Hokkaido University · Environmental Science
Professor Muhammad Mubashar Dogar's research lab specializes in climate dynamics, with a focus on the sensitivity of regional climates—particularly in monsoon and arid regions like the Middle East, North Africa, and South Asia—to external forcings such as explosive volcanic eruptions and large-scale climate modes like ENSO and NAO. The lab employs high-resolution atmospheric modeling and observational data to investigate post-eruption climate responses, including changes in atmospheric circulation, precipitation patterns, and oceanic heat content. A key research direction involves disentangling the complex interactions between volcanism, ENSO, and large-scale climate oscillations such as the NAO, especially in relation to high-latitude winter warming and tropical circulation changes. The lab also examines the role of volcanic aerosols in altering radiative forcing and their indirect climatic effects on global and regional hydrological cycles.
Figures are computed from collected data and may differ slightly.
Abstract It is well observed that the monsoon climate experiences substantial climatic changes following explosive volcanism. Likewise, previous studies show that the monsoon climate regimes, especially, the African and South Asian tropical regions, are adversely affected by El Niño‐Southern Oscillation (ENSO) events. Hence, studying the sensitivity of the monsoon regions to the effect of these forcing factors, that is, explosive volcanism and volcanic‐induced ENSO forcing, is essential for bett
Abstract The Middle East and North Africa (MENA), primarily the Arabian Peninsula (AP), is a region where the rate of mean surface temperature rise per decade is among the highest globally known during the recent past. Moreover, MENA regional climate is very sensitive to internal and external climate drivers. Therefore, it is of significant practical importance to analyze MENA sensitivity to climate trends as well as leading variability modes such as El Niño Southern Oscillation (ENSO), North At
Abstract The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/National Centers for Environmental Prediction Climate Forecast System Reanalysis, an
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 esse
Abstract High‐latitude winter warming was observed following strong tropical volcanism, which has long been believed to be due to the volcanic‐induced positive North Atlantic Oscillation (NAO) phase. However, recent works argue that this warming is caused by El Niño–Southern Oscillation (ENSO) variability instead of volcanoes. Moreover, some studies further argue that El Niño and volcanoes work together to produce this post‐volcanic NAO winter warming. To better understand these arguments on pos
It is strongly believed that the explosive eruptions produce negative radiative forcing that causes long-term perturbations in the ocean. Moreover, it is anticipated that a sporadic strong cooling should initiate more vigorous vertical mixing of the upper ocean, and therefore cools the ocean more effectively than a uniform radiative forcing. However, the long-term simulations show that on average the ocean heat content responses to periodic and constant forcings are comparable. To better underst
The rationale for this study lies in the fact that the mid-latitude regions are largely affected by the global and regional scale circulation changes. Moreover, earlier studies emphasize that the variation in atmospheric concentration of heat-trapping gases, cloud amount and moisture contents produce substantial regional climatic changes. Therefore, it is of significant practical importance to analyze the sensitivity of midlatitude regions to anthropogenic forcing, especially, the CO 2 radiative
Abstract Following strong tropical volcanism, the Middle East and North Africa (MENA) region witnessed significant winter cooling, conventionally attributed to volcanically forced positive phase of North Atlantic Oscillation (NAO) and direct volcanic effects. However, coexisting positive phase of El Niño–Southern Oscillation (ENSO) prompts that this enhanced winter cooling may stem from ENSO forcing rather than volcanic-induced NAO. To address this complexity, we analyzed ENSO-preconditioned vol
Abstract Volcanic eruptions are among the strongest climate drivers, yet their regional impacts on the Middle East and North Africa (MENA) remain poorly constrained. Post-eruption amplified winter cooling in MENA is often attributed to a volcanically forced positive North Atlantic Oscillation (NAO), but the concurrent occurrence of El Niño–Southern Oscillation (ENSO) complicates attribution. Furthermore, summer climatic responses, including tropical warming and mid-latitude cooling, remain under
It is known that volcanic radiative impacts could produce long-term perturbations of the ocean heat content. In this study we systematically compare the effect of periodic volcanic forcing with an equivalent time-average radiative cooling. One could expect that a sporadic strong cooling should initiate more vigorous vertical mixing of the upper ocean layer and therefore cools the ocean more effectively than a uniform radiative forcing. However, the long-term simulations show that on average the
Open papers in the app to read, cite, and organize with AI.
