Blar i Bergen Open Research Archive på forfatter "Gao, Yongqi"
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Arctic sea ice and Eurasian climate: A review
Gao, Yongqi; Sun, Jianqi; Li, Fei; He, Shengping; Sandven, Stein; Yan, Qing; Zhang, Zhongshi; Lohmann, Katja; Keenlyside, Noel; Furevik, Tore; Suo, Lingling (Peer reviewed; Journal article, 2014-11-28)The Arctic plays a fundamental role in the climate system and has shown significant climate change in recent decades, including the Arctic warming and decline of Arctic sea-ice extent and thickness. In contrast to the ... -
Assessing the influence of sea surface temperature and arctic sea ice cover on the uncertainty in the boreal winter future climate projections
Cheung, Ho-Nam; Keenlyside, Noel Sebastian; Koenigk, Torben; Yang, Shuting; Tian, Tian; Xu, Zhiqing; Gao, Yongqi; Ogawa, Fumiaki; Omrani, Nour-Eddine; Qiao, Shaobo; Zhou, Wen (Journal article; Peer reviewed, 2022)We investigate the uncertainty (i.e., inter-model spread) in future projections of the boreal winter climate, based on the forced response of ten models from the CMIP5 following the RCP8.5 scenario. The uncertainty in the ... -
Atlantic Multidecadal Oscillation modulates the impacts of Arctic sea ice decline
Li, Fei; Orsolini, Yvan; Wang, Huijun; Gao, Yongqi; He, Shengping (Peer reviewed; Journal article, 2018-03)The Arctic sea ice cover has been rapidly declining in the last two decades, concurrent with a shift in the Atlantic Multidecadal Oscillation (AMO) to its warm phase around 1996/1997. Here we use both observations and model ... -
Contributors to linkage between Arctic warming and East Asian winter climate
Xu, Xinping; He, Shengping; Gao, Yongqi; Zhou, Botao; Wang, Huijun (Journal article; Peer reviewed, 2021)Previous modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change ... -
Diagnosing ocean tracer transport from Sellafield and Dounreay by equivalent diffusion and age
Orre, Steinar; Gao, Yongqi; Drange, Helge; Deleersnijder, Eric (Peer reviewed; Journal article, 2008-09-27)A simple approach for estimating the equivalent diffusion for diagnosing tracer transport is proposed. Two different expressions are derived; one is based directly on an analytical solution of the two-dimensional ... -
The Effect of Diapycnal Mixing on the Ventilation and CFC-11 Uptake in the Southern Ocean
Gao, Yongqi; Drange, Helge (Advances in Atmospheric Sciences;21(5), Journal article, 2004-03-04)The Miami Isopycnic Coordinate Ocean Model (MICOM) is used to investigate the effect of diapycnal mixing on the oceanic uptake of CFC-11 and the ventilation of the surface waters in the Southern Ocean (south of 45°S). Three ... -
Effects of diapycnal and isopycnal mixing on the ventilation of CFCs in the North Atlantic in an isopycnic coordinate OGCM
Gao, Yongqi; Drange, Helge; Bentsen, Mats (Peer reviewed; Journal article, 2003)Simulated distributions of the chlorofluorocarbons CFC-11 and CFC-12 are used to examine the ventilation of the North Atlantic Ocean in a global version of the Miami Isopycnic Coordinate Ocean Model (MICOM). Three simulations ... -
Eurasian Cooling Linked to the Vertical Distribution of Arctic Warming
He, Shengping; Xu, Xinping; Furevik, Tore; Gao, Yongqi (Journal article; Peer reviewed, 2020)Observations show that deep Arctic winter warming, extending from surface to mid‐troposphere, has concurred with below‐average temperature over central Eurasia. Modeling studies focusing on the response to Arctic sea ice ... -
Evaluating Global Ocean Carbon Models: The Importance of Realistic Physics
Doney, S. C.; Lindsay, K.; Caldeira, Ken; Campin, J. M.; Drange, Helge; Dutay, J. C.; Follows, M.; Gao, Yongqi; Gnanadesikan, A.; Gruber, N.; Ishida, A.; Joos, Fortunat; Madec, G.; Maier-Reimer, E.; Marshall, J. C.; Matear, R. J.; Monfray, P.; Mouchet, A.; Najjar, R.; Orr, J. C.; Plattner, G. K.; Sarmiento, J. L.; Schlitzer, R.; Slater, R.; Totterdell, I. J.; Weirig, M. F.; Yamanaka, Y.; Yool, A. (Peer reviewed; Journal article, 2004-09-15)A suite of standard ocean hydrographic and circulation metrics are applied to the equilibrium physical solutions from 13 global carbon models participating in phase 2 of the Ocean Carbon-cycle Model Intercomparison Project ... -
Evaluating Impacts of Recent Arctic Sea Ice Loss on the Northern Hemisphere Winter Climate Change
Ogawa, Fumiaki; Keenlyside, Noel; Gao, Yongqi; Koenigk, Torben; Yang, Shuting; Suo, Lingling; Wang, Tao; Gastineau, Guillaume; Nakamura, Tetsu; Cheung, Ho Nam; Omrani, Nour-Eddine; Ukita, Jinro; Semenov, Vladimir (Journal article; Peer reviewed, 2018)Wide disagreement among individual modeling studies has contributed to a debate on the role of recent sea ice loss in the Arctic amplification of global warming and the Siberian wintertime cooling trend. We perform coordinated ... -
Evaluation of ocean carbon cycle models with data-based metrics
Matsumoto, K.; Sarmiento, J. L.; Key, R. M.; Aumont, O.; Bullister, J. L.; Caldeira, Ken; Campin, J. M.; Doney, S. C.; Drange, Helge; Dutay, J. C.; Follows, M.; Gao, Yongqi; Gnanadesikan, A.; Gruber, N.; Ishida, A.; Joos, Fortunat; Lindsay, K.; Maier-Reimer, E.; Marshall, J. C.; Matear, R. J.; Monfray, P.; Mouchet, A.; Najjar, R.; Plattner, G. K.; Schlitzer, R.; Slater, R.; Swathi, P. S.; Totterdell, I. J.; Weirig, M. F.; Yamanaka, Y.; Yool, A.; Orr, J. C. (Journal article; Peer reviewed, 2004-04-02)New radiocarbon and chlorofluorocarbon-11 data from the World Ocean Circulation Experiment are used to assess a suite of 19 ocean carbon cycle models. We use the distributions and inventories of these tracers as quantitative ... -
Impact of Arctic sea ice variations on winter temperature anomalies in northern hemispheric land areas
Köenigk, Torben; Gao, Yongqi; Gastineau, Guillaume; Keenlyside, Noel; Nakamura, Tetsu; Ogawa, Fumiaki; Orsolini, Yvan; Semenov, Vladimir A.; Suo, Lingling; Tian, Tian; Wang, Tao; Wettstein, Justin; Yang, Shuting (Peer reviewed; Journal article, 2018-07-30)Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models have been used in order to evaluate the respective impact of the observed Arctic sea ice and sea surface temperature (SST) ... -
Inception of the Northern European Ice Sheet due to contrasting ocean and insolation forcing
Risebrobakken, Bjørg; Dokken, Trond Martin; Otterå, Odd Helge; Jansen, Eystein; Gao, Yongqi; Drange, Helge (Peer reviewed; Journal article, 2007-01)About 115,000 years ago the last interglacial reached its terminus and nucleation of new ice sheet growth was initiated. Evidence from the northernmost Nordic Seas indicate that the inception of the last glacial was related ... -
Influence of solar wind energy flux on the interannual variability of ENSO in the subsequent year
He, Shengping; Wang, Hui-Jun; Gao, Yongqi; Li, Fei; Li, Hui; Wang, Chi (Peer reviewed; Journal article, 2018)Previous studies have tended to adopt the quasi-decadal variability of the solar cycle (e.g. sunspot number (SSN) or solar radio flux at 10.7 cm (F10.7) to investigate the effect of solar activity on El Niño–Southern ... -
Marine-based multiproxy reconstruction of Atlantic multidecadal variability
Svendsen, Lea; Hetzinger, Steffen; Keenlyside, Noel; Gao, Yongqi (Peer reviewed; Journal article, 2014-02-28)Atlantic multidecadal variability (AMV) is known to impact climate globally, and knowledge about the persistence of AMV is important for understanding past and future climate variability, as well as modeling and assessing ... -
Modulation of the Aleutian–Icelandic low seesaw and its surface impacts by the Atlantic Multidecadal Oscillation
Li, Fei; Orsolini, Yvan; Wang, Huijun; Gao, Yongqi; He, Shengping (Peer reviewed; Journal article, 2018-01)Early studies suggested that the Aleutian–Icelandic low seesaw (AIS) features multidecadal variation. In this study, the multidecadal modulation of the AIS and associated surface climate by the Atlantic Multidecadal ... -
North Atlantic Modulation of Interdecadal Variations in Hot Drought Events over Northeastern China
Li, Huixin; He, Shengping; Gao, Yongqi; Chen, Huopo; Wang, Huijun (Journal article; Peer reviewed, 2020)Based on the long-term reanalysis datasets and the multivariate copula method, this study reveals that the frequency of summer hot drought events (SHDEs) over northeastern China (NEC) shows interdecadal variations during ... -
Oceanic forcing of the global warming slowdown in multi-model simulations
Xu, Xinping; He, Shengping; Furevik, Tore; Gao, Yongqi; Wang, Huijun; Li, Fei; Ogawa, Fumiaki (Journal article; Peer reviewed, 2020)Abstract Concurrent with the slowdown of global warming during 2002–2013, the wintertime land surface air temperatures over Eurasia, North America, Africa, Australia, South America, and Greenland experienced notable ... -
On the recent time history and forcing of the inflow of Atlantic Water to the Arctic Mediterranean
Nilsen, Jan Even Øie; Hátún, Hjalmar; Sandø, Anne Britt; Bethke, Ingo; Laurantin, Olivier; Gao, Yongqi; Drange, Helge; Furevik, Tore (Extended Abstract for The ACIA International Scientific Symposium on Climate Change in the Arctic, Conference lecture, 2004) -
Pacific contribution to decadal surface temperature trends in the Arctic during the twentieth century
Svendsen, Lea; Keenlyside, Noel; Muilwijk, Morven; Bethke, Ingo; Omrani, Nour-Eddine; Gao, Yongqi (Journal article; Peer reviewed, 2021)Instrumental records suggest multidecadal variability in Arctic surface temperature throughout the twentieth century. This variability is caused by a combination of external forcing and internal variability, but their ...