Seminars / Lectures
New Book by IITM
REAL TIME FORECAST
High resolution air quality forecast at 400 meter over Delhi
Air quality forecast at 10 km over North India
IITM Publication Highlights
The Role of an Indian Ocean Heating Dipole in the ENSO Teleconnection to the North Atlantic European region in early winter during the twentieth century in reanalysis and CMIP5 simulations
In this study the role of an Indian Ocean heating dipole anomaly in the transition of the North Atlantic– European (NAE) circulation response to El Niño–Southern Oscillation (ENSO) from early to late winter is analyzed using a twentieth-century reanalysis and simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5). It is shown that in early winter a warm (cold) ENSO event is connected through an atmospheric bridge with positive (negative) rainfall anomalies in the western Indian Ocean and negative (positive) anomalies in the eastern Indian Ocean. The Indian Ocean heating dipole response to ENSO is much weaker in late winter (i.e., February and March) and not able to force significant signals in the North Atlantic region. CMIP5 multimodel ensemble reproduces the early winter Indian Ocean heating dipole response to ENSO and its transition in the North Atlantic region to some extent, but with weaker amplitude. Generally, models that have a strong early winter ENSO response in the subtropical South Asian jet region along with tropical Indian Ocean heating dipole also reproduce the North Atlantic response.
(Joshi M.K. et al. Journal of Climate, 34, February 2021, DOI:10.1175/JCLI-D-20-0269.1)
Prediction of Extreme Events: Current Status and Future Pathways against the Backdrop of Climate Change
The study analyses the role of tropical Pacifc sea surface temperature (SST) biases in simulating the mean and interannual variability of Indian summer monsoon rainfall (ISMR) using the hindcasts from Monsoon Mission CFSv2 (MMCFS) and ECMWF-SYSTEM4 (ES4) prediction systems. ES4 simulates the mean and annual cycle of ISMR better than MMCFS when initialized with February initial conditions (3-month lead, Feb IC). At the same time, interannual variability (IAV) and skill (correlation between the ensemble mean hindcast and observations) are the highest (least) for MMCFS (ES4). May IC (0-month lead) hindcasts of both the models have similar mean, annual cycle, IAV and skill. A close to observed mean SST in the tropical Pacifc and proper ENSO-Monsoon teleconnection is essential for the better skill of ISMR in the present generation seasonal prediction models.
(Pillai P.A., Rao Suryachandra A. et al. Climate Dynamics, Online, January 2021, DOI:10.1007/s00382-020-05555-1)
Factors responsible for consecutive deficit Indian monsoons during 2014 and 2015
Increased frequency of droughts in the recent decade (2002, 2004, 2009, 2014, 2015 being drought years) and the severity of their impact makes drought prediction an inherent component of forecasts for drought mitigation and preparedness. During 2014 and 2015, India experienced deficit monsoon for two successive years. The study explores the factors responsible for the droughts during 2014 and 2015 and how well the state-of-the-art coupled model capture the consecutive droughts. The study shows that not only tropical sea surface temperatures (SSTs) but also extratropical SSTs can influence the rainfall over India. Extratropical SSTs impacted the rainfall during 2014 by modulating the strength and location of subtropical jet and tropospheric temperature gradient. On the other hand, tropical SSTs over Pacific Ocean influenced the rainfall during 2015 by modulating the atmospheric teleconnections via Walker circulation.
(Pradhan M., Rao Suryachandra A. et al. Theoretical and Applied Climatology, January 2021, DOI:10.1007/s00704-020-03486-9)
Interplay between subseasonal rainfall and global predictors in modulating interannual to multidecadal predictability of the ISMR
The subseasonal modes being the building blocks of the monsoon, their net linear contribution may approximate the predictability limit of the Indian Summer Monsoon Rainfall (ISMR). It is estimated that an average of about 76% (R ∼ 0.87) of the ISMR variance predictable around the 1960s is decreased to about 64% (R ∼ 0.79) in the recent past four decades. This study further reveals the need for a reasonable simulation of subseasonal modes, particularly the synoptics and their interactions with the regional as well as global predictors to improve the ISMR forecast.
(Saha Subodh Kumar, Konwar M. et al. Geophysical Research Letters, 48: e2020GL091458, January 2021, DOI: 10.1029/2020GL091458)
New Publications
Understanding balloon-borne frost point hygrometer measurements after contamination by mixed-phase clouds
Jorge T., Brunamonti S., Poltera Y., Wienhold F.G., Luo B.P., Oelsner P., Hanumanthu S., Singh B.B., Körner S., Dirksen R., Naja M., Fadnavis S., Peter T., Atmospheric Measurement Techniques, 14, January 2021, DOI:10.5194/amt-14-239-2021, 239–268
Gain of one-month lead time in seasonal prediction of Indian summer monsoon prediction: comparison of initialization strategies
Srivastava Ankur, Rao Suryachandra A., Pradhan M., Pillai P.A., Prasad V.S., Theoretical and Applied Climatology, November 2020, DOI:10.1007/s00704-020-03470-3, 1-14
Propagation of cloud base to higher levels during Covid-19-Lockdown
Latha R., Murthy B.S., Sandeepan B.S., Bhanage V., Rathod Aditi, Tiwari Arpit, Beig G., Singh S., Science of the Total environment, December 2020, DOI:10.1016/j.scitotenv.2020.144299, 1-9
COVID-19 and environmental -weather markers: Unfolding baseline levels and veracity of linkages in tropical India
Beig G., Bano S., Sahu S.K., Anand V., Rathod A., Yadav R., Mangaraj P., Murthy B.S., Singh S., Latha R., Shinde R., Environmental Research, 191: 110121, December 2020, DOI:10.1016/j.envres.2020.110121
IITM Events
Curtain Raiser Ceremony
As part of IISF-2020, IITM organised a virtual Curtain Raiser Ceremony for High-Altitude Cloud Physics Laboratory, Mahabaleshwar and Clean Air Event on 18 December 2020.
71st Constitution Day (Samvidhan Diwas) 2020
IITM has celebrated the Constitution Day (Samvidhan Diwas) on 26 November 2020. Preamble of the Constitution was read by the Director and all IITM officials.
MoES Webinar Series: Earth Sciences Popular Lectures
As an initiative by Ministry of Earth Sciences (MoES), DESK at IITM Pune (MoES) is organizing "Earth Sciences Popular Lectures" webinar series in coordination with MoES & its Institutions.