A process‐based framework for quantifying the atmospheric preconditioning of surface‐triggered convection

Tawfik, Ahmed B.; Dirmeyer, Paul A.

doi:10.1002/2013gl057984

Cited by 71 publications

(42 citation statements)

References 48 publications

(56 reference statements)

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“…One challenge in land-atmosphere interaction studies is the strong dependence of the results on the analysis scale [Jones and Brunsell, 2009;Taylor et al, 2013]. Many studies have focused on local-scale interactions [Findell and Eltahir, 2003;Ek and Holtslag, 2004;Santanello et al, 2009;Gentine et al, 2013;Tawfik and Dirmeyer, 2014]. These studies provide strong evidence that atmospheric modification by the land surface can lead to convection.…”

Section: Discussionmentioning

confidence: 99%

Synoptic conditions related to soil moisture‐atmosphere interactions and unorganized convection in Oklahoma

et al. 2015

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Atmospheric modification by anomalously dry or wet soils can both enhance and suppress convective activity. However, the local‐scale and mesoscale feedback governing soil moisture‐precipitation coupling are embedded within the larger synoptic‐scale environment. Despite their importance, synoptic‐scale atmospheric conditions are rarely considered in studies examining soil moisture‐atmosphere interactions. We combine self‐organizing maps of 500 hPa geopotential height, spatial synoptic classification, and Hybrid Single‐Particle Lagrangian Integrated Trajectory model air mass trajectories to determine if the synoptic‐scale environment affects the ability of the land surface to force unorganized convection in Oklahoma. We identify several synoptic patterns that significantly impact the frequency of unorganized convection. Synoptic patterns characterized by midlevel troughs over the Southern Great Plains are less frequently associated with unorganized convective events. These patterns exhibit cool air advection in the midlevel and lower level of the atmosphere and are linked to suppression of convective activity. The synoptic patterns characterized by 500 hPa ridging over the study region are more frequently associated with unorganized convective events. These patterns likely result in increased net radiation, vapor pressure deficit, and more homogenously dry soils. Unorganized convective events that occur during these synoptic conditions initiate preferentially over dry soils. We present evidence that the synoptic‐scale environment can influence whether and how the land surface has an impact on convection.

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Section: Discussionmentioning

confidence: 99%

Synoptic conditions related to soil moisture‐atmosphere interactions and unorganized convection in Oklahoma

et al. 2015

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“…Only HI low is significantly correlated with P under the low regime. Future study may benefit from the inclusion of the heated condensation framework (Tawfik & Dirmeyer, 2014).…”

Section: Mechanisms Associated With Contrasting Sm-p Interactions 22mentioning

confidence: 99%

Does Soil Moisture Affect Warm Season Precipitation Over the Southern Great Plains?

Welty

Zeng

2018

Geophysical Research Letters

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Numerous observational and modeling studies have addressed the impact of soil moisture on subsequent precipitation (primarily its initiation), yet consensus remains elusive. Here we quantify the relationship between soil moisture and precipitation amplification over the U.S. Southern Great Plains. Warm season (June–September) days for the 2002–2011 period (with ~1220 total days) are partitioned into three dynamic regimes based on daily water vapor convergence, among which afternoon precipitation event days are identified based on simple criteria. We find that antecedent soil moisture conditions are negatively correlated with subsequent afternoon precipitation magnitude for low dynamic regimes, but this correlation becomes positive for high dynamic regimes. In contrast, this correlation is markedly reduced in magnitude and becomes insignificant when all regime days are considered. These results are also confirmed by analyzing the precipitation histogram and diurnal cycle. Furthermore, different pathways are provided for precipitation amplification for low and high dynamic regimes.

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“…The HCF was developed by Tawfik and Dirmeyer [2014] and further elaborated upon in Tawfik et al [2015a,b]. The HCF was designed to represent the atmospheric background state with respect to convection using profiles of temperature and specific humidity.…”

Section: New Hcf Convective Triggering Criterionmentioning

confidence: 99%

“…h def has been shown to accurately capture convective triggering and the atmospheric background state with respect to convection over maritime land-sea breeze initiated convection [Tawfik and Dirmeyer, 2014], as well as responding to low-level jet and mesoscale convection systems over the United States Central Plains [Tawfik and Dirmeyer, 2014;Tawfik et al, 2015a]. Therefore, in order to initiate convection the HCF trigger requires the availability of large-scale convective instability allied with sufficient local surface heating.…”

Section: Journal Of Advances In Modeling Earth Systems 101002/2016msmentioning

confidence: 99%

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The heated condensation framework as a convective trigger in the NCEP Climate Forecast System version 2

Bombardi

Tawfik

Manganello

et al. 2016

J Adv Model Earth Syst

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An updated version of the Heated Condensation Framework (HCF) is implemented as a convective triggering criterion into the National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2). The new trigger replaces the original criteria in both the deep (Simplified Arakawa‐Schubert – SAS) and shallow (SAS based) convective schemes. The performance of the original and new triggering criteria is first compared against radiosonde observations. Then, a series of hindcasts are performed to evaluate the influence of the triggering criterion in the CFSv2 representation of summer precipitation, the diurnal cycle of precipitation, and hurricanes that made landfall. The observational analysis shows that the HCF trigger better captures the frequency of convection, where the original SAS trigger initiates convection too often. When implemented in CFSv2, the HCF trigger improves the seasonal forecast of the Indian summer monsoon rainfall, including the representation of the onset dates of the rainy season over India. On the other hand, the HCF trigger increases error in the seasonal forecast of precipitation over the eastern United States. The HCF trigger also improves the representation of the intensity of hurricanes. Moreover, the simulation of hurricanes provides insights on the mechanism whereby the HCF trigger impacts the representation of convection.

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A process‐based framework for quantifying the atmospheric preconditioning of surface‐triggered convection

Cited by 71 publications

References 48 publications

Synoptic conditions related to soil moisture‐atmosphere interactions and unorganized convection in Oklahoma

Synoptic conditions related to soil moisture‐atmosphere interactions and unorganized convection in Oklahoma

Does Soil Moisture Affect Warm Season Precipitation Over the Southern Great Plains?

The heated condensation framework as a convective trigger in the NCEP Climate Forecast System version 2

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