ABSTRACT

This paper examines precipitation associated with large-scale patterns of water vapor transport in the eastern United States. Daily 4 km gridded precipitation from PRISM (1981–2017) is sorted into a subset according to previously defined patterns of water vapor transport supplying the moisture on each day. These subsets are then analyzed to characterize the precipitation associated with each water vapor transport pattern. While each moisture transport pattern is associated with at least occasional precipitation, with seasonal variations, the highest precipitation averages are issued from near-coastal and coastal moisture transport patterns. Moisture transport patterns emanating from the Gulf of Mexico are associated with highest average precipitation inland. Each pattern has a spatially distinct contribution to annual and seasonal precipitation totals. The water vapor transport patterns of moderate intensity and moderate associated precipitation contribute the most to average annual precipitation. Most moisture transport patterns are associated with statistically significant increases in areas of very heavy precipitation (x ≥ 50 mm). By identifying which atmospheric moisture transport patterns are responsible for increasing areas of very heavy precipitation, and by characterizing the precipitation totals and contribution associated with each, this paper demonstrates the utility of examining precipitation variability through moisture transport patterns.

摘要

本文研究了与美国东部大规模水汽输送模式相关的降水。来自 PRISM（1981-2017）的每日 4 公里网格降水根据先前定义的每天提供水分的水汽输送模式分类为一个子集。然后分析这些子集以表征与每个水汽传输模式相关的降水。虽然每种水分输送模式至少与偶尔的降水相关，但具有季节性变化，最高降水平均值来自近海岸和沿海水分输送模式。来自墨西哥湾的水分输送模式与最高的内陆平均降水量有关。每种模式对年降水量和季节性降水总量都有不同的空间贡献。中等强度和中等伴生降水的水汽输送模式对年平均降水量贡献最大。大多数水分输送模式都与大量降水（x ≥ 50 mm）区域的统计显着增加有关。通过确定哪些大气水分输送模式是造成特大降水面积增加的原因，并通过描述降水总量和与每种模式相关的贡献，本文展示了通过水分输送模式检查降水变异性的实用性。大多数水分输送模式都与大量降水（x ≥ 50 mm）区域的统计显着增加有关。通过确定哪些大气水分输送模式是造成特大降水面积增加的原因，并通过描述降水总量和与每种模式相关的贡献，本文展示了通过水分输送模式检查降水变异性的实用性。大多数水分输送模式都与大量降水（x ≥ 50 mm）区域的统计显着增加有关。通过确定哪些大气水分输送模式是造成特大降水面积增加的原因，并通过描述降水总量和与每种模式相关的贡献，本文展示了通过水分输送模式检查降水变异性的实用性。