1. NAME : DR. M. DILEEP KUMAR
2. DATE OF BIRTH : 10 - 11- 1954
AND PLACE Kaikalur, Andhra Pradesh
3. NATIONALITY : Indian
4. SEX : Male
5. MARITAL STATUS : Married
6. FATHER : Sri. M. RAMA RAO
7. PRESENT ADDRESS : Chemical Oceanography Division,
National Institute of Oceanography ,
Dona Paula, GOA 403 004.
INDIA.
8. EARLY EDUCATION : mostly at Zilla Parishad High School,
Kaikalur, A. P.
9. QUALIFICATIONS:
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Degree University Year Division Subject
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Ph.D Andhra 1988 By Thesis Chemistry
( Chem. Oceano.)
M.Sc. Andhra 1978 First Marine Sciences
( Chem. Oceano.)
B.Sc. Andhra 1975 First Chemistry (Main)
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10. PROFESSIONAL EXPERIENCE :
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Position Institute Duration
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Scientist "EI" National Institute of 1993 onwards
Oceanography
Scientist "C" -do- 1988-93
Scientist "B" -do- 1983-88
Trainee Scientist -do- 1982-83
Senior Research -do- 1981-82
Fellow
Junior Research -do- 1979-81
Fellow
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11. AREA OF INTEREST : Ocean Sciences
(a) Biogeochemical cycles of elements in the Oceans.
(b) Speciation of elements in seawater and sediments.
(c) Control of seawater composition.
(d) Estuarine chemistry.
12. SKILLS :
(a) Atomic Absorption Spectroscopy.
(b) Spectrophotometry.
(c) Spectrofluorimetry.
(d) Flow Injection Analysis.
(e) General Chemical Analysis.
(f) Shipboard scientific works.
(g) Thermodynamic computations.
(h) Coulometry
(i) Gas Chromatography
13. RESEARCH EXPERIENCE :18 years of Research Experience in
Oceanography.
.
14. RESEARCH PAPERS : THIRTY. THREE
PUBLISHED
15. TECHNICAL REPORTS : One.
V. Kesava Das, M. Dileep Kumar, D. V. Rama Raju, S.W.A. Naqvi, A. Rajendran, and T. Balasubramanian (1981) Status Report on Salinity Power, NIO,Goa, 52p.
16. BOOKS/SPECIAL PUBLICATIONS
(a) Editorial Committee Member of "Oceanography of the Indian Ocean", edited by B. N. Desai, 1992, Oxford-IBH, New Delhi, 772 p.
(b) Co-edited a Special Issue of the Marine Chemistry (Elsevier) journal, Vol. 47 (1994), issue 3/4 (November), pp. 191-298 on "Chemistry of the northern Indian Ocean".
17. MEMBERSHIPS :
(a) Past member of the Estuarine and Brackish Water Sciences Association, U.K.
(b) Past member of the Geochemical Society, U.S.A.
(c) Past member, Indian Association for Limnology and Oceanography.
(d) Member, Americal Geophysical Union
18. AWARDS AND HONOURS :
(a) Council of Scientific and Industrial Research's ( India )
YOUNG SCIENTIST AWARD - Earth Sciences in 1988.
(b) Raman Research Fellowship was awarded by the CSIR for advanced research at the University of Hawaii, U. S. A., in 1991.
19. VISITS UNDERTAKEN ABROAD :
(a) Participated in XIX General Assembly of the International Union of Geodesy and Geophysics held at Vancouver, Canada, during August 1987.
(b) Imparted training to oceanographers of West Indies during the Caribbean Oceanography and Resources Exploration Cruise on board ORV Sagar Kanya during March-June 1990, in the Caribbean Sea.
(c) Visited University of Hawaii for six months for advanced research from May to November 1991.
(d) Participated in February 1996 Ocean Sciences meeting of AGU at San Diego, and also delivered an invited talk at the University of Washington, Seattle USA.
(e) Upon invitation by the International IGBP Office to prepare a minfesto on the International Surface Ocean - Lower Atmsophere Study (SOLAS) Programme, planned to succeed the JGOFS Programme, in January 1997, CIBA Foundation, London.
20. SEMINARS/SYMPOSIA
(a) XIX General Assembly of the International Union of Geodesy and Geophysics held at Vancouver, CANADA, during 9-22 August 1987: Presented a paper on ‘Models on the significance of oxides and hydroxides in the regulation of seawater composition’.
(b) National Symposium on International Geosphere-Biosphere Programme held at Madras, 14-17 December 1992: Presented a paper on ‘Carbon dioxide and nitrous oxide in the North Indian Ocean’.
(c) Asian Workshop and Training Programme on measurement techniques and the inventories of greenhouse gases, New Delhi, 30 October-4 November 1995. Presented a paper on ‘Carbon cycle and oceans’. Also acted as a Resource Person.
(d) Asian least cost greenhouse gas abatement strategy Workshop, New Delhi, 6- 10 November 1995. Acted as a Resource Person.
(e) American Geophysical Union ‘Ocean Sciences’ meeting, San Diego, 12-16 February 1996. Presented a paper on ‘Decadel Changes of dissolved oxygen in the minimum of the Arabian Sea’.
(f) National Symposium on Coastal and Estuarine processes around India, September 10-11, 1997. Presented a paper on ‘Influence of run-off and upwelling on air-sea fluxes of carbon dioxide in coastal waters of India’.
21. INVITED TALKS
(a) Delivered a talk on ‘Carbon cycle and oceans’ at the ‘Asian Workshop and Training Programme on measurement techniques and the inventories of greenhouse gases’, New Delhi, 30 October-4 November 1995.
(b) Delivered an invited talk on Carbon dioxide in the North Indian Ocean at the School of Oceanography, University of Washington, USA, on 19 February 1996.
(c) Delivered an invited talk on Why is the North Indian Ocean so interesting biogeochemically ? at the School of Environmental Sciences, University of East Anglia, Norwich, UK on 14 January 1997.
22. REVIEWER
Reviewed several manuscripts for the following journals:
Deep-Sea Research
Marine Chemistry
Proceedings of the Indian Academy of Sciences (Earth & Planetary Sciences)
Current Science
Indian Journal of Marine Sciences
Reviewed Ocean related chapters in the Intergovernmental Panel on Climatic Change Report 1995.
23. NATIONAL PROGRAMMES UNDERTAKEN
Active in national programmes of GLOBAL CHANGE (International Geosphere- Biosphere Programme). Under the aegies of this programme the following core projects are being carried out:
(a) IGBP-Greenhouse gases: 1990-1994
Initiated systematic carbon dioxide measurements in seawater, for the first time in India, in the North Indian Ocean.
(b) IGBP-Joint Global Ocean Flux Study (India) - Arabian Sea: 1994-1998
This is the Indian component of the International JGOFS under IGBP.
Leader of the chemistry group working on the biogeochemical cycling of carbon and nitrogen in the Arabian Sea. The results clearly established the Arabian Sea as a perennial sorce of atmospheric carbon dioxide.
(c) IGBP-Land-Ocean Interactions in the Coastal Zone - 1998-
Attempts to study the carbon flow in the system land-ocean-atmosphere system, central westcoast of India.
(d) Bay of Bengal Monsoon Experiment - from 1999-
To study biogeochemical cycling of dimethyl sulphide in the Bay of Bengal.A National Programme is being finalised.
24. OTHER IMPORTANT PROJECTS
(a) Modelling of Oceanic Chemical Processes - 1983-1990
Chemical speciation studied and developed models on the significance of oxygen in regulating the trace metal composition of seawater, including near hydrothermal systems in the deep Sea..
(b) Dimethyl Sulphide (DMS) in the North Indian Ocean- 1995-99
(IGBP related)
Leading the project that made the first ever measurements of DMS in aquatic systems of India. The results so far established large seasonal and spatial variability of this climatically important gas which has a negative effect on global warming.
25. INTERNATIONAL COLLABORATIVE PROJECTS
Associated with the following Projects:
(a) TROPHIC DYNAMICS : Indo-US Project
(b) PALEOCEANOGRAPHY: Indo-French Project
26. ADDITIONAL INFORMATION :
(a) Invited to deliver a lecture at the International Symposium on the " Chemistry of the Mediterranean", in 1984, held at Primosten, Yugoslavia.
(b) Member of the Indian National Science Academy delegation for participation in the XIX General Assembly of the International Union of Geodesy and Geophysics held at Vancouver, CANADA, during 9-22 August 1987.
(c) Participant in the YOUNG SCIENTISTS MEET with the PRIME MINISTER of India held in April 1989 for making recommendations on the means of promoting and encouraging Science and Technology in the country.
(d) Nominated to train scientists of the West Indies in Chemical Oceanography under the Commonwealth Program.
(e) Invited to deliver a lecture at the Ocean Carbon dioxide Experts meeting’ by Intergovernmental Oceanographic Commission in 1994 in Malta.
(f) Invited to deliver a lecture at the ‘Asian Workshop on Inventories of greenhouse gases’ held at NPL, New Delhi, by National IGBP Committee, October 1995.
Dr. Kumar has contributed significantly to understand the factors regulating cycling of chemical substances (trace and bioessential) and their residence times in the ocean..
Stability of oxidation states and elemental residence times
His work provides chemical evidence for the anomalous presence of thiosulphate ion and Cr (III) states in seawater. His results strongly suggest that ionic potential and oxygen as oxides and hydroxides play important roles in the dissolution and precipitation processes of elements in the ocean. A model proposed in this respect facilitated the estimation of unknown seawater-crustal rock partition coeffieients and residence times for Americium, Iridium and Rhodium in the oceans. Kumar’s study on rare earth elements (REE) yielded a distribution coefficient of 10-2.59 between oceanic reservoir and the crustal rock. He had also derived equations for estimating the sedimentation rates and residence times of REEs in the marine environment.
Cation hydrolysis and scavenging/precipitation of metals
Kumar’s consideration of hydrolytic processes as a regulating mechanism of trace metals in seawater revealed widely variable reaction intensities for cations when temperature increased from 2 to 250oC, typical of hydrothermal mixing near Mid-Oceanic Ridge System in the world oceans. It has been found that the neutral metal complexes would prevail in seawater with increase in temperature and can facilitate the formation of precipitates. His work also shed light on the reduction in pH required for hydrolytic transformation with increasing temperature thus favouring their adsorption onto suspended matter in seawater. He proved that divalent cobalt, manganese and lead exhibit undersaturation even at 250oC at their concentration levels in seawater. Thus he provided evidence and mechanisms for the formation of potential hydroxide phases near hydrothermal vents.
Regeneration and removal constants of materials in the ocean
He proposed a regeneration model, based on the decomposition processes of biogenic matter in the sea, to evaluate fluxes of trace metals and their life times in the oceans. This proved to be more advantageous compared to the earlier methods in view of the fact that not only this computes for various oxidation states of any particular element and to a specific depth range of seawater column but also this model does not need data from river inputs and/or sedimentation rates, the latter values being highly variable.
Quantification of regenerated materials in the oceans
Kumar proposed the use of multi-watermass mixing model for high precision estimates of regenerated fractions of dissolved materials. While 1/3 of the dissolved silica in water column is found to be due to regeneration in the benthic layers of the north Indian Ocean for Radium-226 it is about 1/2. Results revealed an entry of ~10% more Antarctic Bottom Water into the Bay of Bengal than into the Arabian Sea. Through this work the Influence of Indonesian Throughflow on regenerated substances in Indian Ocean has been identified to be substantial. The North Indian Ocean is a significant source of regenerated materials to the South Indian Ocean.
Biogeochemical cycling of carbon in the North Indian Ocean
Kumar’s work, during the last 5 years, has significantly contributed to understanding the mechanisms of in the biogeochemical cycling of carbon dioxide in the North Indian Ocean under International Geosphere-Biosphere Programme (Global Change). He led the investigations on carbon and nitrogen dynamics in the Arabian Sea as a part of the Joint Global Ocean Flux Study (India).
The North Indian Ocean is of global importance as it houses diverse physico- and biogeochemical regimes, and the most intense oxygen deficient conditions in intermediate layers; which have been, for the first time, found to be seasonally highly variable. Realising the unique potential of this region,which has global implications, Kumar has initiated and carried out systematic studies on the carbon dioxide system through developing high precision methodologies.
Dynamics of dissolved & particulate carbon
A comprehensive study on the dissolved organic carbon in the Arabian Sea established its non-conservative behaviour together with large variability in its oxidation. Coupling between dissolved organic carbon and nitrification/denitrification highlighted the dominant role of microbes in carbon turnover in the Arabian Sea that eventually led to reducing conditions in the North. Seasonal changes in reducing conditions seem to be driven by enhanced productivity through winter convection and also through the efficient operation of ‘microbial loop’ in the Arabian Sea. Occurrence of Intermediate Nepheloid Layers has been found in the Arabian Sea, which is unusual in the oceans except in eastern Pacific. These particles are invariably associated with secondary nitrite and high particulate protein and electron transports. This led his group to propose that this bacterial maximum could have been due to efficient utilization of dissolved organic carbon under reducing conditions. The extent of oxidation of dissolved organic carbon has been found to determine the magnitude of carbon dioxide increase in the North Arabian Sea. Regional variability in skeletal carbonate dissolution in water column was also found to be caused by corrosivity of waters and inhibition by faecal pellets. The Arabian Sea is more corrosive to carbonates than the Bay of Bengal.
His latest results from the JGOFS (India) programme revealed significant quantities of Transparent Exopolymer Particles (TEP) in the Arabian Sea than in the Bay of Bengal. Contrasting the earlier findings by other workers, these results suggested that adequate ‘particulate carbon substrate’ is available to meet the microbial demands in denitrifying layers of the Arabian Sea. On the other hand, strong TEP-mineral association found in the Bay of Bengal suggests rapid sedimentation of carbon particles in the bay than elsewhere in the Indian Ocean. These results are of great significance to unravel the intriguing processes in carbon cycling in this region.
Sources & sinks of carbon
A build up in the partial pressure of carbon dioxide, by 3-4 times to that in the atmosphere, was found in the deep North Indian Ocean. Budget calculations, in addition to these results, led to the conclusion that the Arabian Sea could be a significant source not only to atmospheric carbon dioxide but also to two important marginal seas; the Red Sea and the Persian Gulf. The role of the Antarctic Bottom Water in maintaining the carbon dioxide budgets in the North Indian Ocean has been realised to be significant . Most significantly, his works established that while the Bay of Bengal is a seasonal sink for atmospheric carbon dioxide the Arabian Sea acts as a source despite the large seasonal variability. His extensive coverage of the eastern and central Arabian Sea under the JGOFS programme yielded valuable results that led to depicting this region as a perennial source of atmospheric carbon dioxide where larger fluxes occur in Southwest monsoon.
Biogeochemistry of Dimethyl Sulphide
Kumar recently initiated measurements of Dimethyl Sulphide (DMS) in the country in view of its global significance in forming aerosols and Cloud Condensation Nuclei in addition to effecting the albedo changes. He found that significant quantities of DMS (10-60 ng/l) present in surface waters were reduced to <5 ng/l with the onset of winter phytoplankton bloom in the Arabian Sea. This led to the dominance of methane thiol in winter. Therefore the efflux of DMS from the north Arabian Sea would be significant during oligotrophic conditions in the Arabian Sea.
1. M. Dileep Kumar (1981) The oxidation state diagram Stability of dissolved sulphur species in seawater.
MARINE CHEMISTRY, 10: 475-486.
2. M. Dileep Kumar (1983) The significance of oxygen as oxides and hydroxides in controlling the abundance and residence times of elements in seawater.
MARINE CHEMISTRY, 14: 121-132.
3. M. Dileep Kumar (1983) Ionic Potential as a controller of seawater composition.
INDIAN JOURNAL OF MARINE SCIENCES, 12: 233-235.
4. M. Dileep Kumar (1984) Ionic Potential correlations with chemical processes of rare earths in the sea.
MARINE CHEMISTRY, 14: 253-258.
5. M. Dileep Kumar, K. Somasundar and A. Rajendran (1985) Stability of Phosphorus species in seawater.
INDIAN JOURNAL OF MARINE SCIENCES, 14: 20-23.
6. M. Dileep Kumar and C. V. G. Reddy (1985) Thermodynamic metastability of chromium (III) & chromium speciation in natural waters.
INDIAN JOURNAL OF MARINE SCIENCES, 14: 151-155.
7. M. Dileep Kumar (1986) A regeneration model to estimate addition fluxes and removal constants of trace metals in seawater.
MARINE CHEMISTRY, 19: 323-335.
8. M. Dileep Kumar (1987) Cation hydrolysis and the regulation of trace metal composition in seawater.
GEOCHIMICA ET COSMOCHIMICA ACTA, 51: 2137-2145.
9. M. Dileep Kumar (1987) Models on the significance of oxides and hydroxides in the regulation of seawater composition, XIX IUGG General Assembly, PROCES- VERBAUX No. 17, 314.
10. K. Somasundar, A. Rajendran and M. Dileep Kumar (1987) Property-Property relations: 22 and 9oC discontinuities in the Arabian Sea.
OCEANOLOGICA ACTA, 10: 293-300.
11. D. Satyanarayana, B. R. Prasada Reddy, M. Dileep Kumar and A. Ramesh (1987) Chemical oceanographic studies on the Bay of Bengal-north of Visakhapatnam.
In:CONTRIBUTIONS IN MARINE SCIENCE, p.329-338.
12. K. Somasundar, A. Rajendran, M. Dileep Kumar and R. Sen Gupta (1990) Carbon and Nitrogen Budgets of the Arabian Sea.
MARINE CHEMISTRY, 30: 363-377.
13. M. Dileep Kumar, A. Rajendran, K. Somasundar, B. Haake, A. Jenisch, Z. Shuo, V. Ittekkot and B. N. Desai (1990) Dynamics of dissolved organic carbon in the northwestern Indian ocean.
MARINE CHEMISTRY, 31: 299-316.
14. A. Rajendran, M. Dileep Kumar, A. A. Khan, D. Knight, A. O' Reilly, I. Chang Yen, A. B. Wagh and B. N. Desai (1991) Some aspects of nutrient chemistry of the caribbean sea.
CARIBB. MAR. STUD., 2: 81-86
15. A. Rajendran, M. Dileep Kumar and J. Bakkar(1992) Control of manganese and iron in Skagerrak sediments.
CHEMICAL GEOLOGY, 98: 111-129.
16. M. Dileep Kumar, A. Rajendran, K. Somasundar, V. Ittekkot and B. N. Desai (1992) Processes controlling carbon components in the Arabian Sea.
OCEANOGRAPHY OF THE INDIAN OCEAN (PROC. INTERNATIONAL SYMPOSIUM ON THE INDIAN OCEAN, ed. B. N. Desai, Oxford-IBH, New Delhi), pp.313-325.
17. M. Dileep Kumar, M. D. George and R. Sen Gupta (1992) Indian River inputs into the oceans : a Synthesis.
OCEANOGRAPHY OF THE INDIAN OCEAN (PROC.INTERNATIONAL SYMPOSIUM ON THE INDIAN OCEAN, ed. B.N. Desai, Oxford-IBH, New Delhi), pp.347-358.
18. S. W. A. Naqvi, R. Sen Gupta and M. Dileep Kumar (1992) Carbon dioxide and nitrous oxide in the Arabian Sea.
In 'INTERACTIONS BETWEEN GLOBAL CLIMATE SUBSYSTEMS, The Legacy of Hann, Geophysical Monograph 75, IUGG volume 15, American Geophysical Union, pp. 85-92.
19. S. W. A. Naqvi, M. Dileep Kumar, P. V. Narvekar, S. N. de Souza, M. D. George and C. D'Silva (1993) An Intermediate nepheloid layer associated with high microbial metabolic rates and denitrification in the Northwest Indian Ocean.
JOURNAL OF GEOPHYSICAL RESEARCH, 98(C9): 16,469-16,479.
20. M. Dileep Kumar, M. D. George and M. D. Rajagopal (1993) Intertidal zones as carbon dioxide source to the coastal oceans.
INDIAN JOURNAL OF MARINE SCIENCES, 22: 221-224.
21. A. Rajendran, M. Dileep Kumar, N. Ramaiah, V. Ittekkot and B. N. Deasi (1993) Variable relationships of DOC with oxygen in the Northwestern Indian Ocean and their ecological implications.
SCOPE/UNEP Sonderband Heft 76: 73-83.
22. M. D. George, M. Dileep Kumar, S. W. A. Naqvi, S. Benerjee, S. N. de Souza, P. V. Narvekar and D. A. Jayakumar (1994) A study of the carbon dioxide system in the northern Indian Ocean during premonsoon.
MARINE CHEMISTRY, 47: 243-254.
23. S. W. A. Naqvi, D. A. Jayakumar, M. Nair, M. D. Kumar and M. D. George (1994) Nitrous oxide in the western Bay of Bengal.
MARINE CHEMISTRY, 47: 269-278.
24. C. K. Rao, S. W. A. Naqvi, M. D. Kumar, S. J. D. Varaprasad, D. A. Jayakumar, M. D. George and S. Y. S. Singbal (1994) Hydrochemistry of the Bay of Bengal:possible reasons for a different water-column cycling of carbon and nitrogen from the Arabian Sea.
MARINE CHEMISTRY, 47: 279-290.
25. M. Dileep Kumar, S. W. A. Naqvi, D. A. Jayakumar, M. D. George, P. V. Narvekar and S. N. de Sousa (1995) Carbon dioxide and nitrous oxide in the North Indian Ocean.
CURRENT SCIENCE, 69: 672-678
26. S. W. A. Naqvi, M. S. Shailaja, M. Dileep Kumar and R. Sen Gupta (1996) Respiration rates in subsurface waters of the northern Indian Ocean: Evidence for low decomposition rates of organic matter within the water column in the Bay of Bengal.
DEEP-SEA RESEARCH II, 43: 73-81.
27. M. Dileep Kumar, S. W. A. Naqvi, M. D. George and D. A. Jayakumar (1996) A sink for atmospheric carbon dioxide in the Bay of Bengal.
JOURNAL OF GEOPHYSICAL RESEARCH, 101: 18,121-18,125.
28. S. N. de Sousa, M. Dileep Kumar, S. Sardesai, V. V. S. S. Sarma and P. V. Shirodkar (1996) Seasonal variability in oxygen and nutrients in the central and eastern Arabian Sea.
CURRENT SCIENCE, 71: 847-851.
29. V. V. S. S. Sarma, M. Dileep Kumar, M. D. George and A. Rajendran (1996) Seasonal variations in inorganic carbon components in the central and eastern Arabian Sea.
CURRENT SCIENCE, 71: 852-856.
30. M. Madhupratap, S. Prasanna Kumar, P. M. A. Bhattathiri, M. Dileep Kumar, S. Raghukumar, K. K. C. Nair and N. Ramaiah (1996) Mechanism of the biological response to winter cooling in the northeastern Arabian Sea.
NATURE (London), 384: 549-552.
31. M. Dileep Kumar and Y. H. Li (1996) Spreading of water masses and regeneration of 226Ra and Silica in the Indian Ocean.
DEEP-SEA RESEARCH II, 43: 83-110.
32. M. Dileep Kumar, V. V. S. S. Sarma, N. Ramaiah, M. Gauns and S. N. de Sousa (1998) Biogeochemical significance of transport exopolymer particles in the Indian Ocean. GEOPHYSICAL RESEARCH LETTERS, 25, 81-84.
33. V. V. S. S. Sarma, M. Dileep Kumar and M. D. George (1998) The central and eastern Arabian Sea as a perennial source to atmospheric carbon dioxide.
TELLUS, 50B, 179-184