摘要
Satellite-derived surface temperature data is increasingly required to supplement the limited weather stations for the assessment of temperature trend over the data-sparse Antarctic Ice Sheet. To accomplish this, it is essential to assess the relationship and difference between satellite-based land-surface temperature (LST) retrieval and air temperature observation. In this study, we made a comparison between monthly averaged LST from Moderate Resolution Imaging Spectroradiometer (MODIS) and the corresponding air temperature at the nominal heights of 1 m and 2 m from automatic weather stations (AWSs) over the Lambert Glacier basin, East Antarctica. This comparison reveals a statistically significant correlation between the two types of temperature measurements with correlation coefficient (R) above 0.6. Also, the time difference between satellite overpass and air temperature observation is not critical for the R values. Although MODIS LST evidently deviates from air temperature (Mean difference fluctuates from 2.87°C to 8.08°C) probably due to the temperature inversion effect, heterogeneity in surface emissivity, representative of AWS measurements and satellite self limitation. MODIS LST measurements have a great potential for the accurate evaluation or monitoring of regional air temperature over Antarctica, and thus better improve current reconstruction of spatial and temporal reconstruction variability in Antarctic temperature.
Satellite-derived surface temperature data is increasingly required to supplement the limited weather stations for the assessment of temperature trend over the data-sparse Antarctic Ice Sheet. To accomplish this, it is essential to assess the relationship and difference between satellite-based land-surface temperature (LST) retrieval and air temperature observation. In this study, we made a comparison between monthly averaged LST from Moderate Resolution Imaging Spectroradiometer (MODIS) and the corresponding air temperature at the nominal heights of 1 m and 2 m from automatic weather stations (AWSs) over the Lambert Glacier basin, East Antarctica. This comparison reveals a statistically significant correlation between the two types of temperature measurements with correlation coefficient (R) above 0.6. Also, the time difference between satellite overpass and air temperature observation is not critical for the R values. Although MODIS LST evidently deviates from air temperature (Mean difference fluctuates from 2.87°C to 8.08°C) probably due to the temperature inversion effect, heterogeneity in surface emissivity, representative of AWS measurements and satellite self limitation. MODIS LST measurements have a great potential for the accurate evaluation or monitoring of regional air temperature over Antarctica, and thus better improve current reconstruction of spatial and temporal reconstruction variability in Antarctic temperature.
