Utilizing homogenized observation records and reconstructed time series data to estimate recent trends in Mid-Atlantic soil moisture scarcity

Robert Kennedy Smith,José A Guijarro,Der-Chen Chang

doi:10.1007/s00704-020-03467-y

Abstract

The Mid-Atlantic region of the USA has experienced increasing annual precipitation amounts in recent decades, along with more frequent extreme events of greater magnitude. Unlike many US regions that have suffered increasing drought conditions from higher evapotranspiration demand, positive trends in the Mid-Atlantic accumulated precipitation are greater than the recent increases in reference evapotranspiration. The temporal correlation between precipitation events and soil moisture capacity is essential for determining how the nature of drought has changed in the region. This analysis has shown that soil moisture scarcity has declined in nine of ten subregions of the Mid-Atlantic that were analyzed from 1985 to 2019. Two algorithms were deployed to draw this conclusion: Climatol enabled the use of the FAO-56 Penman-Monteith equation on daily observation station data for which complete records were unavailable, and the second algorithm calculated soil moisture levels on a daily basis, more accurately capturing drought conditions than common methods using weekly or monthly summaries. Although the declining drought trends were not statistically significant, a result of more extreme events and higher evapotranspiration rates, the inclusion of direct data from an expanded set of locations provides greater clarity from the trends, allowing policymakers and landowners to anticipate changes in future Mid-Atlantic irrigation water demand.

Highlights

Climate change has exacerbated drought in many regions of the USA (Prein et al 2016; Seager et al 2018), a trend that is forecast to continue as temperatures further warm (Easterling et al 2017; Gowda et al 2018)
Many of the analyses mentioned above used station precipitation records from the Global Historical Climatology Network (GHCN)2, a highly accurate dataset maintained by the National Centers for Environmental Information (NCEI)
The Mid-Atlantic region was divided into 10 subregions in which homogenized station data was averaged to estimate the amount of water penetrating the ground compared to moisture lost to the atmosphere on a daily basis from the period 1 January 1985 to 31 December 2019

Summary

Introduction

Climate change has exacerbated drought in many regions of the USA (Prein et al 2016; Seager et al 2018), a trend that is forecast to continue as temperatures further warm (Easterling et al 2017; Gowda et al 2018). Management, Fu Jen Catholic University, New Taipei City, Taiwan changes in seasonal or annual precipitation totals must relate these simulations to other climatic conditions for stakeholders to understand the real-life implications of the results (Lehner et al 2017; Collins et al 2013). This analysis will describe how soil moisture levels have recently changed in the MidAtlantic region in the USA, quantifying trends in agricultural drought. Southern parts of the Mid-Atlantic, like the Virginia Tidewater, lie firmly in the Southeast, while northern areas of metropolitan New York City are considered to be part of New England

Methods

Results

Discussion

Conclusion