Land And Sea Breezes

air circulation along coasts during summer, developed when the overall pressure gradient is at its lowest. During the day, the Sun warms the land more than the adjacent sea and so the air above the land becomes warmer and thus rises. This produces a convective motion with the cooler air for the sea moving onto the land. At night the situation is reversed because the sea is warmer than the land.

Taken from Dictionary of Science

¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤

A sea-breeze (or onshore breeze) is a wind from the sea that develops over land near coasts. It is formed by increasing temperature differences between the land and water which create a pressure minimum over the land due to its relative warmth and forces higher pressure, cooler air from the sea to move inland. Generally, air temperature gets cooler relative to nearby locations as one moves closer to a large body of water.

At night, the land cools off quicker than the ocean due to differences in their specific heat values, which forces the dying of the daytime sea breeze. If the land cools below that of the adjacent sea surface temperature, the pressure over the water will be lower than that of the land, setting up a land breeze as long as the environmental surface wind pattern is not strong enough to oppose it. If there is sufficient moisture and instability available, the land breeze can cause showers or even thunderstorms, over the water. Overnight thunderstorm development offshore due to the land breeze can be a good predictor for the activity on land the following day, as long as there are no expected changes to the weather pattern over the following 12–24 hours. This is mainly because the strength of the land breeze is weaker than the sea breeze. The land breeze will die once the land warms up again the next morning.

Taken from Wikipedia

Nadir

the lowest point -- the pole which is vertically below the observer in the CELESTIAL SPHERE. It is opposite to the ZENITH.

Taken from Dictionary of Science

________

The nadir (from Arabic نظير nathir, "opposite") is the direction pointing directly below a particular location; that is, it is one of two vertical directions at the location, orthogonal to a horizontal flat surface there. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related sciences (e.g., meteorology), the nadir at a given point is the local vertical direction pointing in the direction of the force of gravity at that location. The direction opposite of the nadir is the zenith.

Nadir also refers to the downward-facing viewing geometry of an orbiting satellite, such as is employed during remote sensing of the atmosphere, as well as when an astronaut faces the Earth while performing an EVA.

The word is also used figuratively to mean the lowest point of a person's spirits.

The term nadir can also be used to represent the lowest point reached by a celestial body during its apparent orbit around a given point of observation. This can be used to describe the location of the Sun, but it is only technically accurate for one latitude at a time and only possible at the low latitudes. The sun is said to be at the nadir at a location when it is at the zenith at the location's antipode.

Taken from Wikipedia