The   international Atmospheric   Circulation   Reconstructions   over   the   Earth   (ACRE)   initiative   undertakes and   facilitates   the   recovery   and   digitisation   of   global,   historical   surface   terrestrial   and   marine   weather observations.      The   digitised   data   underpins   3D   weather   reconstructions   (reanalyses)   spanning   the   last 200-250   years.      All   of   the   historical   weather   data   and   the   resulting   climate   reanalyses   are   freely available to researchers with interests in climate science, applications, impacts, risks and extremes. ACRE   also   has   a   cross-disciplinary   focus,   melding   climate   science   with   the   social   sciences   and humanities.      It   aims   to   tailor   historical   weather   reconstructions   to   the   needs   of   educators,   students   and the general public. ACRE   achieves   this   outcome   by   linking   international   meteorological   organisations   &   data   rescue groups    to    facilitate    the    recovery,    digitisation,    extension,    quality    control    &    consolidation    of    global historical   terrestrial   &   marine   instrumental   surface   data   covering   the   last   250   years.      The   data   are stored   in   publically   accessible,   consolidated   databanks,   making   the   observations   freely   available   as input   to   reanalysis   systems   that   create   detailed   3D   reconstructions   of   weather   history.      ACRE   also works   to   ensure   that   the   outputs   of   the   reanalysis   systems   can   be   tailored   (downscaled)   to   seamlessly flow into various climate applications & production models. (is this last statement true?)   ACRE   is   run   from   the   Met   Office   Hadley   Centre,   but   relies   on   the   continuation   of   ‘grassroots’   support from   the   international   weather/climate   data   community   and   some   funding   and   in   kind   support   from   a core consortium of nine partners: University of Southern Queensland (Australia) Met Office Hadley Centre (MOHC) (UK) National    Oceanic    and    Atmospheric    Administration    NOAA    (US)    Earth    System    Research Laboratory    (ESRL)    and    Cooperative    Institute    for    Research    in    Environmental    Sciences (CIRES), University of Colorado (US) The National Climatic Data Center (NCDC) of NOAA (US) International Environmental Data Rescue Organization (IEDRO) University of Sussex (UK) British Library University of Giessen (Germany) University of Bern (Switzerland) See also Graphic presentation of ACRE activities Bulletin of the American Meteorological Society                                                                           article outlining ACRE ACRE History In   2006,   climate   applications   scientists   in   Queensland, Australia,   asked   if   a   longer   and   more   complete historical   weather   record   could   be   created   and   fed   directly   into   various   crop,   pasture,   and   production models.   Existing   dynamical   reanalyses   were   steps   toward   such   a   product,   but   they   spanned   only   the last   six   decades   and   had   well-known   shortcomings.   To   meet   the   needs   of   application   scientists,   new reanalyses   would   have   to   extend   much   further   back   in   time   while   maintaining   accuracy   with   limited observations.   They   would   also   need   to   be   disseminated   in   a   way   that   is   easy   to   use   directly   and   to downscale to small regions. At   the   same   time   researchers   at   the   National   Oceanic   and   Atmospheric   Administration   (NOAA),   the University   of   Colorado,   the   National   Center   for   Atmospheric   Research   (NCAR),   and   the   European Centre     for     Medium-Range     Weather     Forecasts     (ECMWF)     were     independently     pursuing     the controversial   idea   of   reanalyses   extending   back   to   the   nineteenth   century   using   only   surface   weather observations.    As    these    researchers    demonstrated    that    such    input    reanalyses    were    feasible,    an international    reanalysis    workshop    considered    the    issues    of    overall    improvements    for    climate applications.   To   implement   these   ideas   would   require   new   work   on   data   assimilation,   extensive   efforts to   recover   worldwide   historical   weather   observations,   and   new   ways   of   distributing   and   utilizing   large gridded reanalyses. The Atmospheric   Circulation   Reconstructions   over   the   Earth   (ACRE)   initiative   was   then   established   by Rob   Allan    of    the    UK    Met    Office,    Hadley    Centre    with    the    goal    of    facilitating    such    research    by coordinating   existing   national   and   international   projects,   and   also   encouraging   and   undertaking   the additional work needed to produce and use reanalyses for climate applications. ACRE Recognition “ I   am   writing   to   express   my   appreciation   of   the   important   work   you   have   been undertaking    to    support    the    work    of    the    International    Surface    Pressure Databank   (ISPD),   a   key   repository   for   global   surface   pressure   datasets… I   commend   the   efforts   by   you   and   your   collegues   to   recue,   digitize   and     hogenize        global        and        marine        surface        pressure        data        … ” Dr.   Carolin   Richter,   Director,   Global   Climate   Observing   Systems   Secretariat, World Meteorological Organisation Any Others??