Congbin Fu

Regional Climate Model Intercomparison Project for Asia

Improving the simulation of regional climate change is one of the high-priority areas of climate study because regional information is needed for climate change impact assessments. Such information is especially important for the region covered by the East Asian monsoon where there is high variability in both space and time. To this end, the Regional Climate Model Intercomparison Project (RMIP) for Asia has been established to evaluate and improve regional climate model (RCM) simulations of the monsoon climate. RMIP operates under joint support of the Asia–Pacific Network for Global Change Research (APN), the Global Change System for Analysis, Research and Training (START), the Chinese Academy of Sciences, and several projects of participating nations. The project currently involves 10 research groups from Australia, China, Japan, South Korea, and the United States, as well as scientists from India, Italy, Mongolia, North Korea, and Russia. RMIP has three simulation phases: March 1997–August 1998, which c...

Developed and developing world responsibilities for historical climate change and CO2 mitigation

At the United Nations Framework Convention on Climate Change Conference in Cancun, in November 2010, the Heads of State reached an agreement on the aim of limiting the global temperature rise to 2u2009°C relative to preindustrial levels. They recognized that long-term future warming is primarily constrained by cumulative anthropogenic greenhouse gas emissions, that deep cuts in global emissions are required, and that action based on equity must be taken to meet this objective. However, negotiations on emission reduction among countries are increasingly fraught with difficulty, partly because of arguments about the responsibility for the ongoing temperature rise. Simulations with two earth-system models (NCAR/CESM and BNU-ESM) demonstrate that developed countries had contributed about 60–80%, developing countries about 20–40%, to the global temperature rise, upper ocean warming, and sea-ice reduction by 2005. Enacting pledges made at Cancun with continuation to 2100 leads to a reduction in global temperature rise relative to business as usual with a 1/3–2/3 (CESM 33–67%, BNU-ESM 35–65%) contribution from developed and developing countries, respectively. To prevent a temperature rise by 2u2009°C or more in 2100, it is necessary to fill the gap with more ambitious mitigation efforts.

An virtual numerical experiment to understand the impacts of recovering natural vegetation on the summer climate and environmental conditions in East Asia

By applying a regional integrated environmental model system (RIEMS), a virtual numerical experiment is implemented to study the impacts of recovering natural vegetation on the regional climate and environmental conditions. The results show that recovering the natural vegetation in large scale could have significant influence on summer climate in East Asia. Not only would it be able to change the surface climate, but also to modify to certain extent the intensity of monsoon circulation. Although this is a virtual experiment at an extremely ideal condition, the implication of the simulating results is that the on-going nation-wide activities to recover the crop land for forest and pasture must be managed according to the local natural climate, hydrological and soil conditions. Only under such a condition, would the recovering of natural vegetation bring about significant climate and environmental benefits at regional scale.

Calibrating and Evaluating Reanalysis Surface Temperature Error by Topographic Correction

Abstract Based on the observed daily surface air temperature data from 597 stations over continental China and two sets of reanalysis data [NCEP–NCAR and 40-yr ECMWF Re-Analysis (ERA-40)] during 1979–2001, the altitude effects in calibrating and evaluating reanalyzed surface temperature errors are studied. The results indicate that the accuracy of interpolated surface temperature from the reanalyzed gridpoint value or the station observations depends much on the altitudes of original data. Bias of interpolated temperature is usually in proportion to the increase of local elevation and topographical complexity. Notable improvements of interpolated surface temperature have been achieved through “topographic correction,” especially for ERA-40, which highlights the necessity of removal of “elevation-induced bias” when using and evaluating reanalyzed surface temperature.

Correlations between North Atlantic Oscillation Index in winter and eastern China Flood/Drought Index in summer in the last 530 years

The time series of winter North Atlantic Oscillation Index (NAOI) in the period of 1429–1983 developed by Glueck and summer Flood/Drought Index (FDI) of eastern China in the period of 1470–1999 from 100 stations are used in this paper to study the potential impact of North Atlantic Oscillation on the climate in China. The analysis has explored some significant lag correlations between FDI and NAOL The maximum positive correlation coefficients between NAOI and area-mean FDI in eastern and northern China lagging 2–3 years reach at 0.001 significance level, and while there are also negative correlation between NAOI and FDI in central and southern China at significance level of 0.05–0.01. The correlation between FDI and NAOI is time-dependent, i.e. the correlation coefficients between two indices vary from period to period. The highest correlation appeared in the period of 1636–1742, around the Little Ice Age, with the significant level of far above 0.001. The second significant period was from 1951 to 1999, at the level of 0.005–0.002. Both the power spectrum analysis and Morlet wavelet transformation have presented an interesting phenomenon: the area-mean FDIs in eastern and northern China share almost the same oscillation periods with NAOI in the inter-annual, decadal and centurial scales’ oscillations, i.e. 4–5, about 10, 20–30, around 50 and 80–100 years, etc. The Mann-Kendall Rank Statistic test reveals the significant trend and decadal abrupt changes in the series of area-mean FDIs in eastern and northern China in the past 530 years, while the NAOI in the past 400 years, did not show such trend at the significance level, but presented more frequent changes than those of FDI in China. This difference is perhaps due to the fact that the amplitude of the extremes of reconstructed NAOI series is less than that from instrumental records.

New evidence for effects of land cover in China on summer climate

The effects of land cover in different regions of China on summer climate are studied by lagged correlation analysis using NOAA/AVHRR normalized difference vegetation index (NDVI) data for the period of 1981–1994 and temperature, precipitation data of 160 meteorological stations in China. The results show that the correlation coefficients between NDVI in previous season and summer precipitation are positive in most regions of China, and the lagged correlations show a significant difference between regions. The stronger correlations between NDVI in previous winter and precipitation in summer occur in Central China and the Tibetan Plateau, and the correlations between spring NDVI and summer precipitation in the eastern arid/semiarid region and the Tibetan Plateau are more significant. Vegetation changes have more sensitive feedback effects on climate in the three regions (eastern arid/semi-arid region, Central China and Tibetan Plateau). The lagged correlations between NDVI and precipitation suggest that, on interannual time scales, land cover affects summer precipitation to a certain extent. The correlations between NDVI in previous season and summer temperature show more complex, and the lagged responses of temperature to vegetation are weaker compared with precipitation, and they are possibly related to the global warming which partly cover up the correlations.

MONSOON REGIONS : THE HIGHEST RATE OF PRECIPITATION CHANGES OBSERVED FROM GLOBAL DATA

The global dibtributiorls of the rale of precipitation change at seasonal, interannual and interdeadel scales are computed from the observed global data sets. The analysis has revealed that the monscnn regions in hie and West Africa, and to lesser extent Australia, have the highest rate of precipitation change at all time scales in the world. Thew changes are manifested as seasonal jump, high interannual and interdecadal variability and abrupt changes between climate regimes.

Regional integrated environmental modeling system: development and application

The demand for high-confidence regional climate change scenarios is increasing. It is therefore vitally important to better understand the behavior of Earth’s climate system on regional scale and advance the knowledge of regional responses to global climate. With their ability to represent meso-scale forcings, such as coastline, complex topography, anthropogenic aerosols and land cover/use changes, Regional Climate Models (RCMs) are developed and used worldwide to investigate the effects of the above-mentioned meso-scale forcings on the local circulations that regulate the regional distribution of climatic variables. Considering the complexity of Asian Monsoon system, which is not only a physical process but also modulated by the interaction among physical, biological, chemical and social processes, a modeling framework Regional Integrated Environmental Modeling System (RIEMS) was proposed, developed and well tested before it was widely used in regional climate studies in the East Asia monsoon region.