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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:01 |
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Conference: Bucharest University Faculty of Physics 2024 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Attribution of the monthly cumulative number of warm spell days
to anthropogenic and natural factors, based on observational data
Authors:
Comaniciu (Dima) Daniela, Sanda Voinea
*
Affiliation:
University of Bucharest, Faculty of Physics
E-mail
danieladima2015@gmail.com
Keywords:
attribution, warm spell days,anthropogenic and natural factors
Abstract:
The warm spell days have a significant impact on the human health, on economy and agriculture, on ecosystems. In a warming world, their frequency is expected to increase. The attribution of warm spell days to specific forcing factors is of significant importance and is usually performed through numerical simulations. However, the accuracy of the attributions through this method is limited by the model imperfections. For example, some recent such extreme events were more pronounced that anticipated by model integrations. Alternatively, in present study we attempt the attribution based on observational data.
Monthly warm spell days persistency is defined here as the total number of days in a month above the 90th percentile, in which only groups of at least 3 consecutive days are counted. Two persistency fields are constructed, for months May and August, for the 1950-2023 period. The dominant modes of the two global fields of warm spell days persistency are identified using the Empirical Orthogonal Functions (EOF) method, with the goal to use their corresponding time components in order to associate them with specific forcing factors, through correlations.
The results have the potential to quantify the contributions of anthropogenic and natural factors to the warm spell days in different regions. As the model have limitations in simulating internal variability, this can not be performed in an optimal way based on numerical simulations.
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