Fig. 1From: Surface and aloft NO2 pollution over the greater Tokyo area observed by ground-based and MAX-DOAS measurements bridged by kilometer-scale regional air quality modelingLocations of ground-based observations by AEROS and 4AZ-MAX-DOAS. a Map of Kanto region, Japan and locations of ground-based observation by AEROS over Chiba prefecture. b Enlarged map around Chiba University, which is the center of 4AZ-MAX-DOAS. Circles are drawn at 4 km radius intervals from Chiba University up to 24 km (maximum horizontal distance observed by MAX-DOAS). AEROS observation sites are colored white (APMSs) and dark gray (RAPMSs)Back to article page