If Heat Rises, How Come Snow Accumulates On Mountains Why Is It Colder Up There ((HOT))
Thinking about the beauty of the mountains got us to thinking about why some of them have snow at the top (called a snowcap) and others don't. Since the top of a mountain is closer to the Sun, shouldn't it be warmer up there? And doesn't heat rise? So why is there snow?
If heat rises, how come snow accumulates on mountains Why is it colder up there…
Clouds are formed when air contains as much water vapor (gas) as it can hold. This is called the saturation point, and it can be reached in two ways. First, moisture accumulates until it reaches the maximum amount the volume of air can hold. The other method reduces the temperature of the moisture filled air, which in turn lowers the amount of moisture it can contain. Saturation, therefore, is reached through evaporation and condensation, respectively. When saturation occurs, moisture becomes visible water droplets in the form of fog and clouds.
It should be noted that condensation by itself does not cause precipitation (rain, snow, sleet, hail). The moisture in clouds must become heavy enough to succumb to gravity and return to earth's surface. This occurs through two processes. In cold clouds ice crystals and water droplets exist side by side. Due to an imbalance of water vapor pressure, the water droplets transfer to the ice crystals. The crystals eventually grow heavy enough to fall to earth. In the second process, water droplets in warm clouds collide and change their electric charge. Droplets of unlike charge attract one another and merge, thereby growing until they have sufficient weight to fall.
Even when it is very warm and sunny, there might not be any clouds and the sky is a clear blue. The usual reason for the absence of clouds will be the type of pressure, with the area being under the influence of a high pressure or anticyclone. Air would be sinking slowly, rather than rising and cooling. As the air sinks into the lower part of the atmosphere, the pressure rises, it becomes compressed and warms up, so that no condensation takes place. In simple terms, there are no mechanisms for clouds to form under these pressure conditions.
The snow surface temperature is controlled by the air temperature above. The colder the air above, the colder the snow layers near the surface will be, especially within the top 30 to 45 centimeters (12 to 18 inches). Snow near the ground in deeper snowpack is warmer because it is close to the warm ground. The ground is relatively warm because the heat stored in the ground over the summer is slow to dissipate. In addition, snow is a good insulator, similar to the insulation in the ceiling of a house, and thus slows the flow of heat from the warm ground to the cold air above.
Storms moving from the north usually carry little moisture. The frequency of such storms increases during the fall and winter months, and decreases rapidly in the spring. The accompanying outbreaks of polar air are responsible for the sudden drops in temperature often experienced in the plains sections of the State. Occasionally these outbreaks are attended by strong northerly winds which come in contact with moist air from the south; the interaction of these air masses can cause a heavy fall of snow and the most severe of all weather conditions of the high plains, the blizzard. This cold air is frequently too shallow to cross the mountains to the western portion of the State so while the plains are in the grip of a very severe storm, the weather in the mountains and western valleys may be mild.
A spring flood potential results from the melting of the snow pack at the higher elevations. In a year of near-normal snow accumulations in the mountains and normal spring temperatures, river stages become high, but there is no general flooding. In years when snow cover is heavy, or when there is widespread lower elevation snow accumulation and a sudden warming in the spring, there may be extensive flooding.
Winds carry moist air over the land. When air reaches the mountain, it rises because the mountains are in the way. As the air rises, it cools, and because cool air can carry less moisture than warm air, there is usually precipitation (rain).
No, the climate on a mountain varies depending on what altitude (how high) you are up a mountain. At the foothills (near the bottom) there may be a tropical climate, whilst the peaks (the very top of mountains) may be covered in ice. The uppermost level of mountains is often bare rock and snow. Tibet and the Himalayas and other mountain ranges such as the Rocky Mountains or the Andes are good examples of this.
You can often see snow on the top of mountains all year round, because the temperature at the top of mountains is lower than at the bottom. The higher the place is above sea level the colder it will be.
Generally the climate on mountains get progressively colder with increased altitude (the higher up you go). This happens because as altitude increases, air becomes thinner and is less able to absorb and retain heat. The cooler the temperature the less evaporation there is, meaning that there is more moisture in the air.
The snowpack is the snow that accumulates in mountains during winter and provides fresh water to the valleys below as it melts in spring and summer. It is an important contributor to many rivers, and impacts river flow and water availability for agriculture, particularly in regions, such as California, where precipitation is concentrated in winter.
First, as average temperatures during autumn, winter, and spring become warmer, the likelihood that storms will occur while temperatures are above freezing increases, leading to an increase in the amount of precipitation that falls as rain instead of snow. Second, as spring temperatures increase, spring melt occurs earlier in the year. Despite increased temperature, increased precipitation may result in substantial increases of snow at very high elevations, where precipitation was less abundant in the past, but future temperatures are projected to be rarely above freezing. At colder locations where temperature is consistently below freezing (usually at higher elevations or in the interior), increased future precipitation could result in increased snowpack.
During the coldest months, a loss of heat by radiation at night and moist air crossing the Cascades and mixing with the colder air in the inland basin results in cloudiness, for and occasional freezing drizzle. A "chinook" wind which produces a rapid rise in temperature occurs a few times each winter. Frost penetration in the soil depends to some extent on the vegetative cover, snow cover and the duration of low temperatures. In an average winter, frost in the soil can be expected to reach a depth of 10 to 20 inches. During a few of the colder winters with little or now snow cover, frost has reached a depth of 25 to 35 inches.
This area includes fruit producing valleys along the Okanogan, Methow and Columbia Rivers, grazing land along the southern Okanogan highlands, the Waterville Plateau and part of the channeled scablands. The elevation varies from approximately 1,000 feet in the lower river valleys to 3,000 feet over the Waterville Plateau and Okanogan highlands. North-south ranges of mountains extending into southern British Columbia reach elevations of 4,000 to 5,000 feet within a few miles of the Okanogan River. The annual precipitation increases from 11 inches in the valley to 16 inches over some of the Plateau. Winter season snowfall varies from 30 to 70 inches. Both rainfall and snowfall increase in the higher elevations. Snow can be expected after the first of November and to remain on the ground from the first of December until March or April. Snow accumulates to a depth of 10 to 20 inches in the valleys and over the Waterville Plateau, increasing to 40 inches in the higher grazing areas.
Cold continental air moving southward through Canada will occasionally cross the higher mountains and follow the north-south valleys into the Columbia Basin. On clear, calm winter nights, the loss of heat by radiation from over a snow cover produces ideal conditions for low temperatures. The lowest temperature in the state, -48 F, was recorded December 30, 1965, at Mazama and Winthrop. In January, the average maximum temperature is near 30 F and the minimum temperature is 15 F. Minimum temperatures from -10 to -20F are recorded almost every winter and temperatures ranging from -25 to -42 F have been recorded in the colder valleys. In July, the average maximum temperature is 85 to 90 and the minimum temperature 45 to 50 F. Maximum temperatures reach 100 F on a few afternoons each summer and temperatures between 105 to 110 F have been recorded. The record high temperature of 118 F was recorded at Ice Harbor Dam on August 5, 1961. Temperatures in the mountains decrease three to five degrees Fahrenheit with each 1,000 feet increase in elevation. The average date of the last freezing temperatures can be expected in the colder valleys by the first of September and before mid-October in the warmer areas.
Tourist business and recreational activities are rapidly becoming an important source of income. The climate, mountains, ocean beaches, lakes, rivers, national parks and forest areas permit a vast range of recreational activities. In the mountains the ski season begins in November and continues until late spring. The season for camping, hiking and fishing in the higher mountain lakes and streams begins as the snow melts and continues until early fall.
In the fall hunters flock to the mountains seeking their limit of deer, elk, and other game, while those looking for birds scatter over the lowlands. In summer the numerous lakes and warm sunny days east of the Cascades are inviting to many, while to others the cooler marine air and ocean beaches in western Washington are a welcome relief from summer heat in other sections of the county.
Snow is not necessarily colder in deeper spots. The temperature at the surface of the snow is controlled by the air temperature. The colder the air above the colder will be the snow layers near the surface, say within the top 12 to 18 inches. The snow near the ground in deeper snowpacks however is warmer because it is close to the warm ground. The ground is warm because the heat stored in the ground over the summer is slow to leave the ground because snow is a good "insulator," just like the insulation in the ceiling of your house, and thus slows the flow of heat from the warm ground to the cold air above.