Analysis of a Vortex Precipitation Event over Southwest China Using AIRS and In Situ Measurements

A strong precipitation event caused by the southwest vortex（SWV）, which affected Sichuan Province and Chongqing municipality in Southwest China on 10–14 July 2012, is investigated. The SWV is examined using satellite observations from AIRS（Atmospheric Infrared Sounder）, in situ measurements from the SWV intensive observation campaign, and MICAPS（Marine Interactive Computer-Aided Provisioning System） data. Analysis of this precipitation process revealed that：（1）heavy rain occurred during the development phase, and cloud water content increased significantly after the dissipation of the SWV;（2） the area with low outgoing longwave radiation values from AIRS correlated well with the SWV;（3） variation of the temperature of brightness blackbody（TBB） from AIRS reflected the evolution of the SWV, and the values of TBB reduced significantly during the SWV＇s development; and（4） strong temperature and water vapor inversions were noted during the development of the SWV. The moisture profile displayed large vertical variation during the SWV＇s puissant phase,with the moisture inversion occurring at low levels. The moisture content during the receding phase was significantly reduced compared with that during the developing and puissant phases. The vertical flux of vapor divergence explained the variation of the moisture profile. These results also indicate the potential for using AIRS products in studying severe weather over the Tibetan Plateau and its surroundings, where in situ measurements are sparse.

A comprehensive benchmark dataset for the validation of building component heat,air,and moisture(HAM)models

Numerical heat,air and moisture(HAM)modeling allows predicting hygrothermal responses of building components with higher efficiency and less effort than laboratory experiments and field measurements.However,inaccuracy and/or incorrectness may appear in the predictions for the same case through different HAM models,primarily due to limitations or deviations in the description of physical phenomena and/or the implementation of mathematical algorithms.User preferences,biases,and/or mistakes with respect to implementing material properties,boundary conditions and other factors may also yield disparity.While a correct implementation of the numerical models is typically verified by the developers,the validity of the HAM models may remain questionable without the confrontation with experimental datasets.However,well-determined criteria and well-documented datasets for establishing the correct prediction of the transient hygrothermal responses of building components by HAM models remain very scarce.To address this issue,a dedicated benchmark experiment was conducted in the hot box-cold box(HB-CB)setup at KU Leuven,Belgium,on four wall assemblies composed of calcium silicate board,mineral wool,wood fiber board,and vapour barrier in different orders.Temperature,relative humidity,heat fluxes and moisture masses,as hygrothermal responses,were monitored under quasi-steady state boundary conditions.Full-scale characterization of the materials from the same batch was performed,along with a determination of the surface transport coefficients within the HB-CB setup.This comprehensive dataset allows a proper model validation by incorporating experimental datasets of material properties and surface transport coefficients and by confronting simulated hygrothermal responses with experimental evidence.In addition,sensitivity analysis can be performed to obtain insights into the impact of uncertainties in characterizing material properties on hygrothermal simulation predictions.

The Dynamic and Thermodynamic Effects of Relative and Absolute Sea Surface Temperature on Tropical Cyclone Intensity

Several numerical experiments were performed to investigate the dynamic and thermodynamic effects of sea surface temperature （SST） on tropical cyclone （TC） intensity. The results reveal that the relative SST within a radius of 2-3 times the radius of maximum wind contributes positively and greatly to TC intensity, while the remote SST far away from the TC center could reduce storm intensity. The change of air sea temperature and moisture differences may be the reason why TC intensity is more sensitive to the relative rather than the absolute SST. As the inflow air moves toward the eyewall, warmer （colder） remote SST can gradually increase （decrease） the underlying surface air temperature and moisture, and thus decrease （increase） the air sea temperature and moisture differences, which lead to less （more） energy fluxes entering the eyewall and then decrease （increase） the TC intensity and make it less sensitive to the absolute SST change. Finally, with all the related dynamic and thermodynamic processes being taken into account, a schematic diagram for the effects of relative SST and absolute SST on TC intensity is proposed.