Interview with Professor T.N. Krishnamurti
Dr Taba recounts:
In recent years, it has found many applications in the transport of chemical species. Five years later, Krish presented the first numerical solution for the complete non-linear balanced omega equation, which was an extension of the work done by Norman Phillips2. The solution of the complete non-linear balanced w-equation provided vertical motions as forced by dynamics, physics and the partitioning from its many components. This work helped the diagnosis of tropical and extra-tropical weather systems. In 1969, he carried out the first major experiment on numerical weather prediction over tropical latitudes, based on a multi-level grid point model. It took the model nearly 24 hours to spin up an inter-tropical convergence zone. This problem is now being handled much better within a mesoscale resolution for the entire global model. In 1972, Krish produced the first mapping of divergent east-west circulation for the summer and winter seasons. It was realized that a major east-west divergent circulation many times the size of the Walker circulation was ever present in tropical latitudes. This work has been important for our understanding of El Niño-monsoon teleconnections. Readers might recall that, soon after the launch of the geostationery satellite, ATS III, in the late 1970s, cloud-tracked winds over the Atlantic Ocean become available. With these data and commercial aircraft wind reports, Krish was able to carry out a preliminary analysis of westward propagative easterly waves of the Atlantic Ocean. He and his collaborators wrote a couple of important papers. During the early 1990s, Krish wrote several papers showing that physical initialization within high-resolution global models leads to major improvement of short-range forecasts, especially for hurricanes and monsoons. The importance of opening the concept of physical initialization, i.e. initialization of satellite raingauge-based rain for global numerical weather prediction was shown some time in 1991. Having developed a very-high-resolution global spectral model and a comparable physical initialization component, Krish became engaged, in 1993, in a number of studies on hurricane and monsoon forecasts. These studies emphasized the organization of meso-convective prescription elements within the larger-scale tropical environment for the improvement of medium-range forecasts.
We come now to one of the most or perhaps the most important achievement of Krish and his group, a major event of the year 1999: introduction of the notion of “superensemble” for weather and seasonal forecasts. The superensemble is a dynamical-statistical prediction system for improving the accuracy of weather and seasonal climate forecasts. Multi-seasonal climate forecasts with atmospheric global circulation models have shown great promise in recent studies. The strategy for the multi-model superensemble partitions the forecast time-line into two components. The first of these, called the training period, utilizes the multi-model multi-seasonal forecasts and the observed fields to derive a statistic. The second phase, called the forecast phase, utilizes the multi-model forecasts and the aforementioned statistics to obtain superensemble forecasts. Krish says that major success has already been achieved and that the statistical superensemble provides higher skill for short- to medium-range forecasts than all other participating models. Krish and his group are currently examining superensembles of climate change and for coupled atmosphere-ocean modelling. The superensemble will be used in live or real-time forecasting very soon.
Krishnamurti is a much honoured and greatly respected atmospheric scientist and is the author of more than 120 scientific papers. He is a member or fellow of several societies and professional bodies such as the American Meteorological Society (AMS); the American Geographical Union; the Royal Meteorological Society; the Meteorological Society of Japan; and Sigma X; as well as Counsellor, AMS, 1979-1982. He has received many awards: the Second Half Century Award; the Charney Award ((1974), the second highest award of the AMS); the first Creativity Award of the National Science Foundation (1981); the Carl Gustaf Rossby Research Medal ((1985), the highest AMS award); the Robert O. Lawson Distinguished Professor Award ((1985), the highest award conferred to a faculty by Florida State University (FSU)); Florida Scientist Year Award (1985); the IMO Prize (1996) and the FSU Professional Excellence Programme Award (1997). Krish is a hard-working man who relays to his students his own passion for science. They respect him for his scientific knowledge, his work ethics and, above all, his willingness to share information. For all he has done for WMO and for international meteorology, the global meteorological community is greatly in his debt.
This interview took place in Paris, France, in September 1999.
H.T. — Could you please tell us about the date and place of your birth and your parents?
T.N.K. — Our family came from Chennai (Madras), India. We moved to New Delhi where my father, T.J. Natarajau, worked in Foreign Affairs for the British Government and later in the External Affairs Ministry of the Indian Government. I was born in 1932. We moved to New York in 1954 and my father became the Indian Ambassador to the United Nations. He retired in 1964 and returned to Madras. My mother, Meena Natarajau, was a devout Hindu, spending a good part of her life at prayer in a small temple in our residence. She was well versed in Sanskrit and had read many religious Indian texts, including the Vedas. It was in such a professional and spiritual context that I was brought up.
H.T. — What about your primary and secondary school?
T.N.K. — All my primary and secondary education was completed at the Harcourt Butler Higher Secondary School in New Delhi in the 1940s. I completed my higher secondary education in 1948. Prior to 1947, this school had a mix of teachers from India and Great Britain. Sir Harcourt Butler, from London, was a magnate in the leather industry. He opened a leather technology institute at Kanpur in India. Kanpur shoes were well known all over the world in those days. Funds from this enterprise benefited our high school.
H.T. — At what stage did you decide to become a meteorologist?
T.N.K. — The decision to pursue meteorology as a career entered my mind when I was a student of physics at Delhi University. My parents were living not far from the India Meteorological Department (IMD) and I had the opportunity to visit the library in the famous old building at Lodi Road, which had been built during the days of C.W.B. Normand3. Occasional lectures by various dignitaries introduced me to the science of meteorology. Among these was Dr P.R. Pisharoty, who had just completed his Ph.D. at UCLA in 1954. He presented an excellent lecture on the quasi-geostrophic transport of heat in the general circulation. I also worked on an unpaid project, “Monsoon Break”, for one of the IMD scientists and made the decision to enter the Master’s degree programme in that field. That was my introduction to meteorology.
H.T. — Tell us more about your university studies.
In 1998, some 45 years later, I revisited Andhra University to receive an award. The Department of Meteorology had not changed much, although much of the city, Visakapatnam, had grown into an impressive seaside resort on the Bay of Bengal.
H.T. — Why did you choose the University of Chicago to study meteorology?
T.N.K. — The decision in 1954 to follow my postgraduate education in Chicago was not a difficult one in view of its eminent and famous faculty, comprising Herbert Riehl4, George Platzman, Sverre Pettersson, Dave Fultz, Roscoe Braham, Horace Byers, Eric Palmén, Chester Newton and Ted Fujita. This was after the era of Rossby, whom I did not meet. Also, Chicago was fairly close to New York, where my parents were living.
H.T. — What was the subject of your PhD. thesis? Who were your professors?
T.N.K. — My Ph.D. dissertation topic was on the subtropical jet stream of winter. That was a first global mapping on the structure of the jet stream. Eric Palmén suggested that I work on that topic. Herbert Riehl was my major professor. In fact, this work was an extension of the work that Dr Mohri from Japan and yourself, Hessam Taba (in Stockholm), had done where you examined the jet over Japan. Hessam, you also wrote a pioneering paper around 1960 on one day in the life of the subtropical jet stream. That demonstrated that the Hadley cell even shows up from one day’s tropical datasets and that was based on a careful hand analysis of global weather maps. The paper was published in Tellus about one year after my dissertation which provided a global assimilation of the subtropical jet stream. That was a memorable period. I had the good fortune of receiving advice from Herbert Riehl, Sverre Pettersson and Eric Palmén. My Ph.D. dissertation committee also included George Platzman and Dave Fultz. George Platzman was the greatest teacher. He was lucid in his presentations and also a great biographer. His biographies of Richardson, Charney and Haurwitz are masterpieces. George was the teacher most respected by the students. He introduced me to the subject of spectral modelling in 1956. Some 42 years later, I wrote a textbook on global spectral modelling, that was published by Oxford University Press. The 1950s were a period when large-scale observational meteorology was at a high level at the Chicago school.
H.T. — In 1960, you moved to the University of California Los Angeles (UCLA). What did you do? How long did you stay?
T.N.K. — I moved to UCLA in 1960 and became a faculty member, teaching synoptic meteorology. I was still there a year later, when Jacob Bjerknes was examining sea-level pressure data and noted the relationship of the El Niño/Southern Oscillation. He was indeed far ahead of others in seeing the significance of these early findings. Around that time, Arakawa was publishing his first work on the now well-known Arakawa Jacobean during 1962. I was an assistant professor at the UCLA faculty until 1966, teaching tropical meteorology. Some top-level graduate students were in my laboratory, including David Baumhefner, Jan and Julia Paegle, Steve Esbensen and John Brown. They became illustrious scientists in the USA in later years.
H.T. — In the 1960s, you were a visiting lecturer abroad. Please tell us something about these visits.
T.N.K. — In 1963, my wife Ruby and I had the unique opportunity of visiting the University of Buenos Aires, for a four-month period, under a Ford Foundation Fellowship. I learned some Spanish and lectured on numerical weather prediction using mostly the English language. I made many friends and introduced the concept of the non-linear balanced w-equation, which we tried to solve on a Mercury-Ferranti paper-tape computer. Isadoro Orlanski, who later graduated from the Massachusetts Institute of Technology (MIT), was assigned as my programmer and, later on, he entered the field of meteorology. Sometime thereafter, he became a top scientist at the Geophysical Fluid Dynamics Laboratory at Princeton. I also came into contact with Maria Louisa Altinger de Schwarlkoff and Julia Nognes Paegle, who also became well-known scientists in later years. Rolando García5 was then Dean of Arts and Sciences at the University of Buenos Aires with one of the finest departments of meteorology. Political change had a major impact on the University of Buenos Aires in the late 1960s.
In 1967, my wife and I visited Imperial College in London. At that time, Profs Sheppard, Pierce, Ludlam and Scorer were part of the faculty, which was the lead department in atmospheric sciences in the United Kingdom. B.J. Mason6 had left and was Head of the United Kingdom Met. Office. I gave a month-long series of lectures on numerical weather prediction. I also met some of the Met. Office personnel, including the trio of Bushby, Sawyer7 and Knighting. I became good friends with Andrew Gilchrist and we worked together on planning the Global Atmospheric Research Programme (GARP) Atlantic Tropical Experiment (GATE) in later years. I also met David Pedgley, who later visited FSU for a year. Robert Pierce was a welcome visitor to our group in 1969. These contacts with the Met. Office and Imperial College were most memorable, in terms of science and experimental planning, and helped my research in later years.
H.T. — In 1964, you became Associate Professor at the Naval Postgraduate School, albeit it for only a few months?
T.N.K. — Ruby completed her Ph.D. in physics and joined Stanford University and I joined the faculty at the Naval Postgraduate School at Monterey, which had a few civilian employees. George Haltiner was Chairman of the Department. He was, without a doubt, one of the nicest persons heading a department and was most concerned about his entire faculty. The naval officers needed flying hours in their preparations for the Viet Nam War and it was not unusual for students to miss classes to cover flying hours. The School had excellent facilities for research and I had several bright students, among them Jerry Jarrell, current Director of the National Hurricane Center in Miami. On the other hand, living in San José entailed a major commuting exercise. I commuted a total of 134 miles each day (round trip) and my wife had to drive 60 miles the other way. This, along with slower highways (then) and occasional fog, led to a driving speed of 5 miles per hour, at times. Our short six-month stay in northern California constituted a transition period in both our careers.
H.T. — You then moved to FSU and became Associate Professor in the Department of Meteorology.
T.N.K. — FSU was a well-known school in tropical meteorology, with Profs Noel LaSeur, Charles Jordan and Michael Garstang forming a core of the faculty in this area. Seymour Hess and Richard Craig were other well-known faculty members. This was then a second-tier meteorology school. MIT, and the Universities of Chicago and Washington were at the top level. LaSeur and Jordan gave me full freedom to teach courses in tropical meteorology and I was able to develop a large research programme. At US universities, the faculties have to raise funds to support their graduate students. This annual drama is quite a challenge. Most US faculties spend a good deal of time teaching, publishing research papers, attending conferences and seeking funds, usually from federal agencies. The Department of Meteorology at FSU celebrated its 50th anniversary last year (1999). Werner Baum8 (who died on 4 September 1999) founded the Department in 1948 and was Dean of Arts and Sciences until recently.
H.T. — In which way did your responsibilities change when you were appointed a full professor ?
T.N.K. — I became a full professor at FSU in 1970. I was so involved in research and teaching, that the transition from being an associate professor was not noticeable. I developed a laboratory for tropical meteorology and numerical weather prediction that comprised some 25 people. I could never distinguish research and teaching, they always complemented each other.
H.T. — In 1985 you were designated a Robert O. Lawton Distinguished Professor. What does this award mean?
T.N.K. — I received that chair from the University in 1985. It is the highest honour that the FSU bestows. It provides me with some freedom in my educational pursuits. Beyond that, it provides a small research funding that helps my laboratory.
H.T. — In 1995 you became Director of the Cooperative Institute for Tropical Meteorology at FSU. What was the relation between this Institute and the Department of Meteorology?
H.T. — From 1970 to the present, you have supervised and tutored more than 40 Ph.D. students. This is an enormous achievement by any standard. Do you maintain contact with your former students?
T.N.K. — FSU has traditionally had a strong programme in tropical meteorology. That started in the early 1950s with Noel Laseur and Charles Jordan, whose team I joined in 1967. Tropical meteorology was the field of many aspiring young scientists from developing countries. They received support (from WMO, their governments, and US fellowships/assistantships). Tallahassee attracted many of them. Many also came from more advanced countries to learn tropical methods for their modelling interests. Yet, at the rate of simply one Ph.D. per year, I have had the privilege of having roughly 40 students complete their Ph.D. degrees and I keep in touch with most of them. A large number of WMO trainees came to Tallahassee during the last three decades for education and research. I was fortunate in having people such as Joseph Adejokun (who later became Director of the Nigerian Meteorological Service), Colin Depradine (current Director of the Caribbean Institute of Meteorology in Barbados), K.S. Yap (Deputy Director of the Malaysian Meteorological Service), D. Sukawat (Deputy Director-General of the Thailand Meteorological Service), and Saad Mohalfi (Deputy Head of the Saudi Arabian Meteorological Service). There are numerous others: Dialo Matienga of Nigeria, Peter Kiange of Kenya, to name but two, who underwent training in my laboratory. I am indeed indebted to WMO for providing support for their visits. My successful American Ph.D. students include Mukut Mathur, M. Kanamitsu, Arun Kumar, Hua Lu Pan (National Centres for Environmental Prediction), John Molinari (Professor at the State University of New York), Fred Carr (current Chairman of the Department of Meteorology at the University of Oklahoma), Bonoua Lahouri (NASA-Goddard), Richard Pasch, Jack Beven and Naomi Surgi (National Hurricane Center), Phil Rasch and Simon Low Nam (National Center for Atmospheric Research) and several others.
While I was visiting the University of Nairobi as an external examiner during the 1970s, I came across many young, bright people; three of those, Fred Semazzi (currently with the International CLIVAR Project Office, Southampton, United Kingdom) and Matthew Fulakeza (who received his Ph.D. under me at FSU and is currently at Columbia University) and Buruhani Nyenzi (United Republic of Tanzania), have done very well in their careers. They all started in the Class II training programme at the WMO Regional Meteorological Training Centre (RMTC) at Nairobi.
My ties with Nairobi also brought me in touch with Laban Ogallo. We published a joint atlas on African meteorology covering a decade of datasets. This atlas, of some 500 pages, covered monthly mean fields for most variables such as precipitation, clouds, sea-surface temperature (over adjoining oceans) and the anomalies. It was a useful reference at the drought monitoring centres in Africa.
H.T. — You have always contacts with scientists from other countries. Have many gone to visit you?
T.N.K. — A stream of eminent scientists has come to our laboratory over many years, including Robert Pierce (University of Reading, United Kingdom), Philippe Bougeault (Météo-France), David Pedgley (United Kingdom), William Heckley (ECMWF), Fedor Mesinger (University of Belgrade, Yugoslavia), Daniel Cadet (France) and many others.
I was fortunate in having scientific interactions, during such visits, with D.R. Sikka, S. Gadgil, H. Bhalme, S.K. Mishra, D.R. Chakraborty, N. Keshavamurthy, D. Subrahmaniam, A.K. Mitra, Roy Bhowmik, P.C. Joshi, U.C. Mohanty, O.P. Sharma, M.C. Sinha, R. Gairola, A.K. Bohra and many others. This collaboration helped me immensely in monsoon research. As a result, we have developed close ties with many research institutions in India. Another important long-term visitor from India was H.S. Bedi, who worked with me on global spectral modelling. We prepared jointly a textbook (along with my former Ph.D. student from India, Vivek Hardiker), which has been translated into other languages. Oxford University Press published this book in 1998.
H.T. — Let us talk about your contacts with WMO.
T.N.K. — In the 1970s, I was quite involved with GARP, starting with the planning of GATE. By 1972, we were busy talking about and planning this experiment, which was held in the tropical eastern Atlantic Ocean in the summer of 1974. Prior to the experiment, the Scientific Committee, headed by B.J. Mason, met several times at Bracknell. I worked with Doug Sargeant (head of the US management team) at Rockville, Maryland, every month for a year, planning the synoptic subprogramme. The aim of GATE was to provide understanding of the Cumulus-broadscale interactions, i.e. the Cumulus parameterization issue. It was a successful experiment that provided datasets from 10 research aircrafts, 31 ships and many surface- ship- and aircraft-based instruments. Joachim Kuettner9 was head of field operations. The datasets covered the synoptic-scale, boundary-layer, radiation and oceanographic measurements. Some scientists are still publishing papers using these valuable tropical datasets. The other major experiment of GARP in which I participated was MONEX, the monsoon experiment.
My other contact with WMO was the lecture I gave during the Eighth World Meteorological Congress in 1979. That provided me with an opportunity to meet members of the WMO Executive Council. During these visits, I had the possibility to discuss with all concerned questions related to the improvement of education and training in developing countries. I was asked to prepare a textbook on tropical meteorology for the WMO blue series for use by WMO Regional Meteorological Training Centres. I completed this work in 1979 and, for the last 20 years, the compendium has remained a useful text in tropical meteorology10.
For the last 12 years, I have headed the WMO/CAS Steering Committee on Limited Area Modelling. I also organized numerous training courses for WMO’s limited area modelling initiative under CAS over the last 15 years. These workshops, which were held all over the tropical world and also in Trieste, Italy, provided an opportunity for young meteorologists from many countries to interact.
H.T. — What about your participation in other field experiments?
T.N.K. — Although I participated in several other field experiments, I shall mention only two. I was a science team member in several of NASA’s initiatives. One of these was called TRACE-A, held in October 1992, which was a tropospheric chemistry experiment on ozone. Although everyone has heard of the ozone hole in the Antarctic stratosphere, not many know about the situation in South Africa and South America. Here, biomass burning (of farmlands after harvsting) leads to the formation of ozone that is advected by lower troposphere wind circulations, causing an accumulation of ozone near the Greenwich Meridian and 10°S over the tropical Atlantic Ocean. Our role in FSU was to provide the meteorological support for this field experiment. We have provided similar support for INDOEX, the international atmospheric field experiement over the Indian Ocean, headed by V. Ramanathan of the University of California in San Diego.
More recently, in the summer of 1998, I participated, with my students, in a major NASA hurricane experiment called CAMEX 3 (Convection and Meteorology Experiment). This was a unique experiment for the surveillance of hurricanes, in which, for about six weeks, seven research aircrafts participated. Ramesh Kakar of NASA was the principal scientist behind this initiative. The experiment was unique in that it produced as many as 130 dropwindsonde observations in a single day’s surveillance of a hurricane. It was designed to improve our understanding and prediction of hurricane intensity. We are currently analysing this major dataset.
H.T.— You are an educator and also a film producer. Could you tell us about this activity?
T.N.K. — Making animation films is most rewarding for educational purposes. Vector motion films, using semi-Lagrangian advection principles are an aid to the visualization of hurricanes, monsoons, jet streams and daily tropical weather. I have prepared 50 such educational films, including a number for WMO. I have participated in a number of field experiments related to atmospheric chemistry since 1992, where the role of my laboratory was to provide meteorological support for pollution, aerosol/ozone transport issues. For these initiatives, vector motions, back trajectories and passive transport films were most useful and appreciated by many atmospheric chemists.
A series of films on the onset and life cycle of the monsoon of 1979 and the life cycle of the most intense typhoon (Tip of 1979) were some of our best efforts and were used by the WMO Education and Training Programme (ETRP); I would encourage these techniques. Readers of the Bulletin may know that Dr Hasler of NASA-Goddard is well known for making some of the best illustrative, four-dimensional animation of weather events. His products are worth exploring for the ETRP.
H.T. — You have been associate editor, editor and chief editor of several journals and scientific publications. Does this part of your work demand much attention?
T.N.K. — I was chief editor of the Monthly Weather Review during the years, 1991-1994 and an editor of the Journal of Atmospheric Sciences from 1976 to 1989. I also serve on the editorial board for Tellus, the Journal of Meteorology and Atmospheric Physics, Advances in Atmospheric Sciences and Kluwer academic publications. This is part of the life of a teacher. Reviewing papers helps me keep abreast of scientific advances. The job of a chief editor, although time-consuming, has put me in touch with numerous experts. The job of helping scientists, especially from developing countries, in their publishing pursuits has been most rewarding.
H.T. — You have received many awards and recognitions. Could you mention some?
T.N.K. — I shall start with the awards I received from the AMS. The highest and the second highest awards of the AMS, the Rossby Medal and the Charney Award, were presented to me in 1974 and 1985 respectively. The citations recognized my work in tropical meteorology and modelling, especially in the areas of monsoons and hurricanes. What is pleasant about this is that people unknown to me nominated and supported me for these awards. The award of the IMO Prize in 1996 was a special occasion in Tallahassee. The Secretary-General of WMO, Prof. G.O.P. Obasi, came with the President of WMO, Dr John Zillman, and the Executive Secretary of the American Meteorological Society, Dr Richard Hallgren. Also present were a number of scientists, including Roscoe Braham from Chicago and Richard Anthes (University Cooperation for Atmospheric Research). Their personal tributes, covering 30 years of acquaintance, were most touching.
H.T. — A man with your knowledge and reputation must have an important message to send to young persons who may wish to take up meteorology as a career. What would you say?
This alone can provide the necessary background for a successful meteorological career. I may be somewhat biased in my outlook, but that is what I feel.
H.T. — Can you please tell us about one outstanding event in your professional life?
T.N.K. — I was at UCLA when Jacob Bjerknes made his great findings on El Niño/Southern Oscillation around 1961. He had in his office two student assistants, Major Gomel of the US Air Force and Vesna Jurcec from Yugoslavia. They were preparing five-day averaged charts over the Pacific Ocean. Missing data required them to use from one to five observations to obtain these five-day averages. I watched over this group whenever Bjerknes was out of town. I felt that the method of averaging and handling data would not lead to anything big. When Bjerknes returned from Norway and looked at these data and started on his map, he chuckled (a rare event) tand said hat something very big was to come out of these charts. The signal was strong compared to the noise. The rest, as you know, is history.
H.T. — Is there anything you wish you had done?
T.N.K. — My wife and I have several interests, including teaching, research, gardening, following top tennis, travelling (mostly to conferences) and sightseeing. I have enjoyed this meteorological career through which I have had useful interactions with thousands of scientists, teachers and others for 35 years. It would be hard for me to think of what else I would have preferred to have done.
H.T. — What are you doing nowadays?
T.N.K. — I have not retired yet. I am still running a research laboratory with over 20 people (graduate students plus postdoctoral scientists). Right now, the big research is on the skill of multi-model superensembles for weather and seasonal climate forecasts. This powerful new technique utilizes multi-model forecasts (from the past and the present). The past performance of the models against analysis (observations) is assessed via simple statistics. These statistics are shown to have an important degree of resilience with respect to the time-scales for which one is predicting. The future forecasts for the multi-models plus the statistics enable us to make a superensemble forecast into the future. We show that the methodology outperforms all current prediction models in the area of global numerical weather prediction, seasonal climate forecasts and the prediction of hurricane tracks and intensity.
H.T. — You are a man of exceptional talent and enormous energy. Your research work has covered a wide area, with emphasis on tropical meteorology. Your latest work will certainly improve our knowledge of forecasting weather and climate events and, in particular, our ability to track hurricanes. Perhaps the meteorological world has finally found in you the Superman to handle this wretched phenomenon. It was nice talking to you.