TY - JOUR
T1 - Classification of aerosol-cloud interaction regimes over Tokyo
AU - Misumi, Ryohei
AU - Uji, Yasushi
AU - Miura, Kazuhiko
AU - Mori, Tatsuhiro
AU - Tobo, Yutaka
AU - Iwamoto, Yoko
N1 - Funding Information:
The authors sincerely thank Mr. Asato Maeda and Ms. Masami Yokoyama, former graduate students at the Tokyo University of Science, for their support with observations and analysis of CCN data. The XRAIN data used in this study were provided by the Ministry of Land, Infrastructure, Transport and Tourism through the Data Integration and Analysis System (DIAS). The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (https://www.ready.noaa.gov) used in this study. This work was supported by JSPS KAKENHI (Grant Number JP21H01163).
Funding Information:
The authors sincerely thank Mr. Asato Maeda and Ms. Masami Yokoyama, former graduate students at the Tokyo University of Science , for their support with observations and analysis of CCN data. The XRAIN data used in this study were provided by the Ministry of Land, Infrastructure, Transport and Tourism through the Data Integration and Analysis System (DIAS) . The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website ( https://www.ready.noaa.gov ) used in this study. This work was supported by JSPS KAKENHI (Grant Number JP21H01163 ).
Publisher Copyright:
© 2022 The Authors
PY - 2022/7
Y1 - 2022/7
N2 - Previous studies on the aerosol indirect effect have demonstrated that there are three regimes (aerosol-limited, updraft-limited, and transitional regimes). However, this classification of regimes has not been widely used in field observations as it requires measurements of updraft or supersaturation near the cloud base (Smax), which are not easy to perform. In this study, we attempted to classify the regimes using the effective supersaturation (Seff) which is relatively easy to estimate by matching cloud droplet number concentration (Nc) and supersaturation spectra of cloud condensation nuclei. Parcel model simulations were performed to examine the suitability of Seff as a proxy for Smax. Further, 35 low-level cloud cases observed around 458 m over Tokyo were classified into three regimes. In the aerosol-limited regime, Nc increased more rapidly with an increment of aerosols than in the other two regimes, indicating that the regime classification using Seff was sufficiently robust. The aerosol-limited regime in Tokyo appeared frequently when northerly winds prevailed, indicating the impact of local pollution sources around Tokyo on the aerosol cloud interaction. The results imply that anthropogenic aerosol emissions affect the climate of Tokyo.
AB - Previous studies on the aerosol indirect effect have demonstrated that there are three regimes (aerosol-limited, updraft-limited, and transitional regimes). However, this classification of regimes has not been widely used in field observations as it requires measurements of updraft or supersaturation near the cloud base (Smax), which are not easy to perform. In this study, we attempted to classify the regimes using the effective supersaturation (Seff) which is relatively easy to estimate by matching cloud droplet number concentration (Nc) and supersaturation spectra of cloud condensation nuclei. Parcel model simulations were performed to examine the suitability of Seff as a proxy for Smax. Further, 35 low-level cloud cases observed around 458 m over Tokyo were classified into three regimes. In the aerosol-limited regime, Nc increased more rapidly with an increment of aerosols than in the other two regimes, indicating that the regime classification using Seff was sufficiently robust. The aerosol-limited regime in Tokyo appeared frequently when northerly winds prevailed, indicating the impact of local pollution sources around Tokyo on the aerosol cloud interaction. The results imply that anthropogenic aerosol emissions affect the climate of Tokyo.
KW - Aerosol-indirect effect
KW - Aerosol-limited regime
KW - Cloud droplet
KW - Tokyo Skytree
UR - http://www.scopus.com/inward/record.url?scp=85126950787&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85126950787&partnerID=8YFLogxK
U2 - 10.1016/j.atmosres.2022.106150
DO - 10.1016/j.atmosres.2022.106150
M3 - Article
AN - SCOPUS:85126950787
SN - 0169-8095
VL - 272
JO - Journal de Recherches Atmospheriques
JF - Journal de Recherches Atmospheriques
M1 - 106150
ER -
