TY - CHAP
T1 - A coupled atmosphere-chemistry data assimilation
T2 - Impact of ozone observation on structure of a tropical cyclone
AU - Park, Seon Ki
AU - Lim, Sujeong
AU - Županski, Milija
N1 - Publisher Copyright:
© Springer International Publishing Switzerland 2017.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Ozone (O3) generally shows lower concentration inside the eyewall and higher concentration around the eye in tropical cyclones (TCs). In this study, we identify the impact of O3 observations on TC structure through a coupled atmospherechemistry data assimilation (DA) system. We applied the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and an ensemble-based DA algorithm-the maximum likelihood ensemble filter (MLEF) to a case TC over East Asia, Typhoon Nabi (2005). The ensemble forecast with 32 ensembles shows larger background state uncertainty over the TC. The assimilation of O3 observations, with a 6 h assimilation window, impacts both O3 itself and wind field in the vicinity of TC. Several measures for verification, including the cost function, root mean square (RMS) error with respect to observations and degrees of freedom for signal (DFS), indicate improvement of the analysis fields through the O3 DA. The cost function and RMS error have decreased by 17 and 9%, respectively. The DFS shows large reduction in uncertainty, indicating a strong positive impact of observations in the TC area.
AB - Ozone (O3) generally shows lower concentration inside the eyewall and higher concentration around the eye in tropical cyclones (TCs). In this study, we identify the impact of O3 observations on TC structure through a coupled atmospherechemistry data assimilation (DA) system. We applied the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and an ensemble-based DA algorithm-the maximum likelihood ensemble filter (MLEF) to a case TC over East Asia, Typhoon Nabi (2005). The ensemble forecast with 32 ensembles shows larger background state uncertainty over the TC. The assimilation of O3 observations, with a 6 h assimilation window, impacts both O3 itself and wind field in the vicinity of TC. Several measures for verification, including the cost function, root mean square (RMS) error with respect to observations and degrees of freedom for signal (DFS), indicate improvement of the analysis fields through the O3 DA. The cost function and RMS error have decreased by 17 and 9%, respectively. The DFS shows large reduction in uncertainty, indicating a strong positive impact of observations in the TC area.
UR - http://www.scopus.com/inward/record.url?scp=85029122659&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-43415-5_20
DO - 10.1007/978-3-319-43415-5_20
M3 - Chapter
AN - SCOPUS:85029122659
SN - 9783319434148
SP - 455
EP - 466
BT - Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications (Vol. III)
PB - Springer International Publishing
ER -