The sun, originally, but the sun actually heats the earth, and warm air rises from the surface of the earth and is trapped by greenhouse gases in the atmosphere. This is mostly how the air gets warm.
The air you breathe needs to be warmed to match the body’s internal temperature, which is around 98.6°F (37°C). This is important for efficient gas exchange in the lungs, as cooler air can cause discomfort and reduce the effectiveness of oxygen absorption. Additionally, warming the air helps to protect the delicate tissues of the respiratory system from cold air, which can lead to irritation and increased susceptibility to infections.
In additional to radiating heat into the room many gas fireplaces have a heat exchanger- cool air is drawn into the shell around the firebox, and warmed air comes out of the vents at the top.
A parcel of air is uplifted when it initially gains heat from the surface causing convective uplift.When the air is warmed by the surface it will expand and become less dense relative to air that surrounds it. - See more at: http://www.chacha.com/question/can-you-briefly-describe-how-convective-uplift-occurs#sthash.JinBHwPh.dpuf
It is warmed by geothermal energy which is created by RADIOACTIVE DECAY http://en.wikipedia.org/wiki/Geothermal_(geology)
Convectional rainfall occurs as a result of one of the three mechanisms that produce rain. When a fluid, such as air, is warmed from the bottom, for instance by earth warmed by sunlight, the lighter air rises drawing cooler air in underneath it. This sets up a so-called convectional flow. If the air near the ground is moist then when the it rises it will form clouds whose droplets coalesce to form convectional rain.
Inhaled air is warmed and moistened in the nasopharynx and oropharynx.
in the night
warms the air
When you exhale, the air has been warmed by your body during the breathing process. As you breathe in air, it first enters your nasal cavity, where it is humidified and warmed to body temperature. This warmed air then moves to your lungs for gas exchange, and when you exhale, that warmth is transferred to the exhaled air.
what happens to air when it touches the warmed air
When air is warmed, it expands and becomes less dense, causing it to rise. As it rises, it creates lower pressure at the surface. This is because there are fewer air molecules pressing down on a given area as the warmed air moves away.
Warm front
Air gets warmed and cleaned as it passes through the nasal cavity, where it is humidified, filtered, and warmed by the mucus and tiny hairs called cilia. Additionally, the air is further warmed and cleaned in the trachea and bronchi by the same mechanisms of mucus and cilia before reaching the lungs.
in the esophagus.___.
whay is it
air is filtered, warmed, and moistened.
warmed, moistened and cleaned by the nose and mouth