Characteristics of the gravity waves (GWs) in the lower stratosphere, produced by typhoon “Lekima” (2019) after its landfall, are studied using simulations with the high‐resolution WRF‐ARW4.2 model. In particular, the Characteristics and sources of the GWs are investigated. The results show that the GWs have a significant wavelength of 200–400 km and a significant period of 2.5–10 hr. The characteristics of stratospheric gravity wave induced by the typhoon after landing are affected by a westerly trough at mid‐latitude. The GWs are reconstructed by Fourier inversion transform in the significant spectral region in order to reveal the source of waves inducing the stratospheric GWs. The frequency of reconstruction gravity waves varies with time, and the meridional wavenumber varies with latitude. The GW intensity (GWI) has two peak values during the interested period from 10 to 11 August 2019. The first peak in GWI is the result of the in‐phase superposition of the GWs induced by the jet stream and the typhoon, when the two waves propagate almost in the same direction. The second intensity peak occurred when the trough moved away. The correlation between GWI and the typhoon and the trough are analyzed. It is found that the main factor affecting the changes of GWI is the northward movement of the trough. The location and strength of the typhoon and trough and their interaction are used to fit variations in GWI.

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34Urbanization modifies atmospheric energy and moisture balances, forming distinct 35 features, e.g., urban heat islands (UHIs) and enhanced or decreased precipitation. 36These produce significant challenges to science and society, including rapid and incudes complex topography with mountains, plains, and coastal areas (Fig. 1a), and 261 seven of the 10 most polluted Chinese cities, with 40% of days during 2013 (mostly in 262 winter) having "very hazardous" air quality (CMEP 2014 adaptation, air quality, planning, and emergency-response management. 298The critical science needed to achieve these goals was identified as increased WUQ), and one rural (SDZ) tower (all PBL observational sites are shown in Fig. 1). 335Other operational PBL sensors ( conditions. Photos of a selection of these instruments and sites are shown in Fig. 2. flown over pre-approved flight paths (Fig. 1) at altitudes from 600 to 3 600 m (at 300 357 m intervals). The aircraft is equipped with atmospheric gas and aerosol instrumenta- Additional observation data (e.g., weather radar, aircraft, and lightning) will be added. BTH area centered on Beijing (a somewhat larger area than in Fig. 1a). 439Additional details on all of these steps are provided by Zhang et al. (2017a (Fig. 1) were used to show that the dominant linear relationship between * and also 494 exists over urban canopies. The strong wind shear from the rough urban surfaces produces 495 turbulence in near neutral urban stability conditions, shown by Bornstein 1968 to exist over 496 NYC, as stable boundary layers over urban canopies are thus hard to maintain. The role of 497 surface roughness on turbulent mixing is also reflected in the increasing slope (Fig. 4) Table 4a shows the average midday (1000-1400 LST) radiative and energy fluxes 515Although MIY has higher outgoing longwave radiation, the net all-wave radiations 516 are nearly equal. Significant differences existed, however, in the surface energy 517 partitions, as IAP has smaller turbulent sensible and latent heat fluxes, and thus a 518 larger (estimated) residual heat storage. Another contributing factor to urban heat 519 storage is its anthropogenic heat flux source (discussed below). 520Daily mean Bowen ratios (ratio of turbulent sensible to latent-heat flux; Table 4b Normalized relative backscatter (NRB) data from two MPL lidar (in a vertical to 545 zenith scan mode) were also used to concurrently estimate midday PBL heights on 11 546August 2015 from 1250-1402 LST, both alone a mobile route (Fig. 1b) and at a fixed 547 site (adjacent to the urban IAP tower). As MPL instruments cannot be absolutely Beijing and fluxes from the 140-m level of the IAP tower (Fig. 1b). The modeling 574 period was 4-11 July 2015, which included dry (6 th -11 th ) and wet (4 th -5 th ) days. 575Results show major improvement for daytime "total" sensible plus latent heat flux 576 values ( Fig. 7a and b), although the timing of its peak was about 2 h too late. The 577 increased latent heat flux during the EC simulation (ac...

The aim of this paper is to propose a new type of preference relation, the intuitionistic fuzzy linguistic preference relation (IFLPR). Taking as base the 2-tuple fuzzy linguistic representation model, we introduce the definition of the IFLPR, and its transitivity properties. We present an approach to group decision making based on IFLPRs and incomplete-IFLPRs, respectively. The score function and accuracy function are applied to the ranking and selection of alternatives. Finally, we give an example of IFLPRs in group decision making, and a comparative of the exploitation of the IFLPR with the exploitation of the traditional fuzzy linguistic preference relations.

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This study investigates the effects of tropospheric vertical wind shear on gravity waves generated by tropical cyclones using idealized tropical cyclone simulations with different vertical profiles of environmental zonal wind. It is found that without shear, gravity wave momentum fluxes are distributed uniformly over a broad spectral range, with fluxes in opposite directions showing symmetry. Westerly shear in the troposphere leads to asymmetry between eastward and westward momentum fluxes, resulting in net westward fluxes and a resultant westward drag forcing on the background flow in the lower stratosphere. Under westerly shear, the active momentum fluxes extend to shorter horizontal wavelengths, and contract to longer periods and slower phase speeds. In addition, clear local peaks appear at large horizontal wavelengths, long periods, and moderate phase speeds, particularly for westward momentum fluxes.

Typhoon In-Fa hit continental China in July 2021 and caused an unprecedented rainfall amount, making it a typical case to examine the ability of numerical models in forecasting landfalling typhoons. The record-breaking storm was simulated using a 3-km-resolution weather research and forecast (WRF) model with spectral bin microphysics scheme (BIN) and two-moment seven-class bulk parameterization scheme (BULK). The simulations were then separated into three different typhoon landfall periods (i.e., pre-landfall, landfall, and post-landfall). It was found that typhoon intensity prediction is sensitive to microphysical schemes regardless of landfall periods, while typhoon track prediction tends to be more (less) sensitive to microphysical schemes after (before) typhoon landfall. Moreover, significant differences exist between BIN and BULK schemes in simulating the storm intensity, track, and rainfall distribution. BIN scheme simulates stronger (weaker) typhoon intensity than BULK scheme after (before) landfall, while BULK scheme simulates typhoon moving faster (slower) than BIN scheme before (after) landfall. BIN scheme produces much more extensive and homogeneous typhoon rainbands than BULK scheme, whereas BULK scheme produces stronger (weaker) rainfall in the typhoon inner (outer) rainbands. The possible reasons for such differences are discussed. At present, the ability of WRF and other mesoscale models to accurately simulate the typhoon precipitation hydrometeors is still limited. To evaluate the performances of BIN and BULK schemes of WRF model in simulating the condensed water in Typhoon In-Fa, the observed microwave brightness temperature and radar reflectivity from the core observatory of Global Precipitation Mission (GPM) satellite are directly used for validation with the help of a satellite simulator. It is suggested that BIN scheme has better performance in estimating the spatial structure, overall amplitude, and precise location of the condensed water in typhoons before landfall. During typhoon landfall, the performance of BIN scheme in simulating the structure and location of the condensate is close to that of BULK scheme, but the condensate intensity prediction by BIN scheme is still better; BULK scheme performs even better than BIN scheme in the prediction of condensate structure and location after typhoon landfall. Both schemes seem to have poorer performances in simulating the spatial structure of precipitation hydrometeors during typhoon landfall than before/after typhoon landfall. Moreover, BIN scheme simulates more (less) realistic warm (cold) rain processes than BULK scheme, especially after typhoon landfall. BULK scheme simulates more cloud water and larger convective updraft than BIN scheme, and this is also reported in many model studies comparing BIN and BULK schemes