Climate Change

World Meteorological Day 2019: The Sun, the Earth and the weather

This year, the day is focusing on the role of the Sun on the Earth and the changing pattern of our climate and weather

 
By Akshit Sangomla
Last Updated: Monday 25 March 2019
Sun and Earth
Representational Photo. Credit: Getty Images Representational Photo. Credit: Getty Images

Every year, on March 23, the World Meteorological Organisation (WMO) commemorates its founding by observing World Meteorological Day. This year, the organisation is celebrating its 69th anniversary.

Every year, the WMO chooses a theme around which the day is celebrated. This year, the theme is “The Sun, the Earth and the weather”.

This recognises the critical role that the Earth’s nearest star plays in what transpires on the planet. The energy that the Sun sends towards the Earth is taken up by all life forms to perform their biological functions. It also regulates global climate, which, in turn, influences local weather conditions. The same energy is also absorbed by the oceans which carry it around the planet, creating further conditions for diverse marine life to exist.

This year’s theme also sits in perfectly with the next cycle of the Sun’s activity starting in 2020, also known as the Solar Cycle 25. A research paper published by Indian scientists in the journal Nature Communications on December 6, 2018, finds that the next solar cycle will be either slightly stronger or similar to the previous cycle (Solar Cycle 24).

The Sun’s activity, influenced by its magnetic nature, fluctuates in 11-year cycles and affects the atmospheric conditions on Earth through changes in the Sun’s radiation and sudden bursts of solar energy known as “solar flares”.

The last few cycles of the Sun have shown a weakening trend and some scientists had even proposed that this would touch a record minimum known as a “Maunder minimum”, the likes of which were last seen between 1645 and 1715.

During this period, astronomers had observed no sun spots. The current weakening of the Sun’s activity led to speculation that a “mini Ice Age” is close by and that devastating effects of human-induced global warming could be partially offset by global cooling. The occurrence of such a minimum over decades would have led to a much cooler global climate.

The current prediction reverses this trend and debunks the theory of a global cooling phase compensating global warming due to greenhouse gas emissions, which have reached a record high.

This World Meteorological Day, scientists and people should also recognise the increasing unpredictability of our climate and weather. This is when deadly weather-related disasters are becoming far too common all around the world. The recent Cyclone Idai, which brought death and destruction to Mozambique, Zimbabwe and Malawi and affected more than 2 million people, is just one such example. The total impact of the deadly storm has still not been accounted for, but it has been touted as one of the worst weather-related disasters in the Southern Hemisphere.

In India, the India Meteorological Department (IMD) got its seasonal outlooks of temperatures wrong for the just-ended winter season. At the start of the winter season, IMD had said the two months of December 2018 and January 2019 would be “warmer than usual”. It had also stated that cold waves would be “below normal” in the regions that generally experience cold waves.

This turned out to be true for only about three weeks. On December 19, 2018, IMD announced that a “dry cold wave and ground frost conditions were prevailing in Rajasthan, Punjab, Haryana and Delhi”. The next day, the weather agency found that cold wave conditions had reached as far as Gujarat and Madhya Pradesh. December 2018 turned out to be the third-coldest month in Delhi in the last 50 years.

The reason for this was a lack of strong Western Disturbances (WDs) coming into India from the west in December. But then, cold wave conditions persisted till February in many areas and the winter stayed on till March because of an increased frequency and intensity of WDs in January and February, which also extended into March.

In January 2019, the IMD was also confused about the status of the El Nino Southern Oscillation (ENSO) with respect to other weather agencies around the world.

While Japan’s Meteorological Agency (JMA), which is also the Asian arm of the World Meteorological Organisation (WMO), says El Nino conditions are prevailing and that there is an 80 per cent chance of the El Nino phenomenon staying on till the spring of 2019, the IMD says the conditions would be El Nino neutral, which means neither El Nino (warming) nor La Nina (cooling), are currently prevailing in the equatorial Pacific Ocean.

To the present day, IMD maintains that only warm neutral conditions are prevailing in the equatorial Pacific Ocean. This is when other weather agencies have already declared weak El Nino conditions.

For example, the Climate Prediction Centre (CPC) of the National Weather Service in the United States declared that weak El Nino conditions have been prevailing in the equatorial Pacific Ocean since January 2019.

On the other hand, the Australian Bureau of Meteorology (ABM) has said though ENSO is in a neutral phase, the sub surface of the ocean is still warm and El Nino conditions could be back later in 2019.

This only underscores the fact that weather agencies around the world, under the leadership of WMO, need to coordinate better and become better at predicting our rapidly changing climate. 

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