An Assessment of the South Asian Summer Monsoon Variability for Present and Future Climatologies Using a High Resolution Regional Climate Model (RegCM4.3) under the AR5 Scenarios

Hassan, Mujtaba; Du, Pengfei; Jia, Shaofeng; Iqbal, Waheed; Mahmood, Rashid; Ba, Wulong

doi:10.3390/atmos6111833

Cited by 27 publications

(9 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Whether this is due to temporal variability or is part of a long-term trend toward weakening shamals is unclear. There is a great deal of uncertainty around the influence of climate change on the future of the monsoon, but some models project a trend toward increasing strength in the coming decades (Hassan et al, 2015;Niu et al, 2015), and the strengthening of the low pressure zone over India would potentially result in enhanced shamal activity over the Gulf, providing capacity for protective cooling of water columns above reefs. However, while the monsoon may strengthen on average, it is also expected to become increasingly variable from year-to-year (Turner and Annamalai, 2012;Sharmila et al, 2015), which would result in the continued recurrence of the low-wind summers that allow temperatures to build past coral bleaching and mortality thresholds.…”

Section: Shamal Winds and The Future Of Gulf Reefsmentioning

confidence: 99%

Coral Bleaching in the Persian/Arabian Gulf Is Modulated by Summer Winds

Paparella

Vaughan

et al. 2019

Front. Mar. Sci.

View full text Add to dashboard Cite

Corals in the Persian/Arabian Gulf are the most thermally tolerant in the world, but live very near the thresholds of their thermal tolerance. Warming sea temperatures associated with climate change have resulted in numerous coral bleaching events regionally since the mid-1990s, but it has been unclear why unusually warm sea temperatures occur some years but not others. Using a combination of 5 years of observed sea-bottom temperatures at three reef sites and a meteorologically linked hydrodynamic model that extends through the past decade, we show that summer sea-bottom temperatures are tightly linked to regional wind regimes, and that strong 'shamal' wind events control the occurrence and severity of bleaching. Sea bottom temperatures were primarily controlled by latent heat flux from wind-driven surface evaporation which exceeded 300 W m −2 during shamal winds, double that of typical breeze conditions. Daily temperature change was highly correlated with wind speed, with breeze winds (<4 m s −1) resulting in increased warming, while faster winds caused cooling, with the magnitude of temperature decline increasing with wind speed. Using observed and simulated data from 2012 to 2017, we show that years with reported bleaching events (2012, 2017) were characterized by low winds speeds that resulted in temperatures persisting above coral bleaching threshold temperatures for >5 weeks, while the cooler intervening years (2013-2016) had summers with more frequent and/or strong shamal events which repeatedly cooled temperatures below bleaching thresholds for days to weeks, providing corals temporary respite from thermal stress. Using observed data from 2012 onward and simulated data from 2008 to 2011, we show that the severity of bleaching events over the past decade was linked to both the number of cumulative days above bleaching thresholds (rather than total days, which obfuscates the cooling effects of occasional brief shamal events), as well as to maxima. We show that winds of 4 m s −1 represents a critical threshold for whether or not corals cross bleaching threshold temperatures, and provide simulations to forecast sea-bottom temperature change and recovery times under a range of wind conditions. The role that wind-driven cooling may play on coral reefs globally is discussed.

show abstract

Section: Shamal Winds and The Future Of Gulf Reefsmentioning

confidence: 99%

Coral Bleaching in the Persian/Arabian Gulf Is Modulated by Summer Winds

Paparella

Vaughan

et al. 2019

Front. Mar. Sci.

View full text Add to dashboard Cite

show abstract

“…Future changes in precipitation, T max and T min were calculated by comparing them to the baseline period. In this study, the period from 1981 to 2010 was selected as the baseline period because this 30-year period has been used in the majority of climate change studies across the world [5,19,20]. A 30-year period is considered sufficient to define the local climate, as it is anticipated that it will comprise different situations such as dry, wet, cool, and warm years or sub-periods.…”

Section: Bias Correctionmentioning

confidence: 99%

“…Under the projected future climate, it is plausible that grievous and extreme weather events (i.e. severe floods and droughts) will occur in global monsoon areas [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

projected changes in temperature and precipitation in Sarawak state of Malaysia for selected CMIP5 climate scenarios

Hussain¹,

Yusof²,

Mustafa³

et al. 2017

Int. J. SDP

View full text Add to dashboard Cite

This article explores the projected changes in precipitation, maximum temperature (T max) and minimum temperature (T min) in the Malaysian state of Sarawak under Representative Concentration Pathways (RCPs) with the CanESM2 Global Circulation Model. The Statistical Downscaling Model (SDSM) was used to downscale these climate variables at three stations in Sarawak. The model performed well during the validation period and thus was used for future projections under three RCPs with the CanESM2 General Circulation Model. It is noted that the T max will increase by 1.94°C at Kuching, 0.09°C at Bintulu and 1.29°C at Limbang, when comparing the period of 2071-2100 with the baseline period of 1981-2010, under the most robust scenario of RCP8.5. T min is also expected to increase by 1.21°C at Kuching, 0.15°C at Bintulu and 2.08°C at Limbang, under the RCP 8.5 projection for the same period. The precipitation at Kuching and Bintulu is expected to increase slightly to 1.6% and 1.4% at Kuching and Bintulu respectively; however, the seasonal shift is projected as follows: lesser precipitation during the December-February period and more during the June-August season. On the other hand, precipitation is expected to increase at Limbang during all seasons, when compared with the period of 1981-2010; it is expected that under RCP4.5 the annual precipitation at Limbang will increase by 10.5% during the 2071-2100 period.

show abstract

“…We conclude here that, in contrast to the present scenario, BoB experienced remarkable oscillations in productivity and surface water CO 2 budget during the last 300 ky, controlled by variation in the intensity of global and regional physical processes. In view of the alarming influence of global warming on marine productivity 42 , monsoonal variability 43 and ocean acidification 44 , the high-resolution long term natural variability observed here will be useful in vulnerability modeling of BoB 11 . The paleo productivity data coupled with δ 15 N may also help in reconstructing paleoxygenation and denitrification 45 processes in BOB.…”

Section: Discussionmentioning

confidence: 99%

Salinity stratification controlled productivity variation over 300 ky in the Bay of Bengal

Silva

Mazumdar

Mapder

et al. 2017

Sci Rep

View full text Add to dashboard Cite

The unique hydrographic setting of the Bay of Bengal (BoB) makes it an ideal tropical marine system to study the influence of regional and global forcings on productivity and [CO2aq] through the late quaternary. Enormous fresh water flux into the BoB and consequent salinity stratification significantly weaken the convective mixing and wind driven processes which are commonly responsible for transport of nutrients to the euphotic zone driving primary productivity. Here we present a high resolution organic carbon-CaCO3 MAR and δ13CTOC records for the last 300 ky from the BoB. The results show significant productivity variation at marine isotope sub-stages and millennial timescales. Colder sub-stages and stadials (Dansgard-Oeschger cycle) show a boost in productivity which may be attributed to thinning of low salinity cap, thereby facilitating efficient nutrient transport across the euphotic zone by the combination of wind driven processes (entrainment and upwelling), convective mixing and cold core eddies. The [CO2aq] was a net result of global pCO2 variation and regional processes. Our long term high-resolution data indicates a possibility of marked change in productivity/biogeochemistry of BOB in the future due to global warming, thus affecting the coastal economy.

show abstract

An Assessment of the South Asian Summer Monsoon Variability for Present and Future Climatologies Using a High Resolution Regional Climate Model (RegCM4.3) under the AR5 Scenarios

Cited by 27 publications

References 74 publications

Coral Bleaching in the Persian/Arabian Gulf Is Modulated by Summer Winds

Coral Bleaching in the Persian/Arabian Gulf Is Modulated by Summer Winds

projected changes in temperature and precipitation in Sarawak state of Malaysia for selected CMIP5 climate scenarios

Salinity stratification controlled productivity variation over 300 ky in the Bay of Bengal

Contact Info

Product

Resources

About