Water Vapor And Weather Change

By Clinton N. Maxwell

In a very basic way, the water vapor that makes up clouds is a major catalyst of weather change. Though we may not be able to see it, water vapor is there, throughout the earth's atmosphere. Almost all of it comes from evaporating water rising from the oceans. Ocean water is heated by the sun and when the liquid is changed to the lighter form, gas, it rises. This evaporation is one of the keys to starting climate changes.

Scientists recognized three basic processes in which an air mass may rise. There is the process of convection, as simply described above. But this process can also happen above soil and pavement surfaces, which gather heat rapidly. Moisture from these surfaces can also rise into the atmosphere and eventually form clouds.

A second process that may cause an air mass to rise involves the collision of warm and cold fronts. Clouds can form if there is sufficient moisture in warm air that is forced over a cold front.
Air can also be lifted if it comes into contact with a large geographic feature such as a mountain range. Scientists term this type of rising air mass "orographic lifting." If the air contains enough water vapor, clouds form (often in unusual shapes).

It is widely understood that an air mass will continue to rise if it is warmer than the air that surrounds. Conditions are unstable if the air mass continues to rise. It is also true that cold air at higher levels, above warmer air, means unstable conditions. Stable conditions would generally exist if the opposite were true, warm over cold.

Since the atmosphere enveloping the earth can't hold an infinite amount of vapor, the air becomes saturated. At this time (called the dewpoint), the water vapor begins to condense, changing back to its original state, liquid. Overall air temperature has a significant effect on this process, since air that is warmer can hold more vapor.

Clouds are born when this condensation process occurs well above the ground. But there is another key to the "proper" formation of clouds through condensation. The surrounding air must be dirty, containing dust particles and pollutants that are suspended in the air. These small particles act as the core or nuclei for water molecules to cling to. (Many laymen consider fog to be completely different from clouds, but the major difference is the altitude at which the "cloud" forms. (The condensation process is the same.)

There is one more key element to the formation of various types of clouds and to the type of precipitation experience on the ground. Temperature changes have a major effect on how water vapor acts in the atmosphere as well. If the temperature at a higher level in the atmosphere is below the freezing point, vapor may turn to ice directly. It stands to reason that higher-level clouds generally contain ice crystals, while lower level cloud formation features droplets of water. A particular combination of any of these factors leads to weather conditions beneficial or harmful to life on earth.

Clinton Maxwell's reports can be encountered on different web pages linked to climate changes. His articles on alicante temperatures can be found on http://www.alicante-spain.com in addition to many different web publications.

Article Source: http://EzineArticles.com/?expert=Clinton_N._Maxwell

Weather Systems - Precipitation In The Making

By Vince L. Paxton

For those who study weather on a daily basis, movement of air masses is at the heart of most changes in weather conditions. These huge areas of warm air or cold air (weather fronts) move up or down in the atmosphere, as well as horizontally, sometimes covering hundreds of miles in a short time. The sun does not heat the atmosphere on a consistent basis. Variations in temperature occur, depending on the location. The large masses of air move about, part of nature's attempt to maintain balance.

But it is not just the movement of a single air mass that is key in determining the type of weather we experience. Instead, the confrontation between two masses of air often cause significant changes in conditions. A mass of air moving into a particular region will encounter another mass. The area where these two air masses meet, where the conflict occurs, is commonly called a front.

For general weather watching purposes, when a cold air mass moves in and attempts to replace a warmer mass, meteorologists and weather watchers call it a cold front. When the moving air mass is warm and it meets a cold air mass, the area of contact is called a warm front.

However, movement of these huge areas of air is not limited to straight-line, horizontal activity.
A warm mass encountering a colder section of air will ride over the top of the cooler mass, causing clouds to be formed through condensation. Essentially, the difference in temperature between the two air masses triggers a reaction in the water vapor of the masses. Most of the time, an observer of this activity will see cirrus clouds high in the atmosphere, with clouds forming at a slightly lower level later. Heavy stratus clouds appear, generally producing precipitation and windy conditions.

Over long periods of time, there is some consistent frontal activity, which produces the various climate conditions found around the world. Scientists have learned that weather changes produced by a cold front will often be more volatile than the activity caused by a warmer mass of air. A cold front meeting a warm air mass forces the warmer up, quickly. This movement results in unstable conditions and convection. Massive cumulus clouds will result, with storms forming along the boundary between the two masses of air. In addition, the rising air produces a low-pressure area, with stronger winds resulting. Most of the time area residents will experience heavy rain. Precipitation tends to linger after the passage of this frontal activity.

Less common but still of interest is the overtaking of a slow-moving warm front by a cold air mass. The warm air is pushed to a higher elevation but the air masses continue to travel together. This front between two air masses, one above another, is known as an occluded front, which usually have stratus clouds and some rain as companions.

While displacement of one air mass by another is quite common, sometimes these two sections of the atmosphere have the same strength. When one cannot replace the other, meteorologists and weather watchers see a stationary front. Extended periods of cloudiness and precipitation are the features of this unique climate condition

Being passionate about climate and weather fronts, Vince Paxton is publishing lots of web pages on this specific topic. His publications on weather forecast for benidorm spain can be discovered on http://www.alicante-spain.com/benidorm-weather.html

Article Source: http://EzineArticles.com/?expert=Vince_L._Paxton

A Look at Punta Cana Weather

By Jennifer Bailey

The weather in the Dominican Republic remains tropical year-round with the temperatures averaging around 25°C (77°F). The summer and winter seasons differ by only a slight variation in temperature. Visitors coming to the Dominican Republic, practically any time of the year can expect to be treated with extended periods of blue sunny skies -- ideal weather for getting a nice tan.

The best time to visit Punta Cana is during the "cool" season from November to April. During these months, the weather is pleasantly warm with relatively low levels of humidity and low precipitation. Temperatures along the coast are constant around 29°C (84°F) during the day and drop to a comfortable 20°C (68°F) at night.

The "hot" season runs roughly from May to October when the average temperature rises to 31°C (87°F) during the daytime and drops to about 22°C (72°F) at night. But with the high humidity levels during this season, the temperature feels much hotter. Rains do bring some respite from the heat during May through August, but usually this turns out to be no more than a 30-minute tropical shower. It is advised that travelers pack light and include a lot of cool and light fitting cotton clothing.

Despite such minimal difference between the temperatures in summer and winter, the climate tends to vary a lot from year to year due to the influence of the weather phenomena known as "El Niño" and "La Niña" among others. The greatest threat to the Dominican Republic comes from hurricanes. The Caribbean hurricane season lasts from June 1 to November 30. August and September are the more hurricane-prone months. The major resorts have become adept at getting back on their feet quickly after a hurricane.

As in most tropical areas, in Punta Cana too the menace of mosquitoes looms large. The mosquitoes usually appear after dusk but they are seasonal and more noticeable in the rainy season. Visitors are advised to wear long, comfortable cotton pants after dusk and use insect repellent sprays before venturing outside.

Punta Cana Info provides detailed information about Punta Cana resorts, hotels, real estate, beaches, weather, and the Punta Cana airport. Punta Cana Info is the sister site of Cozumel Web.