基于观测数据的全球空气冻融指数（1973-2021）

冻融指数是气候变化的一个重要敏感指示器，也被广泛应用于冻土变化研究中。研究全球范围内冻融指数的空间分布特征与时间变化趋势，可为全球冻土环境评估、工程建设以及应对气候变化提供依据。该数据集基于1973—2021年覆盖全球陆地且超过14 000个站点的逐日气温观测数据，计算空气冻结指数（FI）和空气融化指数(TI)。冻结/融化指数，是冻结/融化期内日平均气温低于/高于 0 ℃的温度累计值。考虑到指数计算要覆盖整个冻结/融化期，并保证计算时段的连续，北半球以该年7月1日至次年6月30日为一个冻结期，以该年1月1日至12月30日为一个融化期，南半球冻结/融化时段相反。对于有缺测年份的站点未进行填补处理，一方面避免了插值对结果带来的不确定性误差，二是尽可能保留了数据的真实性与准确性。开展全球冻融指数研究，可以有效全面了解近地表热状态，并可以为探究冻融状态变化提供重要的支撑。

Freeze-thaw indices are important sensitive indicators of climate change, and are also widely used in research on permafrost changes. Studying the spatial distribution characteristics and temporal trends of freeze-thaw indices globally can provide a basis for global permafrost environment assessment, engineering construction, and climate change adaptation. This dataset calculates the Air Freeze Index (FI) and Air Thaw Index (TI) based on daily air temperature observation data from more than 14,000 global land-based stations spanning the period 1973–2021. The freeze/thaw index refers to the cumulative temperature value where the daily average air temperature is below/above 0 ℃ during the freeze/thaw period. Considering that the index calculation needs to cover the entire freeze/thaw period and ensure the continuity of the calculation period, for the Northern Hemisphere, one freeze period is defined as July 1 of the current year to June 30 of the following year, and one thaw period is defined as January 1 to December 30 of the current year; for the Southern Hemisphere, the freeze/thaw periods are reversed. No gap-filling processing was performed for stations with missing observation years, which on one hand avoids the uncertainty errors brought by interpolation to the results, and on the other hand preserves the authenticity and accuracy of the data as much as possible. Conducting global freeze-thaw index research can effectively and comprehensively understand the near-surface thermal state, and provide important support for exploring changes in freeze-thaw conditions.

搜集汇总

背景与挑战

背景概述

该数据集是基于1973-2021年全球超过14,000个站点的逐日气温观测数据，计算空气冻结指数（FI）和空气融化指数（TI），用于研究冻融指数的空间分布和时间变化趋势。数据集具有年时间分辨率、高空间分辨率（≤1米），并以开放获取方式共享，旨在为全球冻土环境评估、工程建设和气候变化应对提供依据。数据以Excel格式存储，包含站点、经纬度、海拔、年份和指数值，便于分析和应用。