1850—2100年北极阿拉斯加地区最大河冰厚度时空变化特征  

Spatiotemporal variations in the maximum river ice thickness across Alaska from 1850 to 2100

作　　者：杨瑞敏 周茅先 YANG Ruimin;ZHOU Maoxian(School of Agriculture and Forestry Economics and Management,Lanzhou University of Finance and Economics,Lanzhou 730020,China)

机构地区：[1]兰州财经大学农林经济管理学院,甘肃兰州730020

出　　处：《冰川冻土》2023年第2期468-479,共12页Journal of Glaciology and Geocryology

基　　金：中国科学院国际大科学计划培育专项(131B62KYSB20180003);中国科学院前沿科学重点研究项目(QYZDJ-SSW-DQC021);甘肃省科技计划项目(20CX4ZA068)资助。

摘　　要：在极地放大效应的影响下,北极气温以较全球平均更快的速度变暖,从而导致了北极冰冻圈系统的剧烈变化。河冰是北极冰冻圈系统的重要组成部分,是气候变化的敏感指示器,同时影响当地的生态、水文和多年冻土等。本研究利用Stefan方程,使用实测河冰厚度数据、CMIP6历史实验数据和四个未来情景(SSP126、SSP245、SSP370和SSP585)的1850—2100年近地表日气温数据,建立了阿拉斯加地区1850—2100年最大河冰厚度,并分析其时空变化特征。研究表明:阿拉斯加地区多年平均最大河冰厚度呈现南薄北厚的特点;在东西方向上,1850—2000年的平均最大冰厚呈现东薄西厚的特点,但未来100年在东西方向上无显著差异(P<0.05)。1850—2100年阿拉斯加地区最大河冰厚度整体上呈显著下降趋势。其中,1850—2014年下降速率为(-0.72±0.25)cm·(10a)^(-1)(P<0.05);随着社会脆弱性的加剧和辐射强迫的增强,2015—2100年阿拉斯加地区河冰减薄的速度明显增大,在SSP126、SSP245、SSP370和SSP585情景下分别为(-1.39±0.76)cm·(10a)^(-1)、(-3.10±0.73)cm·(10a)^(-1)、(-6.09±0.79)cm·(10a)^(-1)和(-7.45±0.63)cm·(10a)^(-1)(显著性均达到了P<0.05)。1850—2100年最大河冰厚度的下降速率在空间上呈现出自东南向西北加快的趋势。The temperature in Alaska increased more rapidly than the average global warming,which results in drastic changes in cryosphere.Meanwhile,these changes in cryosphere would further provide feedback to the climate system,enhancing and amplifying the magnitude of global warming.As an important component of the cryosphere,river ice is a sensitive indicator of climate change.Changes in river ice affect hydrology,permafrost,ecosystem,etc.In addition,river ice thickness(RIT)directly influences traffic safety because the ice road is an important transportation in Alaska.Therefore,the study of river ice thickness changes in Alaska is of great significance.The scientific objectives of this study are to investigate variations in the maximum river ice thicknesses(MRIT)using ground-based measurements of 48 river gauge sites spanning 12 river basins across Alaska,to analysis the relationship between MRIT and temperature based on meteorological stations data,and to reconstruct and predict the MRIT from 1850 through 2100 using Stefan equation and daily air temperature outputs of the coupled model intercomparison project phase 6(CMIP6)historical experiment and four shared socioeconomic pathways(SSP)future scenarios(SSP126,SSP245,SSP370 and SSP585).The results show that:The average MRITs in 1850—1900,1900—1950,1950—2000,2015—2015 and 2050—2100 showed a trend of gradually thickening from south to north.The average MRITs in 1850—1900,1900—1950 and 1950—2000 thickened from east to west,but MRITs of 2015—2015 and 2050—2100 did not change significantly along the east-west direction.The overall MRIT across Alaska showed a significant decline from 1850 to 2100.The decline rate from 1850 to 2014 was(-0.72±0.25)cm·(10a)^(-1).The decline rate from 2015 to 2100 was(-1.39±0.76)cm·(10a)^(-1) under the SSP126 scenario,(-3.10±0.73)cm·(10a)^(-1) under SSP245,(-6.09±0.79)cm·(10a)^(-1) under SSP370 and(-7.45±0.63)cm·(10a)^(-1) under SSP585.The decline rates in 2015—2100 accelerate under the four future scenarios.The

关 键 词：河冰 Stefan方程 冻结指数 CMIP6 北极阿拉斯加 

分 类 号：P343.63[天文地球—水文科学]