TY - JOUR
T1 - The role of humic-like substances as atmospheric surfactants in the formation of summer-heavy rainfall in downtown Tokyo
AU - Sugo, Toshiki
AU - Okochi, Hiroshi
AU - Uchiyama, Ryunosuke
AU - Yamanokoshi, Eri
AU - Ogata, Hiroko
AU - Katsumi, Naoya
AU - Nakano, Takanori
N1 - Funding Information:
Asahi Group Foundation (grant number: none).
Funding Information:
Nippon Life Insurance Foundation (grant number: none).
Funding Information:
WNI WxBunka Foundation (grant number: none).
Publisher Copyright:
© 2020 The Authors
PY - 2019/11
Y1 - 2019/11
N2 - In order to study the impact of organic aerosols in the formation of UHR (hereafter UHR = urban-induced heavy rain), we analyzed humic-like substances (hereafter HULIS) that serve as major atmospheric surfactants as well as the major inorganic ions in rainwater collected on an event basis at the Nishi-Waseda Campus of Waseda University in Shinjuku, Tokyo. Fulvic and humic acid fractions in HULIS was determined by the DEAE (Diethylaminoethyl cellulose) -UV method. The total wet deposition flux of HULIS in UHR was 33.5 times higher than that found in a normal rainfall and 57.3 times higher than that found in THR (hereafter THR = typhoon heavy rain). The accumulation of HULIS to acidic anions such as NO3− and SO42− in UHR compared to other types of rain indicates that HULIS in UHR accelerated the growth of cloud droplets via reduction of surface tension, which likely led to the rapid development of cumulonimbus clouds.
AB - In order to study the impact of organic aerosols in the formation of UHR (hereafter UHR = urban-induced heavy rain), we analyzed humic-like substances (hereafter HULIS) that serve as major atmospheric surfactants as well as the major inorganic ions in rainwater collected on an event basis at the Nishi-Waseda Campus of Waseda University in Shinjuku, Tokyo. Fulvic and humic acid fractions in HULIS was determined by the DEAE (Diethylaminoethyl cellulose) -UV method. The total wet deposition flux of HULIS in UHR was 33.5 times higher than that found in a normal rainfall and 57.3 times higher than that found in THR (hereafter THR = typhoon heavy rain). The accumulation of HULIS to acidic anions such as NO3− and SO42− in UHR compared to other types of rain indicates that HULIS in UHR accelerated the growth of cloud droplets via reduction of surface tension, which likely led to the rapid development of cumulonimbus clouds.
KW - Cloud droplet growth
KW - Cumulonimbus development
KW - Urban heat island
KW - Urban-induced heavy rain
UR - http://www.scopus.com/inward/record.url?scp=85103119990&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85103119990&partnerID=8YFLogxK
U2 - 10.1016/j.cacint.2020.100022
DO - 10.1016/j.cacint.2020.100022
M3 - Article
AN - SCOPUS:85103119990
SN - 2590-2520
VL - 3
JO - City and Environment Interactions
JF - City and Environment Interactions
M1 - 100022
ER -