The Radiative and Cloud Responses to Sea Salt Aerosol Engineering in GFDL Models

Mahfouz, Naser G. A.; Hill, Susan; Guo, Huan; Ming, Yi

doi:10.1029/2022gl102340

Cited by 4 publications

(1 citation statement)

References 60 publications

(103 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We note that CDNC equal to 600 cm −3 is likely not attainable in practice (Alterskjaer & Kristjánsson, 2013). Furthermore, MCB experiments using sea salt emission changes show that much of radiative forcing is due to direct aerosol scattering, rather than cloud brightening (Ahlm et al., 2017; Mahfouz et al., 2023). However, we argue that the precise implementation of the regional shortwave forcing has only modest effects on the large scale climate response, as we find few significant differences in the CESM2 coupled climate response to these CDNC perturbations versus sea salt emission increases with similar forcing location and magnitude (Figure S1 in Supporting Information ).…”

Section: Methodsmentioning

confidence: 99%

Effect of Regional Marine Cloud Brightening Interventions on Climate Tipping Elements

Hirasawa,

Hingmire,

Singh

et al. 2023

Geophysical Research Letters

View full text Add to dashboard Cite

It has been proposed that increasing greenhouse gas (GHG) driven climate tipping point risks may prompt consideration of solar radiation modification (SRM) climate intervention to reduce those risks. Here, we study marine cloud brightening (MCB) SRM interventions in three subtropical oceanic regions using Community Earth System Model 2 experiments. We assess the MCB impact on tipping element‐related metrics to estimate the extent to which such interventions might reduce tipping element risks. Both the pattern and magnitude of the MCB cooling depend strongly on location of the MCB intervention. We find the MCB cooling effect reduces most tipping element impacts; though differences in MCB versus GHG climate response patterns mean MCB is an imperfect remedy. However, MCB applied in certain regions may exacerbate certain GHG tipping element impacts. Thus, it is crucial to carefully consider the pattern of MCB interventions and their teleconnected responses to avoid unintended climate effects.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of Regional Marine Cloud Brightening Interventions on Climate Tipping Elements

Hirasawa,

Hingmire,

Singh

et al. 2023

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

IMO2020 Regulations Accelerate Global Warming by up to 3 Years in UKESM1

Jordan,

Henry

2024

Earth's Future

View full text Add to dashboard Cite

The International Maritime Organization (IMO) introduced new regulations on the sulfur content of shipping emissions in 2020 (IMO2020). Estimates of the climatic impact of this global reduction in anthropogenic sulfate aerosols vary widely. Here, we contribute to narrowing this uncertainty with two sets of climate model simulations using UKESM1. Using fixed sea‐surface temperature atmosphere‐only simulations, we estimate an IMO2020 global effective radiative forcing of 0.139 ± 0.019 Wm−2 and show that most of this forcing is due to aerosol‐induced changes to cloud properties. Using coupled ocean‐atmosphere simulations, we note significant changes in cloud top droplet number concentration and size across regions with high shipping traffic density, and—in the North Atlantic and North Pacific—these microphysical changes translate to a decrease in cloud albedo. We show that IMO2020 increases global annual surface temperature on average by 0.046 ± 0.010°C across 2020–2029; approximately 2–3 years of global warming. Furthermore, our model simulations show that IMO2020 helps to explain the exceptional warming in 2023, but other factors are needed to fully account for it. The year 2023 also had an exceptionally large decrease in reflected shortwave radiation at the top‐of‐atmosphere. Our results show that IMO2020 made that more likely, yet the observations are within the variability of simulations without the reduction in shipping emissions. To better understand the climatic impacts of IMO2020, a model intercomparison project would be valuable whilst the community waits for a more complete observational record.

show abstract

Impacts of marine cloud brightening scheme on climatic extremes in the Tibetan Plateau

Zhang,

Zhu,

Crabbe

2023

Open Geosciences

View full text Add to dashboard Cite

As an ecologically fragile plateau and major water source in Asia, the Tibetan Plateau (TP) has grown warmer over recent decades, contributing to frequent occurrence of extreme climate events. It is urgently needed to find a suitable option to mitigate climate change impacts in the TP. The marine cloud brightening (MCB) scheme is proposed to mitigate global warming through the increasing cloud droplet number concentration of low marine clouds to reflect some solar radiation back into space. Until now, impacts of MCB scheme on the TP have not been investigated. In this study, we utilized 13 Expert Team on Climate Change Detection and Indices to assess the evolution of climate extremes over the TP with/without MCB implementation. We found that although the MCB is implemented over ocean only, it would cause significant changes on climate extremes in the TP which is very far from oceans and much higher than sea level. During 2030–2059, MCB implementation can decrease warm temperature extremes, leading to a significant decrease in the TXx index by 6–18°C, the TX90p index by 15–45 days, and the TN90p index by 15–50 days. MCB implementation would also have some cooling effects on cold temperature extremes, leading to an increase in the ID index by 30–80 days, the TX10p index by 22–32 days, and the TN10p index by about 12 days and a decrease in the TNn index by 0.5–1.5°C. Although MCB implementation would not have much impacts on precipitation extremes, it would significantly increase the area of the region with <10% drought frequency, and increase the drought intensity in the west of Lhasa city.

show abstract

The Radiative and Cloud Responses to Sea Salt Aerosol Engineering in GFDL Models

Cited by 4 publications

References 60 publications

Effect of Regional Marine Cloud Brightening Interventions on Climate Tipping Elements

Effect of Regional Marine Cloud Brightening Interventions on Climate Tipping Elements

IMO2020 Regulations Accelerate Global Warming by up to 3 Years in UKESM1

Impacts of marine cloud brightening scheme on climatic extremes in the Tibetan Plateau

Contact Info

Product

Resources

About