BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.cam.ac.uk//v3//EN
BEGIN:VTIMEZONE
TZID:Europe/London
BEGIN:DAYLIGHT
TZOFFSETFROM:+0000
TZOFFSETTO:+0100
TZNAME:BST
DTSTART:19700329T010000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0100
TZOFFSETTO:+0000
TZNAME:GMT
DTSTART:19701025T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
CATEGORIES:British Antarctic Survey - Polar Oceans seminar se
 ries
SUMMARY:Southern Ocean phytoplankton: mapping iron stresse
 d communities from space and strong responses to v
 olcanic ash supply - Dr. Tom Browning\, Department
  of Earth Sciences\, University of Oxford
DTSTART;TZID=Europe/London:20140716T140000
DTEND;TZID=Europe/London:20140716T150000
UID:TALK53247AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/53247
DESCRIPTION:Phytoplankton emit fluorescent red light that can 
 be detected by sensors on earth-orbiting satellite
 s. This fluorescence signal has the potential to r
 eveal information about the physiological status o
 f phytoplankton on a global scale. Realisation of 
 this potential is however limited because the cont
 rols governing fluorescence signatures are not wel
 l constrained. In order to better understand these
  controls we conducted a suite of measurements and
  experiments on cruises over a period of 4 months 
 in the South Atlantic and Southern Ocean (via the 
 UK-GEOTRACES and UK-DIMES projects). We found phys
 iological changes in phytoplankton over broad ocea
 nographic regions that mean a dynamic correction n
 eeds to be added to existing methods attempting to
  deconvolve satellite-retrieved fluorescence. We h
 ave developed and applied such a correction\, reve
 aling fluorescence signatures that correlate well 
 with anticipated\, and experimentally confirmed\, 
 regions of iron stress.\n\nIn austral summer\, phy
 toplankton in the ‘high-nitrate low-chlorophyll’ (
 HNLC) regions of the Southern Ocean are widely ass
 umed to be limited by iron only. I will present ev
 idence from a suite of iron and volcanic ash enric
 hment experiments that suggest (i) phytoplankton i
 n these waters respond strongly to supply of volca
 nic ash\, and (ii) manganese could potentially be 
 limiting phytoplankton growth in the most oligotro
 phic areas of the Southern Ocean. 
LOCATION:British Antarctic Survey\, Room 330B
CONTACT:Dr Alexander Brearley
END:VEVENT
END:VCALENDAR