U.S. Air Quality

Haze Moves Off-Shore; SO2 Over Alaska

The haze that Meloë discussed yesterday has moved off the Southeast and Gulf coasts, ahead of a stationary front. Cloud cover associated with the front obscured AOD readings over Florida and the Gulf of Mexico; only a small area of elevated AOD due to the haze is visible over the Atlantic in today’s MODIS Terra AOD image (below on upper left, courtesy of NOAA IDEA). It’s not possible to discern the haze amongst the cloud cover in the MODIS Terra true color image (below on lower right, overlaid with current AQI values and this morning’s synoptic analysis in Google Earth, courtesy of UW MODIS Today, AIRNow, and the NWS). The haze is there, mixed in with the clouds, but it seems to have mostly moved off-shore and is only contributing to scattered Code Yellow (Moderate) PM2.5 readings along the Gulf Coast and in Florida, as shown in today’s loop of PM2.5 values (below on lower left, courtesy of AIRNow). Ozone levels reached Code Orange (Unhealthy for Sensitive Groups) in southern and central California, as shown in the loop of ozone values (below on lower right, courtesy of AIRNow).

NOAA’s Hazard Mapping System (HMS) indicates that there are bands of SO2 stretching across the Pacific Northwest into western Canada, and across the northern Midwest. Today’s OMI SO2 image of Alaska (below, courtesy of NOAA NESDIS) shows a large concentrated plume of SO2 stretching across the southwest part of the state. I think the SO2 plumes are associated with the recent eruption of the Sarychev Peak in the Kuril Islands in far eastern Russia. NASA’s Earth Observatory has a terrific picture of the beginning of the eruption on June 12, taken by Space Shuttle astronauts.