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Dogar, Muhammad Mubashar
- Decadal Climate Variability and Predictability
Abstract Views :297 |
PDF Views:93
Authors
Affiliations
1 Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow 226 007,, IN
2 Department of Earth Science and Engineering, King Abdullah University of Science and Technology, Thuwal 4700, SA
1 Birbal Sahni Institute of Palaeobotany, 53 University Road, Lucknow 226 007,, IN
2 Department of Earth Science and Engineering, King Abdullah University of Science and Technology, Thuwal 4700, SA
Source
Current Science, Vol 110, No 8 (2016), Pagination: 1397-1398Abstract
To address the challenges and advancement in modern climate research, a workshop on the decadal climate variability and predictability (DCVP) was held recently. The main objective of this workshop was to integrate expert scientific opinion in making use of updated observational records and state-of-the-art coupled climate models to understand the slowdown in the rate of global surface temperature change since the late 1990s, and make timely progress to identify and address these climatic events.Full Text
- Impact of Tropical Volcanic Eruptions on Hadley Circulation Using a High-Resolution AGCM
Abstract Views :249 |
PDF Views:88
Authors
Affiliations
1 Earth Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, SA
1 Earth Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, SA
Source
Current Science, Vol 114, No 06 (2018), Pagination: 1284-1294Abstract
The direct radiative effects of volcanic eruptions resulting in solar dimming, stratospheric warming, global surface cooling and reduction in rainfall are well documented. However, eruptions also cause indirect climatic impacts that are not well understood. For example, solar dimming induced by volcanic aerosols could cause changes in tropical Hadley circulation that in turn largely affect evaporation and precipitation patterns. Therefore, understanding the sensitivity of HC to volcanism is essential, as this circulation is directly related to precipitation changes in the tropics and with other large-scale circulations. Hence, to better understand the post-eruption sensitivity of HC and associated changes in the hydrologic cycle, simulations for the El Chichón and Pinatubo tropical eruptions were conducted using a high-resolution atmospheric model (HIRAM), effectively at 25 and 50 km grid spacing. The model simulated results are then compared with observational and reanalysis products. Both the model and observational analysis show posteruption weakening, shrinking and equatorward displacement of the updraft branch of HC caused by the equatorward shift of midlatitude jets and hemispheric land–sea thermal gradient. The Intertropical Convergence Zone (ITCZ) is tightly coupled to the rising branch of HC, hence, post-eruption weakening and equatorward displacement of HC cause weakening of ITCZ that adversely affects rainfall distribution in the monsoon-fed regions, especially the South Asian and African tropical rain-belt regions. The model-produced post-eruption distribution of cloud contents suggests a southward shift of ITCZ. The HIRAM results are largely in agreement with the reanalysis, observations and previous studies indicating that this model performs reasonably well in reproducing the global and regional-scale dynamic changes caused by volcanic radiative forcing.Keywords
Atmospheric Models, Jet Streams, Monsoon Circulation and ITCZ, Tropical Volcanic Eruptions.Full Text
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