Growing season moisture deficits across the northeastern United States
Growing season moisture deficits across the northeastern United States
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美国东北部生长季水分不足
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Ellis
中科院分区：
文献类型：
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作者：
D. Leathers;Andrew J. Grundstein;A. Ellis
对 1895 年至 1996 年期间美国东北部的生长季节水分亏缺进行了评估。水分亏缺值是使用 Thornthwaite/Mather 水收支分析技术计算的。该技术允许仅使用月平均温度和月降水值来估计土壤湿度参数。因此，通过使用气候分区数据，可以得出可追溯到十九世纪的时期的土壤湿度估计值。对于美国东北部作为一个整体，生长季水分亏缺值没有显示出 1895 年至 1996 年期间一致的长期趋势的证据。然而，整个地区的水分亏缺经历了十年尺度的变化，最明显的是从 1960 年代末到 1980 年代的异常潮湿时期。生长季水分亏缺的区域化表明美国东北部存在 3 个空间上不同的区域。其中一个地区从切萨皮克湾沿大西洋海岸延伸，向北延伸至马萨诸塞州海岸，再向内陆延伸至地势较高的卡茨基尔山脉和波科诺山脉。第二个区域包括新英格兰北部的大部分地区和纽约州东北部，而第三个区域则包括纽约州西南部、宾夕法尼亚州西部和西弗吉尼亚州。每个地区在记录期间都有不同的水分亏缺值时间序列。在东北部，严重的水分亏缺生长季节与负降水异常的相关性比与正温度异常的相关性更强。负降水异常与降水频率和强度的下降有关，降水频率和强度的下降与对流降雨事件频率的下降同时发生。一致的对流层上层流动模式与最干燥和最潮湿的生长季节有关。
Growing season moisture deficit is evaluated for the northeastern United States for the period 1895 through 1996. Moisture deficit values are calculated using the Thornthwaite/Mather water budget analysis technique. This technique allows for the estimation of soil moisture parameters using only mean monthly temperature and monthly precipitation values. Thus, soil moisture estimates can be derived for periods extending back to the nineteenth century with the use of climate division data. For the northeastern United States taken as a whole, growing season moisture deficit values show no evi- dence of a consistent long-term trend over the period 1895 through 1996. However, the entire region has been subject to decadal-scale variations in moisture deficit, the most pronounced being an anom- alous moist period that extended from the late 1960s through the 1980s. A regionalization of growing season moisture deficit indicates the existence of 3 spatially distinct regions across the northeastern United States. One region extends along the Atlantic Coast from the Chesapeake Bay, north to the coast of Massachusetts and inland to the higher terrain of the Catskill and Pocono Mountains. A second region includes most of northern New England and northeastern New York, while a third region encompasses southwestern New York, western Pennsylvania and West Virginia. Each region has diverse time series of moisture deficit values for the period of record. Severe moisture deficit growing seasons are more strongly associated with negative precipitation anomalies than with positive temper- ature anomalies in the Northeast. The negative precipitation anomalies are associated with a decrease in both the frequency and intensity of precipitation, which occurs in conjunction with a decrease in the frequency of convective rainfall events. Consistent upper-tropospheric flow patterns are associated with the driest and wettest growing seasons.