气候与环境研究
氣候與環境研究
기후여배경연구
CLIMATIC AND ENVIRONMENTAL RESEARCH
2014年
6期
693-702
,共10页
热带降雨测量卫星微波成像仪%液态水路径%水平分辨率
熱帶降雨測量衛星微波成像儀%液態水路徑%水平分辨率
열대강우측량위성미파성상의%액태수로경%수평분변솔
TRMM Microwave Imager (TMI)%Liquid water path%Horizontal resolution
选取热带测雨卫星（Tropical Rainfall Measuring Mission，TRMM）微波成像仪（TRMM Microwave Imager， TMI）液态水路径（liquid water path，LWP）轨道像元数据为研究对象，探讨了将瞬时探测以及逐月的像元数据进行格点化（0.1°、0.25°、0.5°、1.0°和2.5°五种格点分辨率）时，格点数据的失真情况。对 TMI 瞬时探测的个例分析结果表明，细分辨率（0.1°、0.25°和0.5°）格点能保留原始像元数据的细节；而随着网格变粗，细节受到较大的平滑。因此对于中尺度到天气尺度的天气系统分析而言，将卫星轨道数据处理到网格尺度不大于0.5°的格点更合适。对逐月 LWP 像元资料格点化处理的分析表明，细分辨率格点能保留 LWP 空间分布细节，尽管5种分辨率下 LWP 的概率密度分布（probability density function，PDF）均相近。因此，对月尺度及以上的气候分析研究而言，格点尺度大小对卫星像元数据格点化的影响不显著。最后利用本实验室计算的 TMI/LWP 格点数据与欧洲中期数值预报中心再分析资料（European Centre for Medium-range Weather Forecasts Interim reanalysis， ERA-Interim）和 NCEP 再分析资料（NCEP Climate Forecast System Reanalysis，NCEP CFSR）进行了对比，发现两种再分析资料都高估了 LWP；TMI/LWP 格点数据与两种再分析资料 LWP 的多年变化趋势大致相同。
選取熱帶測雨衛星（Tropical Rainfall Measuring Mission，TRMM）微波成像儀（TRMM Microwave Imager， TMI）液態水路徑（liquid water path，LWP）軌道像元數據為研究對象，探討瞭將瞬時探測以及逐月的像元數據進行格點化（0.1°、0.25°、0.5°、1.0°和2.5°五種格點分辨率）時，格點數據的失真情況。對 TMI 瞬時探測的箇例分析結果錶明，細分辨率（0.1°、0.25°和0.5°）格點能保留原始像元數據的細節；而隨著網格變粗，細節受到較大的平滑。因此對于中呎度到天氣呎度的天氣繫統分析而言，將衛星軌道數據處理到網格呎度不大于0.5°的格點更閤適。對逐月 LWP 像元資料格點化處理的分析錶明，細分辨率格點能保留 LWP 空間分佈細節，儘管5種分辨率下 LWP 的概率密度分佈（probability density function，PDF）均相近。因此，對月呎度及以上的氣候分析研究而言，格點呎度大小對衛星像元數據格點化的影響不顯著。最後利用本實驗室計算的 TMI/LWP 格點數據與歐洲中期數值預報中心再分析資料（European Centre for Medium-range Weather Forecasts Interim reanalysis， ERA-Interim）和 NCEP 再分析資料（NCEP Climate Forecast System Reanalysis，NCEP CFSR）進行瞭對比，髮現兩種再分析資料都高估瞭 LWP；TMI/LWP 格點數據與兩種再分析資料 LWP 的多年變化趨勢大緻相同。
선취열대측우위성（Tropical Rainfall Measuring Mission，TRMM）미파성상의（TRMM Microwave Imager， TMI）액태수로경（liquid water path，LWP）궤도상원수거위연구대상，탐토료장순시탐측이급축월적상원수거진행격점화（0.1°、0.25°、0.5°、1.0°화2.5°오충격점분변솔）시，격점수거적실진정황。대 TMI 순시탐측적개례분석결과표명，세분변솔（0.1°、0.25°화0.5°）격점능보류원시상원수거적세절；이수착망격변조，세절수도교대적평활。인차대우중척도도천기척도적천기계통분석이언，장위성궤도수거처리도망격척도불대우0.5°적격점경합괄。대축월 LWP 상원자료격점화처리적분석표명，세분변솔격점능보류 LWP 공간분포세절，진관5충분변솔하 LWP 적개솔밀도분포（probability density function，PDF）균상근。인차，대월척도급이상적기후분석연구이언，격점척도대소대위성상원수거격점화적영향불현저。최후이용본실험실계산적 TMI/LWP 격점수거여구주중기수치예보중심재분석자료（European Centre for Medium-range Weather Forecasts Interim reanalysis， ERA-Interim）화 NCEP 재분석자료（NCEP Climate Forecast System Reanalysis，NCEP CFSR）진행료대비，발현량충재분석자료도고고료 LWP；TMI/LWP 격점수거여량충재분석자료 LWP 적다년변화추세대치상동。
Satellite observation data are valuable for model evaluation, but to readily compare satellite-based data with model simulations, swath pixel data must first be gridded. In this study, data distortions caused by gridding (0.1°, 0.25°, 0.5°, 1.0°, and 2.5° gridding resolutions) are investigated using instantaneous and monthly pixel data from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) liquid water path (LWP) data. Results from this case study show that data gridded at grid scales of 0.1°, 0.25°, and 0.5° retain more local details in the instantaneous pixel data, while the details tend to be smoothed out at coarser grid resolutions. So data with grid scales no coarser than 0.5° are suitable for analyzing weather activities from the mesoscale to the synoptic scale. In terms of the monthly pixel LWP, data with gridding resolutions of 0.1°, 0.25°, and 0.5° also retain more detail. Although, probability density functions (PDF) of the LWP show similar patterns at all the gridding scales considered. So when analyzing monthly LWP data, the impact of gridding scales is not significant. Finally, this study compared the gridded TMI LWP data with the European Centre for Medium-range Weather Forecasts Interim reanalysis (ERA-Interim) and NCEP Climate Forecast System Reanalysis (CFSR), and found that both of these reanalyses overestimate the magnitudes of the LWP. Gridded TMI LWP data, the ERA-Interim, and the CFSR show reasonably similar regularities in the variance of the LWP.
