共查询到19条相似文献，搜索用时 125 毫秒
1.
采用2012年8月1—30日ATMS(Advanced Technology Microwave Sounder)卫星微波资料,在WRFDA系统中进行资料特征统计分析以及偏差订正试验。针对2012年8月第13号台风“启德”、第14号台风“天秤”和第15号台风“布拉万”,检验同化ATMS卫星微波资料对台风路径预报的影响。结果表明:偏差订正前,ATMS除个别窗区通道和湿度通道偏差大于对应AMSUA/MHS通道外,其余通道偏差均小于后者;与AMSUA/MHS相比,ATMS偏差随扫描位置的变化较小且平滑,ATMS96个扫描点的资料均可用;ATMS窗区通道偏差最大,温度中层通道偏差最小;使用ATM S资料导出的偏差订正系数,可减小温度和湿度通道偏差,相比于直接使用NOAA-18偏差订正系数,可改善台风路径和最低气压预报;个例研究表明,同化中加入ATMS资料后可使台风路径预报偏差降低31%。 相似文献
2.
本研究通过将GOES-16 ABI观测亮温和ERA5再分析资料的全天空模拟亮温进行对比分析,发现观测亮温和模拟亮温对流低值区位置大体接近,也能够定性反映出对流从发展到减弱的日变化过程,但亮温低值区域的强度存在较大差异。即使把高分辨率ABI通道13观测亮温平均到ERA5分辨率(0.25°×0.25°),在热带对流区的低亮温强度仍然高于ERA5全天空模拟亮温。因此利用主成分分析(Principal Component Analysis,PCA)和离散傅里叶变换(Discrete Fourier Transform,DFT)对任意选择的两对流区域内的观测和模拟亮温进行了尺度分析和对比。在其中对流较强的区域内,当ABI观测亮温的主成分分量从1增加到9时,水平特征尺度从700 km逐渐减小到150 km。ERA5全天空模拟亮温从主成分1增加到4时,水平特征尺度从950 km减小到270 km空间尺度,但当主成分4增加到9时,特征尺度几乎不变。在对流较弱的另一区域也能够发现ERA5模拟亮温对对流水平特征尺度有明显高估。ERA5模拟亮温各主成分的相位和观测亮温存在2 h以内的误差。由于ERA5全天空... 相似文献
3.
根据微波湿度计MHS(Microwave Humidity Sounder)辐射率资料及GRAPES(Global/Regional Assimilation and Pr Ediction System)模式的特点,建立适用于MHS资料的偏差订正系统,该系统包括扫描和气团偏差订正,其中气团偏差订正考虑水汽资料的特性,采用三种不同预报因子组合的方案。偏差订正结果表明:MHS各个通道的扫描偏差表现出不同特征;偏差订正后观测残差基本服从均值为零的高斯分布,且观测残差的均值有所降低并随时间变化平稳;三种气团偏差订正方案都有明显的订正效果,其中方案三的订正效果最佳。 相似文献
4.
FY 2F红外亮温资料模拟与偏差分析 总被引：2，自引：0，他引：2
为了实现西太平洋及东亚区域FY-2F可见红外自旋扫描辐射计(VISSR)资料的直接同化,本文利用飓风天气预报模式(WRF For Hurricane,HWRF)和快速辐射传输模式(Community Radiative Transfer Model,CRTM)对FY-2F的亮温资料进行了模拟。在有云情况下,中高纬度锋面云系模拟的相对较好,而低纬热带云团模拟偏差较大。对于晴空条件下模拟的红外1、2、4通道(IR1、2、4)亮温,受陆地下垫面发射率不均匀的影响模拟偏差较大,且辐射传输模式平均而言低估了地表发射率。海洋下垫面的资料模拟情况要明显好于陆地。IR4通道在白天受太阳短波影响观测亮温偏高。去除受云污染的资料仅保留晴空观测资料,通过格点统计插值(Community Gridpoint Statistical Interpolation,GSI)质量控制和偏差订正,IR2通道平均偏差减小约50%,IR3通道平均偏差从3.7 K减小到0.34 K。而IR1通道质量较好,偏差订正前后几乎没有变化。 相似文献
5.
利用风云三号B星(FY-3B)微波成像仪(Microwave Radiation Imager,MWRI)一级亮温数据和每6 h一次的热带气旋(tropical cyclone, TC)最佳路径数据进行时空匹配,建立了TC微波亮温数据集。该数据集包含了2011—2016年全球六大海盆生成的热带风暴级别以上的TC共计538个,以及对应每个TC的微波十通道亮温和36.50 GHz、89.00 GHz的极化校正亮温度,并简要阐明了该数据集在热带气旋研究方面的潜在应用,尤其对TC生命周期内的微波亮温特征及TC强度变化研究提供了有力的数据支撑。 相似文献
6.
热带测雨卫星(Tropical Rainfall Measuring Mission,TRMM)在2001年8月轨道高度从350 km升高至402 km,搭载于其上的微波成像仪(TRMM Microwave Imager,TMI)的入射角随之发生变化,进而使得相应探测结果(亮温)发生改变,从而导致由此反演的大气参数出现虚假的突变。为保证轨道抬升前后TMI亮温资料的连致性,以便更好地用于气候研究,本研究首先分析了洋面轨道抬升前后亮温的差异及变化原因,然后结合微波辐射传输模式,分析了不同环境参数对亮温变化的影响,在此基础上用线性变换的方式对轨道抬升后的亮温进行了修正,并从不同角度检验修正效果。结果表明,轨道抬升前后亮温呈线性关系,低频垂直极化通道亮温轨道抬升后升高了0.8-1.6 K,其他通道亮温变化不大。经过修正,轨道抬升前后的亮温趋于一致,月平均亮温偏差明显减小,低频垂直极化通道亮温在轨道抬升期间的突变被消除,亮温变得连续平稳,可用于气候研究。 相似文献
7.
利用美国环境预报中心(NCEP)的GSI(Gridpoint Statstical Interpolation)业务同化系统,采用三维变分同化方法(3DVAR)和三维变分混合同化方法(3DVAR-Ensemble),针对2013年5月8日发生在我国华南地区的一次强降水天气过程进行了数值模拟试验研究,设计了不同组试验方案,将常规观测资料和AMSU-A\MHS\ATMS辐射率亮温资料直接同化进入区域大气模式WRF中,对比分析不同同化试验方案对模式初始场及降水预报效果的影响。数值试验结果表明:从初始时刻的同化增量来看,各试验组均改变了初始场结构,但增量的大小和分布却不同。加入ATMS微波资料的分析增量要小于同化AMSU-A+MHS的;Hybrid同化方法使用具有"流依赖"的背景误差协方差在一定程度上减小了模拟区域周围的虚假增量,使初始场的分布更真实和合理。从降水模拟的强度和空间分布评估结果来看,使用Hybrid方法同化ATMS的资料可以比较准确预报出降水中心的位置。综合而言,采用Hybrid的方法同化ATMS的资料最优。 相似文献
8.
云雨条件下AMSR2微波成像资料同化试验及其在台风预报中的应用 总被引：2，自引：1，他引：1
采用WRF-ARW和WRFDA的3.8版本进行云雨条件下AMSR2(Advanced Microwave Scanning Radiometer 2)卫星微波成像资料的同化试验,并选择2014年7月第9号台风"威马逊"为研究对象,检验同化云雨条件下的AMSR2资料对台风预报结果的影响。结果表明:(1)云雨条件下的质量控制方案所保留的像元明显多于晴空条件下质量控制方案,且亮温模拟结果更加接近观测;(2)云雨影响的加入使得风场、高度场和海平面气压场的模拟结果好于晴空条件下模拟,且对台风中心有增温、增湿的作用。(3)云雨条件下模拟对台风的路径和强度预报均有改善。 相似文献
9.
提供高时间分辨率大气温度湿度廓线的地基微波辐射计近年来广泛使用,多通道观测亮温的数据质量是大气廓线产品合理性的基本保障。一般定期液氮绝对定标可以更好维护亮温数据质量,但实际操作颇为不易。辐射传输模式作为一种辅助工具,可以检验和认识地基微波辐射计观测亮温的数据质量。本文针对三个辐射传输模式:MonoRTM、ARTS和MWRT,结合北京探空观测资料、北京观象台和河北香河站同类型的德国RPG地基微波辐射计观测资料,分析比较了三个模式的模拟与观测亮温差异,评估不同辐射传输模式对地基微波辐射计观测的模拟能力。地基微波辐射计14个通道观测亮温与模式模拟的差异统计比较发现:三个模式的模拟结果与地基微波辐射计大部分通道的观测亮温都很接近,与观测结果具有很好一致性（如相关系数高达0.99）,而对温度通道ch8（51.26 GHz）和ch9（52.28 GHz）,三个模式模拟与观测相关系数明显较低（<0.80）,并且存在显著的绝对偏差（4～5 K）,表明模式在这两个通道的模拟能力有待提高。三个模式中,MonoRTM模式在温度通道ch8、ch9和ch10（53.86 GHz）存在明显的系统性偏差,尤其是ch8高达5 K;ARTS模式对水汽通道ch1（22.24 GHz）的模拟能力相对较弱;MWRT模拟与观测亮温在多个通道上相对更为接近和稳定,尤其系统性偏差最小。此外,探空廓线与地基观测站的空间位置不一致,对地基微波辐射计水汽通道的模拟结果影响较为显著,而对水汽不敏感的温度通道影响甚微。两地观测亮温与模式模拟的比对,初步表明北京观象台地基微波辐射水汽通道的观测质量有待改进。 相似文献
10.
采用中尺度数值模式WRF(Weather Research and Forecasting)中FY-3C卫星MWHS-2(Micro-Wave Humidity Sounder 2)卫星资料的直接同化模块,利用WRF-3DVAR(Three Dimensional Variation)方法对三江源地区的两次降水过程进行同化对比试验,详细对比分析了FY-3C搭载的MWHS-2微波湿度仪和NOAA-18(National Oceanic and Atmospheric Administration-18)搭载的MHS(Microwave Humidity Sounder)微波湿度仪两种同化资料对模拟结果的影响。结果表明：MWHS-2和MHS资料同化的模拟结果基本一致,对于30 mm以下的降水,无论同化与否,模拟的降水范围均会偏大;但对于30 mm以上的降水,模拟范围和量级均偏小。资料同化增强了500 hPa西南风场,从而加大了水汽输送的强度,使得高空槽偏向西南,同时加强了300 hPa风场扰动,在共同作用下从而导致了30 mm以上的降水范围的增大,对降水量级结果能有一定改善,但降水落区相较... 相似文献
11.
The second Advanced Technology Microwave Sounder(ATMS)was onboard the National Oceanic and Atmospheric Administration(NOAA)-20 satellite when launched on 18 November 2017.Using nearly six months of the earliest NOAA-20 observations,the biases of the ATMS instrument were compared between NOAA-20 and the Suomi National Polar-Orbiting Partnership(S-NPP)satellite.The biases of ATMS channels 8 to 13 were estimated from the differences between antenna temperature observations and model simulations generated from Meteorological Operational(MetOp)-A and MetOp-B satellites’Global Positioning System(GPS)radio occultation(RO)temperature and water vapor profiles.It was found that the ATMS onboard the NOAA-20 satellite has generally larger cold biases in the brightness temperature measurements at channels 8 to 13 and small standard deviations.The observations from ATMS on both S-NPP and NOAA-20 are shown to demonstrate an ability to capture a less than 1-h temporal evolution of Hurricane Florence(2018)due to the fact that the S-NPP orbits closely follow those of NOAA-20. 相似文献
12.
Satellite Data Assimilation of Upper-Level Sounding Channels in HWRF with Two Different Model Tops 
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下载免费PDF全文 ZOU Xiaolei WENG Fuzhong Vijay TALLAPRAGADA LIN Lin ZHANG Banglin WU Chenfeng QIN Zhengkun 《Acta Meteorologica Sinica》2015,29(1):1-27
The Advanced Microwave Sounding Unit-A(AMSU-A) onboard the NOAA satellites NOAA-18 and NOAA-19 and the European Organization for the Exploitation of Meteorological Satellites(EUMETSAT)Met Op-A, the hyperspectral Atmospheric Infrared Sounder(AIRS) onboard Aqua, the High resolution Infra Red Sounder(HIRS) onboard NOAA-19 and Met Op-A, and the Advanced Technology Microwave Sounder(ATMS) onboard Suomi National Polar-orbiting Partnership(NPP) satellite provide upper-level sounding channels in tropical cyclone environments. Assimilation of these upper-level sounding channels data in the Hurricane Weather Research and Forecasting(HWRF) system with two different model tops is investigated for the tropical storms Debby and Beryl and hurricanes Sandy and Isaac that occurred in 2012. It is shown that the HWRF system with a higher model top allows more upper-level microwave and infrared sounding channels data to be assimilated into HWRF due to a more accurate upper-level background profile. The track and intensity forecasts produced by the HWRF data assimilation and forecast system with a higher model top are more accurate than those with a lower model top. 相似文献
13.
Fengyun-3 D(FY-3 D) satellite is the latest polar-orbiting meteorological satellite launched by China and carries 10 instruments onboard. Its microwave temperature sounder(MWTS) and microwave humidity sounder(MWHS) can acquire a total of 28 channels of brightness temperatures, providing rich information for profiling atmospheric temperature and moisture. However, due to a lack of two important frequencies at 23.8 and 31.4 GHz, it is difficult to retrieve the total precipitable water vapor(TPW) and cloud liquid water path(CLW) from FY-3 D microwave sounder data as commonly done for other microwave sounding instruments. Using the channel similarity between Suomi National Polar-orbiting Partnership(NPP) advanced technology microwave sounder(ATMS) and FY-3 D microwave sounding instruments, a machine learning(ML) technique is used to generate the two missing low-frequency channels of MWTS and MWHS. Then, a new dataset named as combined microwave sounder(CMWS) is obtained,which has the same channel setting as ATMS but the spatial resolution is consistent with MWTS. A statistical inversion method is adopted to retrieve TPW and CLW over oceans from the FY-3 D CMWS. The intercomparison between different satellites shows that the inversion products of FY-3 D CMWS and Suomi NPP ATMS have good consistency in magnitude and distribution. The correlation coefficients of retrieved TPW and CLW between CMWS and ATMS can reach 0.95 and 0.85, respectively. 相似文献
14.
Accurate information on atmospheric temperature of tropical cyclones (TCs) is important for monitoring and prediction of their developments and evolution. For hurricanes, temperature anomaly in the upper troposphere can be derived from Advanced Microwave Sounding Unit (AMSU) and Advanced Technology Microwave Sounder (ATMS) through either regression-based or variational retrieval algorithms. This study investigates the dependency of TC warm core structure on emission and scattering processes in the forward operator used for radiance computations in temperature retrievals. In particular, the precipitation scattering at ATMS high-frequency channels can significantly change the retrieval outcomes. The simulation results in this study reveal that the brightness temperatures at 183 GHz could be depressed by 30–50 K under cloud ice water path of 1.5 mm, and thus, the temperature structure in hurricane atmosphere could be distorted if the ice cloud scattering was inaccurately characterized in the retrieval system. It is found that for Hurricanes Irma, Maria, and Harvey that occurred in 2017, their warm core anomalies retrieved from ATMS temperature sounding channels 4–15 were more reasonable and realistic, compared with the retrievals from all other channel combinations and earlier hurricane simulation results. 相似文献
15.
2016年12月发射升空的FY-4A是中国第二代静止轨道气象卫星,该星上搭载了可提供东半球近实时高分辨率卫星观测数据的扫描辐射成像仪——AGRI（Advanced Geostationary Radiation Imager）。在其观测数据应用于大气参数反演或同化前,数据偏差的定量化分析是一个必要环节。采用快速辐射传输模式RTTOV（Radiative Transfer for the TIROS Operational Vertical Sounder）,基于欧洲中期天气预报中心（ECMWF）第5个全球再分析数据产品（ERA5）对AGRI的7个红外通道（通道08—14）进行了模拟,并利用MODIS云检测产品对模拟结果进行了晴空筛选,以期得到一些对AGRI的定量应用有价值的偏差分析结果。观测-模拟（O-B）的偏差分析结果显示:海洋和陆地上,通道10（7.1 μm）存在明显大于其他红外通道的系统性偏差,这很可能来源于ERA5在对流层中层对水汽的高估。通道08为近红外短波通道,地表反射作用影响强烈,陆地上存在较大的平均偏差,而海洋上平均偏差小于0.4 K。通道14在ERA5近地层气温偏高及定标偏差的影响下,海洋存在接近1 K的平均偏差;陆地上存在2 K左右的平均偏差。其余各红外通道在海洋和陆地上的平均偏差分别在0.6和1.3 K以下。偏差影响因子分析结果显示:地表海拔高度、观测天顶角对偏差也存在一定程度的影响;海洋上偏差分布存在季节变化可能来源于再分析资料中海表温度估算的季节性误差。 相似文献
16.
正1Met Office, Exeter EX1 3PB, UK2National Satellite Meteorological Center, China Meteorological Administration, Beijing 100081, China 相似文献
17.
Belmadani Ali Dalphinet Alice Chauvin Fabrice Pilon Romain Palany Philippe 《Climate Dynamics》2021,56(11):3687-3708
Tropical cyclones are a major hazard for numerous countries surrounding the tropical-to-subtropical North Atlantic sub-basin including the Caribbean Sea and Gulf of Mexico. Their intense winds, which can exceed 300 km h−1, can cause serious damage, particularly along coastlines where the combined action of waves, currents and low atmospheric pressure leads to storm surge and coastal flooding. This work presents future projections of North Atlantic tropical cyclone-related wave climate. A new configuration of the ARPEGE-Climat global atmospheric model on a stretched grid reaching ~ 14 km resolution to the north-east of the eastern Caribbean is able to reproduce the distribution of tropical cyclone winds, including Category 5 hurricanes. Historical (1984–2013, 5 members) and future (2051–2080, 5 members) simulations with the IPCC RCP8.5 scenario are used to drive the MFWAM (Météo-France Wave Action Model) spectral wave model over the Atlantic basin during the hurricane season. An intermediate 50-km resolution grid is used to propagate mid-latitude swells into a higher 10-km resolution grid over the tropical cyclone main development region. Wave model performance is evaluated over the historical period with the ERA5 reanalysis and satellite altimetry data. Future projections exhibit a modest but widespread reduction in seasonal mean wave heights in response to weakening subtropical anticyclone, yet marked increases in tropical cyclone-related wind sea and extreme wave heights within a large region extending from the African coasts to the North American continent.
相似文献18.
2010年11月5日发射的风云三号B星 (FY-3B) 是我国第2代极轨气象卫星的第2颗星。其上装载的微波湿度计 (MWHS) 在183 GHz水汽吸收线设计了3个大气探测通道,在大气窗区150 GHz设置了双极化通道。该文主要对FY-3B微波湿度计系统进行介绍,分析其在轨5年的性能,对仪器在轨关键性能参数进行了长时间序列分析,结果表明:仪器各通道灵敏度均优于0.4 K,其中通道1,2,4,5的灵敏度优于0.3 K,定标精度稳定在0.3~0.55 K,未出现恶化现象, 同类型在轨载荷星下点处匹配数据交叉比对,相关系数优于96%。分析表明,该仪器在轨性能和数据质量均优于FY-3A微波湿度计。同时,利用微波湿度计实测数据,着重分析2015年6—7月若干台风的生成、演化、增强和消亡的整个过程,并对台风区域强降雨监测进行分析。 相似文献
19.
S. R. H. Rizvi E. L. Bensman T. S. V. Vijaya Kumar A. Chakraborty T. N. Krishnamurti 《Meteorology and Atmospheric Physics》2002,79(1-2):13-32
Summary
In the past, various field experiments were conducted using special aircrafts to enhance the observational database of hurricanes.
Dropwindsondes (or “dropsondes”) are generally deployed to collect additional observations in the vicinity of the hurricane
center. In addition to dropsondes, during the Third Convection and Moisture Experiment (CAMEX-3), which was conducted over
the Atlantic Ocean and Gulf of Mexico during August–September 1998, LASE was also used to measure vertical moisture profiles.
Four hurricanes: Bonnie, Danielle, Earl and Georges were targeted during this campaign.
This paper describes the resulting impact of CAMEX-3 data, especially the LASE moisture profile data, on the hurricane analysis
and forecast. The data were analyzed using a spectral statistical interpolation technique and the forecasts were made using
the FSUGCM at T126 resolution with 14 σ-vertical levels. Results indicate that the LASE data had a significant impact on the
moisture analysis. The reanalysis was slightly drier away from the hurricane center and wetter close to the center. Spiraling
bands, both dry and wet, of moisture were clearly seen for hurricane Danielle. The LASE data did not affect the wind analysis
significantly, however when it was used along with dropsonde observations the hurricane intensity and its structure were well
represented and the forecast track produced from the reanalyzed initial condition had less forecast errors. The LASE and dropsonde
observations were in good agreement.
Received February 27, 2001 Revised July 31, 2001 相似文献