My Science School

Mawsynram is a town in the East Khasi Hills district of Meghalaya state in Northeastern India, 60.9 kilometres from Shillong, the state capital. Mawsynram receives the highest rainfall in India. It is reportedly the wettest place on Earth, with an average annual rainfall of 11,872 millimetres (467.4 in), According to the Guinness Book of World Records, Mawsynram received 26,000 millimetres (1,000 in) of rainfall in 1985. Mawsynram received 745.2 mm of rainfall on 19 August 2015, probably the highest rainfall received by the town in recent times.] On June 17th 2022, Mawsynram set a new record by receiving 1003.6 mm in a span of 24 hours which has now become its highest single day record for the month of June and for its all time single day record beating its former record of 944.7 mm on June 7th 1966. 

Mawsynram is located at 25° 18? N, 91° 35? E, at an altitude of about 1,400 metres (4,600 ft), 15 km west of Cherrapunji, in the Khasi Hills in the state of Meghalaya (India). Under the Köppen climate classification, Mawsynram features a subtropical highland climate (Cwb) with an extraordinarily showery, rainy and long monsoonal season and a short dry season. Based on the data of a recent few decades, it appears to be the wettest place in the world, or the place with the highest average annual rainfall. Mawsynram receives over 10,000 millimeters of rain in an average year, and the vast majority of the rain it gets falls during the monsoon months. A comparison of rainfalls for Cherrapunji and Mawsynram for some years is given in Table 1. Mawsynram receives the highest rainfall in India. Although it is reportedly the wettest place on Earth, with an average annual rainfall of 11,872 millimetres (467.4 in), this claim is disputed by Lloró, Colombia, which reported an average yearly rainfall of 12,717 millimetres (500.7 in) between 1952 and 1989 and López de Micay, also in Colombia, which reported 12,892 mm (507.6 in) per year between 1960 and 2012. According to the records observed by the Indian Meterological Department, it was seen that while its neighbour, Cherrapunji is having a significant decreasing trend in rainfall, Mawsynram on the other hand is experiencing a slight increase in its rainfall pattern which put its average annual rainfall from 1950 to 2000 at 12393 mm and from 2000 to 2020 at 12120 mm. The precipitation table below shows the average monthly record from 1950-2000.

Credit : Wikipedia 

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An area of land that is either covered by water or saturated with water, wetlands are those areas where water covers the soil. While most scientists consider swamps, bogs, and marshes to be the three main kinds of wetlands, there are other types like peatlands, sloughs, and mires as well. Even though wetlands were seen as wastelands for most of history as they don't support development, it has since been realised that these are among the most valuable ecosystems on Earth. Governments began recognising the value of wetlands from the 1970s and laws have been put in place in parts of the world to protect wetlands.

Categories of Wetlands

Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands.

Coastal/Tidal Wetlands

Coastal/tidal wetlands in the United States, as their name suggests, are found along the Atlantic, Pacific, Alaskan and Gulf coasts. They are closely linked to our nation's estuaries where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends.

Inland/Non-tidal Wetlands

Inland/non-tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins and "potholes"), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Certain types of inland wetlands are common to particular regions of the country. 

Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year -- such as vernal pools-- often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

Credit : EPA 

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The tundra refers to a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen. Tundra ecosystems are also found on the mountaintops here, where the climate is cold and windy, and rainfall is scant. These lands are covered with snow for much of the year, which melts during the summer. Yet it hosts a few species of wildlife acclimatised to harsh conditions. As the tundra faces the threat of global warming, so do its inhabitants.

Plants and Animals in Tundras:

Mountain goats, sheep, marmots, and birds live in mountain—or alpine—tundra and feed on the low-lying plants and insects. Hardy flora like cushion plants survive in the mountain zones by growing in rock depressions, where it is warmer and they are sheltered from the wind.

The Arctic tundra, where the average temperature is -34 to -6 degrees Celsius (-30 to 20 degrees Fahrenheit), supports a variety of animal species, including Arctic foxes (Vulpes lagopus), polar bears (Ursus maritimus), gray wolves (Canis lupus), caribou (Rangifer tarandus), snow geese (Anser caerulescens), and musk oxen (Ovibos moschatus). The summer growing season is just 50 to 60 days, when the sun shines up to 24 hours a day.

The relatively few species of plants and animals that live in the harsh conditions of the tundra are essentially clinging to life. They are highly vulnerable to environmental stresses like reduced snow cover and warmer temperatures brought on by global warming.

Climate Change Impact on Tundras

The Arctic tundra is changing dramatically due to global warming, a term that falls within a wider range of trends scientists now prefer to call climate change. The impacts in this region are broad and somewhat unpredictable. Animals that are typically found farther south, like the red fox (Vulpes vulpes), are moving north onto the tundra. This means the red fox is now competing with the Arctic fox for food and territory, and the long-term impact on the sensitive Arctic fox is unknown.

Other tundra denizens, such as the wolf spider (Lycosidae spp.), are growing bigger and thriving. Shrubs are getting taller, contributing to declines in the sensitive groups of lichen that caribou and other species depend on for food. Lakes and ponds are evaporating or draining away.

Ctedit : National geographic society 

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Soil degradation refers to the decline of soil quality due to its improper use, usually for agriculture, industry, and urban activity. Degraded soil can have lower amount of fertility and organic matter, and be high in salinity, acidity, and toxicity. Since soil is inevitable for all life forms on our planet, the continuous decline in soil quality can have disastrous results such as desertification, flooding, landslides, loss of wildlife, etc.

Various Causes of Soil Degradation

1. Physical Factors

There are several physical factors contributing to soil degradation distinguished by the manners in which they change the natural composition and structure of the soil. Rainfall, surface runoff, floods, wind erosion, tillage, and mass movements result in the loss of fertile top spoil thereby declining soil quality.

2. Biological Factors

Biological factors refer to the human and plant activities that tend to reduce the quality of the soil. Some bacteria and fungi overgrowth in an area can highly impact the microbial activity of the soil through biochemical reactions, which reduces crop yield and the suitability of soil productivity capacity.

Human activities such as poor farming practices may also deplete soil nutrients thus diminishing soil fertility. The biological factors affect mainly lessens the microbial activity of the soil.

3. Chemical Factors

The reduction of soil nutrients because of alkalinity or acidity or waterlogging are all categorized under the chemical components of soil degradation. In the broadest sense, it comprises alterations in the soil’s chemical property that determine nutrient availability.

4. Deforestation

Deforestation causes soil degradation on the account of exposing soil minerals by removing trees and crop cover, which support the availability of humus and litter layers on the surface of the soil.

5. Misuse or excess use of fertilizers

The excessive use and the misuse of pesticides and chemical fertilizers kill organisms that assist in binding the soil together. Most agricultural practices involving the use of fertilizers and pesticides often entail misuse or excessive application, thereby contributing to the killing of soil’s beneficial bacteria and other micro-organisms that help in soil formation.

6. Industrial and Mining activities

Soil is chiefly polluted by industrial and mining activities. As an example, mining destroys crop cover and releases a myriad of toxic chemicals such as mercury into the soil thereby poisoning it and rendering it unproductive for any other purpose.

7. Improper cultivation practices

There are certain agricultural practices that are environmentally unsustainable and at the same time, they are the single biggest contributor to the worldwide increase in soil quality decline. The tillage on agricultural lands is one of the main factors since it breaks up the soil into finer particles, which increase erosion rates.

8. Urbanization

Urbanization has major implications on the soil degradation process. Foremost of all, it denudates the soil’s vegetation cover, compacts soil during construction, and alters the drainage pattern.

9. Overgrazing

The rates of soil erosion and the loss of soil nutrients, as well as the topsoil, are highly contributed by overgrazing. Overgrazing destroys surface crop cover and breaks down soil particles, increasing the rates of soil erosion. As a result, soil quality and agricultural productivity are greatly affected.

Fatal Effects of Soil Degradation

1. Land degradation

Soil quality decline is one of the main causes of land degradation and is considered to be responsible for 84% of the ever-diminishing acreage. Year after year, huge acres of land lost due to soil erosion, contamination, and pollution.

2. Drought and aridity

Drought and aridity are problems highly influenced and amplified by soil degradation. As much as it’s a concern associated with natural environments in arid and semi-arid areas, the UN recognizes the fact that drought and aridity are anthropogenic induced factors especially as an outcome of soil degradation.

3. Loss of arable land

Because soil degradation contributes to land degradation, it also means that it creates a significant loss of arable land. As stated earlier, about 40% of the world’s agricultural land is lost on the account of soil quality depreciation caused by agrochemicals and soil erosion.

4. Increased flooding

The land is commonly altered from its natural landscape when it rids its physical composition from soil degradation. For this reason, the transformed land is unable to soak up water, making flooding more frequent.

5. Pollution and clogging of waterways

Most of the soil eroded from the land together with the chemical fertilizers and pesticides utilized in agricultural fields are discharged into waterways and streams. With time, the sedimentation process can clog waterways, resulting in water scarcity.

SOLUTIONS : There are many solutions to soil degradation, which include: practicing responsible farming techniques, active forestation, as well as preventing soil erosion and pollution. In addition, soil degradation can be avoided through responsible developments in urban and residential environments.

Permafrost is permanently frozen ground comprising soil, rocks, and sand, and often spans the Arctic regions. Found both on land and below the ocean floor, it covers vast expanses, and is a habitat for several animals and plants. Melting permafrost is a concern because it releases vast amounts of trapped greenhouse gases into the atmosphere.

What is Permafrost Made Of?

Permafrost is made of a combination of soil, rocks and sand that are held together by ice. The soil and ice in permafrost stay frozen all year long.

Near the surface, permafrost soils also contain large quantities of organic carbon—a material leftover from dead plants that couldn’t decompose, or rot away, due to the cold. Lower permafrost layers contain soils made mostly of minerals.

A layer of soil on top of permafrost does not stay frozen all year. This layer, called the active layer, thaws during the warm summer months and freezes again in the fall. In colder regions, the ground rarely thaws—even in the summer. There, the active layer is very thin—only 4 to 6 inches (10 to 15 centimeters). In warmer permafrost regions, the active layer can be several meters thick.

How Does Climate Change Affect Permafrost?

As Earth’s climate warms, the permafrost is thawing. That means the ice inside the permafrost melts, leaving behind water and soil.

Thawing permafrost can have dramatic impacts on our planet and the things living on it. For example:

1. Many northern villages are built on permafrost. When permafrost is frozen, it’s harder than concrete. However, thawing permafrost can destroy houses, roads and other infrastructure.
2. When permafrost is frozen, plant material in the soil—called organic carbon—can’t decompose, or rot away. As permafrost thaws, microbes begin decomposing this material. This process releases greenhouse gases like carbon dioxide and methane to the atmosphere.
3. When permafrost thaws, so do ancient bacteria and viruses in the ice and soil. These newly-unfrozen microbes could make humans and animals very sick. Scientists have discovered microbes more than 400,000 years old in thawed permafrost.
4. Because of these dangers, scientists are closely monitoring Earth’s permafrost. Scientists use satellite observations from space to look at large regions of permafrost that would be difficult to study from the ground.

Credit : Climate kids

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La Nina is a climatic pattern that refers to the cooling of the ocean surfaces along the tropical west coast of South America. During this weather pattern, warm ocean water and clouds move westwards increasing the chances of places like Indonesia and Australia getting much more rain than usual. These fluctuations tend to leave the regions of southwestern U.S. extremely dry.

The most severe La Nina occurrence in recent history was the 1988-89 event, which led to a seven-year drought in California. La Niña is a complex weather pattern that occurs every few years, as a result of variations in ocean temperatures in the equatorial band of the Pacific Ocean, The phenomenon occurs as strong winds blow warm water at the ocean's surface away from South America, across the Pacific Ocean towards Indonesia. As this warm water moves west, cold water from the deep sea rises to the surface near South America; it is considered to be the cold phase of the broader El Niño–Southern Oscillation (ENSO) weather phenomenon, as well as the opposite of El Niño weather pattern. The movement of so much heat across a quarter of the planet, and particularly in the form of temperature at the ocean surface, can have a significant effect on weather across the entire planet.

Tropical instability waves visible on sea surface temperature maps, showing a tongue of colder water, are often present during neutral or La Niña conditions.

La Niña events have occurred for hundreds of years, and occurred on a regular basis during the early parts of both the 17th and 19th centuries. Since the start of the 20th century, La Niña events have occurred during the following years:

1903–04
1906–07
1909–11
1916–18
1924–25
1928–30
1938–39
1942–43
1949–51
1954–57
1964–65
1970–72
1973–76
1983–85
1988–89
1995–96
1998–2001
2005–06
2007–08
2008–09
2010–12
2016
2017–18
2020–22

Credit :  Wikipedia 

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Jet streams are bands of strong wind that generally blow from the west to the east across the world. They impact weather, air travel and many other things that take place in our atmosphere. They form when warm air masses meet cold air masses in the atmosphere. The fast-moving air currents in a jet stream can impact the weather system in a region affecting temperature and precipitation. But if a weather system is far away from a jet stream, it might hover over one place, causing heat waves or floods.

What Causes Jet Streams?

Jet streams form when warm air masses meet cold air masses in the atmosphere.

The Sun doesn’t heat the whole Earth evenly. That’s why areas near the equator are hot and areas near the poles are cold.

So when Earth’s warmer air masses meet cooler air masses, the warmer air rises up higher in the atmosphere while cooler air sinks down to replace the warm air. This movement creates an air current, or wind. A jet stream is a type of air current that forms high in the atmosphere.

On average, jet streams move at about 110 miles per hour. But dramatic temperature differences between the warm and cool air masses can cause jet streams to move at much higher speeds — 250 miles per hour or faster. Speeds this high usually happen in polar jet streams in the winter time.

How Do Jet Streams Affect Air Travel?

Jet streams are located about five to nine miles above Earth’s surface in the mid to upper troposphere — the layer of Earth’s atmosphere where we live and breathe.

Airplanes also fly in the mid to upper troposphere. So, if an airplane flies in a powerful jet stream and they are traveling in the same direction, the airplane can get a boost. That’s why an airplane flying a route from west to east can generally make the trip faster than an airplane traveling the same route east to west.

How Do Jet Streams Affect Weather?

The fast-moving air currents in a jet stream can transport weather systems across the United States, affecting temperature and precipitation. However, if a weather system is far away from a jet stream, it might stay in one place, causing heat waves or floods.

Earth’s four primary jet streams only travel from west to east. Jet streams typically move storms and other weather systems from west to east. However, jet streams can move in different ways, creating bulges of winds to the north and south.

How Does the Jet Stream Help Us Predict the Weather?

Weather satellites, such as the Geostationary Operational Environmental Satellites-R Series (GOES-R), use infrared radiation to detect water vapor in the atmosphere. With this technology, meteorologists can detect the location of the jet streams.

Monitoring jet streams can help meteorologists determine where weather systems will move next. But jet streams are also a bit unpredictable. Their paths can change, taking storms in unexpected directions. So satellites like GOES-16 can give up-to-the-minute reports on where those jet streams are in the atmosphere — and where weather systems might be moving next.

Credit : Science jinks 

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