Unveiling the Indian Ocean forcing on winter eastern warming - western cooling pattern over North America.

While the tropical Pacific teleconnection to North America has been studied extensively, the impact of the Indian Ocean on North American climate has received less attention. Here, through observational analysis and hierarchy atmospheric model simulations with different complexity, we find that the Indian Ocean plays a crucial role in North American winter climate through a teleconnection termed the Indian Ocean - North America pattern. We show that in the warm Indian Ocean phase, this teleconnection contributes to anomalously cold winters along the west coast of the United States through advection with increased mountain snowfall, while simultaneously leading to warmer conditions over the Great Lakes region.

Hyper-FET's Phase-Transition-Materials Design Guidelines for Ultra-Low Power Applications at 3 nm Technology Node.

In this work, a hybrid-phase transition field-effects-transistor (hyper-FET) integrated with phase-transition materials (PTM) and a multi-nanosheet FET (mNS-FET) at the 3 nm technology node were analyzed at the device and circuit level. Through this, a benchmark was performed for presenting device design guidelines and for using ultra-low-power applications. We present an optimization flow considering hyper-FET characteristics at the device and circuit level, and analyze hyper-FET performance according to the phase transition time (TT) and baseline-FET off-leakage current (I) variations of the PTM.

Optimization of Gate-All-Around Device to Achieve High Performance and Low Power with Low Substrate Leakage.

In this study on multi-nanosheet field-effect transistor (mNS-FET)-one of the gate-all-around FETs (GAAFET) in the 3 nm technology node dimension-3D TCAD (technology computer-aided design) was used to attain optimally reduced substrate leakage from options including a punch-through-stopper (PTS) doping scheme and a bottom oxide (BO) scheme for bottom isolation, with the performance improvement being shown in the circuit-level dynamic operation using the mNS-FET. The PTS doping concentration requires a high value of >5 × 10 cm to reduce gate induced drain leakage (GIDL), regardless of the presence or absence of the bottom isolation layer. When the bottom isolation is applied together with the PTS doping scheme, the capacitance reduction is larger than the on-state current reduction, as compared to when only the PTS doping concentration is applied.

East Antarctic cooling induced by decadal changes in Madden-Julian oscillation during austral summer.

While West Antarctica has experienced the most significant warming in the world, a profound cooling trend in austral summer was observed over East Antarctica (30°W to 150°E, 70° to 90°S) from 1979 to 2014. Previous studies attributed these changes to high-latitude atmospheric dynamics, stratospheric ozone change, and tropical sea surface temperature anomalies. We show that up to 20 to 40% of the observed summer cooling trend in East Antarctica was forced by decadal changes of the Madden-Julian oscillation (MJO).

Interpretation of the Top-of-Atmosphere Energy Flux for Future Arctic Warming.

With the trend of amplified warming in the Arctic, we examine the observed and modeled top-of-atmosphere (TOA) radiative responses to surface air-temperature changes over the Arctic by using TOA energy fluxes from NASA's CERES observations and those from twelve climate models in CMIP5. Considerable inter-model spreads in the radiative responses suggest that future Arctic warming may be determined by the compensation between the radiative imbalance and poleward energy transport (mainly via transient eddy activities). The poleward energy transport tends to prevent excessive Arctic warming: the transient eddy activities are weakened because of the reduced meridional temperature gradient under polar amplification.

Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution.