基于冻结数模型的多情景多模型全球冻土分布数据集（1950-2099）

多年冻土是冰冻圈的重要组成部分，主要分布在北半球高纬度和高海拔地区，对气候变化极为敏感。随着气候变暖，全球多年冻土正在发生严重退化，对区域水文循环、碳循环、生态环境和工程建设等产生了重大影响。本数据集基于空气冻结数模型和降尺度的CMIP6数据集中的气温数据计算了空气冻结数（F），以一种新方法来确定诊断冻土分布的最优冻结数阈值（Ft），利用Kappa系数作为分类准确性的衡量标准，将模拟的冻土分布图与现有的冻土分布图进行比较，确定最优的Ft来诊断全球冻土分布。考虑高纬度多年冻土和高海拔多年冻土的不同，高纬度多年冻土的分布主要受纬度的影响，而高海拔多年冻土同时受纬度和海拔的影响，确定了诊断高纬度多年冻土和高海拔多年冻土的最优冻结数阈值分别为0.55和0.53，进一步确定了诊断季节性冻土的最优冻结数阈值为0.10，诊断瞬时冻土的最优冻结数阈值为0.01。根据最优冻结数阈值，本数据集提供了多模型（ACCESS-CM2、BCC-CSM2-MR、CMCC-ESM2等25个模型）多情景下（Historical、SSP126、SSP245、SSP370和SSP585）的历史时期和未来时期全球冻土分布数据，该数据集的空间分辨率为0.25°。

Permafrost is an essential component of the cryosphere, mainly distributed in high-latitude and high-altitude regions of the Northern Hemisphere, and is extremely sensitive to climate change. With global warming, global permafrost is undergoing severe degradation, exerting significant impacts on regional hydrological cycles, carbon cycles, ecological environments, engineering construction, and other aspects. This dataset calculates the Air Freeze Number (F) based on the Air Freeze Number Model and air temperature data from the downscaled CMIP6 dataset. A novel method is employed to determine the optimal freeze number threshold (Ft) for diagnosing permafrost distribution. Using the Kappa coefficient as a metric for classification accuracy, the simulated permafrost distribution map is compared with existing permafrost distribution maps to identify the optimal Ft for diagnosing global permafrost distribution. Considering the differences between high-latitude permafrost and high-altitude permafrost—where the distribution of high-latitude permafrost is mainly affected by latitude, while high-altitude permafrost is influenced by both latitude and altitude—the optimal freeze number thresholds for diagnosing high-latitude permafrost and high-altitude permafrost are determined to be 0.55 and 0.53, respectively. Furthermore, the optimal freeze number threshold for diagnosing seasonal frozen soil is set at 0.10, and that for instantaneous frozen soil is 0.01. Based on the optimal freeze number thresholds, this dataset provides global permafrost distribution data for both historical and future periods under multiple models (25 models including ACCESS-CM2, BCC-CSM2-MR, CMCC-ESM2, etc.) and multiple scenarios (Historical, SSP126, SSP245, SSP370, and SSP585). The spatial resolution of this dataset is 0.25°.

搜集汇总

背景与挑战

背景概述

该数据集是一个基于空气冻结数模型和CMIP6气温数据的全球冻土分布数据集，时间跨度为1950年至2099年，覆盖历史与未来时期。它采用最优冻结数阈值方法（高纬度多年冻土阈值为0.55，高海拔多年冻土阈值为0.53，季节性冻土阈值为0.10，瞬时冻土阈值为0.01），提供多模型（25个模型）和多情景（Historical、SSP126、SSP245、SSP370、SSP585）下的数据，空间分辨率为0.25°，适用于研究气候变化对冻土分布的影响。