Local Winds and Fronts

The distinction between the cooling and heating of earth surfaces and their daily or annual cycles can produce a variety of local, regional, and expected winds.

Land and Sea Breezes

• Through the day, the earth heats up much faster than the sea and gets warmer. As a result, the air rises above the land, creating a low-pressure area, while the water remains comparatively calm, and the pressure over the sea is comparatively high, causing the wind to flow from the sea to the land. This wind is called sea breeze
• The reversal of state occurs during the night. The land tends to lose heat more quickly and is much more relaxed than the sea. The force gradient is from land to sea, resulting in a land wind. This wind is called land breeze

Mountain and Valley Winds: 

• During the day, the slopes of hilly regions heat up, causing air to travel upslope, and to fill the ensuing gap, air from the valley winds up the valley. This wind is called the valley breeze
• The slopes cool down at night, and dense air flows into the valley as the mountain wind
• The katabatic wind is the chilly air that descends from the high plateaus and ice fields into the valley
• On the leeward side of the mountain ranges, another type of warm breeze blows
• While crossing mountain ranges, the moisture in these winds condenses and precipitates
• The dry air is warmed up by the adiabatic process as it descends the leeward side of the slope. The snow may melt quickly due to the dry air

Air Masses

• When air remains in a homogeneous area for a long enough period, it takes on the properties of that area. The enormous ocean surface or vast plains might be homogeneous zones
• An air mass is a type of air that has specific temperature and humidity properties. It is characterized as a vast mass of air with slight horizontal temperature and moisture change
• The source regions are the homogeneous surfaces over which air masses develop
• The source regions are used to classify the air masses
• Tropical and subtropical oceans are warm
• The scorching deserts of the subtropics
• The oceans at high latitudes are relatively cold
• The continents in high latitudes are blanketed in snow and are extremely cold
• The Arctic and Antarctica are permanently ice-covered continents

As a result, the following air masses have been identified: 

• Maritime tropical
• Continental tropical 
• Maritime polar 
• Continental arctic 
• Continental polar 
• Air masses in the tropics are warm, whereas air masses in the poles are cool

Fronts

• The boundary area between two separate air masses is referred to as a front
• The creation of these fronts is referred to as frontogenesis
• We know four different kinds of fronts
• The cold front is formed when cold air flows towards a warm air mass and makes contact
• Warm Front: When a warm air mass flows towards a cold air mass, the contact zone is a warm front
• When the front is motionless, it is referred to as a stationary front
• The occluded front is formed when an air mass is elevated above the earth’s surface
• The fronts occur in the middle latitudes and are marked by a steep temperature and pressure gradient
• They generate dramatic temperature changes and make the air rise, forming clouds and precipitation