---
_id: '9137'
abstract:
- lang: eng
text: Pools of air cooled by partial rain evaporation span up to several hundreds
of kilometers in nature and typically last less than 1 day, ultimately losing
their identity to the large-scale flow. These fundamentally differ in character
from the radiatively-driven dry pools defining convective aggregation. Advancement
in remote sensing and in computer capabilities has promoted exploration of how
precipitation-induced cold pool processes modify the convective spectrum and life
cycle. This contribution surveys current understanding of such cold pools over
the tropical and subtropical oceans. In shallow convection with low rain rates,
the cold pools moisten, preserving the near-surface equivalent potential temperature
or increasing it if the surface moisture fluxes cannot ventilate beyond the new
surface layer; both conditions indicate downdraft origin air from within the boundary
layer. When rain rates exceed ∼ 2 mm h−1, convective-scale downdrafts can bring
down drier air of lower equivalent potential temperature from above the boundary
layer. The resulting density currents facilitate the lifting of locally thermodynamically
favorable air and can impose an arc-shaped mesoscale cloud organization. This
organization allows clouds capable of reaching 4–5 km within otherwise dry environments.
These are more commonly observed in the northern hemisphere trade wind regime,
where the flow to the intertropical convergence zone is unimpeded by the equator.
Their near-surface air properties share much with those shown from cold pools
sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing
the mesoscale organization when the atmosphere is moist in the lower free troposphere
and dry above, suggesting an optimal range of water vapor paths. Outstanding questions
on the relationship between cold pools, their accompanying moisture distribution
and cloud cover are detailed further. Near-surface water vapor rings are documented
in one model inside but near the cold pool edge; these are not consistent with
observations, but do improve with smaller horizontal grid spacings.
article_processing_charge: No
article_type: original
author:
- first_name: Paquita
full_name: Zuidema, Paquita
last_name: Zuidema
- first_name: Giuseppe
full_name: Torri, Giuseppe
last_name: Torri
- 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: Arunchandra
full_name: Chandra, Arunchandra
last_name: Chandra
citation:
ama: Zuidema P, Torri G, Muller CJ, Chandra A. A survey of precipitation-induced
atmospheric cold pools over oceans and their interactions with the larger-scale
environment. Surveys in Geophysics. 2017;38(6):1283-1305. doi:10.1007/s10712-017-9447-x
apa: Zuidema, P., Torri, G., Muller, C. J., & Chandra, A. (2017). A survey of
precipitation-induced atmospheric cold pools over oceans and their interactions
with the larger-scale environment. Surveys in Geophysics. Springer Nature.
https://doi.org/10.1007/s10712-017-9447-x
chicago: Zuidema, Paquita, Giuseppe Torri, Caroline J Muller, and Arunchandra Chandra.
“A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their
Interactions with the Larger-Scale Environment.” Surveys in Geophysics.
Springer Nature, 2017. https://doi.org/10.1007/s10712-017-9447-x.
ieee: P. Zuidema, G. Torri, C. J. Muller, and A. Chandra, “A survey of precipitation-induced
atmospheric cold pools over oceans and their interactions with the larger-scale
environment,” Surveys in Geophysics, vol. 38, no. 6. Springer Nature, pp.
1283–1305, 2017.
ista: Zuidema P, Torri G, Muller CJ, Chandra A. 2017. A survey of precipitation-induced
atmospheric cold pools over oceans and their interactions with the larger-scale
environment. Surveys in Geophysics. 38(6), 1283–1305.
mla: Zuidema, Paquita, et al. “A Survey of Precipitation-Induced Atmospheric Cold
Pools over Oceans and Their Interactions with the Larger-Scale Environment.” Surveys
in Geophysics, vol. 38, no. 6, Springer Nature, 2017, pp. 1283–305, doi:10.1007/s10712-017-9447-x.
short: P. Zuidema, G. Torri, C.J. Muller, A. Chandra, Surveys in Geophysics 38 (2017)
1283–1305.
date_created: 2021-02-15T14:20:07Z
date_published: 2017-11-14T00:00:00Z
date_updated: 2022-01-24T12:41:45Z
day: '14'
doi: 10.1007/s10712-017-9447-x
extern: '1'
intvolume: ' 38'
issue: '6'
keyword:
- Geochemistry and Petrology
- Geophysics
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1007/s10712-017-9447-x
month: '11'
oa: 1
oa_version: Published Version
page: 1283-1305
publication: Surveys in Geophysics
publication_identifier:
issn:
- 0169-3298
- 1573-0956
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
status: public
title: A survey of precipitation-induced atmospheric cold pools over oceans and their
interactions with the larger-scale environment
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 38
year: '2017'
...
---
_id: '9138'
abstract:
- lang: eng
text: Convective self-aggregation, the spontaneous organization of initially scattered
convection into isolated convective clusters despite spatially homogeneous boundary
conditions and forcing, was first recognized and studied in idealized numerical
simulations. While there is a rich history of observational work on convective
clustering and organization, there have been only a few studies that have analyzed
observations to look specifically for processes related to self-aggregation in
models. Here we review observational work in both of these categories and motivate
the need for more of this work. We acknowledge that self-aggregation may appear
to be far-removed from observed convective organization in terms of time scales,
initial conditions, initiation processes, and mean state extremes, but we argue
that these differences vary greatly across the diverse range of model simulations
in the literature and that these comparisons are already offering important insights
into real tropical phenomena. Some preliminary new findings are presented, including
results showing that a self-aggregation simulation with square geometry has too
broad distribution of humidity and is too dry in the driest regions when compared
with radiosonde records from Nauru, while an elongated channel simulation has
realistic representations of atmospheric humidity and its variability. We discuss
recent work increasing our understanding of how organized convection and climate
change may interact, and how model discrepancies related to this question are
prompting interest in observational comparisons. We also propose possible future
directions for observational work related to convective aggregation, including
novel satellite approaches and a ground-based observational network.
article_processing_charge: No
article_type: original
author:
- first_name: Christopher E.
full_name: Holloway, Christopher E.
last_name: Holloway
- first_name: Allison A.
full_name: Wing, Allison A.
last_name: Wing
- first_name: Sandrine
full_name: Bony, Sandrine
last_name: Bony
- 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: Hirohiko
full_name: Masunaga, Hirohiko
last_name: Masunaga
- first_name: Tristan S.
full_name: L’Ecuyer, Tristan S.
last_name: L’Ecuyer
- first_name: David D.
full_name: Turner, David D.
last_name: Turner
- first_name: Paquita
full_name: Zuidema, Paquita
last_name: Zuidema
citation:
ama: Holloway CE, Wing AA, Bony S, et al. Observing convective aggregation. Surveys
in Geophysics. 2017;38(6):1199-1236. doi:10.1007/s10712-017-9419-1
apa: Holloway, C. E., Wing, A. A., Bony, S., Muller, C. J., Masunaga, H., L’Ecuyer,
T. S., … Zuidema, P. (2017). Observing convective aggregation. Surveys in Geophysics.
Springer Nature. https://doi.org/10.1007/s10712-017-9419-1
chicago: Holloway, Christopher E., Allison A. Wing, Sandrine Bony, Caroline J Muller,
Hirohiko Masunaga, Tristan S. L’Ecuyer, David D. Turner, and Paquita Zuidema.
“Observing Convective Aggregation.” Surveys in Geophysics. Springer Nature,
2017. https://doi.org/10.1007/s10712-017-9419-1.
ieee: C. E. Holloway et al., “Observing convective aggregation,” Surveys
in Geophysics, vol. 38, no. 6. Springer Nature, pp. 1199–1236, 2017.
ista: Holloway CE, Wing AA, Bony S, Muller CJ, Masunaga H, L’Ecuyer TS, Turner DD,
Zuidema P. 2017. Observing convective aggregation. Surveys in Geophysics. 38(6),
1199–1236.
mla: Holloway, Christopher E., et al. “Observing Convective Aggregation.” Surveys
in Geophysics, vol. 38, no. 6, Springer Nature, 2017, pp. 1199–236, doi:10.1007/s10712-017-9419-1.
short: C.E. Holloway, A.A. Wing, S. Bony, C.J. Muller, H. Masunaga, T.S. L’Ecuyer,
D.D. Turner, P. Zuidema, Surveys in Geophysics 38 (2017) 1199–1236.
date_created: 2021-02-15T14:20:38Z
date_published: 2017-11-01T00:00:00Z
date_updated: 2022-01-24T12:43:13Z
day: '01'
doi: 10.1007/s10712-017-9419-1
extern: '1'
intvolume: ' 38'
issue: '6'
keyword:
- Geochemistry and Petrology
- Geophysics
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1007/s10712-017-9419-1
month: '11'
oa: 1
oa_version: Published Version
page: 1199-1236
publication: Surveys in Geophysics
publication_identifier:
issn:
- 0169-3298
- 1573-0956
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
status: public
title: Observing convective aggregation
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 38
year: '2017'
...
---
_id: '9139'
abstract:
- lang: eng
text: Organized convection in the tropics occurs across a range of spatial and temporal
scales and strongly influences cloud cover and humidity. One mode of organization
found is “self-aggregation,” in which moist convection spontaneously organizes
into one or several isolated clusters despite spatially homogeneous boundary conditions
and forcing. Self-aggregation is driven by interactions between clouds, moisture,
radiation, surface fluxes, and circulation, and occurs in a wide variety of idealized
simulations of radiative–convective equilibrium. Here we provide a review of convective
self-aggregation in numerical simulations, including its character, causes, and
effects. We describe the evolution of self-aggregation including its time and
length scales and the physical mechanisms leading to its triggering and maintenance,
and we also discuss possible links to climate and climate change.
article_processing_charge: No
article_type: original
author:
- first_name: Allison A.
full_name: Wing, Allison A.
last_name: Wing
- first_name: Kerry
full_name: Emanuel, Kerry
last_name: Emanuel
- first_name: Christopher E.
full_name: Holloway, Christopher E.
last_name: Holloway
- first_name: Caroline J
full_name: Muller, Caroline J
id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
last_name: Muller
orcid: 0000-0001-5836-5350
citation:
ama: 'Wing AA, Emanuel K, Holloway CE, Muller CJ. Convective self-aggregation in
numerical simulations: A review. Surveys in Geophysics. 2017;38(6):1173-1197.
doi:10.1007/s10712-017-9408-4'
apa: 'Wing, A. A., Emanuel, K., Holloway, C. E., & Muller, C. J. (2017). Convective
self-aggregation in numerical simulations: A review. Surveys in Geophysics.
Springer Nature. https://doi.org/10.1007/s10712-017-9408-4'
chicago: 'Wing, Allison A., Kerry Emanuel, Christopher E. Holloway, and Caroline
J Muller. “Convective Self-Aggregation in Numerical Simulations: A Review.” Surveys
in Geophysics. Springer Nature, 2017. https://doi.org/10.1007/s10712-017-9408-4.'
ieee: 'A. A. Wing, K. Emanuel, C. E. Holloway, and C. J. Muller, “Convective self-aggregation
in numerical simulations: A review,” Surveys in Geophysics, vol. 38, no.
6. Springer Nature, pp. 1173–1197, 2017.'
ista: 'Wing AA, Emanuel K, Holloway CE, Muller CJ. 2017. Convective self-aggregation
in numerical simulations: A review. Surveys in Geophysics. 38(6), 1173–1197.'
mla: 'Wing, Allison A., et al. “Convective Self-Aggregation in Numerical Simulations:
A Review.” Surveys in Geophysics, vol. 38, no. 6, Springer Nature, 2017,
pp. 1173–97, doi:10.1007/s10712-017-9408-4.'
short: A.A. Wing, K. Emanuel, C.E. Holloway, C.J. Muller, Surveys in Geophysics
38 (2017) 1173–1197.
date_created: 2021-02-15T14:20:56Z
date_published: 2017-11-01T00:00:00Z
date_updated: 2022-01-24T12:42:36Z
day: '01'
doi: 10.1007/s10712-017-9408-4
extern: '1'
intvolume: ' 38'
issue: '6'
keyword:
- Geochemistry and Petrology
- Geophysics
language:
- iso: eng
month: '11'
oa_version: None
page: 1173-1197
publication: Surveys in Geophysics
publication_identifier:
issn:
- 0169-3298
- 1573-0956
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
status: public
title: 'Convective self-aggregation in numerical simulations: A review'
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 38
year: '2017'
...