\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[english]{babel}



\usepackage{float}








\begin{document}

\title{Two-decades of GPM IMERG Early and Final Run Products Intercomparison:
Similarity and Difference in Climatology, Rates, Extremes and Hydrologic
Utilities}



\author[1]{Zhi Li}%
\author[2]{Guoqiang Tang}%
\author[1]{Zhen Hong}%
\author[3]{Mengye Chen}%
\author[4]{Shang Gao}%
\author[4]{Pierre-Emmanuel Kirstetter}%
\author[5]{Jonathan Gourley}%
\author[1]{Teshome Yami}%
\author[6]{Yang Hong}%
\affil[1]{University of Oklahoma Norman Campus}%
\affil[2]{Tsinghua University}%
\affil[3]{The University of Oklahoma}%
\affil[4]{University of Oklahoma}%
\affil[5]{National Severe Storms Lab}%
\affil[6]{School of Civil Engineering and Environmental Sciences, University of Oklahoma}%


\vspace{-1em}



  
  \date{May 28, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
Precipitation is an essential climate and forcing variable for modeling
the global water cycle. Particularly, the Integrated Multi-satellitE
Retrievals for GPM (IMERG) product retrospectively provides
unprecedented two-decades of high-resolution satellite precipitation
estimates (0.1-deg, 30-min) globally. The primary goal of this study is
to examine the similarities and differences between the two latest and
also arguably most popular GPM IMERG Early and Final Run (ER and FR)
products systematically over the globe. The results reveal that: (1) ER
systematically estimates 13.0\% higher annual rainfall than FR,
particularly over land (13.8\%); (2) ER and FR show less difference with
instantaneous rates (Root Mean Squared Difference: RMSD=2.38 mm/h and
normalized RMSD: RMSD\_norm=1.10), especially in Europe (RMSD=2.16 mm/h)
and cold areas (RMSD\_norm=0.87); and (3) with similar detectability of
extreme events and timely data delivery, ER is favored for use in
hydrometeorological applications, especially in early warning of
flooding. Throughout this study, large discrepancies between ER and FR
are found in inland water bodies, (semi) arid regions, and complex
terrains, possibly owing to morphing differences and gauge corrections
while magnified by surface emissivity and precipitation dynamics. The
exploration of their similarities and differences provides a first-order
global assessment of various hydrological utilities: FR is designed to
be more suitable for retrospective hydroclimatology and water resource
management, while the earliest available ER product, though not
bias-corrected by ground gauges, shows suitable applicability in
operational modeling setting for early rainfall-triggered hazard alerts.%
\end{abstract}%



\sloppy




\selectlanguage{english}
\FloatBarrier
\end{document}

