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Roose S, Ajayamohan RS, Ray P, Xie SP, Sabeerali CT, Mohapatra M, Taraphdar S, Mohanakumar K, Rajeevan M. Pacific decadal oscillation causes fewer near-equatorial cyclones in the North Indian Ocean. Nat Commun 2023; 14:5099. [PMID: 37640712 PMCID: PMC10462712 DOI: 10.1038/s41467-023-40642-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/03/2023] [Indexed: 08/31/2023] Open
Abstract
Tropical cyclones do not form easily near the equator but can intensify rapidly, leaving little time for preparation. We investigate the number of near-equatorial (originating between 5°N and 11°N) tropical cyclones over the north Indian Ocean during post-monsoon season (October to December) over the past 60 years. The study reveals a marked 43% decline in the number of such cyclones in recent decades (1981-2010) compared to earlier (1951-1980). Here, we show this decline in tropical cyclone frequency is primarily due to the weakened low-level vorticity modulated by the Pacific Decadal Oscillation (PDO) and increased vertical wind shear. In the presence of low-latitude basin-wide warming and a favorable phase of the PDO, both the intensity and frequency of such cyclones are expected to increase. Such dramatic and unique changes in tropical cyclonic activity due to the interplay between natural variability and climate change call for appropriate planning and mitigation strategies.
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Affiliation(s)
- Shinto Roose
- Arabian Center for Climate and Environmental Sciences, New York University Abu Dhabi, Abu Dhabi, UAE
- Department of Civil Engineering, McGill University, Montreal, Canada
| | - R S Ajayamohan
- Arabian Center for Climate and Environmental Sciences, New York University Abu Dhabi, Abu Dhabi, UAE.
- Department of Meteorology, Abu Dhabi Polytechnic, Institute of Applied Technology, Abu Dhabi, UAE.
| | - Pallav Ray
- Meteorology, Florida Institute of Technology, Melbourne, FL, USA
| | - Shang-Ping Xie
- Scripps Institute of Oceanography, University of California San Diego, San Diego, CA, USA
| | - C T Sabeerali
- Arabian Center for Climate and Environmental Sciences, New York University Abu Dhabi, Abu Dhabi, UAE
- Climate Research and Services, India Meteorological Department, Pune, India
| | - M Mohapatra
- India Meteorological Department, New Delhi, India
| | - S Taraphdar
- Arabian Center for Climate and Environmental Sciences, New York University Abu Dhabi, Abu Dhabi, UAE
- Atmospheric Science & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - K Mohanakumar
- Advanced Centre for Atmospheric Radar Research, Cochin University of Science and Technology, Kochi, India
| | - M Rajeevan
- Ministry of Earth Sciences, New Delhi, India
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Jena C, Ghude SD, Kumar R, Debnath S, Govardhan G, Soni VK, Kulkarni SH, Beig G, Nanjundiah RS, Rajeevan M. Performance of high resolution (400 m) PM 2.5 forecast over Delhi. Sci Rep 2021; 11:4104. [PMID: 33603003 PMCID: PMC7892871 DOI: 10.1038/s41598-021-83467-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/27/2021] [Indexed: 11/20/2022] Open
Abstract
This study reports a very high-resolution (400 m grid-spacing) operational air quality forecasting system developed to alert residents of Delhi and the National Capital Region (NCR) about forthcoming acute air pollution episodes. Such a high-resolution system has been developed for the first time and is evaluated during October 2019-February 2020. The system assimilates near real-time aerosol observations from in situ and space-borne platform in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) to produce a 72-h forecast daily in a dynamical downscaling framework. The assimilation of aerosol optical depth and surface PM2.5 observations improves the initial condition for surface PM2.5 by about 45 µg/m3 (about 50%).The accuracy of the forecast degrades slightly with lead time as mean bias increase from + 2.5 µg/m3 on the first day to - 17 µg/m3 on the third day of forecast. Our forecast is found to be very skillful both for PM2.5 concentration and unhealthy/ very unhealthy air quality index categories, and has been helping the decision-makers in Delhi make informed decisions.
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Affiliation(s)
- Chinmay Jena
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India.
| | - Sachin D Ghude
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India.
| | - Rajesh Kumar
- National Center for Atmospheric Research, Boulder, CO, 80301, USA
| | - Sreyashi Debnath
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
- Department of Atmospheric and Space Sciences, Savitribai Phule Pune University, Pune, India
| | - Gaurav Govardhan
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
- National Center for Medium Range Weather Forecasting, Ministry of Earth Sciences, Noida, UP, India
| | - Vijay K Soni
- India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
| | | | - G Beig
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Ravi S Nanjundiah
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
- Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru, 560012, India
| | - M Rajeevan
- Ministry of Earth Sciences, Prithvi Bhavan, Lodhi Road, New Delhi, 110003, India
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3
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Acharja P, Ali K, Trivedi DK, Safai PD, Ghude S, Prabhakaran T, Rajeevan M. Characterization of atmospheric trace gases and water soluble inorganic chemical ions of PM 1 and PM 2.5 at Indira Gandhi International Airport, New Delhi during 2017-18 winter. Sci Total Environ 2020; 729:138800. [PMID: 32361437 DOI: 10.1016/j.scitotenv.2020.138800] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/14/2020] [Accepted: 04/17/2020] [Indexed: 06/11/2023]
Abstract
Water soluble inorganic chemical ions of PM1 and PM2.5 and atmospheric trace gases were monitored simultaneously on hourly resolution at Indira Gandhi International Airport (IGIA), Delhi during 8 December 2017-10 February 2018. Monitoring was made by MARGA (Monitoring AeRosol and Gases in ambient Air) under winter fog experiment (WIFEX) program of the Ministry of Earth Sciences (MoES), Government of India. The result based on the analysis of the data so generated reveals that Cl-, NH4+, NO3- and SO42- were dominant ions in order which collectively constituted 96.8 and 97.3% of the of the total measured ionic mass in PM1 and PM2.5 respectively. Their overall average concentrations in PM1 were 19.5 ± 19.7, 18.4 ± 10.5, 16.6 ± 8.7 and 10.3 ± 5.7 μg/m3 and in PM2.5 were 36.0 ± 33.9, 32.7 ± 17.2, 28.5 ± 13.6 and 19.9 ± 13.9 μg/m3. Average concentrations of HCl, HNO3, HNO2, SO2 and NH3 trace gases were 0.7 ± 0.3, 2.7 ± 1.1, 6.6 ± 4.7, 22.0 ± 12.3 and 25.7 ± 9.1 μg/m3 respectively. Weather parameters along with low mixing height played significant role in the occurrence of high concentration of these chemical species. NH4+ was the prime neutralizer of the acidic components and mostly occurred in (NH4)2SO4/NH4HSO4, NH4NO3 and NH4Cl molecular forms. Major sources of these chemical species were fossil fuel combustion in aviation activity and transportation, coal burning in thermal power plants, industrial processes and emissions from biomass burning and agro-based activity. The quality of air with respect to PM2.5 always remained deteriorated. It became alarming during low visibility period mainly due to high concentration of Cl-, NO3-, SO42- and NH4+. Both meteorological and chemical processes interactively fed each other which occasionally resulted in fog development and visibility degradation. The knowledge gained by this study will help in simulation of atmospheric processes which lead to fog development and dispersal in the Delhi region.
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Affiliation(s)
- Prodip Acharja
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India; Savitribai Phule Pune University, Ganeshkhind Road, Pune 411007, India
| | - Kaushar Ali
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India.
| | - Dinesh Kumar Trivedi
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - P D Safai
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - Sachin Ghude
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - Thara Prabhakaran
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune 411008, India
| | - M Rajeevan
- Ministry of Earth Sciences, Prithvi Bhavan, Lodhi Road, New Delhi 110003, India
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Ghude SD, Kumar R, Jena C, Debnath S, Kulkarni RG, Alessandrini S, Biswas M, Kulkrani S, Pithani P, Kelkar S, Sajjan V, Chate DM, Soni VK, Singh S, Nanjundiah RS, Rajeevan M. Evaluation of PM 2.5 Forecast using Chemical Data Assimilation in the WRF-Chem Model: A Novel Initiative Under the Ministry of Earth Sciences Air Quality Early Warning System for Delhi, India. CURR SCI INDIA 2020. [DOI: 10.18520/cs/v118/i11/1803-1815] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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5
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Hakkim H, Sinha V, Chandra BP, Kumar A, Mishra AK, Sinha B, Sharma G, Pawar H, Sohpaul B, Ghude SD, Pithani P, Kulkarni R, Jenamani RK, Rajeevan M. Volatile organic compound measurements point to fog-induced biomass burning feedback to air quality in the megacity of Delhi. Sci Total Environ 2019; 689:295-304. [PMID: 31276997 DOI: 10.1016/j.scitotenv.2019.06.438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 06/09/2023]
Abstract
We report the first ambient measurements of thirteen VOCs for investigations of emissions and air quality during fog and non-fog wintertime conditions at a tower site (28.57° N, 77.11° E, 220 m amsl) in the megacity of Delhi. Measurements of acetonitrile (biomass burning (BB) tracer), isoprene (biogenic emission tracer in daytime), toluene (a traffic exhaust tracer) and benzene (emitted from BB and traffic), together with soluble and reactive oxygenated VOCs such as methanol, acetone and acetaldehyde were performed during the winters of 2015-16 and 2016-17, using proton transfer reaction mass spectrometry. Remarkably, ambient VOC composition changes during fog were not governed by solubility. Acetaldehyde, toluene, sum of C8-aromatics (e.g. xylenes), sum of C9-aromatics (e.g. trimethyl benzenes) decreased by ≥30% (>95% confidence interval), whereas acetonitrile and benzene showed significant increases by 20% (>70% confidence interval), even after accounting for boundary layer dilution. During fog, the lower temperatures appeared to induce an emissions feedback from enhanced open BB within Delhi for warming, releasing both gaseous and aerosol pollutants with consequences for fog chemistry, sustenance and intensity. The potential feedback is important to consider for improving current emission parametrizations in models used for predicting air quality and fog in such atmospheric environments.
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Affiliation(s)
- H Hakkim
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - V Sinha
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India.
| | - B P Chandra
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - A Kumar
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - A K Mishra
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - B Sinha
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - G Sharma
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - H Pawar
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - B Sohpaul
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S. Nagar, Manauli PO, Punjab, 140306, India
| | - Sachin D Ghude
- Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India
| | - P Pithani
- Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India
| | - R Kulkarni
- Indian Institute of Tropical Meteorology, Pashan, Pune 411008, India; Savitribai Phule Pune University, Pune, India
| | - R K Jenamani
- Indian Meteorological Department, New Delhi 110003, India
| | - M Rajeevan
- Ministry of Earth Sciences, Government of India, New Delhi 110003, India
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6
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Ali K, Acharja P, Trivedi DK, Kulkarni R, Pithani P, Safai PD, Chate DM, Ghude S, Jenamani RK, Rajeevan M. Characterization and source identification of PM 2.5 and its chemical and carbonaceous constituents during Winter Fog Experiment 2015-16 at Indira Gandhi International Airport, Delhi. Sci Total Environ 2019; 662:687-696. [PMID: 30703726 DOI: 10.1016/j.scitotenv.2019.01.285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/18/2019] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Data on mass concentration of PM2.5 and its carbonaceous and water soluble inorganic chemical ions were compiled through sampling of PM2.5 at Indira Gandhi International Airport, Delhi during Dec. 16, 2015-Feb. 15, 2016 under Winter Fog Experiment (WIFEX) program of the Ministry of Earth Sciences (MoES) and analysing the samples. The data so generated were interpreted in terms of their variation on different time scales and apportioning their sources. It is found that mass concentration of PM2.5 averaged over the whole period of observation was 198.6±55.6. The concentration of organic carbon (OC) and elemental carbon (EC) was 24.7±9.4 and 11.7±4.7μg/m3 respectively with no any trend of increase or decrease over the observational period. SO42-, Cl- and NO3- dominated over other anions with their overall average concentration 34.0±23.1, 32.7±16.1 and 13.3±8.7μg/m3 respectively. Among cations, NH4+ showed highest concentration with an average value of 21.0±10.6μg/m3. Variation of daily average mass concentration of these parameters over the period of observation matched well with the variation of PM2.5 mass concentration indicating thereby to be the major contributors to the PM2.5 mass. NH4+ mostly occurred as NH4Cl and NH4NO3 and poorly as (NH4)2SO4 or NH4HSO4. H+ ion mostly occurred as H2SO4 and occasionally as HNO3. Carbonaceous aerosols and NO3- were mainly generated from fossil-fuel combustion. NH4+ and anthropogenic Cl- were mostly generated by biomass burning. The source of SO42- was found to be industries and thermal power plants. Continental Ca2+ and Mg2+ originated from thermal power plants and soil dust.
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Affiliation(s)
- Kaushar Ali
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India.
| | - Prodip Acharja
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India; Savitribai Phule Pune University, Pune 411007, India
| | - D K Trivedi
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India
| | - Rachna Kulkarni
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India; Savitribai Phule Pune University, Pune 411007, India
| | - Prakash Pithani
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India; Andhra University, Visakhapatnam 530003, India
| | - P D Safai
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India
| | - D M Chate
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India
| | - Sachin Ghude
- Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, NCL Post Office, Pune 411008, India
| | - R K Jenamani
- India Meteorological Department, New Delhi 110 003, India
| | - M Rajeevan
- Ministry of Earth Science, Lodhi Road, New Delhi, India
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8
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Venugopal T, Ali MM, Bourassa MA, Zheng Y, Goni GJ, Foltz GR, Rajeevan M. Statistical Evidence for the Role of Southwestern Indian Ocean Heat Content in the Indian Summer Monsoon Rainfall. Sci Rep 2018; 8:12092. [PMID: 30108244 PMCID: PMC6092415 DOI: 10.1038/s41598-018-30552-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/25/2018] [Indexed: 12/05/2022] Open
Abstract
This study examines the benefit of using Ocean Mean Temperature (OMT) to aid in the prediction of the sign of Indian Summer Monsoon Rainfall (ISMR) anomalies. This is a statistical examination, rather than a process study. The thermal energy needed for maintaining and intensifying hurricanes and monsoons comes from the upper ocean, not just from the thin layer represented by sea surface temperature (SST) alone. Here, we show that the southwestern Indian OMT down to the depth of the 26 °C isotherm during January–March is a better qualitative predictor of the ISMR than SST. The success rate in predicting above- or below-average ISMR is 80% for OMT compared to 60% for SST. Other January–March mean climate indices (e.g., NINO3.4, Indian Ocean Dipole Mode Index, El Niño Southern Oscillation Modoki Index) have less predictability (52%, 48%, and 56%, respectively) than OMT percentage deviation (PD) (80%). Thus, OMT PD in the southwestern Indian Ocean provides a better qualitative prediction of ISMR by the end of March and indicates whether the ISMR will be above or below the climatological mean value.
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Affiliation(s)
- T Venugopal
- Department of Physics, Novosibirsk State University, Novosibirsk, Russia.,Department of Meteorology and Oceanography, Andhra University, Visakhapatnam, India
| | - M M Ali
- Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University, Tallahassee, USA. .,Indian Institute of Tropical Meteorology, Pune, India.
| | - M A Bourassa
- Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University, Tallahassee, USA.,Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, USA
| | - Y Zheng
- Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University, Tallahassee, USA
| | - G J Goni
- Physical Oceanography Division, Atlantic Oceanographic and Meteorological Laboratory (AOML)/NOAA, Miami, USA
| | - G R Foltz
- Physical Oceanography Division, Atlantic Oceanographic and Meteorological Laboratory (AOML)/NOAA, Miami, USA
| | - M Rajeevan
- Ministry of Earth Sciences, Government of India, New Delhi, India
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9
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Rajeevan M, Srinivasan J. Tiruvalam Natarajan Krishnamurti (1932–2018). CURR SCI INDIA 2018. [DOI: 10.18520/cs/v114/i06/1356-1356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Chandra BP, Sinha V, Hakkim H, Kumar A, Pawar H, Mishra AK, Sharma G, Pallavi ,, Garg S, Ghude SD, Chate DM, Pithani P, Kulkarni R, Jenamani RK, Rajeevan M. Odd–Even Traffic Rule Implementation during Winter 2016 in Delhi Did Not Reduce Traffic Emissions of VOCs, Carbon Dioxide, Methane and Carbon Monoxide. CURR SCI INDIA 2018. [DOI: 10.18520/cs/v114/i06/1318-1325] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Roxy MK, Ghosh S, Pathak A, Athulya R, Mujumdar M, Murtugudde R, Terray P, Rajeevan M. A threefold rise in widespread extreme rain events over central India. Nat Commun 2017; 8:708. [PMID: 28974680 PMCID: PMC5626780 DOI: 10.1038/s41467-017-00744-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/20/2017] [Indexed: 11/30/2022] Open
Abstract
Socioeconomic challenges continue to mount for half a billion residents of central India because of a decline in the total rainfall and a concurrent rise in the magnitude and frequency of extreme rainfall events. Alongside a weakening monsoon circulation, the locally available moisture and the frequency of moisture-laden depressions from the Bay of Bengal have also declined. Here we show that despite these negative trends, there is a threefold increase in widespread extreme rain events over central India during 1950-2015. The rise in these events is due to an increasing variability of the low-level monsoon westerlies over the Arabian Sea, driving surges of moisture supply, leading to extreme rainfall episodes across the entire central subcontinent. The homogeneity of these severe weather events and their association with the ocean temperatures underscores the potential predictability of these events by two-to-three weeks, which offers hope in mitigating their catastrophic impact on life, agriculture and property.Against the backdrop of a declining monsoon, the number of extreme rain events is on the rise over central India. Here the authors identify a threefold increase in widespread extreme rains over the region during 1950-2015, driven by an increasing variability of the low-level westerlies over the Arabian Sea.
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Affiliation(s)
- M K Roxy
- Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, 411008, India.
| | - Subimal Ghosh
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Amey Pathak
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - R Athulya
- Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, 411008, India
- Department of Physical Oceanography, Cochin University of Science and Technology, Kochi, 682016, India
| | - Milind Mujumdar
- Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, 411008, India
| | - Raghu Murtugudde
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, 20742, USA
| | - Pascal Terray
- Sorbonne Universites (UPMC, Univ. Paris 06)-CNRS-IRD-MNHN, LOCEAN Laboratory, 4 Place Jussieu, F-75005, Paris, France
- Indo-French Cell for Water Sciences, IISc-IITM-NIO-IRD Joint International Laboratory, IITM, Pune, 411008, India
| | - M Rajeevan
- Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Pune, 411008, India
- Ministry of Earth Sciences, Government of India, Lodhi Road, New Delhi, 110003, India
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12
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Ghude SD, Bhat GS, Prabhakaran T, Jenamani RK, Chate DM, Safai PD, Karipot AK, Konwar M, Pithani P, Sinha V, Rao PSP, Dixit SA, Tiwari S, Todekar K, Varpe S, Srivastava AK, Bisht DS, Murugavel P, Ali K, Mina U, Dharua M, Rao J, Padmakumari B, Hazra A, Nigam N, Shende U, Lal DM, Chandra BP, Mishra AK, Kumar A, Hakkim H, Pawar H, Acharja P, Kulkarni R, Subharthi C, Balaji B, Varghese M, Bera S, Rajeevan M. Winter Fog Experiment Over the Indo-Gangetic Plains of India. CURR SCI INDIA 2017. [DOI: 10.18520/cs/v112/i04/767-784] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Pai DS, Suryachandra Rao A, Senroy S, Pradhan M, Pillai PA, Rajeevan M. Performance of the Operational and Experimental Long-Range Forecasts for the 2015 Southwest Monsoon Rainfall. CURR SCI INDIA 2017. [DOI: 10.18520/cs/v112/i01/68-75] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Azad S, Rajeevan M. Possible shift in the ENSO-Indian monsoon rainfall relationship under future global warming. Sci Rep 2016; 6:20145. [PMID: 26837459 PMCID: PMC4738276 DOI: 10.1038/srep20145] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 12/30/2015] [Indexed: 11/09/2022] Open
Abstract
EI Nino-Southern Oscillation (ENSO) and Indian monsoon rainfall are known to have an inverse relationship, which we have observed in the rainfall spectrum exhibiting a spectral dip in 3-5 y period band. It is well documented that El Nino events are known to be associated with deficit rainfall. Our analysis reveals that this spectral dip (3-5 y) is likely to shift to shorter periods (2.5-3 y) in future, suggesting a possible shift in the relationship between ENSO and monsoon rainfall. Spectral analysis of future climate projections by 20 Coupled Model Intercomparison project 5 (CMIP5) models are employed in order to corroborate our findings. Change in spectral dip speculates early occurrence of drought events in future due to multiple factors of global warming.
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Affiliation(s)
- Sarita Azad
- Indian Institute of Technology Mandi, Mandi 75001 Himachal Pradesh, India
| | - M Rajeevan
- Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pashan 411 008 Pune, India
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Unger E, McMullen A, Lin J, Rajeevan M, Steinau M, Saraiya M. HPV 16 Variants in Invasive Cancers in the US Prior to HPV Vaccine Implementation. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.lb450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- E Unger
- Division of High‐Consequence Pathogens and Pathology Centers for Disease Control and PreventionUnited States
| | - A McMullen
- Division of High‐Consequence Pathogens and Pathology Centers for Disease Control and PreventionUnited States
| | - J‐M Lin
- Division of High‐Consequence Pathogens and Pathology Centers for Disease Control and PreventionUnited States
| | - M Rajeevan
- Division of High‐Consequence Pathogens and Pathology Centers for Disease Control and PreventionUnited States
| | - M Steinau
- Division of High‐Consequence Pathogens and Pathology Centers for Disease Control and PreventionUnited States
| | - M Saraiya
- Division of Cancer Prevention and Control CDCAtlantaGAUnited States
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Roja Raman M, Jagannadha Rao VVM, Venkat Ratnam M, Rajeevan M, Rao SVB, Narayana Rao D, Prabhakara Rao N. Characteristics of the Tropical Easterly Jet: Long-term trends and their features during active and break monsoon phases. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd012065] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Yadav RK, Rupa Kumar K, Rajeevan M. Increasing influence of ENSO and decreasing influence of AO/NAO in the recent decades over northwest India winter precipitation. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011318] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Vernon SD, Unger ER, Rajeevan M, Dimulescu IM, Nisenbaum R, Campbell CE. Reproducibility of alternative probe synthesis approaches for gene expression profiling with arrays. J Mol Diagn 2000; 2:124-7. [PMID: 11229515 PMCID: PMC1906904 DOI: 10.1016/s1525-1578(10)60626-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Before gene expression profiling with microarray technology can be transferred to the diagnostic setting, we must have alternative approaches for synthesizing probe from limited RNA samples, and we must understand the limits of reproducibility in interpreting gene expression results. The current gold standard of probes for use with both microarrays and high-density filter arrays are synthesized from 1 microg of purified poly(A)+ RNA. We evaluated two approaches for synthesizing cDNA probes from total RNA with subsequent hybridization to high-density filter arrays: 1) reverse transcription (RT) of 5 microg total RNA and 2) RT-polymerase chain reaction (RT-PCR) of 1 microg total RNA, using the SMART system. The reproducibility of these two approaches was compared to the current gold standard. All three methods were highly reproducible. Triplicate experiments resulted in the following concordance correlation coefficients to evaluate reproducibility: 0.88 for the gold standard, 0.86 for cDNA probe synthesized by RT from total RNA, and 0.96 for the SMART cDNA probe synthesized from total RNA. We also compared the expression profile of 588 genes for the total RNA methods to that obtained with the gold standard. Of 150 positive genes detected by the gold standard, 97 (65%) were detected by cDNA probe synthesized by RT of total RNA, and 122 (81%) were detected by the SMART cDNA probe. We conclude that SMART cDNA probe produces highly reproducible results and yields gene expression profiles that represent the majority of transcripts detected with the gold standard.
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Affiliation(s)
- S D Vernon
- Centers for Disease Control and Prevention, United States Public Health Service, Department of Health and Human Services, Atlanta, Georgia 30333, USA
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Rajeevan M, Bassett CL. A simple and rapid method for the preparation of phage DNA suitable for Southern analysis. Biotechniques 1992; 12:833-4. [PMID: 1642889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- M Rajeevan
- Department of Botany, University of Georgia, Athens 30602
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