TY - JOUR
T1 - The Israel 4 Cloud Seeding Experiment
T2 - Primary Results
AU - Benjamini, Yoav
AU - Givati, Amir
AU - Khain, Pavel
AU - Levi, Yoav
AU - Rosenfeld, Daniel
AU - Shamir, Uri
AU - Siegel, Ayal
AU - Zipori, Assaf
AU - Ziv, Baruch
AU - Steinberg, David M.
N1 - Publisher Copyright:
© 2023 American Meteorological Society.
PY - 2023/3
Y1 - 2023/3
N2 - After 38 years of operational cloud seeding for rain enhancement in northern Israel, the Israel 4 experiment was conducted to reassess its effect on rainfall and provide a basis to evaluate its utility. Operational seeding started after two randomized experiments, the second ending in 1976, found a large and statistically significant effect of cloud seeding on rainfall. Observational studies in later years raised doubts as to the magnitude of the effect, possibly because of chang-ing climatological conditions. A carefully designed randomized experiment was conducted from 2013 to 2020. A unique feature of the design was the use of forecast rainfall on target, rather than rainfall in an unaffected area, as a control variate to attenuate variability. The Israel 4 experiment was stopped a year earlier than planned, because the result was disap-pointing: a 1.8% increase, p value 5 0.4, and 95% confidence interval of (211%, 16%). These results led to a decision by the Israel Water Authority to stop operational seeding.
AB - After 38 years of operational cloud seeding for rain enhancement in northern Israel, the Israel 4 experiment was conducted to reassess its effect on rainfall and provide a basis to evaluate its utility. Operational seeding started after two randomized experiments, the second ending in 1976, found a large and statistically significant effect of cloud seeding on rainfall. Observational studies in later years raised doubts as to the magnitude of the effect, possibly because of chang-ing climatological conditions. A carefully designed randomized experiment was conducted from 2013 to 2020. A unique feature of the design was the use of forecast rainfall on target, rather than rainfall in an unaffected area, as a control variate to attenuate variability. The Israel 4 experiment was stopped a year earlier than planned, because the result was disap-pointing: a 1.8% increase, p value 5 0.4, and 95% confidence interval of (211%, 16%). These results led to a decision by the Israel Water Authority to stop operational seeding.
KW - Cloud seeding
KW - Experimental design
KW - Orographic effects
KW - Weather modification
UR - http://www.scopus.com/inward/record.url?scp=85149995702&partnerID=8YFLogxK
U2 - 10.1175/jamc-d-22-0077.1
DO - 10.1175/jamc-d-22-0077.1
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AN - SCOPUS:85149995702
SN - 1558-8424
VL - 62
SP - 317
EP - 327
JO - Journal of Applied Meteorology and Climatology
JF - Journal of Applied Meteorology and Climatology
IS - 3
ER -