Temperature and accumulation at the Greenland Summit: Comparison of high‐resolution isotope profiles and satellite passive microwave brightness temperature trends
Temperature and accumulation at the Greenland Summit: Comparison of high‐resolution isotope profiles and satellite passive microwave brightness temperature trends
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DOI：
10.1029/95jd00560
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发表时间：
1995-05
影响因子：
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通讯作者：
C. Shuman;R. Alley;S. Anandakrishnan;J. White;P. Grootes;C. Stearns
中科院分区：
文献类型：
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作者：
C. Shuman;R. Alley;S. Anandakrishnan;J. White;P. Grootes;C. Stearns
由短期自动气象站（AWS）温度数据支持的长期卫星被动微波亮度温度趋势表明，格陵兰峰会地区在秋末和/或冬季经历了第二次温暖期，以及主要的仲夏温暖。1989年、1990年和1991年在格陵兰冰盖项目II（GISP 2）现场附近挖掘的雪坑的高分辨率同位素剖面显示，稳定的同位素比率（δ 18 O和δD）保持了这种独特的温度循环。这表明，在格陵兰峰会上，一年中积雪频繁，同位素记录最初包含了一年中许多时候的温度信息。通过使用AWS气温数据和卫星微波亮度温度的经验推导的发射率模型，我们的方法允许保存在雪中的同位素值与估计的近地表气温相关。密度校正的分布图还可以确定积累的数量和时间。我们的研究结果表明，稳定的同位素比从近地表的雪在格陵兰峰会是目前一个可靠的，高分辨率的温度代理。这一结果增加了对GISP 2和格陵兰冰芯项目（GRIP）深冰芯中同位素信号变化的古气候解释的信心
Long-term satellite passive microwave brightness temperature trends, supported by short-term automatic weather station (AWS) temperature data, show that the Greenland Summit area experiences secondary warm periods in the late fall and/or winter as well as primary midsummer warmth. High-resolution isotope profiles from snow pits dug in 1989, 1990, and 1991 near the Greenland Ice Sheet Project II (GISP2) site reveal that stable isotope ratios (δ 18 O and δD) preserve this distinctive temperature cycle. This indicates that snow accumulation occurs frequently through the year at the Greenland Summit and that the isotope record initially contains temperature information from many times of the year. Through an empirically derived emissivity model using AWS air temperature data and satellite microwave brightness temperatures, our approach allows isotope values preserved in the snow to be related to estimated near-surface air temperatures. Density-corrected profiles allow the amounts and timing of accumulation to be determined as well. Our results indicate that stable isotope ratios from the near-surface snow at the Greenland Summit are currently a reliable, high-resolution temperature proxy. This result increases confidence in the paleoclimatic interpretation of isotope signal variations in the GISP2 and Greenland Ice Core Project (GRIP) deep ice cores