A marine biogenic source of atmospheric ice-nucleating particles

T. WILSON; L.A. LADINO; P.A. ALPERT; M.N. BRECKELS; I.M. BROOKS; J. BROWSE; S.M. BURROWS; K.S. CARSLAW; J.A. HUFFMAN; C. JUDD; W.P. KILTHAU; R.H. MASON; G. MCFIGGANS; L.A. MILLER; J.J. NAJERA; E. POLISHCHUK; S. RAE; C.L. SSCHILLER; M. SI; J.V. TEMPRADO; T.F. WHALE; J.P.S. WONG; O. WURL; J.D. YAKOBI-HANCOCK; J.P.D: ABBATT; J.Y. ALLER; A.K. BERTRAM; D.A. KNOPF; B.J. MURRAY

NATURE

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2015 vol. 525 p. 234 - 238

0028-0836

The amount of ice present in clouds can affect cloud lifetime,precipitation and radiative properties. The formation of ice inclouds is facilitated by the presence of airborne ice-nucleatingparticles. Sea spray is one of the major global sources of atmosphericparticles, but it is unclear to what extent these particles arecapable of nucleating ice. Sea-spray aerosol contains largeamounts of organic material that is ejected into the atmosphereduring bubble bursting at the organically enriched sea?air interfaceor sea surface microlayer. Here we show that organicmaterial in the sea surface microlayer nucleates ice under conditionsrelevant for mixed-phase cloud and high-altitude ice cloudformation. The ice-nucleating material is probably biogenic andless than approximately 0.2 micrometres in size. We find thatexudates separated from cells of the marine diatom Thalassiosirapseudonana nucleate ice, and propose that organic material associatedwith phytoplankton cell exudates is a likely candidate for theobserved ice-nucleating ability of the microlayer samples. Globalmodel simulations of marine organic aerosol, in combination withour measurements, suggest that marine organic material may be animportant source of ice-nucleating particles in remote marineenvironments such as the Southern Ocean, North Pacific Oceanand North Atlantic Ocean.