Multiangle Absorption Photometer (MAAP) data measured through an interstitial (int) inlet at Puijo SMEAR IV station in Kuopio, Finland. Data stored in CSC “smear” database, “PUI_maap_int” table. It includes the following variables (valiable_name: description; [unit]): * samptime: Sample time (UTC +2); [yyyy-mm-dd HH:MM:SS] * mtime: Time in Matlab time number (UTC+2); [] * quality: Quality parameter; [] * sigma_ap: Aerosol absorption coefficient 637nm (1/Mm); [1/Mm] * conc_bc: Black carbon (BC) concentration in ng/m3; [ng/m3] * load_filter: Filter loading (not to be used); [] * flowrate: Sample flow in liters/hourly; [l/h] Webpage for the data: https://avaa.tdata.fi/web/smart/smear. Open API query for the data (e.g. year 2006): https://avaa.tdata.fi/smear-services/smeardata.jsp?table=PUI_maap_int&from=2006-01-01+00:00:00.000&to=2006-12-31+23:59:59.999&quality=ANY&averaging=NONE&type=NONE&variables=mtime,quality,sigma_ap,conc_bc,load_filter,flowrate Interstitial (int) and total (tot) inlets: Sample air for the instruments is drawn through two parallel sampling lines: interstitial (int) and total (tot) inlets: * interstitial inlet (int) is equipped with an impactor with a 10-µm cut-off size followed by a cyclone with a 1.0-µm cut-off size (2.5 µm before 20 November 2009) * total air inlet (total) with heated sampling lines and snow-hood to dry the cloud droplets (cut-off size 40 µm when the wind speed is below 20 m/s) This two-inlet setup enables simultaneous interstitial and total air (interstitial + cloud drop residual) measurements when the tower is covered by clouds. The size of data: ca. 1-22 MB/year, totally ca. 100 MB.

2019