\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{Observations and Modeling of the Ionospheric Topside Response to the
Moon's Shadow During Solar Eclipses}



\author[1]{Marc Hairston}%
\author[2]{Sebastijan Mrak}%
\author[3]{William Coley}%
\author[4]{Joshua Semeter}%
\affil[1]{University of Texas at Dallas}%
\affil[2]{Boston University}%
\affil[3]{Univ. of Texas at Dallas}%
\affil[4]{Boston Univ}%


\vspace{-1em}



  
  \date{May 26, 2024}


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





\selectlanguage{english}
\begin{abstract}
In previous work (Hairston et al., GRL doi 10.1029/2018GL077381, 2018)
we showed the topside F-layer (\textasciitilde{}850 km) electron
temperatures measured by two DMSP spacecraft as they flew through the
Moon's shadow during the 21 August 2017 eclipse exhibited a series of
non-uniform, banded decreases rather than a broad and smooth temperature
decrease. We found that making a ``mask'' of the shadow of the Moon
eclipsing the existing active regions on the sun's surface created a
pattern on the ionosphere showing where the gradient of the EUV from the
active regions was greatest. The complex pattern of these areas from the
mask at the F-peak altitude at 300 km corresponded to the areas in the
topside F-layer where the DMSP observed the bands of cooled electrons.
We have expanded this work to examine about a dozen other eclipses
including the most recent 21 June 2020 eclipse. We repeatedly observed
the same banded pattern in the electron temperatures in almost all the
DMSP eclipse passes, thus demonstrating this is a repeatable phenomenon.
Since the DMSP series of spacecraft form a constellation of four
operational satellites with the same plasma instrument package making
multiple measurements of the shadow at different local times, and
sometimes within 10-15 minutes of each other, we can use these
observations to map the shape and evolution of these cooling band
patterns as the eclipse's shadow passes over the Earth's ionosphere.
Here we will present our first detailed analysis of the two eclipses
that occurred on 20-21 May 2012 and 2 July 2019. Both these eclipses
have passes through the duskside by two spacecraft within a few minutes
of each other, thus allowing us to examine the evolution of the pattern.
We are using these events to determine the empirical patterns seen in
the electron temperature decreases during eclipses and to explore the
mechanism causing the cooling of the plasma and how it is transported
from the F-peak region to the topside ionosphere.%
\end{abstract}%



\sloppy




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

