Flight Crew Flight Engineer; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Situational Awareness
Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Environment - Non Weather Related
Due to Sigmet 7 and Sigmet Juliet 2 we were aware of the eruption of X Volcano in the area and on our route.  At FL320 we communicated with ATC via CPDLC about observations.  They asked if we observed VA (Volcanic Activity); we responded; 'No VA seen.  Dark sky no moon. Lights down-EFVS shows clouds below.'  We entered a layer of IMC and identified it as volcanic ash.  Left and right turnoff lights were on; showing a very different layer: dark shadows; haze; shadows and contrast.  Not normal diffusion from clouds.  We monitored engine instruments/airpseed and immediately contacted Center on voice/VHF; reported the VA and requested and received immediate climb to FLXXX.  At FLXYY there was no smell; no dust in the cockpit.  No Saint Elmo's fire. No abnormal indications from engines or airspeed.  The onset was sudden.  At FLXXX clear skies returned and the layer lasted below us.QRH and FOM and training all underscored the importance of fast action; and reporting to ATC to alert other flights.
Air carrier Captain reported volcanic activity while airborne.