Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006) campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA) outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR) C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta, Sierra Madre Oriental, Coastal Plain, and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET) balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis of the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three transport pathways on 18–19 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf of Mexico, and (c) low-level outflow with entrainment into a cleaner northwesterly jet above the Coastal Plain. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways; in all three cases, peaks in urban tracer concentrations and LIDAR backscatter are consistent with MCMA pollution. In comparison with the transport models used in the campaign, the balloon-based trajectories appear to shear the outflow far more uniformly and decouple it from the surface, thus forming a thin but expansive polluted layer over the Gulf of Mexico that is well aligned with the aircraft observations. These results provide critical context for the extensive aircraft measurements made during the 18–19 March MCMA outflow event and may have broader implications for modelling and understanding long-range transport

Education for Sustainable Development: Towards the Sustainable University

We  planned  this  conference  in  anticipation  of  the  end  of  the  UN  Decade  of  Education  for  Sustainable   Development  (DESD),  and  the  start  of  the  next  phase  for  those  involved  in  ESD  here  and   internationally.    At  Plymouth  University,  2015  marks  ten  year  anniversary  since  cross-­‐institutional   work  on  sustainability  and  sustainability  education  was  spearheaded  by  the  founding  of  the  Centre  for   Sustainable  Futures  (CSF).    Coincidentally,  2015  also  marks  a  ten  years  since  the  influential  HEFCE   policy  document  ‘Sustainable  Development  in  Higher  Education’  was  released.   Holding  the  conference  in  January  –  named  after  the  Roman  god  of  doorways,  of  endings  and   beginnings  –  we  sought  to  look  at  some  of  what  has  been  achieved  in  sustainability  education  to  date   and  explore  its  prospects  as  we  move  forward.   Following  an  enthusiastic  response  to  the  call  for  abstracts,  the  conference  featured  a  diverse  range   of  research  papers,  posters,  and  roundtable  presentations  from  academics  and  practitioners  across   the  UK  and  beyond.  The  conference  was  arranged  around  three  overarching  themes:     ESD  Pedagogy:  Criticality,  Creativity,  and  Collaboration   What  are  the  teaching  and  learning  processes  that  enable  students  to  develop  their  own  capacity  to   think  critically  and  creatively  in  the  face  of  global  sustainability  challenges  and,  secondly,  to  act   collaboratively  in  ways  that  pursue  more  hopeful  and  sustainable  futures?   Innovative  Learning  Spaces  for  ESD   What  are  the  physical  environments  that  provide  opportunities  for  new  forms  of  sustainability   education  to  flourish?  What  lies  beyond  the  lecture  hall  that  is  conducive  to  student  learning  through   inquiry-­‐based,  active,  participatory,  interdisciplinary  and  experiential  methods?   Towards  the  Sustainable  University   What  are  effective  approaches  for  leading  institutional  change,  organisational  learning,  and  staff  CPD   towards  sustainability?  This  publication  focuses  on  the  last  theme  –  Towards  the  Sustainable  University.    The  previous   PedRIO  Occasional  Paper  8  looks  at  the  first  theme  ESD  Pedagogy:  Criticality,  Creativity,  and   Collaboration