2021年全球FY4A AGRI大气水汽总量及分层水汽含量(LPW)实时产品

单位面积上垂直分层水汽柱的水汽含量（单位：g/kg，等价于 cm）。该产品（LPW）垂直分为三层，即低层 LPW_LOW 为地表到边界层附近（0.9
≤σ≤1.0）、中层 LPW_MID（0.7≤σ<0.9）和高层 LPW_HIGH（0.3≤σ<0.7）。由于大气上层（σ<0.3）水汽稀少，因此三层水汽含量总和作为整层大气可降水（TPW）。其中，σ 为地形坐标，它与气压换算关系为：P=0.005+σ*（Ps-0.005）,Ps 为地表气压。在地形平坦地区，低层水汽大约从地表到 900百帕高度，中层大约 900 百帕到 700 百帕高度，高层大约从 700 百帕到 300百帕高度，通常 300 百帕高度以上水汽含量很少。用于监测与诊断暴雨前后的大气环流的湿度场特征；在数值预报模式进行定量同化等。

Water vapor content of vertically stratified atmospheric water vapor columns per unit area (unit: g/kg, equivalent to cm). This product (LPW) is vertically divided into three layers: the low-layer LPW_LOW ranges from the surface to near the boundary layer (0.9 ≤ σ ≤ 1.0), the middle-layer LPW_MID (0.7 ≤ σ < 0.9), and the high-layer LPW_HIGH (0.3 ≤ σ < 0.7). Since water vapor is scarce in the upper atmosphere (σ < 0.3), the sum of the water vapor content of these three layers is used as the total precipitable water (TPW) of the entire atmosphere. Here, σ is the sigma (terrain-following) coordinate, and its conversion relationship with atmospheric pressure is: P = 0.005 + σ*(Ps - 0.005), where Ps is the surface air pressure. In topographically flat areas, the low-layer water vapor roughly spans from the surface to the 900 hectopascal (hPa) level, the middle layer from approximately 900 hPa to 700 hPa, and the high layer from 700 hPa to 300 hPa. Water vapor content is typically very low above the 300 hPa level. This dataset is used to monitor and diagnose the humidity field characteristics of atmospheric circulation before and after rainstorms, as well as for quantitative assimilation in numerical weather prediction models, among other applications.

搜集汇总

背景与挑战

背景概述

该数据集是2021年全球范围的FY-4A卫星AGRI仪器大气水汽实时产品，提供垂直分层（低、中、高层）的水汽含量和总水汽量，用于大气湿度监测和数值预报同化。数据覆盖全年，空间分辨率4000米，以栅格格式存储，需通过离线申请获取。