Ice thickness formation and melting characteristics of Lake Nanhu in Inner Mongolia based on the process-based model of SIMSTRAT
Lake ice is a crucial subject in cryospheric hydrology,and can be a key indicator to represent climate change due to its sensitivity to climate change.Lake ice growth and melt,as a response to climate variations,influence material and energy exchange between lakes and the atmosphere,thereby regulating regional climate and lake ecosystems.The thickness of lake ice is a critical variable in studying its growth and melt processes.Understanding its characteristics is of significant theoretical and practical impor-tance for unraveling lake responses to climate change.In this study,the ice in Lake Nanhu,Inner Mongolia was taken as the study area.Based on the prototype ice measurement data from 2013-2017 and 2022-2023,the ERA5-Land reanalysis data were used as the atmospheric forcing field.The process-based model of SIMSTRAT was used to reconstruct the growth-melt process in Lake Nan-hu from 2003 to 2022,and to investigate its change characteristics.The results showed that:1)The SIMSTRAT model showed a high level of agreement with prototype observations.The mean deviation of the simulated first ice day and final ice day was 3.4 days,while the mean bias for ice thickness was 1.29 cm.The mean absolute error and root mean square error of the ice thickness were 1.29 cm and 1.90 cm,respectively.2)From 2003 to 2022,the average freezing period of Lake Nanhu lasted 119 days,with the ice growth,balance,and melting periods averaging 64,34 and 21 days,respectively.The freezing period exhibited an overall shortening trend at a rate of 4.27 days per decade.Among these,the melting period showed the largest interannual variability,with a shortening rate of 3.67 days per decade.3)Over the past 20 years,the annual average ice thickness of Lake Nanhu ranged from 14 to 30 cm.From 2012 to 2017,interannual fluctuations in ice thickness were pronounced,showing an overall declining trend.Ice thickness increased rapidly during December and January at rates of 0.43 cm/d and 0.55 cm/d respectively,and melted quickly in March at a rate of 0.74 cm/d.4)The SIMSTRAT model further elucidated the comprehensive impact of meteorological factors,in-cluding air temperature,precipitation,and wind speed on lake ice thickness dynamics.Air temperature was identified as the prima-ry factor,with decreased cumulative temperature significantly extending the ice growth and balance periods,concurrently increasing the maximum ice thickness for the year.Precipitation and wind speed also exhibited varying degrees of influence on lake ice thick-ness dynamics.This study enhanced our understanding of lake ice processes and their response to climate change,providing valua-ble insights for future studies in related fields.
Lake icephenologyice thicknessSIMSTRATLake Nanhu in Inner Mongolia
万方数据
维普
