Sciences and Exploration Directorate

Brief Bio


Senior Earth Scientist and Remote Sensing professional and manager with more than 17 years of experience in studying different aspects of Earth System Science. Currently working as a Sr. Scientist and Manager in the Terrestrial Information Systems Lab (Code-619) as part of MODAPS and NASA Land SIPS. Experienced with managing all aspects of a large data production facility. Active research interests include looking at land-atmosphere interactions, natural hazards and air quality, long-term change monitoring and implications for climate change.

Research Interests


Research Interests

Earth Science: Remote Sensing

  • Natural Hazards and Impact of Climate Change
  • Long term change detection using Remote sensing 
  • Land Atmosphere Interactions
  • Interannual variability of climate parameteres and role of human impact

Positions/Employment


MODAPS and LandSIPS Manager

SSAI - Terrestrial Information System (Code 619) GSFC, NASA

April 2022 - Present

  • Lead and manage the entire data production facility comprising MODIS Adaptive Processing System (MODAPS), NRT LANCE and VIIRS NASA LandSIPS.
  • Act as the chief Science SME within the production facility.
  • Chief POC for all matters related to data production, availability, and quality.


MODIS/VIIRS QA Lead

SSAI - Terrestrial Information System (Code 619) GSFC, NASA

January 2018 - March 2022

  • Lead and coordinate all activities of the Land Data Operational Product Evaluation (LDOPE) group, which is part of the NASA Land SIPS and MODIS processing system (MODAPS). 
  • Oversee all data production issues and work closely with the data production team, science team, and various other stakeholders to ensure a smooth workflow and satisfaction of all data quality standards.


Sr. Scientist/ Developer

SSAI - NASA GSFC (Code 619)

December 2014 - June 2018

Develop and validate multiple land science products, derived from NASA EOS and JPSS series of satellite missions like MODIS, Suomi NPP etc. Work closely with different science teams and institutions to develop land algorithms, QA/QC data products, perform systematic data validation and analysis and inter-sensor comparison. 

Research interests include leveraging satellite data to study the impact of climate change on land and atmospheric processes and their mutual feedback. Role of human impact in driving these land atmospheric feedback mechanisms and its steady evolution over the years. 

 


Senior Scientist/Developer

Sigma Space Corp. - NASA GSFC

February 2012 - December 2014

Member of the Terrestrial Information Systems Lab., in GSFC, as part of MODIS LDOPE/NPP LPEATE.  Responsible for development of land algorithms for development of scientific datasets from L1B - L3/L4 for all land related parameters and covering the entire globe, derived from MODIS Terra/Aqua and NPP VIIRS. Responsible for validation of land products. Research focus includes the study of land surface processes and their interaction, leveraging satellite data. 


Lead Analyst

Lanworth/Thomson Reuters - Chicago, IL

December 2004 - December 2011

Plays a leading role in developing workflow and algorithms for providing commodity intelligence to hedge fund
managers, traders and global food companies for major commodity crops like corn, soybean, wheat, cane, canola etc across diverse regions of the globe in USA, Canada, Russia, India, South America and China using geospatial technology.
 

Lead and manage diverse services/consulting projects involving the use of geospatial technology for better strategic and supply chain analysis. This involved spatial mapping of land-cover, hbu potential, natural hazards,
environmental and atmospheric parameters across diverse geographic scales using a plethora of sensors operating in visible to microwave ranges. Also involved large scale land due-diligence studies for different timber merchants and paper companies.
 


Graduate Research Assistant

School of Computational Science, George Mason University - Fairfax, VA, USA

March 2001 - December 2004

  • Designed and executed a number of critical and pioneering research studies aimed at better understanding different aspects of the biosphere, hydrosphere and atmosphere with their respective interactions over inter- annual to decadal time scales. Specifically: • Performed extensive research focusing on possible feedback of land cover and soil moisture on the hydrological cycle and monsoon rainfall over South East Asia. This research combined observational data analysis with comprehensive land surface modeling in an effort to understand the scale of coupling and underlying physics. A part of this research was carried out in NASA Goddard (GSFC).
  • Investigated the inter-annual variability of vegetation and aerosol radiative forcing over Indian sub-continent.
  • Investigated the variability of monsoon rainfall over South Asia and decreasing influence of ENSO vis-à-vis monsoon rainfall.


Internship

Hydrological Sciences Branch, NASA GSFC - Greenbelt, MD, USA

May 2004 - August 2004

Perform land surface modeling to understand the interaction between land-cover and atmosphere. The research was aimed at better predicting the changes in hydrological cycle and monsoonal precipitation because of changes in Land Surface.


Sr. Project Associate

Dept. of Civil Engineering, IIT Kanpur - Kanpur, India

October 1999 - July 2000

Involved in extensive research of climate parameters and their variability over the Indian sub-continent, specifically snow-cover, tropospheric ozone and aerosol. The possible teleconnection pattern of pacific disturbance over Indian sub-continent was thoroughly explored with the aid of datasets from SSM/I, TOMS, GOME etc.


Systems Engineer

Tata Infotech Ltd., (Now part of Tata Consultancy Services, TCS) - New Delhi, India

July 1998 - September 1999

Responsible for development of a complete Hydrological Information System (HIS) for Ground Water Board of the Government of India. The back-end RDBMS used for the project was ORACLE 8.0 and Spatialware. C++, MapInfo 5.5., Visual Basic 5.0 and Map Basic 5.5 were used to develop the forms for HIS user interface extensibility and Crystal Report for generating MIS reports from Hydrology Database. Vertical Mapper 2.1.1 was used for spatial analysis. Certain Statistical Parameters were calculated through a seamless integration of SPSS with MapInfo 5.5. The development platform was Windows -NT 4.0 Workstation and Server.

Education


PhD in Computational Sciences with specialization in Earth Observation and Remote Sensing - 2004, George Mason University

M.S. in Computational Sciences with specialization in Earth Observation and Remote Sensing - 2003, George Mason University

M.tech in Earth Sciences - 1998, IIT Roorkee, India

B.Sc in Geology - 1995, University of Calcutta, India

Professional Societies


American Geophysical Society

2014 - Present

Professional Service


Former Member of the Editorial Board:

Reviewer for Several Peer reviewed Journals like:

  1. Remote Sensing of Environment
  2. Journal of Climate
  3. Remote Sensing
  4. International Journal of Remote Sensing
  5. Geomatics, Natural Hazards and Risk
  6. Water, Air, & Soil Pollution
  7. Sustainability
  8. International Journal of Geo-Information 
  9. The Scientific Pages of Forest Research
  10. Indian Journal of Remote Sensing
  11. Environments

Selected Publications


Refereed

Román, M. O., C. Justice, I. Paynter, et al. P. B. Boucher, S. Devadiga, A. Endsley, A. Erb, M. Friedl, H. Gao, L. Giglio, J. M. Gray, D. K. Hall, G. Hulley, J. Kimball, Y. Knyazikhin, A. I. Lyapustin, R. B. Myneni, P. Noojipady, J. Pu, G. Riggs, S. Sarkar, C. Schaaf, D. Shah, K. H. Tran, E. F. Vermote, D. Wang, Z. Wang, A. Wu, Y. Ye, Y. Shen, S. Zhang, S. Zhang, X. Zhang, M. Zhao, C. C. Davidson, and R. E. Wolfe. 2024. Continuity between NASA MODIS Collection 6.1 and VIIRS Collection 2 land products Remote Sensing of Environment 302 113963 [10.1016/j.rse.2023.113963]

Shah, D., S. Zhang, S. Sarkar, et al. C. Davidson, R. Zhang, M. Zhao, S. Devadiga, P. Noojipady, M. O. Román, and H. Gao. 2024. Transitioning from MODIS to VIIRS Global Water Reservoir Product Scientific Data 11 (1): 209 [10.1038/s41597-024-03028-2]

Li, Y., G. Zhao, D. Shah, et al. M. Zhao, S. Sarkar, S. Devadiga, B. Zhao, S. Zhang, and H. Gao. 2021. NASA’s MODIS/VIIRS Global Water Reservoir Product Suite from Moderate Resolution Remote Sensing Data Remote Sensing 13 (4): 565 [10.3390/rs13040565]

Sarkar, S., A. Chauhan, R. Kumar, and R. P. Singh. 2019. Impact of Deadly Dust storms (May 2018) on Air Quality, Meteorological and Atmospheric Parameters over the Northern Parts of India GeoHealth [10.1029/2018gh000170]

Pahlevan, N., S. Balasubramanian, S. Sarkar, and B. Franz. 2018. Toward Long-Term Aquatic Science Products from Heritage Landsat Missions Remote Sensing 10 (9): 1337 [10.3390/rs10091337]

Sarkar, S., R. P. Singh, and A. Chauhan. 2018. Increasing health threat to greater parts of India due to crop residue burning The Lancet Planetary Health 2 (8): e327-e328 [10.1016/s2542-5196(18)30166-9]

Sarkar, S., R. P. Singh, and A. Chauhan. 2018. Crop Residue Burning in Northern India: Increasing Threat to Greater India Journal of Geophysical Research: Atmospheres [10.1029/2018jd028428]

Román, M. O., Z. Wang, Q. Sun, et al. V. Kalb, S. D. Miller, A. Molthan, L. Schultz, J. Bell, E. C. Stokes, B. Pandey, K. C. Seto, D. Hall, T. Oda, R. E. Wolfe, G. Lin, N. Golpayegani, S. Devadiga, C. Davidson, S. Sarkar, C. Praderas, J. Schmaltz, R. Boller, J. Stevens, O. M. Ramos González, E. Padilla, J. Alonso, Y. Detrés, R. Armstrong, I. Miranda, Y. Conte, N. Marrero, K. MacManus, T. Esch, and E. J. Masuoka. 2018. NASA's Black Marble nighttime lights product suite Remote Sensing of Environment 210 113-143 [10.1016/j.rse.2018.03.017]

Sarkar, S., R. P. Singh, and A. Chauhan. 2018. Anomalous changes in meteorological parameters along the track of 2017 Hurricane Harvey Remote Sensing Letters 9 (5): 488-497 [10.1080/2150704x.2018.1441562]

Pahlevan, N., S. Sarkar, B. A. Franz, S. Velaudhaperumal Balasubramanian, and J. He. 2017. Sentinel-2 MultiSpectral Instrument (MSI) data processing for aquatic science applications: Demonstrations and validations Remote Sensing of Environment 201 47-56 [10.1016/j.rse.2017.08.033]

Sarkar, S. 2017. Phenology and carbon fixing: a satellite-based study over Continental USA International Journal of Remote Sensing 39 (1): 1-16 [10.1080/01431161.2017.1378457]

Singh, R. P., and S. Sarkar. 2017. Methane and Carbon Monoxide emissions associated with Aliso Canyon ground storage blowout 2017 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Austin, Texas 2017 5950-5953 [10.1109/IGARSS.2017.8128364]

Sarkar, S., and R. P. Singh. 2017. June 19 2015 Rainfall Event Over Mumbai: Some Observational Analysis Journal of the Indian Society of Remote Sensing 45 (1): 185-192 [10.1007/s12524-016-0572-7]

Kim, B., and S. Sarkar. 2017. Impact of wildfires on some greenhouse gases over continental USA: A study based on satellite data Remote sensing of Environment 188 (1): 118--126 [10.1016/j.rse.2016.10.047]

Pahlevan, N., S. Sarkar, S. Devadiga, et al. R. E. Wolfe, M. Roman, E. Vermote, G. Lin, and X. Xiong. 2017. Impact of Spatial Sampling on Continuity of MODIS–VIIRS Land Surface Reflectance Products: A Simulation Approach IEEE Transactions on Geoscience and Remote Sensing 55 (1): 183-196 [10.1109/tgrs.2016.2604214]

Pahlevan, N., S. Sarkar, and B. A. Franz. 2016. Uncertainties in coastal ocean color products: Impacts of spatial sampling Remote Sensing of Environment 181 14-26 [10.1016/j.rse.2016.03.022]

Friedenberg, N. A., S. Sarkar, N. Kouchoukos, R. F. Billings, and M. P. Ayres. 2008. Temperature extremes, density dependence, and southern pine beetle (Coleoptera: Curculionidae) population dynamics in east Texas Environmental Entomology 37 (3): 650--659

Sarkar, S., L. Chiu, M. Kafatos, and R. Singh. 2007. Sensitivity of rainfall on land cover change over South East Asia: Some observational results Advances in Space Research 39 (1): 73--78

Prasad, A. K., S. Sarkar, R. P. Singh, and M. Kafatos. 2007. Inter-annual variability of vegetation cover and rainfall over India Advances in space research 39 (1): 79--87

Sarkar, S., R. Chokngamwong, G. Cervone, R. Singh, and M. Kafatos. 2006. Variability of aerosol optical depth and aerosol forcing over India Advances in Space Research 37 (12): 2153--2159

Sahoo, A., S. Sarkar, R. Singh, M. Kafatos, and M. Summers. 2005. Declining trend of total ozone column over the northern parts of India International Journal of Remote Sensing 26 (16): 3433--3440

Dey, S., S. Sarkar, and R. Singh. 2004. Comparison of aerosol radiative forcing over the Arabian Sea and the Bay of Bengal Advances in Space Research 33 (7): 1104--1108

el-Askary, H., S. Sarkar, L. Chiu, M. Kafatos, and T. El-Ghazawi. 2004. Rain gauge derived precipitation variability over Virginia and its relation with the El Nino southern oscillation Advances in Space Research 33 (3): 338--342

Sarkar, S., R. P. Singh, and M. Kafatos. 2004. Further evidences for the weakening relationship of Indian rainfall and ENSO over India Geophysical Research Letters 31 (13):

Dey, S., S. Sarkar, and R. Singh. 2004. Anomalous changes in column water vapor after Gujarat earthquake Advances in Space Research 33 (3): 274--278

Sarkar, S., and M. Kafatos. 2004. Interannual variability of vegetation over the Indian sub-continent and its relation to the different meteorological parameters Remote Sensing of Environment 90 (2): 268--280

Kafatos, M., H. El-Askary, L. S. Chiu, et al. R. B. Gomez, M. Hegazy, J. M. Kinser, X. Liu, Y. Liu, Z. Liu, J. McManus, Y. Nie, J. Qu, F. Salem, S. Sarkar, S. Shen, G. Taylor, H. Wolf, D. Wong, C. Yang, and R. Yang. 2003. Remote sensing and GIS for regional environmental applications Remote Sensing for Environmental Monitoring, GIS Applications, and Geology II 4886 [10.1117/12.463316]

El-Askary, H. M., S. Sarkar, M. Kafatos, and T. A. El-Ghazawi. 2003. A multisensor approach to dust storm monitoring over the Nile Delta IEEE Transactions on geoscience and Remote Sensing 41 (10): 2386--2391

Mishra, N., R. Kanwar, S. Sarakar, P. Dash, and R. Singh. 2002. Use of multi-sensor data for mapping of thar desert Advances in Space Research 29 (1): 51-55 [10.1016/s0273-1177(01)00627-5]

Singh, R., S. Sarkar, and A. Singh. 2002. Effect of El Nino on inter-annual variability of ozone during the period 1978-2000 over the Indian subcontinent and China International journal of remote sensing 23 (12): 2449--2456

Singh, R. P., S. Sarkar, and A. Singh. 2000. Effect of El Niaeo observed over Indian continent from satellite-derived ozone data Eos, Transactions American Geophysical Union 81 (36): 409--413

Sarkar, S., and R. P. Singh. 2000. Inter-annual variability of total ozone deduced from GOME and its relation to observed El Nino of 1997-1998 Current Science 79 (1): 79--81

Non-Refereed

Sarkar, S., R. P. Singh, and A. Chauhan. 2018. Crop residue burning affects large parts of India Nature India [10.1038/nindia.2018.78]

Talks, Presentations and Posters


Other

LONG RANGE TRANSPORT OF AIR MASS FROM THE CROP RESIDUE BURNING (WESTERN PARTS OF INDIA) DURING WINTER SEASON AND ITS IMPACTS ON HUMAN HEALTH AND WEATHER CONDITIONS OVER THE INDO-GANGETIC PLAINS (IGP)

August 16, 2018

Chauhan A, Sarkar S, Gautam G, and Singh R. 42nd COSPAR Scientific Assembly, 2018, Pasadena, California


Changes in Land, Ocean, Meteorological and Atmospheric Parameters Along the Harvey Hurricane Track Observed from GPS, Buoys and Satellite Data

June 22, 2018

Singh R, Sarkar S and Chauhan A. JpGU 2018 (Japan Geoscience Union) at Chiba, Japan


Landsat-Sentinel-2 for aquatic science: Steps towards transitioning from research to operations

2018

Pahlevan N, Sarkar S, Chittimalli S and Subramanian S.  Pecora 20, November 13-17, 2017, Sioux Falls, South Dakota.


Over-water inter-calibration and atmosphere correction for Landsat-8/Sentinel-2

October 19, 2017

Pahlevan N, Sarkar S and Chittimali S. Recent Advances in Quantitative Remote Sensing (RAQRS) Torrent, Spain 2017


Methane and Carbon Monoxide Emissions Associated with Aliso Canyon Ground Storage Blowout

August 2017

IEEE IGARSS 2017, Austin, Texas, USA


Towards Consistent Landsat-Sentinel-2 Products over Coastal/Inland Waters

June 16, 2017

Pahlevan N, Sarkar S, Chittimalli S and Subramanian S. Third International Ocean Colour Science Meeting (IOCS) Lisbon, Portugal, 15-18 May 2017


Urban area monitoring using MODIS time series data

2014

Sarkar, S, Devadiga, S and Masuoka, E., AGU Fall Meeting - 2014


Spatial-Temporal-Vertical Variations of Total Ozone Concentration (TOC) and its Relationship to Other Meteorological Parameters Over the Indo-Gangetic Basin

April 2006

Sahoo, AK and Sarkar, S and Singh, RP and Kafatos, M, AGU Spring Meeting


Vegetation Variability And Its Effect On Monsoon Rainfall Over South East Asia: Observational and Modeling Results

2005

Sarkar, S and Peters-Lidard, C and Chiu, L and Kafatos, M, AGU Fall meeting - 2005


Land cover change and its impact on annual rainfall over South East Asia

2004

Sarkar, S and Chiu, L and Kafatos, M and Singh, 35th COSPAR Scientific Assembly


Early Warning of Coastal Earthquakes Using Land, Ocean and Atmospheric Parameters

2003

Singh, RP and Dey, S and Sarkar, S and Kafatos, M, AGU Fall Meeting - 2003