Meteorology

• Meteorology is the study of atmospheric phenomena and how these are influenced by climate and weather elements like temperature, humidity, air pressure, wind, rainfall, and cloudiness
• The application of meteorology to Fisheries, known as Fisheries Meteorology, is crucial as fisheries are more affected by weather and climate than any other form of food production like agriculture
• Fisheries meteorology examines the effects of weather elements on fish and fishing, including how surface weather elements like wind, waves, and thermal boundaries influence fish availability and distribution
• Weather elements also impact the safety and comfort of fishermen, with larger vessels able to operate in stronger winds compared to smaller ones, affecting fishing operations and landings of fish
• Long-term changes in fisheries are influenced by climate, affecting catch and landings, species dominance, distribution, and total fin fish biomass
• Fluctuations in fish stock abundance can be caused by climatic changes, which in turn are influenced by changes in wind-driven currents that transport larvae and pelagic juveniles, impacting recruitment and stock abundance
• The circulation of the ocean depends mainly on two atmospheric factors: wind and ocean heating, with interactions between the atmosphere and the ocean producing wind-driven and thermohaline circulations
• Heat balance on Earth refers to the balance of incoming and outgoing heat, where the incoming heat must equal the outgoing heat to maintain constant conditions
• Heat absorbed by the land and oceans is exchanged with the atmosphere through conduction, radiation, and latent heat (phase change)
• Of all solar energy reaching Earth, about 30% is reflected back into space, 23% is absorbed by the atmosphere, and just under half (47%) is absorbed by the land and ocean, heating up the Earth's surface
• The greenhouse effect intensifies climate change by trapping longwave, infrared radiation in the atmosphere, heating it up due to greenhouse gases like CO2, methane, and water vapor
• Differential heating of Earth's surface is caused by the curvature of Earth, angle of sunlight, and albedo, resulting in tropics receiving more intense sunlight and heating per unit area than the poles
• Conduction is the transfer of heat through direct contact between the surface and the atmosphere, where heat is transferred from the air to the surface or ground during evening or vice versa during the day, mainly generated by sunlight through radiation
• Conduction is important in heating the lower layers of the atmosphere, with the effect of conduction on air temperature being only a few centimeters in the atmosphere
• Convection is the process where air in contact with the earth rises vertically on heating in the form of currents, further transmitting the heat of the atmosphere, and is confined only to the troposphere
• Advection, the horizontal movement of air, is relatively more important than vertical movement, causing most diurnal (day and night) variations in daily weather in middle latitudes
• In tropical regions like northern India during the summer season, local winds called 'loo' are the outcome of the advection process
• Archimedes' principle states that any body completely or partially submerged in a fluid at rest is acted upon by an upward or buoyant force equal to the weight of the fluid displaced by the body
• The volume of displaced fluid is equivalent to the volume of an object fully submerged in a liquid, and the weight of the displaced portion of the fluid is equivalent to the magnitude of the buoyant force
• The buoyant force on a floating body is equivalent in magnitude to the weight of the floating object and is opposite in direction, resulting in the object neither rising nor sinking
• The application of Archimedes Principle to air movement is seen when there is a pressure gradient or difference in air (or atmosphere) caused by temperature difference, leading to air movement or wind
• Cool air, being denser than warm air, moves downward due to gravitational force, while warm air moves in the opposite direction, creating air disturbance and movements
• If air movements occur at the surface of water (sea or ocean), currents may develop into strong waves
• The major patterns in atmospheric circulation around the tropics are the result of convection, where areas around the equator receive more sunlight than higher latitudes, leading to the rising of warm air and sinking of cool air, creating wind over the Earth's surface
• Coriolis force is an apparent force caused by Earth's rotation, acting on rotating objects, determined by the mass of the object and its rate of rotation, perpendicular to the object's axis
• Coriolis force acts in a north-south direction due to Earth's west to east spin, strongest near the poles and absent at the Equator
• The Coriolis effect is the deflection in the direction of a moving body caused by Coriolis force, deflection is right in the northern hemisphere and left in the southern hemisphere
• The Coriolis effect influences large-scale weather patterns, air currents, and oceanic motion like ocean circulation and upwelling
• Coriolis force influences oceanic motion by causing phenomena like upwelling, which transports nutrients from the bottom to the surface of the water, essential for marine food production and fishing profitability
• In the atmosphere, the Coriolis effect impacts weather patterns like cyclones and trade winds, with cyclones rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere
• The Coriolis effect influences the movement of air currents, like trade winds, where warm air currents are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
• The Coriolis effect impacts human activities such as aviation, where pilots must consider prevailing winds influenced by the Coriolis effect when charting flight paths over long distances