青藏高原多源遥感合成1km积雪覆盖数据集（1995-2018）

青藏高原多源遥感合成1km积雪覆盖数据集（1995-2018）基于国家卫星气象中心的青藏高原光学仪器遥感1km积雪覆盖数据集（1989-2018）和美国雪冰中心的25km近实时逐日全球冰密集度与积雪范围NISE产品数据集（1995-2019）合成得到，覆盖时间从1995年到2018年（每年1-4月和10-12月两个时段），时间分辨率为逐日，覆盖范围为青藏高原（17°N -41°N，65°E -106°E），采用等经纬度投影，空间分辨率为0.01°×0.01°。数据集以日产品表征了卫星观测时刻的地面是否为积雪所覆盖。输入数据源为NOAA或MetOp卫星AVHRR逐日积雪覆盖产品，TERRA卫星MODIS替代AVHRR对应观测通道生成的逐日积雪覆盖产品，以及DMSP卫星SSM/I或SSMIS逐日全球冰密集度和积雪范围NISE产品。数据集合成方法：以青藏高原光学仪器遥感1km积雪覆盖产品为基础，完全信任其积雪和晴空无雪信息，对有云覆盖、无法判识、缺少卫星观测等区域，在相对高空间分辨率海陆模板的辅助下，利用NISE的陆地有效判识结果进行替换。对于部分水陆边界，因NISE产品空间分辨率较低，合成结果有可能仍存在极少量的云覆盖或者无观测数据区域。基于多年地面气象台站雪深观测资料验证表明，本数据集对晴空条件下地面有无积雪的总体判识准确率在91%以上。数据采用标准的HDF4格式存储，内部有积雪覆盖和质量码两个SDS，维度均为4100列×2400行，且文件内部有完备的属性描述。The 1 km multi-source remote sensing synthesized snow cover dataset over the Tibetan Plateau (1995–2018) is developed by integrating two existing datasets: the 1 km optical remote sensing snow cover dataset over the Tibetan Plateau (1989–2018) provided by the National Satellite Meteorological Center, and the 25 km near-real-time daily global sea ice concentration and snow extent NISE product dataset (1995–2019) from the U.S. Snow and Ice Center. The dataset spans the period from 1995 to 2018, with valid data available during two seasonal windows each year: January to April and October to December. It has a daily temporal resolution, covers the entire Tibetan Plateau region located at 17°N – 41°N, 65°E – 106°E, and uses an equirectangular projection with a spatial resolution of 0.01° × 0.01°. Each daily product indicates whether the ground is covered by snow at the time of satellite observation. The input data sources include daily snow cover products from AVHRR instruments onboard NOAA or MetOp satellites, daily snow cover products generated by replacing the corresponding observation channels of AVHRR with MODIS data from the Terra satellite, and daily global sea ice concentration and snow extent NISE products retrieved by SSM/I or SSMIS instruments onboard DMSP satellites. The dataset synthesis method takes the Tibetan Plateau 1 km optical remote sensing snow cover product as the base dataset, fully trusting its identified snow-covered and cloud-free snow-free regions. For areas covered by clouds, unidentifiable regions, or locations without valid satellite observations, the land effective discrimination results from the NISE product are used for replacement with the assistance of a high-spatial-resolution land-sea template. For some land-water boundary zones, due to the relatively low spatial resolution of the NISE product, the synthesized dataset may still retain a small number of cloud-covered or observation-missing areas. Validation based on multi-year in-situ snow depth observations from ground meteorological stations shows that the overall classification accuracy of the dataset for detecting snow cover under clear-sky conditions exceeds 91%. The data are stored in the standard HDF4 format, which contains two Scientific Data Sets (SDS): snow cover and quality code. Both SDS have dimensions of 4100 columns × 2400 rows, and the files have complete internal attribute descriptions.

搜集汇总

背景与挑战

背景概述

该数据集是1995年至2018年青藏高原地区的逐日1km积雪覆盖数据，基于多源遥感产品合成，空间分辨率为0.01°×0.01°，采用HDF4格式存储。数据集通过融合光学仪器遥感和NISE产品，提高了积雪判识的准确性，晴空条件下总体准确率超过91%，适用于冰冻圈和气候变化研究。