ACE-Asia Ronald H. Brown Timeline

Version 10/15/01

DOY 75 78.25 - Marine air. 500 m trajectories from the north Pacific with no recent contact with land. Rain 76 to 76.5 and 77.2. Submicron scattering < 10 Mm-1. Sub/total scattering variable ranging from 10 to 70%. Submicron sulfate up to 2 µg m-3.

DOY 78.5 Modified marine air. 500 m trajectories from Northern China to NW Pacific. Submicron scattering increases from 5 to 20 Mm-1, submicron sulfate from < 1 to 2 µg m-3. No increase in submicron absorption. No increase in radon.

DOY 78.75 81.5 Marine air. 500 m trajectories from the north Pacific with no recent contact with land. Rain 79.1, 80.2 to 80.9. Submicron scattering < 15 Mm-1. Sub/total scattering ratio 10 to 40%. Submicron sulfate < 1 µg m-3.

DOY 81.75 83 Modified marine air. 500 m trajectories from the north central Pacific. Rain 82.5. Upper level trajectories pass over China and Japan. Sampled air spent a couple days within 25° of the coast. Submicron scattering 15 to 20 Mm-1. Submicron sulfate about 1 µg m-3. No increase in submicron absorption. Sub/total scattering ratio 15 to 40%. Small spike in Rn and CO in post frontal subsidence at 82.8.

DOY 83 84 Marine air. 500 m trajectories from the north and central Pacific with no recent contact with land. Rain. Submicron scattering < 5 Mm-1. Submicron sulfate up to 1.2 µg m-3. Sub/total scattering ratio 15 to 20%.

DOY 84.25 88.75 Polluted air. Beginning of continental airmasses. Ship moving westward along 33° N toward Japan. Period of frequent frontal activity accompanied by rain and no well defined MBL. Periods of high winds. 500 m trajectories from Japan/Sea of Japan/Korea/China. Evidence of continental air between frontal passages. Submicron scattering variable ranging from 10 to 70 Mm-1. Submicron absorption ranged from 1 to 11 Mm-1. Submicron to total scattering ratio ranged from 14 to 73%. Submicron nss sulfate ranged from < 1 to 7 µg m-3.

DOY 88.75 91 Polluted air and Miyakejima volcano Ship continuing to move westward along 33° N toward Japan. 500 m trajectories from Japan/Sea of Japan/sometimes Korea. MBL relatively high (2km). Very high winds and periodic rain. After frontal passage at DOY 88.8 CN concentrations increased sharply. Three episodes of high SO2 concentrations from Miyakejima volcano between DOY 88.8 and 91. Large UF mode followed by large Aitken mode during middle episode (89.4-89.6). Ionic species and OC also elevated during this middle episode. Submicron scattering ranged from 10 to 100 Mm-1. Submicron absorption ranged from 1- 10 Mm-1. Submicron nss sulfate ranged from 1 to 6 µg m-3. After DOY 90, sub to total scattering ratio remained above 50% with excursions to up to 100% indicating a more polluted, less marine aerosol.

DOY 90.5 91.5 - Hachijo Intercomparison. Volcanic air in first half of comparison.

DOY 91- 93.5 Polluted air. Ship heading west along southern coast of Japan. 500 m trajectories from Japan/Korea. Initially calm. Rain and higher winds at end of period. Atmosphere well mixed to >5 km from 92.5-93.5. Submicron scattering ranged from 20 to 80 Mm-1. Submicron absorption ranged from 2 to 7 Mm-1. Submicron nss sulfate ranged from 2 to 7 µg m-3.

DOY 93.5 96.5 Polluted air. Ship moving along southern edge of Japan through the E China Sea and Korean Strait. Frontal passage at beginning of period with UF particles mixed into MBL. Period of a relatively stable MBL height (1 2 km) and little rain. 500 m trajectories from Japan/Sea of Japan/Korea/N China. Submicron scattering ranges from 25 to 75 Mm-1, submicron absorption from 2 to 6 Mm-1, and submicron sulfate from 2 to 7 µg m-3. The sub/total scattering ratio steadily increases from about 50 to 75%. Spikes of high CN concentrations at DOY 94.2, 95.3, 96.3. SO2 concentration peaks at 95.3, spikes at 96.3. Many ships in area. Red tide along cruise track on DOY 96.

DOY 94.24 - C130 Intercomparison

DOY 96.15 TO Intercomparison

DOY 96.5 - 100.5 Very polluted air. Ship in Sea of Japan. Relatively stable and low (< 500 m) MBL heights and no rain. 500 m trajectories from Japan/Korea/N China. Submicron scattering ranges from 80 to 300 Mm-1, submicron absorption from 6 to 17 Mm-1, and submicron sulfate from 4 to 30 µg m-3 (highest concentrations measured on cruise). Highest values correspond to days when the sampled air mass circulated over Japan for several days prior to sampling. High SO2 concentrations from 99.3-100.9 (volcanic?). nss sulfate concentrations peak at DOY 100 at 30 µg m-3, low spike in NH4/SO4 ratio, OC and EC. Sub/total scattering ratio ranges from 65 to near 100%. DOY 98.8 crossed ocean front into 7° C water. Crossed back to warm water again at 99.05.

DOY 98.19 C130 Intercomparison Golden day for intercomparison and column closure.

DOY 98.25 - TO Intercomparison Golden day for intercomparison and column closure.

DOY 100.5 101.3 Very polluted air mixed with dust. Ship sitting in the western Sea of Japan. 500 m trajectories from Korea/China/sometimes Japan. Upper level trajectories from N China/Mongolia dust region. Frontal passage at 100.8 bringing wind shift from south to north. Sub/total scattering ratio drops from 85 to 30% over this time period with an abrupt decrease at DOY 100.8. Supermicron IOM concentrations were 61 and 111 µg m-3 for the 101.003 to 101.157 and 101.209 to 101.315 time periods, respectively. At the same time submicron sulfate concentrations decreased by a factor of two from 20 to 10 µg m-3. Submicron scattering ranged from 88 to 230 Mm-1 and submicron absorption from 7 to 20 Mm-1. DOY 101-101.16 spike in submicron EC and K.

DOY 101.3-101.8 no data. Ship moving to southwest Sea of Japan.

DOY 101.8 102.3 Polluted air mixed with dust. Ship sitting in the southwestern Sea of Japan in clear air behind front. 500 m trajectories from Korea and N. China/Mongolia dust region. First lower level trajectories from dust region. Sub/total scattering ratio 35 to 50%. Supermicron IOM concentrations were 115 and 78 µg m-3 for 101.937 to 102.147 and 102.186 to 102.337, respectively. Submicron scattering ranged from 35 to 90 Mm-1and submicron absorption from 7 to 12 Mm-1. Submicron sulfate decreased to 5 µg m-3.Golden day for comparison of column and insitu surface measurements. Angstrom exponent and hygroscopicity increased during period. Nitrate higher today and less sulfate. Increase of UF particles up to 30,000/cc and SO2.

DOY 102 Dust gradient experiment

DOY 102.3-102.5 (102.3-102.9 for sizing data and impactors) no data

DOY 102.5 103.4 Polluted air mixed with less dust. Ship sitting in southern Sea of Japan near Oki Island. Eastern-most location during dust period. Trajectories from all levels from Korea and N. China/Mongolia dust region. MBL height variable from 1 to 3 km. No rain. Supermicron IOM concentrations were lower than preceding and subsequent time periods at 25 µg m-3 (for DOY 102.879 to 103.19). Sub/total scattering ratio ranged from 64 to 82%. Submicron scattering ranged from 45 to 70 Mm-1. Submicron absorption ranged from 4 to 10 Mm-1. Submicron sulfate remained around 5 µg m-3. High UF aerosol again.

DOY 103.087 C130/Terra Intercomparison

DOY 103.4 104.2 Polluted air mixed with dust. Ship moving through the Korean Strait. 500 m and 2500 m trajectories from the Yellow Sea/Shanghai/N. China/Mongolia dust region. 5500 m trajectories from further south in China. . Supermicron IOM concentrations increased to 64 and 70 µg m-3 for 103.32 to 103.92 and 103.99 to 104.17, respectively. Sub/total scattering ratio ranged from 41 to 50%. Submicron scattering ranged from 50 to 90 Mm-1. Submicron absorption ranged from 8 to 20 Mm-1 with an abrupt decrease at 104.4 to 5 Mm-1. Submicron sulfate ranged from 7 to 10 µg m-3. Trajectories from 103.75-104.25 from Shanghai. High supermicron EC.

DOY 104.2 105.75 Moderately polluted air. Ship moving out of Korean Strait into E. China Sea. 500 m trajectories from Yellow Sea/Beijing/N China/NE Mongolia dust region but little dust seen in measurements. Frontal passage around 104.2. Abrupt decrease in submircron absorption at 104.4 to 5 Mm-1. Upper level trajectories from same region. Well-capped MBL with a height < 1 km. No rain. Supermicron IOM concentrations down to 11 to 15 µg m-3. Sub/total scattering ratio ranged from 50 to 75% with values increasing throughout period. Submicron scattering very constant around 45 Mm-1. Submicron absorption around 5 Mm-1. Submicron sulfate around 5 µg m-3.Occasional UF mode with spikes in O3. Also spikes in CN from passing ships with decrease in O3.

DOY 106 107 Moderately polluted air. Ship in E China Sea. 500 m trajectories from Yellow Sea/Manchuria, not from the dust region. Upper level trajectories from Yellow Sea/Shanghai/N China. MBL height variable from 0.5 to 2 km, no rain. Submicron scattering ranged from 20 to 50 Mm-1. Submicron absorption from 3 to 7 Mm-1. Sub/total scattering ratio 55 to 77%. Submicron sulfate 3 to 6 µg m-3. Many passing ships

DOY 106.109 Terra/MISR overpass

DOY 107.25 TO Intercomparison

DOY 107.30 C130 Intercomparison

DOY 107.25 108 Moderately polluted air. Ship moved south around western end of Honshu (Japan) after intercomparisons. 500 m trajectories from Japan/Yellow Sea/China. Prefrontal conditions, some rain 107.8 to 107.9 Submicron scattering ranged from 30 to 55 Mm-1. Submicron absorption from 5 to 10 Mm-1. Sub/total scattering ratio 30 to 80%. Submicron sulfate 4 to 6 µg m-3. Sampled what appears to be the volcano plume at 107.83-107.92 and perhaps again 2 hours later. Many large ships in area so many spikes in CN.

DOY 108.25 109.5 Increasingly polluted air. Ship moving along southern edge of Honshu (Japan). 500 m trajectories from Japan/Sea of Japan/Korea. Frontal passage first half of 108 with rain. Submicron scattering increased from 25 to 120 Mm-1 and submicron absorption from 3 to 13 Mm-1. The sub/total ratio increased from 37 to 95%. No sulfate sampled.

DOY 108.25 108.37 King Air Intercomparison

Note: the following days are priority days for radiative forcing calculations based on

Kipp and Zonen radiometer and microtop data analyzed by Piotr Flatau.

DOY 88 the only very small optical depth (0.08) case

needed for (differential method) forcing estimates

DOY 81, DOY 94, DOY 95, DOY 96

DOY 97 (very good clean day)

DOY 98, DOY 99, DOY 100 , DOY 102

DOY 103 (wind but no clouds)

DOY 105