Greenup values for Interior Alaska 1976 - 2010

Greenup, the frequent rapid transformation of Interior Alaska from Brown space to spring green as the leaves deciduous trees burst forth, is suddenly enough to allow assignment of a single date in a given area to this culmination of a key biological process. Greenup is important for more than just an aesthetic or biological perspective. For example, once Greenup has occurred, there is a rapid increase in evapotranspiration. Which in turn has important consequences in the areas mesoscale meteorology. Here, dates for green around Fairbanks for more than 20 springs are correlated against several different temperature derived indices calculated entirely from routinely available climatological data. We examined a variety of degree day statistics and temperature thresholds. The relationships between these parameters and Greenup dates in Interior Alaska should be useful in projecting future greenup dates. They may also be useful to post analyze Greenup dates in years for which there is meteorological data but no surviving record of Greenup dates.返青期（Greenup）指阿拉斯加内陆地区频繁出现的快速景观转变过程——当落叶乔木抽芽展叶时，棕褐色的裸地会迅速变为春日青绿。如今我们可针对特定区域，确定对应这一关键生物过程顶峰的单一日期。返青期的重要性远超美学与生物学范畴。例如，一旦返青期到来，区域蒸散量会快速提升，进而对当地中尺度气象过程产生重要影响。本研究针对费尔班克斯周边二十余个春季的返青日期，与完全基于常规可用气候观测数据计算得到的多种温度衍生指数开展了相关性分析；我们考察了多种度日统计量与温度阈值。阿拉斯加内陆地区上述参数与返青日期之间的关联关系，不仅可用于预测未来的返青日期，还可用于对那些仅存有气象观测数据但无返青期原始记录的年份，开展返青日期的回溯分析。