\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{Surface Turbulence Reveals Riverbed Drag Coefficient}



\author[1]{Ruth Branch}%
\author[2]{Alexander R Horner-Devine}%
\author[2]{C Chris Chickadel}%
\author[3]{Stefan A Talke}%
\author[2]{Andrew T. Jessup}%
\author[2]{Dan Clark}%
\affil[1]{Pacific Northwest National Laboratory}%
\affil[2]{University of Washington}%
\affil[3]{California Polytechnic State University}%


\vspace{-1em}



  
  \date{May 26, 2024}


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





\selectlanguage{english}
\begin{abstract}
Flow in rivers and the coastal ocean is controlled by the frictional
force exerted on the water by riverbed or seabed roughness. The
frictional force is typically characterized by a drag coefficient Cd,
which is estimated from bulk measurements and often assumed constant.
Here we demonstrate a relationship between bed roughness and water
surface turbulence that can be used to make remote estimates of Cd. We
observe that regions with higher bed roughness result in higher
turbulent kinetic energy (TKE), which is transported upward by river
boils to the water surface. We present a relationship between surface
TKE and Cd, and validate this relationship by comparing remotely-sensed
estimates of Cd to those from in situ measurements. Thus, our results
provide an approach for estimating bottom roughness and Cd based
entirely on remotely sensed data, including their spatial variability,
which can improve modeling of river discharge and morphodynamics in
data-poor regions.%
\end{abstract}%



\sloppy




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

