, the polar long cold climate and the continental climate in the sub-frigid zone, are all arranged in the north and south, and they extend from east to west in addition to the polar ice sheet climate, which is basically similar to the situation in the northern part of Eurasia and has obvious zonal structural characteristics. Since then, the east and the west have compared the distribution and arrangement patterns of climate types: roughly east of west longitude 100, from north to south, it is temperate continental humid climate and subtropical humid climate in turn. Generally speaking, they also alternate from north to south and extend from east to west, which basically embodies the zonal structural characteristics. To the west of west longitude 100, including the great plains and Cordillera mountain area, the drought intensified from east to west due to the deep inland, and the climate type was arranged in the east-west direction, extending from north to south, showing the characteristics of non-zonal zonal structure. On the west coast of the mainland, the order of climate types is temperate maritime climate, subtropical summer arid climate, tropical arid climate and semi-arid climate. Although they alternate regularly from north to south, they all extend from north to south. Therefore, this is a comprehensive embodiment of banded and non-banded structural characteristics.