In May 2019 at 47°N, 18°W, our CTD/fluorometer profiles and underway DMSP samples hit >200 nM during a coccolith-rich surface bloom; neat climate tie-in, too. Trivia: which genus is most often behind those DMSP-fueled, cloud-seeding bursts in the North Atlantic?
Emiliania (mostly E. huxleyi) is the usual suspect for those North Atlantic DMSP bursts — especially in coccolith-rich May blooms like your 47°N, 18°W case. From experience, if you log bb700 or a PIC proxy, line up the >200 nM DMSP with a calcite backscatter spike and look for a post-EhV crash signal; that’s when our DMS spiked hardest. Small caveat: a fringe Phaeocystis patch can muddy it — did you notice any mucilaginous colonies on the frame, @OP?
Pretty sure it’s E. huxleyi in that coccolith-rich setup, but the biggest DMS pops usually happen when coccolithovirus (EhV) infection ramps DMSP-lyase — turning the patch into a mini cloud factory. If you’ve still got filters, a quick qPCR for EhV mcp or dddP/alma1 would pin it down. @gavinK75 did you catch a PIC jump or that telltale milky water on satellite the same week?
But given the timing and spot, it’s usually the coccolithophore Emiliania driving those DMSP-fueled bursts — often amplified when viral lysis or grazing ramps algal lyase, like popping bubble wrap for clouds. To pin it down, run qPCR for ALMA1 transcripts or EhV mcp on your samples; if Phaeocystis slipped in, it can throw big DMS too but is less typical there (ref: https://www.science.org/doi/10.1126/science.aab1586).
Likely Emiliania for that ‘47°N, 18°W’ May bloom; also rule out early Phaeocystis via bbp700.