---
_id: '14453'
abstract:
- lang: eng
text: Squall lines are substantially influenced by the interaction of low-level
shear with cold pools associated with convective downdrafts. Beyond an optimal
shear amplitude, squall lines tend to orient themselves at an angle with respect
to the low-level shear. While the mechanisms behind squall line orientation seem
to be increasingly well understood, uncertainties remain on the implications of
this orientation. Roca and Fiolleau (2020, https://doi.org/10.1038/s43247-020-00015-4)
show that long lived mesoscale convective systems, including squall lines, are
disproportionately involved in rainfall extremes in the tropics. This article
investigates the influence of the interaction between low-level shear and squall
line outflow on squall line generated precipitation extrema in the tropics. Using
a cloud resolving model, simulated squall lines in radiative convective equilibrium
amid a shear-dominated regime (super optimal), a balanced regime (optimal), and
an outflow dominated regime (suboptimal). Our results show that precipitation
extremes in squall lines are 40% more intense in the case of optimal shear and
remain 30% superior in the superoptimal regime relative to a disorganized case.
With a theoretical scaling of precipitation extremes (C. Muller & Takayabu, 2020,
https://doi.org/10.1088/1748-9326/ab7130), we show that the condensation rates
control the amplification of precipitation extremes in tropical squall lines,
mainly due to its change in vertical mass flux (dynamic component). The reduction
of dilution by entrainment explains half of this change, consistent with Mulholland
et al. (2021, https://doi.org/10.1175/jas-d-20-0299.1). The other half is explained
by increased cloud-base velocity intensity in optimal and superoptimal squall
lines.
acknowledgement: The authors gratefully acknowledge funding from the European Research
Council under the European Union's Horizon 2020 research and innovation program
(Project CLUSTER, Grant Agreement No. 805041). This work is also supported by a
PhD fellowship funded by the Ecole Normale Supérieure de Paris-Saclay. Authors are
also grateful to Benjamin Filider, who was of great help and support in the development
of ideas. Eventually, we would like to thank Martin Singh, John M. Peters and an
anonymous reviewer for their valuable comments and suggestions, which greatly improved
the quality of the manuscript.
article_number: e2022MS003477
article_processing_charge: Yes
article_type: original
author:
- first_name: Sophie
full_name: Abramian, Sophie
last_name: Abramian
- first_name: Caroline J
full_name: Muller, Caroline J
id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
last_name: Muller
orcid: 0000-0001-5836-5350
- first_name: Camille
full_name: Risi, Camille
last_name: Risi
citation:
ama: Abramian S, Muller CJ, Risi C. Extreme precipitation in tropical squall lines.
Journal of Advances in Modeling Earth Systems. 2023;15(10). doi:10.1029/2022MS003477
apa: Abramian, S., Muller, C. J., & Risi, C. (2023). Extreme precipitation in
tropical squall lines. Journal of Advances in Modeling Earth Systems. Wiley.
https://doi.org/10.1029/2022MS003477
chicago: Abramian, Sophie, Caroline J Muller, and Camille Risi. “Extreme Precipitation
in Tropical Squall Lines.” Journal of Advances in Modeling Earth Systems.
Wiley, 2023. https://doi.org/10.1029/2022MS003477.
ieee: S. Abramian, C. J. Muller, and C. Risi, “Extreme precipitation in tropical
squall lines,” Journal of Advances in Modeling Earth Systems, vol. 15,
no. 10. Wiley, 2023.
ista: Abramian S, Muller CJ, Risi C. 2023. Extreme precipitation in tropical squall
lines. Journal of Advances in Modeling Earth Systems. 15(10), e2022MS003477.
mla: Abramian, Sophie, et al. “Extreme Precipitation in Tropical Squall Lines.”
Journal of Advances in Modeling Earth Systems, vol. 15, no. 10, e2022MS003477,
Wiley, 2023, doi:10.1029/2022MS003477.
short: S. Abramian, C.J. Muller, C. Risi, Journal of Advances in Modeling Earth
Systems 15 (2023).
date_created: 2023-10-29T23:01:15Z
date_published: 2023-10-01T00:00:00Z
date_updated: 2023-12-13T13:06:40Z
day: '01'
ddc:
- '550'
department:
- _id: CaMu
doi: 10.1029/2022MS003477
ec_funded: 1
external_id:
isi:
- '001084933600001'
file:
- access_level: open_access
checksum: 43e6a1a35b663843c7d3f8d0caaca1a5
content_type: application/pdf
creator: dernst
date_created: 2023-10-30T13:31:42Z
date_updated: 2023-10-30T13:31:42Z
file_id: '14470'
file_name: 2023_JAMES_Abramian.pdf
file_size: 1975210
relation: main_file
success: 1
file_date_updated: 2023-10-30T13:31:42Z
has_accepted_license: '1'
intvolume: ' 15'
isi: 1
issue: '10'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
project:
- _id: 629205d8-2b32-11ec-9570-e1356ff73576
call_identifier: H2020
grant_number: '805041'
name: organization of CLoUdS, and implications of Tropical cyclones and for the
Energetics of the tropics, in current and waRming climate
publication: Journal of Advances in Modeling Earth Systems
publication_identifier:
eissn:
- 1942-2466
publication_status: published
publisher: Wiley
quality_controlled: '1'
scopus_import: '1'
status: public
title: Extreme precipitation in tropical squall lines
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15
year: '2023'
...
---
_id: '14564'
abstract:
- lang: eng
text: Cumulus parameterization (CP) in state‐of‐the‐art global climate models is
based on the quasi‐equilibrium assumption (QEA), which views convection as the
action of an ensemble of cumulus clouds, in a state of equilibrium with respect
to a slowly varying atmospheric state. This view is not compatible with the organization
and dynamical interactions across multiple scales of cloud systems in the tropics
and progress in this research area was slow over decades despite the widely recognized
major shortcomings. Novel ideas on how to represent key physical processes of
moist convection‐large‐scale interaction to overcome the QEA have surged recently.
The stochastic multicloud model (SMCM) CP in particular mimics the dynamical interactions
of multiple cloud types that characterize organized tropical convection. Here,
the SMCM is used to modify the Zhang‐McFarlane (ZM) CP by changing the way in
which the bulk mass flux and bulk entrainment and detrainment rates are calculated.
This is done by introducing a stochastic ensemble of plumes characterized by randomly
varying detrainment level distributions based on the cloud area fraction of the
SMCM. The SMCM is here extended to include shallow cumulus clouds resulting in
a unified shallow‐deep CP. The new stochastic multicloud plume CP is validated
against the control ZM scheme in the context of the single column Community Climate
Model of the National Center for Atmospheric Research using data from both tropical
ocean and midlatitude land convection. Some key features of the SMCM CP such as
it capability to represent the tri‐modal nature of organized convection are emphasized.
acknowledgement: The research of B.K. is supported in part by a Discovery Grant from
the Natural Sciences and Engineering Research Council of Canada (RGPIN-04246-2020).
This research was conducted during the visits of P.M. Krishna to the Center for
Prototype Climate Models at NYU Abu Dhabi and University of Victoria from November
2018 to June 2019 and July 2019 and October 2019, respectively. The authors are
very grateful to the three anonymous reviewers who provided very thoughtful and
constructive comments during the review process that helped greatly improve and
shape the final version of the manuscript.
article_number: e2022MS003391
article_processing_charge: Yes
article_type: original
author:
- first_name: B.
full_name: Khouider, B.
last_name: Khouider
- first_name: BIDYUT B
full_name: GOSWAMI, BIDYUT B
id: 3a4ac09c-6d61-11ec-bf66-884cde66b64b
last_name: GOSWAMI
orcid: 0000-0001-8602-3083
- first_name: R.
full_name: Phani, R.
last_name: Phani
- first_name: A. J.
full_name: Majda, A. J.
last_name: Majda
citation:
ama: Khouider B, GOSWAMI BB, Phani R, Majda AJ. A shallow‐deep unified stochastic
mass flux cumulus parameterization in the single column community climate model.
Journal of Advances in Modeling Earth Systems. 2023;15(11). doi:10.1029/2022ms003391
apa: Khouider, B., GOSWAMI, B. B., Phani, R., & Majda, A. J. (2023). A shallow‐deep
unified stochastic mass flux cumulus parameterization in the single column community
climate model. Journal of Advances in Modeling Earth Systems. American
Geophysical Union. https://doi.org/10.1029/2022ms003391
chicago: Khouider, B., BIDYUT B GOSWAMI, R. Phani, and A. J. Majda. “A Shallow‐deep
Unified Stochastic Mass Flux Cumulus Parameterization in the Single Column Community
Climate Model.” Journal of Advances in Modeling Earth Systems. American
Geophysical Union, 2023. https://doi.org/10.1029/2022ms003391.
ieee: B. Khouider, B. B. GOSWAMI, R. Phani, and A. J. Majda, “A shallow‐deep unified
stochastic mass flux cumulus parameterization in the single column community climate
model,” Journal of Advances in Modeling Earth Systems, vol. 15, no. 11.
American Geophysical Union, 2023.
ista: Khouider B, GOSWAMI BB, Phani R, Majda AJ. 2023. A shallow‐deep unified stochastic
mass flux cumulus parameterization in the single column community climate model.
Journal of Advances in Modeling Earth Systems. 15(11), e2022MS003391.
mla: Khouider, B., et al. “A Shallow‐deep Unified Stochastic Mass Flux Cumulus Parameterization
in the Single Column Community Climate Model.” Journal of Advances in Modeling
Earth Systems, vol. 15, no. 11, e2022MS003391, American Geophysical Union,
2023, doi:10.1029/2022ms003391.
short: B. Khouider, B.B. GOSWAMI, R. Phani, A.J. Majda, Journal of Advances in Modeling
Earth Systems 15 (2023).
date_created: 2023-11-20T09:18:21Z
date_published: 2023-11-01T00:00:00Z
date_updated: 2023-11-28T12:04:42Z
day: '01'
ddc:
- '550'
department:
- _id: CaMu
doi: 10.1029/2022ms003391
file:
- access_level: open_access
checksum: e30329dd985559de0ddc7021ca7382b4
content_type: application/pdf
creator: dernst
date_created: 2023-11-20T11:29:16Z
date_updated: 2023-11-20T11:29:16Z
file_id: '14582'
file_name: 2023_JAMES_Khoulder.pdf
file_size: 6435697
relation: main_file
success: 1
file_date_updated: 2023-11-20T11:29:16Z
has_accepted_license: '1'
intvolume: ' 15'
issue: '11'
keyword:
- General Earth and Planetary Sciences
- Environmental Chemistry
- Global and Planetary Change
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc/4.0/
month: '11'
oa: 1
oa_version: Published Version
publication: Journal of Advances in Modeling Earth Systems
publication_identifier:
eissn:
- 1942-2466
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
scopus_import: '1'
status: public
title: A shallow‐deep unified stochastic mass flux cumulus parameterization in the
single column community climate model
tmp:
image: /images/cc_by_nc.png
legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode
name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
short: CC BY-NC (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15
year: '2023'
...
---
_id: '14654'
abstract:
- lang: eng
text: Two assumptions commonly applied in convection schemes—the diagnostic and
quasi-equilibrium assumptions—imply that convective activity (e.g., convective
precipitation) is controlled only by the large-scale (macrostate) environment
at the time. In contrast, numerical experiments indicate a “memory” or dependence
of convection also on its own previous activity whereby subgrid-scale (microstate)
structures boost but are also boosted by convection. In this study we investigated
this memory by comparing single-column model behavior in two idealized tests previously
executed by a cloud-resolving model (CRM). Conventional convection schemes that
employ the diagnostic assumption fail to reproduce the CRM behavior. The memory-capable
org and Laboratoire de Météorologie Dynamique Zoom cold pool schemes partially
capture the behavior, but fail to fully exhibit the strong reinforcing feedbacks
implied by the CRM. Analysis of this failure suggests that it is because the CRM
supports a linear (or superlinear) dependence of the subgrid structure growth
rate on the precipitation rate, while the org scheme assumes a sublinear dependence.
Among varying versions of the org scheme, the growth rate of the org variable
representing subgrid structure is strongly associated with memory strength. These
results demonstrate the importance of parameterizing convective memory, and the
ability of idealized tests to reveal shortcomings of convection schemes and constrain
model structural assumptions.
acknowledgement: YLH is supported by funding from the European Union's Horizon 2020
research and innovation programme under the Marie Skłodowska-Curie Grant Agreement
No. 101034413. CJM gratefully acknowledges funding from the European Research Council
under the European Union's Horizon 2020 research and innovation program (Project
CLUSTER, Grant Agreement No. 805041). YLH and SCS were supported by the Australian
Research Council (FL150100035). The authors thank Brian Mapes, David Fuchs and Siwon
Song for stimulating and helpful discussions. MC warmly thanks the LMD team in Paris
for their assistance with the LMDZ model. We thank the two anonymous reviewers for
their constructive comments that greatly improved this manuscript.
article_number: e2023MS003726
article_processing_charge: Yes
article_type: original
author:
- first_name: Yi-Ling
full_name: Hwong, Yi-Ling
id: 1217aa61-4dd1-11ec-9ac3-f2ba3f17ee22
last_name: Hwong
orcid: 0000-0001-9281-3479
- first_name: M.
full_name: Colin, M.
last_name: Colin
- first_name: Philipp
full_name: Aglas, Philipp
id: 02eace56-97fc-11ee-b81a-f0939ca85a77
last_name: Aglas
- first_name: Caroline J
full_name: Muller, Caroline J
id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
last_name: Muller
orcid: 0000-0001-5836-5350
- first_name: S. C.
full_name: Sherwood, S. C.
last_name: Sherwood
citation:
ama: Hwong Y-L, Colin M, Aglas P, Muller CJ, Sherwood SC. Assessing memory in convection
schemes using idealized tests. Journal of Advances in Modeling Earth Systems.
2023;15(12). doi:10.1029/2023MS003726
apa: Hwong, Y.-L., Colin, M., Aglas, P., Muller, C. J., & Sherwood, S. C. (2023).
Assessing memory in convection schemes using idealized tests. Journal of Advances
in Modeling Earth Systems. Wiley. https://doi.org/10.1029/2023MS003726
chicago: Hwong, Yi-Ling, M. Colin, Philipp Aglas, Caroline J Muller, and S. C. Sherwood.
“Assessing Memory in Convection Schemes Using Idealized Tests.” Journal of
Advances in Modeling Earth Systems. Wiley, 2023. https://doi.org/10.1029/2023MS003726.
ieee: Y.-L. Hwong, M. Colin, P. Aglas, C. J. Muller, and S. C. Sherwood, “Assessing
memory in convection schemes using idealized tests,” Journal of Advances in
Modeling Earth Systems, vol. 15, no. 12. Wiley, 2023.
ista: Hwong Y-L, Colin M, Aglas P, Muller CJ, Sherwood SC. 2023. Assessing memory
in convection schemes using idealized tests. Journal of Advances in Modeling Earth
Systems. 15(12), e2023MS003726.
mla: Hwong, Yi-Ling, et al. “Assessing Memory in Convection Schemes Using Idealized
Tests.” Journal of Advances in Modeling Earth Systems, vol. 15, no. 12,
e2023MS003726, Wiley, 2023, doi:10.1029/2023MS003726.
short: Y.-L. Hwong, M. Colin, P. Aglas, C.J. Muller, S.C. Sherwood, Journal of Advances
in Modeling Earth Systems 15 (2023).
date_created: 2023-12-10T23:00:57Z
date_published: 2023-12-01T00:00:00Z
date_updated: 2024-02-27T07:26:30Z
day: '01'
ddc:
- '550'
department:
- _id: CaMu
doi: 10.1029/2023MS003726
ec_funded: 1
file:
- access_level: open_access
checksum: 4d060b293da3d203de8769e398edf711
content_type: application/pdf
creator: dernst
date_created: 2023-12-11T08:08:44Z
date_updated: 2023-12-11T08:08:44Z
file_id: '14670'
file_name: 2023_JAMES_Hwong.pdf
file_size: 2783677
relation: main_file
success: 1
file_date_updated: 2023-12-11T08:08:44Z
has_accepted_license: '1'
intvolume: ' 15'
issue: '12'
language:
- iso: eng
license: https://creativecommons.org/licenses/by-nc-nd/4.0/
month: '12'
oa: 1
oa_version: Published Version
project:
- _id: 629205d8-2b32-11ec-9570-e1356ff73576
call_identifier: H2020
grant_number: '805041'
name: organization of CLoUdS, and implications of Tropical cyclones and for the
Energetics of the tropics, in current and waRming climate
publication: Journal of Advances in Modeling Earth Systems
publication_identifier:
eissn:
- 1942-2466
publication_status: published
publisher: Wiley
quality_controlled: '1'
related_material:
record:
- id: '14991'
relation: research_data
status: public
scopus_import: '1'
status: public
title: Assessing memory in convection schemes using idealized tests
tmp:
image: /images/cc_by_nc_nd.png
legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
(CC BY-NC-ND 4.0)
short: CC BY-NC-ND (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 15
year: '2023'
...