Introduction to the Regional Coupled Model WRF4-LICOM: Performance and Model Intercomparison over the Western North Pacific

Regional coupled modeling is one of the frontiers of regional climate modeling,but intercomparison has not been well coordinated.In this study,a community regional climate model,WRF4,with a resolution of 15 km,was coupled with a high-resolution(0.1°)North Pacific Ocean model(LICOM_np).The performance of the regional coupled model,WRF4_LICOM,was compared to that of another regional coupled model,RegCM4_LICOM,which was a coupling of version 4 of the Regional Climate Model(RegCM4)with LICOM_np.The analysis focused on the 2005 western North Pacific summer monsoon rainfall.The results showed that the regional coupled models with either RegCM4 or WRF4 as their atmospheric model component simulated the broad features over the WNP reasonably well.Quantitative intercomparison of the regional coupled simulations exhibited different biases for different climate variables.RegCM4_LICOM exhibited smaller biases in its simulation of the averaged June–July–August SST and rainfall,while WRF4_LICOM better captured the tropical cyclone(TC)intensity,the percentage contributions of rainfall induced by TCs to the total rainfall,and the diurnal cycle of rainfall and stratiform percentages,especially over land areas.The different behaviors in rainfall simulated by the two models were partly ascribed to the behaviors in the simulated western North Pacific subtropical high(WNPSH).The stronger(weaker)WNPSH in WRF4_LICOM(RegCM4_LICOM)was driven by overestimated(underestimated)diabatic heating,which peaked at approximately 450 hPa over the region around the Philippines in association with different condensation–radiation processes.Coupling of WRF4 with LIOCM is a crucial step towards the development of the next generation of regional earth system models at the Chinese Academy of Sciences.

Recombinant-activated factorⅦand neuronal apoptosis in a rat model of intracerebral hemorrhage

BACKGROUND： Activated clotting factor VII has been demonstrated to exhibit obvious anti-apoptosis effects. OBJECTIVE： To observe the effect of activated clotting factor VII on neuronal apoptosis at different time points following rat intracerebral hemorrhage （ICH）. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Neurobiological Laboratory of Second Military Medical University from October 2005 to April 2006. MATERIALS： Recombinant-activated clotting factor Vlla （rFVtla） was purchased from Danish Novo Nordisk, Denmark. In situ cell death detection kit-POD kit was purchased from Roche, Switzerland. Caspase-3 activity determination kit from Biovision, USA. METHODS： A total of 72 healthy, male, Sprague Dawley rats, aged 5-8 months, were randomly assigned to three groups （n = 24）： sham-operated, ICH model, and rFVIla. In the ICH model and rFVIla groups, 80.0μL autologous non-clotting blood from rat tails was injected into the right caudate putamen to establish the ICH. The empty microinjector was inserted into the caudate putamen in the sham-operated group. The ICH model and rFVIla groups were subdivided into four subsets separately： 6, 24, 72 hours and 7 days following ICH. The rats in the rFVIla group were injected with 160 μg/kg rFVIla via the dorsal vein of the penis. MAIN OUTCOME MEASURES： Apoptotic cells were detected in the right caudate putamen by TUNEL; caspase-3 activity by spectrophotometry; and rat neurological function was evaluated by neurological functional impairment scales. RESULTS： Rat neurological function was deteriorated at 24, 72 hours, and 7 days following ICH. The TUNEL-positive cells and caspase-3 activity in the right caudate putamen was significantly increased in the ICH rats （P 〈 0.05）; rFVlla treatment reduced the number of TUNEL-positive cells and caspase-3 activity in the right caudate putamen （P 〈 0.05）, and neurological function was significantly improved （P 〈 0.05）. CONCLUSION： rFVIla was applied within 72 hours after tCH, which reduced the amount of neuronal apoptosis and promoted neurological function restoration by possibly inhibiting caspase-3 activity.

Simulation of the direct effects of dust aerosol on climate in East Asia

The results from some general circulation models show distinct radiative forcing （RF） by dust aerosol, which potentially has an effect on climate change. The direct RF and regional climatic effects of dust aerosol over the East Asian region are investigated in this study using NCAR＇s Community Atmospheric Model version 3.1. The negative RF at the top of the atmosphere （TOA） and the surface （SRF） has been revealed except for some high-albedo regions, which leads to a decrease in the surface air temperature and brings an increase of atmospheric radiative heating under both clear- and all-sky conditions. The decrease in the surface air temperature can be found over a wide region that includes the Indian peninsula and northwest China. It accompanies an increase in eastern China and the Korean peninsula, and temperature changes are not limited to regions with a large dust optical depth. A belt of vapor increase is revealed from the Indian peninsula extending east to northern China, while vapor content evidently deceases in southwest China. An increase in precipitation can also be found in the belt of increased vapor accompanying the reduction of precipitation across the regions to the south of 30~N. The pattern of rainfall change helps to offset the trend of increasing wetness in the south and increasing dryness in the north of China in recent years.

An assessment of precipitation and surface air temperature over China by regional climate models

An analysis of a 20-year summer time simulation of present-day climate （1989-2008） over China using four regional climate models coupled with different land surface models is carried out. The climatic means, interannual variability, linear trends, and extremes are examined, with focus on precipitation and near surface air temperature. The models are able to reproduce the basic features of the observed summer mean precipitation and temperature over China and the regional detail due to topographic forcing. Overall, the model performance is better for temperature than that of precipitation. The models reasonably grasp the major anomalies and standard deviations over China and the five subregions studied. The models generally reproduce the spatial pattern of high interannual variability over wet regions, and low varia- bility over the dry regions. The models also capture well the variable temperature gradient increase to the north by latitude. Both the observed and simulated linear trend of precipitation shows a drying tendency over the Yangtze River Basin and wetting over South China. The models capture well the relatively small temperature trends in large areas of China. The models reasonably simulate the characteristics of extreme precipitation indices of heavy rain days and heavy precipitation fraction. Most of the models also performed well in capturing both the sign and magnitude of the daily maximum and minimum tempera- tures over China.