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ABSTRACT This study proposes a novel integrated transformer structure with simple circuit configuration and miniaturized magnetic components. In a bridgeless flyback rectifier, two flyback converters operate corresponding to the polarity of the AC input, requiring two transformers. This paper proposes a novel winding structure that realizes zero coupling co‐efficient between two sets of windings. This enables the integration of two transformers into a single transformer, preventing their flyback operations from interfering with each other. The integrated transformer has approximately 16% lower volume compared to that of conventional transformers. The proposed integrated transformer was built, evaluated, and verified by designing a 75 W‐bridgeless flyback rectifier with 100 kHz switching frequency. [ABSTRACT FROM AUTHOR]

A modeling protocol (defined by a series of climate model simulations with specified model output) is introduced. Studies using these simulations are designed to improve the understanding of climate impacts using a strategy for climate intervention (CI) known as marine cloud brightening (MCB) in specific regions; therefore, the protocol is called MCB-REG (where REG stands for region). The model simulations are not intended to assess consequences of a realistic MCB deployment intended to achieve specific climate targets but instead to expose responses to interventions in six regions with pervasive cloud systems that are often considered candidates for such a deployment. A calibration step involving simulations with fixed sea surface temperatures (SSTs) is first used to identify a common forcing, and then coupled simulations with forcing in individual regions and combinations of regions are used to examine climate impacts. Synthetic estimates constructed by superposing responses from simulations with forcing in individual regions are considered a means of approximating the climate impacts produced when MCB interventions are introduced in multiple regions. A few results comparing simulations from three modern climate models (CESM2, E3SMv2, and UKESM1) are used to illustrate the similarities and differences between model behavior and the utility of estimates of MCB climate responses that were synthesized by summing responses introduced in individual regions. Cloud responses to aerosol injections differ substantially between models (CESM2 clouds appear much more susceptible to aerosol emissions than the other models), but patterns in precipitation and surface temperature responses were similar when forcing is imposed with similar amplitudes in the same regions. A previously identified La Niña-like response to forcing introduced in the Southeast Pacific is evident in this study, but the amplitude of the response was shown to markedly differ across the three models. Other common response patterns were also found and are discussed. Forcing in the Southeast Atlantic consistently (across all three models) produces weaker global cooling than that in other regions, and the Southeast Pacific and South Pacific show the strongest cooling. This indicates that the efficiency of a given intervention depends on not only the susceptibility of the clouds to aerosol perturbations, but also the strength of the underlying radiative feedbacks and ocean responses operating within each region. These responses were generally robust across models, but more studies and an examination of responses with ensembles would be beneficial. [ABSTRACT FROM AUTHOR]

Solar climate intervention refers to a group of methods for reducing climate risks associated with anthropogenic warming by reflecting sunlight. Marine cloud brightening (MCB), one such approach, proposes to inject sea‐salt aerosol into one or more regional marine boundary layer to increase marine cloud reflectivity. Here, we assess the potential influence of various MCB experiments on Africa's climate using simulations from the Community Earth System Model (CESM2) with the Community Atmosphere Model (CAM6) as its atmospheric component. We analyzed four idealized MCB experiments under a medium‐range background forcing scenario (SSP2‐4.5), which brighten clouds over three subtropical ocean regions: (a) Northeast Pacific (MCBNEP); (b) Southeast Pacific (MCBSEP); (c) Southeast Atlantic (MCBSEA); and (d) these three regions simultaneously (MCBALL). Our results suggest that the climate impacts of MCB in Africa are highly sensitive to the deployment region. MCBSEP would produce the strongest global cooling effect and thus could be the most effective in decreasing temperatures, increasing precipitation, and reducing the intensity and frequency of temperature and precipitation extremes across most parts of Africa, especially West Africa, in the future (2035–2054) compared to the historical climate (1995–2014). MCB in other regions produces less cooling and wetting despite similar radiative forcings. While the projected changes under MCBALL are similar to those of MCBSEP, MCBNEP and MCBSEA could see more residual warming and induce a warmer future than under SSP2‐4.5 in some regions across Africa. All MCB experiments are more effective in cooling maximum temperature and related extremes than minimum temperature and related extremes. Plain Language Summary: We investigate the potential impact of artificially increasing marine cloud reflectivity on Africa's climate. Human influence on the climate is projected to increase the risk of damaging extreme events across the globe. In Africa, one of the most vulnerable regions to climate change, these impacts are already being felt, especially among communities least able to adapt. It is possible to increase the reflectivity of marine clouds by spraying them with sea salt particulates. This approach was proposed as one possible way of reducing warming by reducing the amount of sunlight reaching the earth's surface. The potential implications of such initiatives for the climate system remain uncertain, especially in Africa. In this study, we analyzed a climate model, that simulates increased reflectivity of clouds to assess the potential impacts of artificially brightening clouds over different subtropical marine regions on the African climate, focusing on mean and extreme precipitation and temperature events. Our results suggest that the impact of artificially increasing marine cloud reflectivity depends on the marine region of intervention. Key Points: The climate impacts of Marine Cloud Brightening (MCB) in Africa are highly sensitive to the deployment regionMCB in the Southeast Pacific could effectively cool Africa and reduces temperature and precipitation extremesIn this study, MCB is more effective in cooling maximum temperature and related extremes than minimum temperature and related extremes [ABSTRACT FROM AUTHOR]

We study the sensitivity of South Asian Summer Monsoon (SASM) precipitation to Southern Hemisphere (SH) subtropical Absorbed Solar Radiation (ASR) changes using Community Earth System Model 2 simulations. Reducing positive ASR biases over the SH subtropics impacts SASM, and is sensitive to the ocean basin where changes are imposed. Radiation changes over the SH subtropical Indian Ocean (IO) shifts rainfall over the equatorial IO northward causing 1–2 mm/day drying south of equator, changes over the SH subtropical Pacific increases precipitation over northern continental regions by 1–2 mm/day, and changes over the SH subtropical Atlantic have little effect on SASM precipitation. Radiation changes over the subtropical Pacific impacts the SASM through zonal circulation changes, while changes over the IO modify meridional circulation to bring about changes in precipitation over northern IO. Our findings suggest that reducing SH subtropical radiation biases in climate models may also reduce SASM precipitation biases. Plain Language Summary: Precipitation from South Asian Summer Monsoon (SASM) is of high significance to the livelihoods of over a billion people. As the global climate continues to evolve, it is essential to have a clear understanding of the possible future changes to the SASM. However, current state‐of‐the‐art climate models have difficulties in simulating climatological mean SASM precipitations. Here we study sensitivity of SASM precipitation to subtropical southern ocean radiation as one of the possible causes of SASM precipitation bias. Our experiments indicate that SASM precipitation is sensitive to southern hemisphere (SH) subtropical radiation changes particularly to those in subtropical Pacific. These findings imply that improving SH subtropical radiation biases might improve SASM precipitation simulations in climate models. Key Points: We test if biases in southern hemisphere shortwave radiation contributes to biases in South Asian summer monsoon precipitation in the CESM2Reducing incoming shortwave radiation in the subtropical southern hemisphere reduces dry biases over continental South AsiaThis effect is mostly due to forcing in the South Pacific, with less impact from the Atlantic or Indian Ocean [ABSTRACT FROM AUTHOR]

The magnitude of the aerosol forcing remains among the largest unknowns when assessing climate sensitivity over the historical period. Here, we quantify and explain a crucial but often overlooked source of uncertainty in aerosol forcing: the temporal variability of aerosol emissions. We show that time‐variability in biomass burning (BB) emissions weakens the time‐averaged total aerosol forcing, particularly in the Northern Hemisphere mid‐ to high‐latitudes. BB emissions variability produces weaker (less negative) mean effective radiative forcing (ERF) compared to scenarios with no interannual variability in emissions. Satellite‐estimated BB emissions (and associated variability) result in a June–September absolute ERF (relative to zero BB emissions) of −7.7 W m−2 from 50° to 70°N, compared to −10.4 W m−2 when no emissions variability is used in the Community Earth System Model version 2 (CESM2). This difference in forcing is attributable to nonlinear aerosol‐cloud interactions. Aerosol forcing will be overestimated (i.e., more negative) if emissions are temporally‐smoothed. Plain Language Summary: Aerosols are small particles in the air that can impact the climate, but we don't know exactly how much. One reason for this uncertainty is that the amount of aerosols can change a lot over time, especially when it comes from burning things like wood or plants (i.e., biomass burning emissions). When the amount of these biomass burning aerosols changes a lot from year‐to‐year, it has less of an impact on the climate. This is because clouds react less strongly when aerosol concentrations are high compared to when they are low. If we smooth out the changes in aerosol amounts over time (as is done with most Earth System Model simulations), we will overestimate their cooling impact on the climate. Key Points: The radiative forcing due to aerosols is overestimated if emissions are temporally‐smoothedInterannual variability in aerosol emissions leads to a weakened time‐average cloud radiative effectChanges in time‐average cloud radiative effect with differing aerosol variability are due to nonlinear aerosol‐cloud interactions [ABSTRACT FROM AUTHOR]