The 'Specific Heat' of a substance refers to:
- The energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius.
- The temperature at which a substance melts.
- The radiation emitted by a black body.
- The heat released during condensation.
Explanation: Water's high specific heat (about 5 times that of rock/soil) is why it takes much longer to heat up and cool down.
Consider the following statements regarding the 'Atmospheric Window':
1. It refers to the range of wavelengths where the atmosphere is transparent to terrestrial radiation.
2. It allows some heat to escape directly into space.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: The 'Atmospheric Window' (primarily between 8 and 11 micrometers) is the part of the infrared spectrum where gases like water vapour and CO2 do not absorb radiation, allowing it to bypass the greenhouse effect.
Which of the following describes 'Global Dimming'?
- The reduction in the amount of global direct irradiance at the Earth's surface due to aerosols.
- The loss of atmosphere due to solar winds.
- The shadow cast by the moon during an eclipse.
- The slow cooling of the sun's core.
Explanation: Increased aerosols (pollution/volcanoes) reflect more sunlight back to space, reducing the insolation reaching the ground.
Consider the following statements regarding the 'Angle of Inclination':
1. A smaller angle of inclination means the sun's rays cover a larger area.
2. The intensity of energy per unit area decreases as the angle of inclination decreases.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Near the poles, the angle is small (slanted rays). The same amount of energy is spread over a larger area, and the rays must pass through more of the atmosphere, leading to more scattering and absorption.
Which of the following describes the 'Global Heat Transfer'?
- Surplus heat from the tropics is moved to the poles by winds and ocean currents.
- Heat is transferred from the poles to the equator by cold currents.
- Heat is transferred vertically from the stratosphere to the troposphere.
- The heat budget remains balanced separately for each latitude.
Explanation: There is a surplus of heat between 35°N and 35°S and a deficit at higher latitudes. The Earth's planetary winds and ocean currents act as a transfer mechanism to prevent the tropics from overheating and poles from over-freezing.
How does cloud cover affect the daily range of temperature?
- It increases the range by making days hotter.
- It has no effect on the temperature range.
- It decreases the range by making days cooler and nights warmer.
- It makes the night much colder by absorbing heat.
Explanation: Clouds reflect incoming solar radiation during the day (cooling) and trap outgoing terrestrial radiation at night (warming), thus reducing the overall range between day and night temperatures.
Which of the following regions would expect to have the highest annual range of temperature?
- Tropical Islands
- Interior of Large Continents
- Equatorial Rainforests
- Coastal Cities
Explanation: The 'continentality' effect means land far from the sea heats up intensely in summer and cools rapidly in winter. Coastal and island areas are moderated by the sea's high specific heat.
With reference to the 'Aspect of Slope' in insolation, consider the following:
1. In the Northern Hemisphere, south-facing slopes receive more direct sunlight than north-facing slopes.
2. This phenomenon affects the types of vegetation and local climate.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: In the Northern Hemisphere, the sun is to the south for most of the year. South-facing slopes are 'sunny' (adret) and north-facing are 'shady' (ubac). This creates different micro-climates.
Why is the variation in insolation less at the Equator than at the Poles?
- The rotation speed is highest at the equator.
- The sun's rays are always near-vertical at the equator.
- The duration of day and night is nearly equal throughout the year at the equator.
- The thick cloud cover at the equator blocks solar radiation.
Explanation: The angle of inclination determines the area over which energy is spread. At the equator, rays are almost vertical year-round, leading to high, consistent intensity. At poles, the angle is low and varies greatly with seasons.
Regarding the 'Atmospheric Heat Balance', what is the total units lost to space?
- 100 units
- 35 units
- 65 units
- 14 units
Explanation: To maintain a constant temperature, the Earth must lose exactly what it receives. 35 are reflected immediately, and 65 are radiated back (17 from Earth directly + 48 from the atmosphere), totaling 100.
Consider the following statements:
1. Isotherms are more regular and straight in the Southern Hemisphere than in the Northern Hemisphere.
2. This is due to the vast expanse of water in the Southern Hemisphere.
Which of the statements given above is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: In the Southern Hemisphere, the lack of large landmasses means there is less differential heating, resulting in isotherms that follow the latitudes very closely.
Consider the following pairs regarding the Heat Budget (units remaining 65):
1. Absorbed by the atmosphere: 14 units
2. Absorbed directly by the Earth's surface: 51 units
3. Radiated from Earth directly to space: 17 units
Which of the pairs given above are correctly matched?
- 1 and 3 only
- 1 and 2 only
- 2 and 3 only
- 1, 2 and 3
Explanation: Out of the 65 units that aren't reflected, 14 are absorbed by the atmosphere and 51 by the Earth. Of that 51, 17 units are radiated directly to space, and 34 are absorbed by the atmosphere through conduction, convection, and radiation.
With reference to 'Insolation', consider the following statements:
1. The Earth receives its energy in short-wave electromagnetic radiation.
2. The amount of insolation received at the surface is constant across all latitudes.
3. The solar constant is measured at the top of the atmosphere.
Which of the statements given above are correct?
- 1 and 2 only
- 1 and 3 only
- 1, 2 and 3
- 2 and 3 only
Explanation: Statement 2 is incorrect because insolation varies significantly with latitude due to the angle of inclination of the sun's rays. Statement 1 is correct (short-wave) and Statement 3 is the definition of the solar constant (~1.94 calories per sq. cm per minute).
Consider the following statements about 'Equinoxes':
1. They occur on March 21st and September 23rd.
2. The sun is directly overhead at the Equator.
3. Both poles are equidistant from the sun.
Which of the statements given above are correct?
- 2 and 3 only
- 1, 2 and 3
- 1 and 3 only
- 1 and 2 only
Explanation: During equinoxes, the Earth's tilt is not toward or away from the sun, resulting in equal day and night lengths globally.
Which of the following correctly describes the 'Atmospheric Absorption' of radiation?
- The atmosphere does not absorb any incoming radiation.
- The atmosphere absorbs 35% of incoming solar radiation.
- The atmosphere absorbs 51% of incoming solar radiation.
- The atmosphere absorbs 14% of incoming solar radiation primarily via water vapor and oxygen.
Explanation: According to the standard heat budget, 14 units (out of 100) are absorbed directly by the atmosphere as the solar rays pass through.
Which of the following surfaces would reflect the least amount of solar radiation?
- A calm, deep ocean
- A sandy desert
- A concrete road
- A dense coniferous forest
Explanation: Water has one of the lowest albedos (roughly 2-10% depending on the sun's angle), meaning it absorbs almost all the radiation that hits it.
With reference to 'Conduction', which of the following is true?
- It is the most important method of heating the upper atmosphere.
- Air is a very good conductor of heat.
- It occurs only when two bodies of unequal temperature are in contact.
- It is responsible for the horizontal movement of heat (Advection).
Explanation: Conduction is the transfer of heat through molecular activity. Since air is a poor conductor, this process only heats the few centimeters of air directly touching the Earth's surface.
Which of the following surfaces has an albedo of approximately 20-30%?
- Asphalt
- Grasslands and crops
- Fresh Snow
- Deep Oceans
Explanation: Grasslands typically fall in the 20-30% range. Snow is 80%+, Oceans are <10%, and Asphalt is 5-10%.
Regarding 'Short-wave' vs 'Long-wave' radiation, which is true?
- Earth emits shorter waves than the Sun.
- The hotter the body, the longer the wavelength.
- Wavelength is independent of temperature.
- The hotter the body, the shorter the wavelength.
Explanation: According to Wien's Displacement Law, the peak wavelength of radiation is inversely proportional to temperature. The Sun (6000K) emits short waves; Earth (288K) emits long waves.
The 'Solar Solstice' on December 22nd means:
- The sun is farthest from the Earth.
- The sun is directly overhead at the Tropic of Cancer.
- The sun is directly overhead at the Equator.
- The sun is directly overhead at the Tropic of Capricorn.
Explanation: On December 22nd (Winter Solstice in the North), the Southern Hemisphere is tilted towards the sun, and it is directly overhead at 23.5°S.
What is 'Sensible Heat' in the context of the atmosphere?
- Heat used to change the state of water without changing temperature.
- Heat trapped by the ozone layer.
- Energy emitted by the sun as ultraviolet rays.
- Heat that can be measured by a thermometer.
Explanation: Sensible heat is the energy involved in changing the temperature of a substance (like air or soil) without a phase change. Heat involved in phase changes (evaporation/melting) is Latent Heat.
Consider the following statements about 'Albedo':
1. It is higher over water surfaces than over land surfaces.
2. It increases with the decrease in the angle of the sun's rays.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Statement 1 is incorrect; land generally has higher albedo than water (unless the water is frozen). Statement 2 is correct; when the sun is low on the horizon, more light is reflected off surfaces (like a mirror) rather than absorbed.
In the heat budget, 'Latent Heat' transfer accounts for how many units out of the 100 arriving at the top of the atmosphere?
- 9 units
- 19 units
- 27 units
- 14 units
Explanation: Of the 51 units that reach the Earth's surface, 19 are returned to the atmosphere as latent heat of evaporation.
Which of the following is a result of 'Valley Inversion'?
- Formation of frost in the valley floor while slopes remain warm.
- Intense thunderstorms at the peak of the mountain.
- The melting of glaciers.
- Complete lack of wind in the entire region.
Explanation: On winter nights, cold dense air from the slopes flows down (katabatic winds) and settles in the valley, creating an inversion where the valley floor is colder than the air above.
At which time of the day is the insolation generally the highest?
- Sunrise
- Noon
- 2 PM to 4 PM
- Sunset
Explanation: Insolation (incoming radiation) is highest at noon when the sun is at the highest angle. However, the maximum *temperature* occurs around 2-4 PM due to the lag in terrestrial radiation heating the air.
Which of the following describes the 'Diffuse Blue Sky' radiation?
- Long-wave radiation emitted by the Earth's crust.
- Short-wave radiation scattered by gas molecules and dust in the atmosphere.
- The reflection of light from the moon's surface.
- Direct solar radiation reaching the Earth without interruption.
Explanation: Scattering by molecules smaller than the wavelength of light (Rayleigh scattering) sends blue light in all directions, making the sky appear blue.
What is 'Anomalous Temperature'?
- A temperature reading that is incorrect due to instrument error.
- The temperature at the core of a hurricane.
- The temperature recorded at the top of the atmosphere.
- The difference between the actual temperature and the average temperature for that latitude.
Explanation: Temperature anomalies help show how much warmer or cooler a specific place (like a coastal city) is compared to the global average for its latitude.
Regarding the heating and cooling of the atmosphere, consider the following processes:
1. Conduction: Transfer of heat through molecular contact in the lower layers.
2. Convection: Vertical heating of the atmosphere by rising air currents.
3. Advection: Transfer of heat through horizontal movement of air.
Which of the statements given above are correct?
- 1 and 2 only
- 1 and 3 only
- 1, 2 and 3
- 2 and 3 only
Explanation: All three are primary mechanisms. Conduction is only effective in the bottom-most layer. Convection is vital for cloud formation. Advection is responsible for 'Loo' in northern India and the transport of heat from tropics to poles.
Consider the following statements:
Statement I: The Earth's Heat Budget is a dynamic balance.
Statement II: Small changes in the composition of the atmosphere can disrupt this balance.
Which one of the following is correct in respect of the above statements?
- Statement I is incorrect but Statement II is correct.
- Statement I is correct but Statement II is incorrect.
- Both Statement I and Statement II are correct and Statement II is the correct explanation for Statement I.
- Both Statement I and Statement II are correct and Statement II is not the correct explanation for Statement I.
Explanation: While both are true, Statement II describes the vulnerability of the system (Climate Change), whereas Statement I describes the general physical state of the planet.
Consider the following statements regarding 'Radiation Surplus':
1. It is found in the region between 40°N and 40°S.
2. It drives the general circulation of the atmosphere and oceans.
Which of the statements given above is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: The surplus in the tropics and deficit at the poles creates a temperature gradient that forces heat to move poleward via winds and currents.
Consider the following statements regarding 'Aphelion' and 'Perihelion':
1. During Aphelion, the Earth is farthest from the sun.
2. During Perihelion, the Earth receives more solar energy than at Aphelion.
3. Perihelion occurs annually on July 4th.
Which of the statements given above is/are correct?
- 1, 2 and 3
- 1 and 2 only
- 1 only
- 2 and 3 only
Explanation: Statement 3 is incorrect. Perihelion (nearest to the sun) occurs around January 3rd, while Aphelion (farthest) occurs around July 4th. Because of the proximity, Earth receives roughly 7% more energy at Perihelion.
Consider the following statements regarding the 'Net Radiation' of Earth:
1. Below 35 degrees latitude, there is a net radiation surplus.
2. Above 35 degrees latitude, there is a net radiation deficit.
3. The Earth as a whole has a net radiation of zero over long periods.
Which of the statements given above are correct?
- 1, 2 and 3
- 1 and 3 only
- 1 and 2 only
- 2 and 3 only
Explanation: All are correct. The Earth is in a state of thermal equilibrium (Heat Budget). The imbalance at specific latitudes drives the global atmospheric and oceanic circulation.
Regarding the 'Scattering' of light, which of the following is correct?
- It only happens in the ionosphere.
- It increases the amount of direct insolation reaching the ground.
- It occurs when solar radiation is absorbed by water vapour.
- It is responsible for the blue color of the sky.
Explanation: Dust and gas molecules scatter shorter wavelengths (blue) more than longer ones. At sunrise/sunset, the light travels through more atmosphere, scattering everything but red/orange.
Consider the following statements about 'Terrestrial Radiation':
1. The Earth's surface re-emits energy in the form of long-wave radiation.
2. Long-wave radiation is largely absorbed by atmospheric gases like CO2 and water vapour.
3. The atmosphere is heated more by incoming solar radiation than by terrestrial radiation.
Which of the statements given above is/are correct?
- 1 only
- 1 and 2 only
- 1, 2 and 3
- 2 and 3 only
Explanation: Statement 3 is incorrect. The atmosphere is largely transparent to short-wave (incoming) radiation but opaque to long-wave (outgoing) radiation. Therefore, the atmosphere is heated from below by the Earth.
Regarding the 'Diurnal Range of Temperature', which of the following is true?
- It is highest in the equatorial regions.
- It is lower in the center of continents than on the coast.
- It is highest in hot deserts.
- It is zero at the poles.
Explanation: Deserts have clear skies and dry air, allowing intense heating during the day and rapid cooling (loss of terrestrial radiation) at night.
Which of the following processes accounts for the largest portion of heat transferred from the Earth's surface to the atmosphere?
- Latent Heat of Condensation
- Direct Terrestrial Radiation
- Conduction
- Sensible Heat (Convection)
Explanation: Out of the 34 units absorbed by the atmosphere from the Earth, 19 units are transferred through latent heat (evaporation), making it the most significant heat transfer mechanism.
Which of the following is NOT a greenhouse gas that contributes to the trapping of terrestrial radiation?
- Nitrous Oxide
- Chlorofluorocarbons
- Methane
- Argon
Explanation: Argon is an inert, noble gas and does not absorb long-wave radiation. Methane, Nitrous Oxide, and CFCs are all potent greenhouse gases.
In the Heat Budget, how many units of energy are absorbed by the atmosphere from 'Sensible Heat' (thermals/convection)?
- 9 units
- 6 units
- 19 units
- 35 units
Explanation: Of the 34 units absorbed by the atmosphere from the Earth: 19 come from latent heat, 9 from sensible heat (convection), and 6 from terrestrial radiation.
The term 'Isotherm' refers to a line on a map connecting places with equal:
- Temperature
- Albedo
- Pressure
- Insolation
Explanation: Isotherms are used to show temperature distribution. They generally run parallel to the equator but bend over land and sea due to differential heating.
Which of the following factors causes the isotherms to bend toward the equator over the oceans in the Northern Hemisphere during winter?
- The presence of warm ocean currents.
- Oceans are warmer than the continents during winter.
- The ocean has a higher albedo than land.
- Oceans are cooler than the continents during winter.
Explanation: In winter, land cools faster than water. Oceans remain relatively warm, so a specific temperature (isotherm) will be found at a higher latitude over the sea than over the cold land.
Consider the following statements regarding 'Inversion of Temperature':
1. It is a condition where temperature increases with increasing altitude.
2. It commonly occurs on clear, calm winter nights.
3. It is a permanent feature of the equatorial troposphere.
Which of the statements given above is/are correct?
- 2 and 3 only
- 1, 2 and 3
- 1 only
- 1 and 2 only
Explanation: Statement 3 is incorrect. Inversion is usually a temporary phenomenon. It is common in valleys during winter or during the passage of a cold front, but not a standard feature of the equatorial troposphere.
In the context of the Earth's Heat Budget, if 100 units of energy reach the top of the atmosphere, how many units are reflected back to space as 'Albedo' before reaching the surface?
- 50 units
- 35 units
- 15 units
- 65 units
Explanation: Out of 100 units, 27 are reflected from clouds, 2 from snow/ice, and 6 from space scattering, totaling 35 units. This is the Earth's Albedo.
What happens to 'Relative Humidity' when the air temperature increases without any addition of water vapor?
- It becomes zero.
- It decreases.
- It increases.
- It remains the same.
Explanation: Warm air has a higher capacity to hold water vapor. If the actual amount of vapor stays the same while the capacity increases, the percentage (relative humidity) drops.
What is the result of 'Advection' in the context of the Indian subcontinent?
- Formation of dew on winter mornings.
- Development of the 'Loo' winds in summer.
- The absorption of UV rays by the ozone layer.
- The cooling of the air by 6.5 degrees per kilometer.
Explanation: Advection is the horizontal transfer of heat. The 'Loo' is a hot, dry wind in North India caused by the horizontal movement of heated air masses from the west.
Which of the following is the 'Source' of terrestrial radiation?
- The Stars
- The Clouds
- The Sun
- The Earth's surface
Explanation: Terrestrial radiation is the infrared energy emitted by the Earth after it has been heated by solar insolation.
Consider the following statements regarding the 'Latent Heat of Evaporation' in the heat budget:
1. It represents the energy used to turn water into vapor at the surface.
2. This energy is released into the atmosphere when water vapor condenses into clouds.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Evaporation 'hides' heat in the water vapor (latent heat). When that vapor rises and condenses, the heat is released, warming the surrounding air and driving atmospheric circulation.
With reference to the 'Lag of Temperature', consider the following statements:
1. The maximum temperature of the day occurs exactly at the moment of maximum insolation.
2. The warmest month in the Northern Hemisphere is usually July, even though the summer solstice is in June.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Statement 1 is incorrect because there is a lag between maximum insolation (noon) and maximum temperature (2-4 PM) as the ground continues to heat the air. Statement 2 is correct as it takes time for the land and oceans to reach their peak thermal storage.
Consider the following statements:
1. The duration of the day is 12 hours everywhere on Earth during the Equinoxes.
2. The longest day in the Southern Hemisphere occurs on June 21st.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Statement 2 is incorrect. June 21st is the Summer Solstice in the Northern Hemisphere (longest day) and the Winter Solstice in the Southern Hemisphere (shortest day).
Which of the following atmospheric constituents has the greatest impact on the absorption of short-wave solar radiation?
- Carbon Dioxide
- Ozone
- Nitrogen
- Argon
Explanation: Ozone in the stratosphere absorbs ultraviolet radiation (short-wave). Most other gases are transparent to short-wave radiation and only absorb long-wave radiation.
Which of the following is true during a 'Temperature Inversion'?
- The air is very unstable, leading to thunderstorms.
- The air is very stable, trapping smoke and pollutants near the ground.
- Wind speeds are extremely high.
- Rainfall is very heavy.
Explanation: In an inversion, warm air lies over cold air. Since cold air is denser, it doesn't rise, preventing vertical mixing and trapping smog/fog (common in cities like Delhi in winter).
Which of the following describes the 'Lapse Rate'?
- The rate of ozone depletion.
- The vertical temperature gradient in the troposphere.
- The increase in pressure with depth in the ocean.
- The speed at which a river flows downhill.
Explanation: The normal lapse rate is roughly 6.5°C/km, indicating how air cools as you move further from the Earth's surface.
With reference to the Earth's atmosphere, 'Counter-radiation' refers to:
- Solar radiation reflected by the moon.
- Radiation emitted by the Earth directly to space through the atmospheric window.
- Terrestrial radiation absorbed and re-radiated back to Earth by the atmosphere.
- The magnetic field blocking solar flares.
Explanation: This is a key part of the greenhouse effect—the atmosphere radiates heat back toward the surface, keeping it warmer than it would be otherwise.
Consider the following statements about the 'Greenhouse Effect':
1. It is a natural process that maintains Earth's average temperature at 15°C.
2. Without it, the Earth's average temperature would be around -18°C.
3. It is caused by gases that are transparent to long-wave radiation.
Which of the statements given above is/are correct?
- 2 and 3 only
- 1 and 2 only
- 1 only
- 1, 2 and 3
Explanation: Statement 3 is incorrect. Greenhouse gases are opaque (absorb) long-wave radiation (terrestrial) and transparent to short-wave radiation (solar).
Which of the following factors influence the intensity of insolation at any given point on Earth?
1. Rotation of Earth on its axis.
2. Angle of inclination of the sun's rays.
3. Transparency of the atmosphere.
4. Configuration of land in terms of its aspect.
Select the correct answer using the code given below:
- 1 and 2 only
- 1, 3 and 4 only
- 1, 2, 3 and 4
- 2, 3 and 4 only
Explanation: All four factors influence insolation. Rotation affects the duration of day, angle determines the concentration of energy, transparency (clouds/dust) affects transmission, and aspect (direction of slope) determines exposure.
Regarding 'Differential Heating' of Land and Water, which of the following statements is correct?
- The specific heat of land is higher than that of water.
- Water is a better conductor of heat than land.
- Oceans are more transparent, allowing heat to concentrate only on the surface.
- Land heats and cools faster than water.
Explanation: Water has a higher specific heat (needs more energy to raise temp), it mixes (convection), and it is transparent (energy spreads deep). Land is opaque and has low specific heat, causing rapid temperature changes.
In the Southern Hemisphere, which month would typically show the highest deficit in the heat budget for the mid-latitudes?
- September
- January
- July
- March
Explanation: July is the winter season in the Southern Hemisphere, characterized by the lowest angle of the sun and the shortest days, leading to a significant radiation deficit.
Regarding the distribution of insolation, why do subtropical deserts receive more insolation than the equatorial regions?
- Deserts have a higher albedo.
- They are closer to the sun.
- They have less cloud cover compared to the equatorial regions.
- The sun is never directly overhead at the equator.
Explanation: While the equator has the highest potential insolation, its frequent cloudiness reflects much of it. Subtropical high-pressure belts have clear skies, allowing more direct radiation to reach the surface.
The 'Heat Island' effect is primarily associated with:
- Tropical regions near the equator.
- The center of the Earth's core.
- Volcanic islands in the Pacific.
- Urban areas being warmer than surrounding rural areas.
Explanation: Urban heat islands are caused by low albedo (asphalt), high thermal mass (concrete), and waste heat from human activity (ACs, cars).
Consider the following statements:
1. The Solstice occurs when the sun reaches its maximum or minimum declination.
2. The Arctic Circle experiences 24 hours of daylight during the June Solstice.
Which of the statements given above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: During the June solstice, the North Pole is tilted toward the sun, so everything from the Arctic Circle (66.5°N) to the pole stays in the sun for the full rotation.
With reference to the 'Albedo' of the Earth, which of the following has the highest value?
- Ocean Water
- Dry Sand
- Tropical Rainforest
- Fresh Snow
Explanation: Albedo is the percentage of solar radiation reflected. Fresh snow reflects 70-90% of radiation, whereas oceans and forests have very low albedo (high absorption).