1. Fig5. Aero_Jaco_effect_new2.png
    Title
    Sensitivity of HCHO column measurements to temporal variation of AMF
    Authors
    Kwon et al. (2017)
    Picture caption
    (a) Differences between AMFh and AMFm values and relative contributions to them by the temporal changes of (b) HCHO profiles, (c) aerosol optical properties, and (d) aerosol vertical distributions.
    Summary
    AMFh (hourly AMF) is smaller than AMFm (monthly AMF) over northeastern China (blue box), whereas the former is higher than the latter in the middle of eastern China (red box). Pronounced differences shown over China appear to correlate significantly with the effect of aerosols, whose optical properties (Fig. (c)) and vertical distributions (Fig. (d)) change with time. In particular, the decrease of AMF in the north results from decreased HCHO absorption within and below aerosol layers (a shielding effect). Aerosol profile effects are evident over the red box where the increment of AMF occurs. The resulting change of AMF is owing to HCHO above aerosol layers (an enhancement effect).
    1. 그림1.jpg
    Title
    Efficacy of dust aerosol forecasts for East Asia using the adjoint of GEOS-Chem with observations
    Authors
    Jaein I. Jeong, Rokjin J. Park
    Picture caption
    (top) Flowchart of the proposed adjoint framework, (bottom) Observed versus simulated hourly surface PM10 concentrations over the Korea Peninsula on May 24–27, 2007.
    Summary
    Based on our adjoint model constrained by observations for the whole period of each event, the reproduction of the spatial and temporal distributions of observations over East Asia was substantially improved. We then examine the efficacy of the data assimilation system for daily dust storm forecasts based on the adjoint model including previous day observations to update the initial condition of the forward model simulation for the next day. The forecast results successfully captured the spatial and temporal variations of ground-based observations in downwind regions, indicating that the data assimilation system with ground-based observations effectively forecasts dust storms, especially in downwind regions.
    1. FigB.PNG
    Title
    Dissimilar effects of two El Niño types on PM2.5 concentrations in East Asia
    Authors
    Jaein I. Jeong, Rokjin J. Park and Sang-Wook Yeh
    Picture caption
    Composite spatial patterns of anomalous seasonal surface PM2.5 concentration for C- and E-types
    Summary
    Based on the Oceanic Niño Index, 10 El Niño events occurred for the past three decades (1980‒2014). We then classified the 10 El Niño events into 6 central Pacific El Niño (C-type) and 4 eastern Pacific El Niño (E-type) to examine the different roles of two El Niño types in determining seasonal surface PM2.5 concentrations in East Asia. We find opposite impacts on the seasonal surface PM2.5 concentrations depending on two El Niño types, such that the surface PM2.5 concentrations during the E-type period are higher than the climatological mean value, especially in northern East Asia. The peak increase of as much as 20% occurs in winter and is sustained until the following spring. However, the C-type period shows a decrease in seasonal PM2.5 concentrations in northern East Asia compare to the climatological mean, and the peak decrease of as much as 10% occurs in the following spring. The different of two El Niño types also have dissimilar impacts on surface PM2.5 concentrations in southeastern China.