Gopikrishnan G S
Fulbright-Kalam Climate Fellow 2024-25,
Lamont-Doherty Earth Observatory (LDEO),
Columbia Climate School, Columbia University, New York, USA
Prime Minister's Research Fellow,
Atmospheric and Climate Science Laboratory (ATMOS Lab)
Centre for Ocean, River, Atmosphere and Land Sciences (CORAL)
Indian Institute of Technology Kharagpur
Unmasking the Global Climate Crisis: Science, Impacts and Actions.
The Enigmatic World of Tropospheric Ozone: Atmospheric Chemistry - Climate Interactions
Ozone is a gas made up of three oxygen atoms. It occurs naturally in small (trace) amounts in the upper atmosphere (the stratosphere). Ozone protects life on Earth from the Sun’s ultraviolet (UV) radiation. In the lower atmosphere (the troposphere) near the Earth’s surface, ozone is created by chemical reactions between air pollutants from vehicle exhaust, gasoline vapors, and other emissions. At ground level, high concentrations of ozone are toxic to people and plants.
RECENT PUBLICATIONS
Global tropical and extra-tropical tropospheric ozone trends and radiative forcing deduced from satellite and ozonesonde measurements for the period 2005–2020
G.S. Gopikrishnan and J. Kuttippurath
Tropospheric ozone (TPO) is significantly rising in the global tropics (0.2–0.4 DU/yr).
TPO shows regional insignificant negative trends in the southern hemisphere (0.1–0.2 DU/yr).
Multi-Linear Regression can explain 95% variability of tropical tropospheric ozone.
Ozone induced radiative forcing (RF) in the tropics is within the range ±0.5 W/m2.
Ozone-driven RF makes a temperature rise of 0.2–0.3 °C from 2006 to 2020.
No severe ozone depletion in the tropical stratosphere in recent decades
J. Kuttippurath, G.S. Gopikrishnan, R. Muller, S. Godin-Beekmann, J. Brioude
Stratospheric ozone is an important constituent of the atmosphere. Significant changes in its concentrations have great consequences for the environment in general and for ecosystems in particular
The amount of column ozone in the tropics is relatively small (250–270 DU) compared to high and mid-latitudes
In addition, the tropical total ozone trend is very small , as estimated for the period 1998–2022.
The current understanding and observational evidence do not provide any support for the possibility of an ozone hole occurring outside Antarctica today with respect to the present-day stratospheric halogen levels.
Four Years of National Clean Air Programme (NCAP) in Indian cities: Assessment of the impact on surface ozone during the period 2018–2022
G.S. Gopikrishnan and J. Kuttippurath
Frequency of 8 h ozone exposure exceeding 100 ppb/year reduced after NCAP implementation.
Most stations show negative trends in surface ozone (0–0.03 ppb month−1) from 2018 to 2022.
Most cities, except in winter, shows an NOx-limited regime, where O3 production is limited by NOx.
Some cities show positive ozone trends; indicating the need for tailored mitigation strategies.
G.S. Gopikrishnan, J. Kuttippurath, P.K. Thapliyal and M.V. Shukla
This study makes use of collocated measurements of INSAT-3D and INSAT-3DR with those from 18 radiosondes, Atmospheric Infrared Sounder (AIRS), and reanalysis data within the troposphere (1,000–100 hPa) to validate INSAT temperature profiles
Daytime temperature retrievals from INSAT‐3DR have been improved by 0.5–1 K
Nighttime observations have a similar bias (1–2 K) and RMSD for both INSAT‐3D and 3DR
RECENT EVENTS
TROPMET 2023
Changing Dynamics of Arid Region and Impact on Weather and Climate over Indian Subcontinent
The Lalit, New Delhi, 21-23 May, 2024
PMRF Review Seminar 2024
Departmental seminar at CORAL, IIT Kharagpur
"Surface Ozone over India: Sources, Drivers and the Effectiveness of Air Quality Policies"
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