Book Review of “Monsoon Prediction” by R. R. Kelkar in Current Science

The 25 June 2009 issue (Vol 96, No. 12) of Current Science carries this review of the book “Monsoon Prediction” by Prof. R. R. Kelkar:

The history of monsoon prediction in India dates back to 1886. India Meteorological Department (IMD) has the distinction of being the first national weather service in the world to start the operational monsoon prediction work. It all started in 1886, when Blanford used the relationship between winter Himalayan snow cover and Indian monsoon for predicting the ensuing monsoon rainfall. Sir Gilbert Walker, in 1910s and 1920s, initiated high-quality research in understanding the monsoon variability and development of statistical models. Since then, meteorologists have been working relentlessly to understand and predict Indian monsoon variability and numerous research papers have been published on this important topic. Many reviews have also been published. Monsoon prediction is now a challenging research area with plenty of scope and opportunity. However, we did not have a good compilation of all the results pertaining to monsoon prediction research. The book under review fills this gap. The author, R. R. Kelkar, who served IMD for more than 35 years was also responsible for operational monsoon prediction in IMD. He has used his rich experience in shaping this useful book. The book also includes a critical analysis of our prediction capability and its future scope and opportunities.

The book contains six chapters, describing the major components of the monsoon, global and regional teleconnections, different methods of seasonal monsoon prediction, characteristics of intra-seasonal variations and prediction, projection of monsoon in the 21st century and finally, problems and prospects associated with monsoon prediction.

The first chapter describes different ways of defining a monsoon, monsoon regions, and major climatological features of the Indian monsoon. There are many ways of defining a monsoon. But for the Indians, it is the annual cycle of rains over the country. Monsoon theories included the simple land–sea breeze theory to a complex theory that involves the atmosphere, land and ocean. Indian monsoon variability is influenced by many components of the global climate system. They are known as teleconnection patterns, linking the Indian monsoon variability to major climate anomalies around the world such as Eurasian snow cover and snow depth, El Nino/Southern Oscillation (ENSO), sea surface temperature anomalies over the Indian and Atlantic oceans, and land surface temperature anomalies.

In the second chapter, various monsoon teleconnection patterns are discussed. Teleconnections with ENSO and snow cover are probably studied more and are discussed in detail. However, a detailed discussion on the role of Indian Ocean climate anomalies (Indian Ocean Dipole and EQUINOO) on Indian monsoon is missing. The relationship between sunspot activity and Indian monsoon is a research area with some renewed interest.

In India, statistical models are extensively used for monsoon prediction (long-range forecast). Most of these statistical models are based on the same principles used by Gilbert Walker in 1920s. IMD now uses an updated statistical model for issuing operational long range forecasts based on the ensemble technique. Chapter 3 discusses the details of these statistical models, including the parameters used in the model. The models include simple linear regression, discriminant models for probability distributions and the latest ensemble method based on projection pursuit regression.

Prediction of the quantum of rainfall during the whole season (seasonal prediction) is useful for planning purposes. However, for the farmers, prediction on intra-seasonal timescales (for example, 15–20 days) is more relevant for their day-to-day operations. Similarly, prediction of intra-seasonal activities such as onset and withdrawal, and the active–break cycles of the Indian monsoon is crucial for agricultural planning. However, little work has been done on this important area. Prediction of various monsoon intra-seasonal elements is discussed in Chapter 4. This is an emerging area of research both in India and abroad. This chapter also includes a brief discussion on the use of atmospheric and coupled general circulation models for seasonal monsoon prediction.

In the particular context of climate change due to global warming, it is important to know the future projections of the Indian monsoon. Chapter 5 discusses the projection of the Indian monsoon behaviour in the 21st century. The chapter starts with a discussion on the observed climate change over India using instrumental datasets, followed by future emission scenarios and climate projections. Even though there is no appreciable trend in the quantum of monsoon rainfall averaged over the country, there are significant trends in monsoon rainfall over different parts of the country. Also, there are temporal changes during the monsoon season. Most of the current climate models indicate that monsoon rainfall would increase in future climate. However, there are many uncertainties in the climate model projections. Most of the current climate models are unable to simulate the observed features of the Indian monsoon in their totality. It is important to understand and appreciate these uncertainties in the global climate models in interpreting and using the future climate-change projections.

In the final chapter, the problems and prospects of monsoon prediction are discussed. There are known limitations of the statistical models, like secular variations of correlation, choice of optimum number of predictors and training period, etc. However, in spite of these known constraints, statistical models continue to be popular for several reasons. The users, while interpreting forecasts from these statistical models, should understand and appreciate the limitations of these models. There are other issues like the definition of all-India summer monsoon rainfall (averaged over the whole country and whole season from 1 June to 30 September), changes in the global teleconnection patterns, especially with ENSO. Statistical models cannot be used for prediction on much smaller spatial and temporal scales. For this specific need, we have to use dynamical models. The future prospects of monsoon prediction are completely dependent on the skill of advanced dynamical models, which showed an improvement in the model skill over the recent years. Specifically, monsoon field experiments and Indian climate research programmes will improve our understanding of the monsoon variability and thus monsoon prediction.

This book is specifically designed on monsoon prediction as it discusses the current state-of-the-art of monsoon prediction, its problems and prospects. It provides a critical analysis on how good we are in monsoon prediction and what are its future prospects in the context of improvement in dynamical models and monsoon field experiments. The book contains a good compilation of useful and updated references at the end of each chapter. The book will be useful to meteorologists, especially operational forecasters and students in meteorology and anyone interested in knowing more about monsoon prediction.

- M. RAJEEVAN

Book Review of “Satellite Meteorology” by R. R. Kelkar in WMO Bulletin

The April 2009 issue (Vol 58, No. 2) of the WMO Bulletin published by the World Meteorological Organization, Geneva,  carries this review of the book “Satellite Meteorology” by Prof. R. R. Kelkar:

Satellite Meteorology

R. R. Kelkar. BS Publications (2007).
ISBN 81-7800-137-3.
xix + 251 pp.
Price: US$ 26

Observing our weather from space—referred to here as satellite meteorology (SM)—has revolutionized our understanding of how the atmosphere, ocean, land and cryosphere operate and interact as part of a system. By the unique virtue of being global, satellite data have radically transformed the way meteorologists perform numerical weather prediction (NWP). Today, gigabytes of radiances from satellites are routinely assimilated into weather forecast models.

This book traces the fascinating history of satellite meteorology and its application to NWP, starting from the beginning of the space era up to the current state-of-the-art sensors, providing the reader with a comprehensive introduction to remote-sensing, climate monitoring and weather forecasting, with a particular focus on Indian meteorology. In particular, the book covers (and illustrates with nice colour figures) a variety of remote-sensing topics ranging from the orbits of the satellites, the types of radiation they sense, the physical understanding of their measurement and the retrieval of ocean, land and atmospheric parameters, up to the exploitation of their data to study tropical weather systems and constrain, validate and initialize NWP models.

The book constitutes very good material for university students planning a career in physics or Earth sciences, as well as a reference for scientists involved in Earth system research or operational weather prediction, in particular over tropical regions.

The author, R. R. Kelkar, who [was] ISRO Space Chair Professor at the University of Pune, India, has a long experience in satellite meteorology at the India Meteorological Department, and has done a very good job in synthesizing this fast growing field, highlighting its potential,as well as the related challenges and opportunities.

Reviewed by Pierre-Philippe Mathieu

“Surface Meteorological Instruments and Measurement Practices” – A Book by Dr G P Srivastava

This new book deals with a large variety of surface meteorological instruments used by countries all over the world. It discusses at length the basic principles of measurement of various weather parameters, the design features and functional details of the instruments, their operational and standardization procedures and international measurement practices to be followed to obtain global data reliability.

The book is suitable for all those dealing with meteorological instruments and measurements in the field and in the laboratories of the meteorological services; for numerous other organizations engaged in studies and management of wind and solar energy, atmospheric pollution, agriculture, etc. and as a text and reference book for teachers and students of atmospheric and environmental sciences at the universities, agricultural colleges, secondary schools and allied teaching institutions.

Dr. G.P. Srivastava has successfully accomplished a most difficult task of bringing together all these aspects (design, operation, maintenance, etc. in this book. It epitomizes his deep knowledge and decades of experience in the field. I am sure it will be useful to a wide variety of readers.

For more information on how to obtain this book click on http://www.atlanticbooks.com/detail/9788126909681.html

To order the book contact the publishers  Atlantic Publishers and Distributors (P) Ltd., 7/22, Ansari Road, Darya Ganj, New Delhi–110 002
Tel.: 2327 3880, 2327 5880, 2328 0451, Fax : +91-11-2328 5873 or send an email to orders@atlanticbooks.com

ISBN: 978-81-269-0968-1 Price: Rs. 1495.00

Monsoon FAQs

1. What are monsoons?
2. Why are they observed only in certain parts of the world?
3. Why is the Indian southwest monsoon more intense and more regular than all other monsoons?
4. Why is Edmund Halley’s 17^th century explanation of the monsoon still talked about?
5. Why is the southwest monsoon so important to India?
6. Is the monsoon predictable?
7. Why is it easy to forecast the monsoon rainfall with statistical models?
8. Why do good statistical models fail occasionally?
9. How many predictors should a statistical model ideally have?
10. Is it possible to foretell future rainfall from past rainfall?
11. Why has no one developed a good dynamical model of the monsoon yet?
12. How believable are seasonal forecasts based on dynamical models?
13. How important is El Nino to India?
14. Is an El Nino a signal of drought over India?
15. Why is La Nina good for India?
16. How do distant factors like Eurasian snow or North Atlantic temperature, control the Indian monsoon?
17. What can satellites tell us about the monsoon?
18. Has the monsoon rainfall over India shown any increasing or decreasing trend over the last century?
19. How is global warming likely to affect the Indian monsoon?
20. Will there be more droughts or floods?
21. Is there any climate model that we can trust as far as the monsoon is concerned?
22. What is the benefit of monsoon field experiments and international observational programmes?
23. Will we ever succeed in our attempts to give accurate monsoon predictions?
24. Or is the monsoon not predictable beyond a certain limit?

The answers to these questions (and many more) will be found in a new book “Monsoon Prediction” by Prof. R. R. Kelkar, which will soon be published. Watch this space for details.

The Weather-cock

The poet-philosopher-artist, Kahlil Gibran (1883-1931), was born in northern Lebanon. His parents migrated to the United States of America in 1895 and he grew up in the Syrian community in the South End of Boston, Massachusetts. Kahlil Gibran’s literary masterpiece, The Prophet (1923), which he illustrated with his own mystical drawings, is an expression of the deepest human impulses. Another very renowned work of his, Jesus the Son of Man (1928), is an inspired and unorthodox portrayal of Christ’s essential character.

The following excerpt is taken from Gibran’s collection of parables in The Forerunner (1920): 

The Weather-cock 

Said the weather-cock to the wind, “How tedious and monotonous are you! Can you not blow any other way but in my face? You disturb my God-given stability.” And the wind did not answer. It only laughed in space.  

God’s Role in Natural Disasters (1)

On 15 January 1934, at 2:21 pm IST, there was a massive earthquake of magnitude 8.3 on the Richter scale with its epicentre located at latitude 26.6 °N and longitude 86.8 °E on the Bihar-Nepal border (Ref. 1).

Tremors of the Bihar earthquake were felt as far as Allahabad, where Jawaharlal Nehru had been standing in the verandah of his house talking to a group of farmers. He could hardly keep his balance and had to cling to a column nearby. Doors were banging and the tiles over the roof of Swaraj Bhawan were sliding down. The shocks ended after some time and the episode was soon forgotten. Nehru wrote that he could not have guessed what those two or three minutes had meant to the millions of people in Bihar (Ref. 2).

In fact, as many as 7,000 people were said to have perished in Bihar and another 3,000 in Nepal, although unofficial estimates put the casualty figures much higher. The district towns of Monghyr and Muzaffarpur suffered the maximum damage and loss of lives, but Kathmandu and Darjeeling were also badly affected.

Nehru later went on a tour of the earthquake-affected areas, when he read with a great shock a statement of Mahatma Gandhi to the effect that the earthquake had been a punishment for the sin of untouchability. On this, Nehru raised several rhetorical questions like: If the earthquake was a divine punishment for sin, how are we to discover for which sin we are being punished? Why did not the earthquake visit the land of untouchability itself? Was it a judgment on the prevailing zamindari system since many rich land owners had suffered losses in the earthquake? Could the British rulers interpret it as a divine punishment because Bihar had been taking a leading role in the freedom movement? Since Nehru did not attempt to answer these questions, it is obvious that he had posed them just to indicate that Gandhi’s logic was flawed or difficult to understand. Nehru concluded that it was astounding to suggest that human customs could cause movements in the earth’s crust (Ref 2).

There was another person who was equally surprised and disturbed by Gandhi’s statement about the Bihar earthquake: Rabindranath Tagore. However, Tagore took the cautious route of first checking with Gandhi whether he had really said what had been ascribed to him. True to his character, Gandhi did not disown his statement, nor did he give any excuse of being mis-reported, but confirmed that he had indeed linked the Bihar earthquake with the sin of untouchability while he was at Tinnevelly. He added that he had spoken with great deliberation and out of the fullness of his heart, and he had spoken what he had believed.

Gandhiji responded to Tagore with fairness and openness. He printed Tagore’s criticism in his own journal, Harijan, but followed it with a spirited rejoinder (Ref. 3). Accusing Gandhi of unreason, Tagore had argued that physical catastrophies must have their origin in physical facts. He believed in the inexorableness of the universal law in the working of which God himself never interferes. He felt that our own sins and errors, however enormous, could never have enough force to drag the structure of creation to ruins.

Gandhi’s defence was that we do not know all the laws of God nor their working. Taking a broader view, Gandhi expressed his belief that visitations like droughts, floods, earthquakes and the like, with seemingly physical origins, were somehow connected with man’s morals, though this connection cannot be proved. While the physical effects of an earthquake would be forgotten and repaired, the moral lessons would have to be learnt. Disagreeing with Tagore, Gandhi asserted that human sins do have the force to ruin the physical world. His message was that natural disasters should draw us nearer to God, humble us, and make us readier for facing God (Ref. 3).

The questions raised by Gandhi, Tagore and Nehru in the aftermath of the Bihar earthquake of 1934, were not new. These issues had been a subject of debate for thousands of years before the event, and such questions are put forth even today. In the Holy Bible, there are literally hundreds of references in the Old Testament which make no secret of God’s intentions to bring disaster on the nations of the earth. God seems to be ever ready with his package of sword, plague and famine, with earthquakes and hailstorms added. But He also acts fair in the sense that He gives the vulnerable populations sufficient advance warnings of the impending disasters, either directly or through His messengers. He always explains to the people the reasons behind His decrees and also what He expects to accomplish by inflicting the planned disasters. Out of His many purposes behind disasters, the most common one is to make people leave their sinful ways and realize that He is God.

Even in the New Testament, where God’s image changes to that of a loving father, no respite is offered to humanity from disasters. The package of sword, earthquake, famine and pestilence would be unleashed at the end of the age. It is interesting to read an account of how Jesus reacts to the news of two local disasters, the slaughter of some Galileans by Pontius Pilate and the collapse of a tower in Jerusalem killing several people. Jesus’ audience is perhaps expecting from him an explanation about the role of a loving God in a suffering world. Instead, Jesus confronts the gathering around him with a question of his own: Do you think that those who suffered were worse sinners or more guilty than all the others? He then goes to answer his own question: I tell you, no! But unless you repent, you too will all perish (Ref. 4).

Historical records tell us that down the ages, millions of human beings have perished in natural disasters. At the same time, we also know that in the day of disaster, countless people have sought refuge in God, dwelt with Him in safety, and received His protection, comfort and consolation. To me, the key issue here is to try to comprehend that neither God’s wrath, nor His love, nor His forgiveness, nor His grace, is limited by or is in proportion to the degree of human sinfulness. Had it been otherwise, divine judgment would have been a terror for the earth and human salvation an impossibility.

References: (1) IMD web site www.imd.gov.in, (2) Jawaharlal Nehru: An Autobiography, Chapter LVIII Earthquake, 1936, (3) Sabyasachi Bhattacharya: The Mahatma and the Poet, Part IV, Documents 3-6, 1997, (4) Holy Bible, New International Version, Luke 13:1-4, Luke 21:10-11.

P. S 1: Another earthquake struck almost the same place on the Bihar-Nepal border on 21 August 1988 but it had a lesser magnitude of 6.4 on the Richter scale. It took a death toll of 850, caused structural damages to thousands of buildings and totally ruined many villages in Bihar. But this time there was no speculation about the earthquake having been the result of a divine intervention. Perhaps secular India had come of age.

P. S. 2: If human beings are really incapable of interfering in natural processes, then what is all this talk of climate change about?

A Prayer in the Time of Rain

Robert Louis Stevenson is remembered for his great literary works, poetry and novels of adventure (The Strange Case of Dr. Jekyll and Mr. Hyde 1886, Treasure Island  1883, A Child’s Garden of Verses 1885). Very different from these are his Prayers Written at Vailima, the place where he died of a brain haemorrhage on December 3, 1894. Here is an extract from these Prayers:

We thank Thee, Lord, for the glory of the late days and the excellent face of thy sun.

We thank Thee for good news received. We thank Thee for the pleasures we have enjoyed and for those we have been able to confer.

And now, when the clouds gather and the rain impends over the forest and our house, permit us not to be cast down.

Let us not lose the savour of past mercies and past pleasures; but, like the voice of a bird singing in the rain, let grateful memory survive in the hour of darkness.

If there be in front of us any painful duty, strengthen us with the grace of courage; if any act of mercy, teach us tenderness and patience.

The Four Winds of the Bible (1)

Wind is a vector quantity having both speed and direction. For purposes of comparison, statistical analysis, or computation of averages, the wind vectors have to be broken into their zonal component (east, west) and meridional component (north, south). Here, by convention, an east wind or easterly wind means one that is blowing from the east, and so on.

The Bible contains several references to the power of the wind, its variability and its destructive potential. Besides such allegorical imagery, in many places the wind is referred to in practical terms. Only the four basic directions, east, west, north and south, are talked about, and intermediate directions are rarely mentioned, like for example, the nor’easter encountered by Paul in his final voyage (Acts 27:14).

Out of the four winds of the Bible, the east wind is the one which is mentioned most often and it is generally described as a very strong, hot and dry wind. The book of Genesis (verses 41:6, 41:23, 41:27) talks of the heads of grain that sprouted and then got withered by the scorching east wind. The book of Ezekiel (verses 17:10, 19:12) tells how the strong and tall vine was uprooted and got completely withered and stripped of its fruit by the dry east wind.

The east wind of the Bible is also a fierce wind (Isaiah 27:8, Job 38:24), it can destroy ships on the high seas (Psalm 48:7, Ezekiel 27:26), it can scatter and sweep out people (Job 15:2, 27:21, Jonah 4:8, Jeremiah 18:17).

The book of Exodus describes how God brought in ten different forms of plagues over Egypt. The seventh plague was the plague of hail, and it was followed the next day by the eighth plague which was the plague of locusts (Exodus 10:13). The sequence was such that the massive hailstorms had already rendered the ground wet. The next morning God used the east wind to bring in a swarm of locusts, which found in the wet sandy soil an ideal environment to lay eggs and breed in huge numbers. Whatever had survived the hail, was completely devoured by the locusts. The following day, God changed the direction of the wind to a very strong west wind. It caught up the locusts and carried them into the Red Sea, and not a locust was left anywhere in Egypt (Exodus 10:19).

The strong and dry east wind again played a major role in the parting of the waters of the Red Sea that enabled the Israelites to cross it. God used the strong east wind to drive the sea back, turn it into dry land and divide the waters (Exodus 14:21). The sheer power of the east wind that made all this possible, was remembered for long (Psalm 28:26).

In the book of Hosea, there is a warning for any one who feeds on the wind, pursues the east wind all day, and multiplies lies and violence (12:1). An east wind from the Lord will come, blowing in from the desert; his spring will fail and his well dry up. His storehouse will be plundered of all its treasures (13:15). Hosea speaks of the fruitless deeds of evildoers in these words (8:7): They sow the wind and reap the whirlwind.

Headline Weather: (1) Under a Cloud

Anyone who is familiar with satellite images of the earth knows that wherever there is a cloud, the surface of the earth is blocked from the satellite’s view. This is because the cloud top directly reflects the sun’s radiation back to space, or the cloud absorbs the emission from the ground and radiates from its top at a cooler temperature. This does not matter for meteorological satellites, as their objective is to get images of the clouds. But in the case of remote sensing satellites designed for monitoring the earth’s resources, or cartographic satellites that map the ground features, this is a serious impediment, as they cannot do their job over areas that are hidden so to say ‘under a cloud’.

The phrase ‘under a cloud’, however, has a different meaning in non-meteorological usage. As per the dictionary, being ‘under a cloud’ is synonymous with being in trouble, disgrace or disfavour. It is therefore used very freely and conveniently by journalists and writers of news headlines, to draw attention to what may be suspicious or strange. So much so, that when I made a Google News search today for ‘under a cloud’, it yielded as many as 4,981 results in 0.1 seconds.

If what I got from my search is to be believed (and why not?), the whole world seemed to be living under a cloud, of one form or another. There were news headlines about development under a toxic cloud, and lawmaking under an ethics cloud. There was a horse running a race under a legal cloud, and another horse doing the same but under an injury cloud. One sporting event was under a safety cloud, another was under a police cloud and a third opened under a cloud that was really there in the sky. There was one reference to the beginning of a new life under a corruption cloud.

A newspaper itself was said to be under a black cloud. Many different meetings in different countries were said to have taken place under a cloud. A president was sworn in under a cloud, an official refused to quit under a cloud, a prince’s military career could possibly come under a cloud. A medicine trial was under a cloud, and a person who died at a ripe old age was said to have lived under a cloud.

There were two interesting headlines, one about a ban on smoking under a cloud, for whatever that meant, and the other about a ray of hope coming under a cloud, while that ray could have come through the cloud or from behind it!. But there was one news item that warned about an all-inclusive and most widespread cloud: Climate forecast puts earth’s future under a cloud!

If you truly want to go under a cloud and get wet, go to Cherrapunji or Mawsynram, the wettest places on earth. Or to take an easier route, follow Binoo K. John: Under a Cloud, Penguin Books India, 2004. Or if you want some lighter stuff, particularly if you are a fan of Inspector Ghote, read H. R. F. Keating: Under a Monsoon Cloud, Arrow Books, 1987.

– R. R. Kelkar, 15 June 2007.

Pioneer British Meteorologists in India: (1) Henry Piddington

We are quite familiar with how a tropical cyclone looks like from space, through the images that weather satellites send down. Television news channels often present animated sequences of the images that clearly show the cloud bands swirling around the centre or the eye of the cyclone, anticlockwise in the northern hemisphere and clockwise in the southern hemisphere.

In the early nineteenth century, little was known about these violent tropical storms, except that they wrecked ships on the high seas and caused untold destruction and loss of life while crossing the coastline. But there was one man who had unravelled their structure and visualized their rotating nature. He was Henry Piddington, first a British sea captain, and then the President of the Marine Courts of Inquiry at Calcutta (now Kolkata). He had made a thorough investigation of a storm that had struck disaster on the east coast of India in December 1789, killing over 20,000 people. He presented his results before the Asiatic Society of Bengal at Calcutta in 1840, and described the storm as a ‘cyclone’, a name derived from the Greek word ‘kuklos’ meaning going around, or encircling, like the coil of a snake.

Piddington introduced this newly coined word in the books that he wrote soon thereafter on the laws that governed the tropical storms. In 1844, Piddington published a book entitled “The Horn-Book for the Law of Storms for the Indian and China Seas”. In 1848, he published an enlarged version of this book, with the title “The Sailor’s Horn-Book for the Law of Storms”. He is said to have published yet another book in 1852, entitled “Conversations about Hurricanes: for the Use of Plain Sailors”. This was written in the style of a ship’s captain training an apprentice sailor, about how to deal with storms, how to know that they are approaching, and how to take advantage of them. The book included transparent storm cards with wind arrows that could help the captain of a ship caught in a storm to sail with the wind into safer waters.  

Piddington was engaged in scientific research in varied disciplines like botany, geology, mineralogy and soil chemistry, besides of course meteorology. He published numerous papers in the Journal of the Asiatic Society of Bengal. He was also the Secretary of the Agri-Horticultural Society of India at Calcutta. At the suggestion of Rev. Dr. William Carey, of the Serampore Mission, who had similar scientific interests, he compiled the English Index to the Plants of India.

It is said that in 1854, Piddington wrote an open letter to Lord Dalhousie that the new port that he was building at Calcutta would not be able to withstand the fury of a tropical cyclone if hit by one.  Dalhousie, however, did not heed this advice. Port Canning was built, but it was indeed destroyed by a cyclone in 1867 and later abandoned.

By 1875, the name cyclone had gained the official acceptance of the international meteorological community. Today, however, tropical cyclones are called by this original name only in India and the adjoining seas, Arabian Sea, Bay of Bengal, and the Indian Ocean. Over other oceanic basins, they are now commonly known as hurricanes or typhoons.

Henry Piddington, who was born in 1797, died at Calcutta in 1858.

(This post is based upon information derived from various sources, printed and web-based, and some of the details may need to be corrected. – R. R. Kelkar, June 2007)