Extended Range Prediction System

Short Range Ensemble Prediction System

IITM Research Report

On the dynamics of extended breaks during 2017 monsoon, by Susmitha Joseph, A.K. Sahai, A. Dey, R. Mandal and Aparnna Ravi P., IITM RR-143

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IITM Publication Highlights

Bay of Bengal branch of Indian Summer Monsoon and its association with spatial distribution of rainfall patterns over India

This latest IITM study reports that, the changes in surface temperature/pressure spatial pattern between India and South China Sea (SCS) region play an important role in the distribution of the rainfall. For the first time, the life cycle of south Bay monsoon flow and its interaction with SCS are discussed and likely to warrant special attention for modelers trying to understand the spatial distribution of rainfall over India. (Sinha N., Chattopadhyay R., Chakraborty S., November 2018)

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Coupled model fidelity in capturing atmospheric internal processes during organization and intensification of boreal summer intra-seasonal oscillation

The study investigates the Climate Forecast System version 2 (CFSv2) model fidelity in capturing large-scale dynamical field and the energy conversion processes during organization and intensification of Boreal Summer Intra-Seasonal Oscillation (BSISO). Experiment is carried out to make 10-year free run to evaluate the model. Based on rainfall analyses, two types of events are defined one strong and other with weaker intensity. The result reveals that model over estimates the BSISO intensity starting from the initial phase. Strong events based on MERRA data show a persistent increasing lower-level moisture convergence with respect to convection centre (CC) and a collocated vertical velocity with CC. However, model moisture convergence and vertical velocity are slightly stronger than observation at the initial phase but it is not persisting in the subsequent lags. The analysis of eddy kinetic energy (EKE) budget equation shows that the model intra-seasonal EKE is very weak at 850 hPa level. The vertical structure of EKE has shown that a positive EKE at the lower to middle troposphere increases in the subsequent lags but it is very weak for model. The analysis of each term of EKE budget has shown that the barotropic energy conversion (?CK) and convergence of eddy geopotential fluxes (?FG) are the dominant contributors for positive EKE tendency in the ERA analysis and both the terms increase as the BSISO approaches towards its organized and intense phase. However for model, the above terms are very weak. The EKE advection through large-scale background flow (?AM) and synoptic-scale eddy (?AE) adds negatively to the EKE tendency for strong events. However for model, the magnitudes of the above terms are higher than that of the observation for both strong and weak events. Thus, the model has deficiency in capturing the dynamical processes and the energy conversion processes properly. (Sahadat Sarkar, P. Mukhopadhyay , R. Phani Murali Krishna, Somenath Dutta, August 2018)

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Tree-ring reconstruction of summer temperature of Sikkim Himalaya since 1705 C.E.

A 437-year Tsuga dumosa (D.Don) Eichler (i.e., Himalayan hemlock) tree-ring chronology for northern Sikkim and a subsequent summer (JAS) temperature reconstruction during the past 304 years is presented. Dendroclimatic analysis indicates a strong negative relationship between late-summer mean temperatures (July-August-September; JAS) and tree growth. This relationship enables us to reconstruct the JAS mean temperature over northern Sikkim since 1705 C.E. The 304-year (1705-2008 C.E.) reconstructed temperature series shows similar warm and cool epochs, which have been observed in many other temperature reconstructions in the region and other proxy records of glacial fluctuations. An overall steady decreasing trend in the regional surface temperature is observed since 1705 C.E., while an increasing trend with intermittent, short and cool epochs are noticed from 1850 C.E. to the present. Global teleconnections of the reconstructed temperature variations indicate the important roles of the Pacific Decadal Oscillation (PDO), El Niñouthern Oscillation (ENSO), and volcanic eruptions as drivers of temperature variations in the Sikkim region of the Himalayas. (H. P. Borgaonkar, Naveen Gandhi, Somaru Ram, R. Krishnan, May 2018)

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New Publications

Case study of turbulence in the Nocturnal Boundary Layer during the Indian Summer Monsoon

Burman Pramit Kumar Deb, Prabha Thara V., Morrison R., Karipot A.,Boundary Layer Meteorology, 169, October 2018, DOI:10.1007/s10546-018-0364-4, 115-138

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An evaluation of the dissimilarity in heat and momentum transport through quadrant analysis for an unstable atmospheric surface layer flow

Chowdhuri Subharthi, Prabha T.V., Environmental Fluid Mechanics, online, October 2018, 1-24

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Surface PM2.5 estimate using satellite-derived Aerosol Optical Depth over India

Krishna R.K., Ghude S., Kumar Rajesh, Beig G., Kulkarni Rachana, Nivdange S., Chate D., Aerosol and Air Quality Research, online, October 2018, DOI:10.4209/aaqr.2017.12.0568, 1-13

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Aerosol-induced perturbation of surface fluxes over different landscapes in a tropical region

International Journal of Remote Sensing, online, October 2018, DOI:10.1080/01431161.2018.1523586, 1-20

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IITM Events

Outreach Programme of IISF-2018

IITM organized an outreach programme and seminar under the IISF-2018. It included open day, scientific awareness programme and competitions (Poster, Drawing and Quiz) for local school students.

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Green Good Deeds campaign

As part of the "Green Good Deeds" campaign of the Union Ministry of Environment, Forest and Climate Change (MoEFC), IITM organized outreach/awareness activities and quiz competition among local students.

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Sci. & Training Workshop: Climate Change over High Mountains of Asia (8-12 October 2018)

A science and training workshop on the theme "Climate Change over the High Mountains of Asia (HMA)" was held at IITM and was jointly organized by the Centre for Climate Change Research (CCCR), IITM, the Ministry of Earth Sciences (MoES), New Delhi, Divecha Centre for Climate Change (DCCC), Indian Institute of Science, Bengaluru and the Monsoon Asia Integrated Research for Sustainability - Future Earth (MAIRS-FE) at DCCC. The overarching goals of this workshop are envisaged towards integrating the regional climate downscaling activities, facilitating cross-fertilization of scientific expertise and engaging the community of Asian scientists for further capacity building pertaining to the HMA.

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57th Foundation Day Celebration at IITM 17 November 2018

IITM celebrated 57th Foundation Day on 17th November 2018. Dr. Vijay P. Bhatkar, Chancellor, Nalanda University and Guest of Honor, Dr.Satish R. Shetye, NIO Director (Retd.) and Former Vice Chancellor, Goa University is the Chief Guest and Guest of Honor respectively. On this occasion, various awards were presented to the scientists, students, scientific, technical, Administrative support and other staff of the Institute.

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