Category Environtal Studies

What conditions could help more parts of Earth host life?

Researchers find out an often overlooked key role played by the orbit of Jupiter on Earth.

Most planets have eccentric orbits. While circular orbits around a star would ensure that the distance between the star and the planet never changes, these eccentric orbits mean that the planets traverse around a star in an oval-shape. As a result, the planet would receive more heat when it goes closer to the star, affecting the planet’s climate.

Alternative solar system

Based on this knowledge and using detailed data from the solar system as we know it today, researchers from the University of California Riverside created an alternative solar system. In this hypothetical theoretical system, they were able to show that if Jupiter’s orbit were to become more eccentric, then it would lead to big changes in Earth’s orbit, thereby making the Earth more hospitable than it is currently.

This is because Jupiter in this theoretical system would push Earth’s orbit to be even more eccentric. As a result, parts of Earth would sometimes get closer to the sun. This would mean that even parts of Earth’s surface that are now sub-freezing will get warmer. In effect, the habitable range on the surface of the Earth would be increased.

Assumptions proven wrong

 The findings of this research, published in September in Astronomical Journal, go against two long-held scientific beliefs with respect to our solar system. One of these is that the current avatar of Earth is the best in terms of habitability. The second one is that changes to Jupiter’s orbit could only be bad for Earth.

Apart from upending these long-held assumptions, the researchers are looking to apply their findings in the search of exoplanets – habitable planets around other stars. While existing telescopes are adept at measuring a planet’s orbit, the same cannot be said about measuring a planet’s tilt towards or away from a star- another factor that could affect habitability.

The model developed in this research helps us better understand the impact of the biggest planet in our solar system, Jupiter, on Earth’s climate through time. Additionally, it also paves the way to find out how the movement of a giant planet is crucial in making predictions about habitability of planets in other systems.

Picture Credit : Google 

What is a heat dome?

Europe recently experienced an intense heatwave resulting in record temperatures owing to the creation of a heat dome. But what is a heat dome? Come, let’s find out.

A high-pressure system hovering in the atmosphere over Europe trapped the heat in a phenomenon called “heat dome”. This weather phenomenon begins when there is a strong change in ocean temperatures.

Imagine a overhead water tank in summer. As the heat rises, the water in the tank turns warm but the moisture and steam cannot escape due to the tank lid. Similarly, a heat dome occurs when the atmosphere traps a mass of hot ocean air like a lid or cap over an area in dry summer conditions.

When this hot air attempts to escape, the high pressure in the atmosphere pushes it down. Under the dome, the air unable to escape sinks and compresses, releasing even more heat. Besides, it also blocks other weather systems from moving in. This leads to an increase in temperatures at ground level. So people, crops, and other living beings under it suffer terribly.

According to scientists, heat domes are linked to the behaviour of the jet stream, a band of strong winds high in the atmosphere that generally runs from west to east. “Normally, the jet stream has a wavelike pattern, meandering north and then south and then north again. When these meanders in the jet stream become bigger, they move slower and can become stationary. That’s when heat domes can occur.”

This dome of hot air can stretch over vast regions and last for days together, leading to extreme temperatures and the formation of a relentless heatwave. The hotter the temperature the stronger the heat dome gets.

This stagnant weather pattern usually leads to weak winds and a rise in humidity. Heat domes can badly affect us, raising the risk of heat illnesses and deaths as people would not be able to cool down properly.

Picture Credit : Google 

WHAT BRINGS ABOUT THE END OF AN ICE AGE?

The rotation and revolution of Earth, the amount of solar radiation and the amount of carbon dioxide in the atmosphere are all factors that contribute to a warming up of Earth, which ends an ice age. Changes in ocean currents also have a major effect on temperatures on Earth.

Over thousands of years, the amount of sunshine reaching Earth changes by quite a lot, particularly in the northern latitudes, the area near and around the North Pole. When less sunlight reaches the northern latitudes, temperatures drop and more water freezes into ice, starting an ice age. When more sunlight reaches the northern latitudes, temperatures rise, ice sheets melt, and the ice age ends.

Credit: American Museum of Natural History

Picture credit: Google

WHAT ARE THE LARGEST BODIES OF ICE IN THE WORLD?

In today’s world, the ice sheets of Antarctica and Greenland. An ice sheet is a continuous mass of ice covering more than 50,000 km2. The ice sheet in Antarctica covers 14 million km2. It is 1.6 to 6.4 km thick and holds 30 million km2 of ice. The Greenland ice sheet covers about 1.7 million km2.

The Antarctic ice sheet is the largest block of ice on Earth. It covers more than 14 million square kilometers (5.4 million square miles) and contains about 30 million cubic kilometers (7.2 million cubic miles) of water.

The Antarctic ice sheet is about 2 kilometers (1.2 miles) thick. If it melted, sea level would rise by about 60 meters (200 feet).

The Greenland ice sheet is much smaller than the Antarctic Ice sheet, only about 1.7 million square kilometers (656,000 square miles). It is still the second-largest body of ice on the planet.

The Greenland ice sheet interacts much more dynamically with the ocean than the Antarctic ice sheet. The annual snow accumulation rate is more than double that of Antarctica. Glacial melt happens across about half of the Greenland ice sheet, whereas it is much more isolated on the far western part of Antarctica. Greenland’s ice shelves break up much faster than those surrounding Antarctica.

Both the Antarctic and Greenland ice sheets have caused the land under them to sink. Eastern Antarctica is about 2.5 kilometers (1.6 miles) below sea level because of the colossal weight of the ice sheet above it.

Credit: National Geographic

Picture credit: Google

IS ANTARCTICA A DESERT?

A desert is defined by the amount of precipitation (rain, snow, mist and fog) in an area. A region that receives very little precipitation is classified as a desert. There are many types of deserts, including subtropical, coastal and polar deserts. What they all have in common is a barren, windswept landscape, which makes it difficult for plants and animals alike to gain a foothold on land. This all certainly applies to Antarctica.

The average yearly rainfall at the South Pole over the past 30 years was a tiny 10 mm (0.4 in). Most of the continent is covered by ice fields carved by the wind, and craggy mountains covered in glaciers. While Antarctica is home to wonderful forests of low-lying mosses and lichens, there are only two flowering plants that can survive the harsh conditions. And most of the animals we encounter – penguins, seals, whales and seabirds – rely on seafood for sustenance.

Credit: aurora expeditions

 

Picture Credit: Google

HOW OLD IS GLACIER ICE?

  • The age of the oldest glacier ice in Antarctica may approach 1,000,000 years old
  • The age of the oldest glacier ice in Greenland is more than 100,000 years old
  • The age of the oldest Alaskan glacier ice ever recovered (from a basin between Mt. Bona and Mt. Churchill) is about 30,000 years old.

Glacier flow moves newly formed ice through the entire length of a typical Alaskan valley glacier in 100 years or less. Based on flow rates, it takes less than 400 years for ice to transit the entire 140 + mile length of Bering Glacier, Alaska’s largest and longest glacier.

Picture credit: Google