Mirong Song

Institute of Atmospheric Physics, Chinese Academy of Sciences · LASG

Antarctic sea ice has experienced rapid change in recent years, which garners increasing attention for its prediction. In this study, we develop a deep learning model (named ANTSIC-UNet) trained by physically enriched climate variables and evaluate its skill for extended seasonal prediction of Antarctic sea ice concentration (up to 6 months in adva...

Two coupled climate models that participated in the CMIP6 project (Coupled Model Intercomparison Project Phase 6), the Earth System Model of Chinese Academy of Sciences version 2 (CAS-ESM2-0), and the Nanjing University of Information Science and Technology Earth System Model version 3 (NESM3) were assessed in terms of the impact of four new sea ic...

Two coupled climate models which participated the CMIP6 project (Coupled Model Intercomparison Project Phase 6), the Earth System Model of Chinese Academy of Sciences version 2 (CAS-ESM2-0) and the Nanjing University of Information Science and Technology Earth System Model version 3 (NESM3), were assessed in terms of the impact of four new sea ice...

The Arctic has experienced rapid changes in recent decades. For the first time, we intercompare five snow mass budget processes over Arctic sea ice simulated by 22 models from the Coupled Model Intercomparison Project phase 6 (CMIP6) using new diagnostics that have not been available for previous CMIPs. Our analysis suggests that snowfall accumulat...

Current climate models project that Antarctic sea ice will decrease by the end of 21st century. Previous studies have suggested that Antarctic sea ice change have impacts on atmospheric circulation and the mean state of the Southern Hemisphere. However, little is known whether Antarctic sea ice loss may have a tangible impact on climate extremes ov...

The Antarctic sea ice has undergone dramatic changes in recent years, with the highest recorded sea ice extent in 2014 and the lowest in 2017. We investigated the impacts of the observed changes in these two extremes of Antarctic sea ice conditions on the atmospheric circulation in the Southern Hemisphere. We conducted three numerical simulations w...

Arctic sea ice has decreased substantially and is projected to reach a seasonally ice-free state in the coming decades. Little is known about whether dwindling Arctic sea ice is capable of influencing the occurrence of strong El Niño, a prominent mode of climate variability with global impacts. Based on time slice coupled model experiments, here we...

A sea ice model is an important component of an Earth system model, which is an essential tool for the study of sea ice, including its internal processes, interactions with other components, and projected future changes. This paper evaluates a simulation of sea ice by the Chinese Academy of Sciences Earth System Model version 2 (CAS-ESM 2.0), focus...

Several consecutive extreme cold events impacted China during the first half of winter 2020/21, breaking the low-temperature records in many cities. How to make accurate climate predictions of extreme cold events is still an urgent issue. The synergistic effect of the warm Arctic and cold tropical Pacific has been demonstrated to intensify the intr...

Some studies have discussed potential influences of Antarctic sea ice anomalies, Atlantic Multi-decadal Variability (AMV), and Interdecadal Pacific Oscillation (IPO) on the Southern Hemisphere (SH) climate, individually. However, it is not clear how different combinations of them influence the extratropical SH climate. Here we select three differen...

Whether Arctic sea-ice loss has significant impacts on climate extremes in mid- and high-latitudes remains uncertain. Here we show the full response of cold and warm extremes under two Arctic sea-ice loss scenarios utilizing a coupled global climate model that permits the air-sea coupling. Our results show that the amount of Arctic sea-ice loss det...

Recently, an algorithm of surface turbulent heat fluxes over snow/sea ice has been developed based on the theory of maximum entropy production (MEP), which is fundamentally different from the bulk flux algorithm (BF) that has been used in sea ice models for a few decades. In this study, we first assess how well the MEP algorithm captures the observ...

The second version of Chinese Academy of Sciences Earth System Model (CAS-ESM 2) is described with emphasis on the development process, strength and weakness, and climate sensitivities in simulations of the Coupled Model Intercomparison Project (CMIP6) DECK experiments. CAS-ESM 2 was built as a numerical model to simulate both the physical climate...

The second version of the Chinese Academy of Sciences Earth System Model (CAS-ESM2.0) is participating in the Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) experiments in phase 6 of the Coupled Model Intercomparison Project (CMIP6). The purpose of FAFMIP is to understand and reduce the uncertainty of ocean climate changes in response t...

This paper introduces the Flexible Global Ocean–Atmosphere–Land System Model: Grid-Point Version 3 (FGOALS-g3) and evaluates its basic performance based on some of its participation in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) experiments. Our results show that many significant improvements have been achieved by FGOALS-g3...

As a member of the Chinese modelling groups, the coupled ocean-ice component of the Chinese Academy of Science Earth System Model version 2.0 (CAS-ESM2.0) is taking part in the Ocean Model Intercomparison Project Phase 1 (OMIP1) experiment for the Coupled Model Intercomparison Project Phase 6 (CMIP6). The simulation was conducted, and monthly outpu...

Two versions of the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere-Land System model (CAS-FGOALS), version f3-L and g3, are used to simulate the two interglacial epochs of the mid-Holocene and the Last Interglacial in phase 4 of the Paleoclimate Modelling Intercomparison Project (PMIP4), which aims to study the impact of changes in or...

The datasets of the Chinese Academy of Sciences (CAS) Flexible Global Ocean–Atmosphere–Land System (FGOALS-f3-L) model for the baseline experiment of the fully coupled runs in the Diagnostic, Evaluation and Characterization of Klima (DECK) common experiments of phase 6 of the Coupled Model Intercomparison Project (CMIP6) are described in this study...

Observations1–3 and model simulations3,4 show enhanced warming in the Arctic under increasing greenhouse gases, a phenomenon known as the Arctic amplification (AA)5, that is likely caused by sea-ice loss1,3. AA reduces meridional temperature gradients linked to circulation, thus mid-latitude weather and climate changes have been attributed to AA, o...

Warming in the Arctic has been much faster than the rest of the world in both observations and model simulations, a phenomenon known as the Arctic amplification (AA) whose cause is still under debate. By analyzing data and model simulations, here we show that large AA occurs only from October to April and only over areas with significant sea-ice lo...

Rapid declines in Arctic sea ice have captured attention and pose significant challenges to a variety of stakeholders. There is a rising demand for Arctic sea ice prediction at daily to seasonal time scales, which is partly a sea ice initial condition problem. Thus, a multivariate data assimilation that integrates sea ice observations to generate r...

Satellite-derived surface radiative fluxes have been recently improved and extended. However, the accuracy of recent satellite-derived surface radiative fluxes in the Arctic is not well characterized. Here, the authors assess the accuracy of the net surface radiative flux (NETSRF) in the Arctic, focusing on the ice-covered ocean, for three satellit...

Air temperature is a key index reflecting climate change. Air temperature extremes are very important because they strongly influence the natural environment and societal activities. The Arctic air temperature extremes north of 60°N are investigated in the winter. Daily data from 238 stations at north of 60°N from the global summary of the day for...

Large parts of North America, Europe, Siberia, and East Asia have experienced cold snaps and heavy snowfalls for the past few winters, which have been linked to rapid decline of Arctic sea ice. Although the role of reduction in Arctic sea ice in recent cold and snowy winters is still a matter of debate, there is considerable interest in determining...

Here sea ice concentration derived from the Special Sensor Microwave Imager/Sounder and thickness derived from the Soil Moisture and Ocean Salinity and CryoSat-2 satellites are assimilated in the National Centers for Environmental Prediction Climate Forecast System using a localized error subspace transform ensemble Kalman filter (LESTKF). Three en...

The recent decline in the Arctic sea ice has coincided with more cold winters in Eurasia. It has been hypothesized that the Arctic sea ice loss is causing more mid-latitude cold extremes and cold winters, yet there is lack of consensus in modeling studies on the impact of Arctic sea ice loss. Here we conducted modeling experiments with Community At...

Arctic sea ice extent has been declining in recent decades. There is ongoing debate on the contribution of natural internal variability to recent and future Arctic sea ice changes. In this study, we contrast the trends in the forced and unforced simulations of carefully selected global climate models with the extended observed Arctic sea ice record...

In recent decades, the Greenland ice sheet has experienced increased surface melt. However, the underlying cause of this increased surface melting and how it relates to cryospheric changes across the Arctic remain unclear. Here it is shown that an important contributing factor is the decreasing Arctic sea ice. Reduced summer sea ice favors stronger...

In the present study, the LASG/IAP Climate system Ocean Model version 2 (LICOM2) was implemented to replace the original ocean component in the Community Earth System Model version 1.0.4 (CESM1) to form a new coupled model referred to as CESM1+LICOM2. The simulation results from a 300-yr preindustrial experiment by using this model were evaluated a...

The future change of September Arctic sea-ice volume, simulated by 30 state-of-the-art climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), is examined, which depends on both ice extent and ice thickness. In comparison with the September sea-ice extent, the September sea-ice volume has larger spread in the historical simul...

The rapid change in Arctic sea ice in recent decades has led to a rising demand for seasonal sea ice prediction. A recent modeling study that employed a prognostic melt pond model in a stand-alone sea ice model found that September Arctic sea ice extent can be accurately predicted from the melt pond fraction in May. Here we show that satellite obse...

This chapter examines the simulated Arctic and Antarctic sea ice concentration, thickness and extent by the Flexible Global Ocean–Atmosphere–Land System Model Grid-point version 2 (FGOALS-g2) and the Flexible Global Ocean–Atmosphere–Land System Model Spectral version 2 (FGOALS-s2) used in the fifth phase of the Coupled Model Intercomparison Project...

Based on preliminary improvements, future development of the sea ice model of FGOALS will be concentrated primarily in two areas: (1) improvements to the solar transfer parameterizations of shortwave radiation albedo and penetration, and (2) integration of Lagrangian tracking in the sea ice model and coupled climate model. These improvements will a...

The present study describes the long-term evolution of sea surface temperature (SST), sea ice extent in both hemispheres from the preindustrial (PI) control run, and surface air temperature (SAT) from the historical run and three Representative Concentration Pathways (RCP) projects simulated by the Flexible Global Ocean-Atmosphere-Land System Model...

This paper addresses the specter of a September ice-free Arctic in the 21st century using newly available simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5). We find that large spread in the projected timing of the September ice-free Arctic in 30 CMIP5 models is associated at least as much with different atmospheric model co...

Sea ice is an important component in the Earth’s climate system. Coupled climate system models are indispensable tools for the study of sea ice, its internal processes, interaction with other components, and projection of future changes. This paper evaluates the simulation of sea ice by the Flexible Global Ocean-Atmosphere-Land System model Grid-po...

Shortwave radiation physics in CICE4.0 is improved and evaluated. First, we improved surface albedo parameterization that depends on large-scale variables (named SHCE). The improvements include expanding the spectrum from two to four bands, distinguishing direct and diffuse, considering different albedo for wet and dry snow, and effects of sea ice...

This study mainly introduces the development of the Flexible Global Ocean-Atmosphere-Land System Model: Grid-point Version 2 (FGOALS-g2) and the preliminary evaluations of its performances based on results from the pre-industrial control run and four members of historical runs according to the fifth phase of the Coupled Model Intercomparison Projec...

We conduct numerical experiments with an atmospheric general circulation model to answer the question whether the extreme Arctic sea ice anomaly in 2007 contributed to the severe January 2008 snowstorm in China. Results show that the record low Arctic sea ice in September 2007, and follow‐up slow recovery of the Arctic sea ice in October and Novemb...

Associations between the spring Arctic sea ice concentration (SIC) and North American summer rainfall were discussed using the singular value decomposition analysis. Results show that a reduced SIC in the North Atlantic and Pacific sectors of the Arctic, and an enhanced SIC in much of the central Arctic Basin and Beaufort Sea, are accompanied by dr...

While the Arctic region has been warming strongly in recent decades, anomalously large snowfall in recent winters has affected large parts of North America, Europe, and east Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resembla...

Associations between the autumn Arctic sea ice concentrations (SICs) and North American winter precipitation were examined using singular value decomposition. The results show that a reduced SIC in the majority of the Arctic is accompanied by dry conditions over the Great Plains, the southern United States, Mexico, eastern Alaska, and southeastern...

Ferrel Circulation variability in the Southern Hemisphere and its linkages with the tropical and subtropical sea surface temperature (SST) for the period 1979-2009 are investigated. Two dominant spatiotemporal patterns of Ferrel Circulation variability are identified, one showing opposing change between the poleward and equatorward portion of ∼48°S...