Title: Prognostic Power of Extreme Rainfall Scaling Formulas Across Space and Time Scales

Abstract

Some studies documenting changes in extreme precipitation use scaling formulas to approximate the large percentiles of the rainfall distribution from average dynamical and thermodynamical variables, called predictors. Here we instead assess the performance of these formulas as approximations to the rain rates in individual events. We evaluate the accuracies of the scaling relationships as functions of spatial and temporal scales by analyzing tropical rainfall in a superparameterized model. Relationships using full vertical profiles of the predictors are more accurate than those using their values at specific vertical levels because they better characterize the specific dynamics of each event. Both types of scaling relationships perform well over a range of length scales from 200 to 2,000 km and time scales from an hour to a week, and their precision is higher in the case of simulations with superparameterization than with parameterized convection. Uncertainties emerging from the local use of the scaling relationships suggest that they may only characterize the intensification of individual extremes for a warming of 4–5 K or larger. Finally, we argue that these formulas can be used to reconstruct the tail of the rainfall distribution directly from its predictors without prior information on P. While scalings have beenmore » used as diagnostic equations conditioned on the occurrence of extreme rainfall, they are actually able to mimic the prognostic behavior of climate model parameterizations on a variety of scales when estimating the intensity, frequency, and spatial patterns of extremes.« less

Authors:

Fildier, Benjamin  ^[1];

• Search DOE PAGES for author "Fildier, Benjamin"
• Search DOE PAGES for ORCID "0000-0002-6058-7769"

Parishani, H.  ^[2];

• Search DOE PAGES for author "Parishani, H."
• Search DOE PAGES for ORCID "0000-0002-4454-3184"

Collins, W. D.  ^[1]

• Search DOE PAGES for author "Collins, W. D."
• Search DOE PAGES for ORCID "0000-0002-4463-9848"

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+ Show Author Affiliations

1. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Univ. of California, Irvine, CA (United States)

Publication Date:

Wed Nov 28 00:00:00 EST 2018

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1563987

Alternate Identifier(s):

OSTI ID: 1544154

Grant/Contract Number:  

AC02-05CH11231; SC0012548

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Advances in Modeling Earth Systems

Additional Journal Information:

Journal Volume: 10; Journal Issue: 12; Journal ID: ISSN 1942-2466

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; extremes; rainfall; superparameterization; convection; scaling