Sensitivity of the Great Plains Severe-Storm Environment to Soil-Moisture Distribution

Lanicci, John M.; Carlson, Toby N.; Warner, Thomas T.

doi:10.1175/1520-0493(1987)115<2660:sotgps>2.0.co;2

Cited by 91 publications

(46 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the early study of Shukla and Mintz (1982), a large number of observational and numerical studies of land-atmosphere interactions have sought to illuminate the relationship between the terrestrial energy budget, and in particular soil moisture and terrestrial evapotranspiration controls on surface fluxes, and precipitation regimes at local, regional and global scales (e.g., Ookoucki et al 1984;Lanicci et al 1987;Pan and Mahrt 1987;Wetzel 1990;Atlas et al 1993;Pielke et al 1998, among many others). Two modeling studies using GCMs (Global Climate Models) are especially relevant for the Indian subcontinent in the context of this work.…”

Section: Introductionmentioning

confidence: 99%

A Numerical Study of the Hydrometeorological Dryline in Northwest India During the Monsoon

Chiao

Barros

2007

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

This objective of this study is to elucidate the processes that govern the space-time persistence of the hydrometeorological dryline in Northwest India. The working hypothesis is that orographic forcing and land-atmosphere interactions via soil moisture and vegetation processes lock the hydrometeorological line to the Aravalli range and the Thar Desert (a.k.a. the Great Indian Desert). For this purpose, simulations of active and break phases of the 2001 monsoon season were conducted using a mesoscale model (MM5). During the active phases of the monsoon, southeasterly depressions from the Bay of Bengal propagate over northern India, maintaining sustained convergence of moist available energy east of the Aravalli range, leading to increased rainfall and cloudiness patterns consistent with deep convective activity. Drier air originating from the Arabian Sea in the Western Indian Ocean is constrained to the west. During monsoon break phases, moisture convergence from the Bay of Bengal to the Northern India Convergence Zone (NICZ) decreases dramatically, weakening regional circulations east of the Aravalli range. This allows ventilation of the central portion of the NICZ through penetration of westerly dry air, leading to reduced rainfall, lower soil wetness, decrease of latent heat fluxes, and finally lower CAPE and humidity in the lower troposphere. Whereas the inland propagation of monsoon depressions from the Bay of Bengal triggers the onset (demise) of active and break periods, the sustainability of either regime requires strong feedbacks between humidity and stability in the lower troposphere and the surface energy balance: negative in the case of monsoon breaks, positive in the case of active periods. This study shows that, albeit relatively modest (<600 m average elevation), the Aravalli provides sufficient lift (upwind) and descend (downwind) to organize the spatial distribution of updrafts westward (active phase) and eastward (break phase) of the topographic divide in such a way that low level updrafts are nearly suppressed over the Thar Desert. Sensitivity experiments with modified soil and vegetation cover show that daytime latent heat fluxes (and evapotranspiration) play an important role in the spatial orgnization of CAPE and in triggering light rainfall processes in the semi-arid regions of northwest India, whereas the occurrence of heavy rainfall to the east of the Aravalli range is controlled by largescale monsoon dynamics.

show abstract

Section: Introductionmentioning

confidence: 99%

A Numerical Study of the Hydrometeorological Dryline in Northwest India During the Monsoon

Chiao

Barros

2007

Journal of the Meteorological Society of Japan

View full text Add to dashboard Cite

show abstract

“…Lanicci et al (1987) showed that variable soil moisture conditions in the southern plains were important for generating differential surface heating and low-level instability through strong surface evaporation. The soil moisture variations played a role in where the lid, or elevated mixed layer, would be removed and, thus, where and when convection would occur.…”

Section: Introductionmentioning

confidence: 99%

Sensitivity of Forecast Rainfall in a Texas Convective System to Soil Moisture and Convective Parameterization

Gallus¹,

Segal²

2000

Wea. Forecasting

View full text Add to dashboard Cite

The impact of soil moisture on the forecast of a small-scale convective system, and sensitivity of results to the convective parameterization used, are investigated through Eta Model simulations (run in an operational-like setting) of a convective system occurring on 27 May 1997 in Texas. The event was influenced by a southwestward-propagating gravity wave from early morning convection in Arkansas that intersected a slowmoving cold front, releasing extreme conditional static instability. Isolated heavy rainfall, over 100 mm, occurred in some regions. A control simulation with 22-km horizontal resolution reasonably simulated the event, even though mesoscale influences such as the gravity wave important to this event are often poorly captured by numerical models. A series of sensitivity tests were performed to examine the impact of soil moisture on the simulations. Two different convective parameterizations were used for the tests. Although domain average precipitation is found to generally vary in a straightforward way with soil moisture, peak precipitation in the regions of intense convection shows more complex behavior. Sensitivity of precipitation amounts to soil moisture differs significantly among runs having different convective parameterizations. For instance, with the Kain-Fritsch convective scheme, relatively dry soil is found to result in stronger convective outflows that converge with stronger ambient flow to greatly enhance the precipitation in the region where heaviest rainfall occurs. With the Betts-Miller-Janjic scheme, drier soil generally results in less precipitation than in the control run, although some enhancement in peak amount does occur within a narrow range of drying. The differences between the peak quantitative precipitation forecasts in the runs is primarily due to the inclusion of a convective downdraft in the Kain-Fritsch parameterization, and its impact on secondary convective development. Additional sensitivity tests find limited impact from prescribed vegetation coverage. A final sensitivity test shows that precipitation amounts are even more strongly affected by the vertical resolution of the data used to initialize the shallow but moist boundary layer than by variations in the soil moisture or vegetation fraction. KeywordsAgronomy, atmospheric temperature, atmospheric turbulence, computer simulation, gravity waves, moisture, soils, vegetation, wave propagation, weather forecasting, convective system, forecast rainfall, soil moisture, rain, convective system, numerical model, sensitivity analysis, soil moisture, weather forecasting, United States ABSTRACTThe impact of soil moisture on the forecast of a small-scale convective system, and sensitivity of results to the convective parameterization used, are investigated through Eta Model simulations (run in an operationallike setting) of a convective system occurring on 27 May 1997 in Texas. The event was influenced by a southwestward-propagating gravity wave from early morning convection in Arkansas that intersected a slowm...

show abstract

“…Soil-moisture plays a central role in controlling the development of mesoscale circulations, via its influence on the surface energy budget (Ookouchi et al, 1984;Lanicci et al, 1987;Jacobson 1999). Soil moisture is usually estimated in global models by using atmospheric variables as forcing data (Mahfouf, 1991).…”

Section: Mesoscale Simulation: Model Setup Initial and Boundary Condmentioning

confidence: 99%

Mesoscale circulations over complex terrain in the Valencia coastal region, Spain – Part 1: Simulation of diurnal circulation regimes

et al. 2007

View full text Add to dashboard Cite

Abstract. We collected ground-based and aircraft vertical profile measurements of meteorological parameters during a 2-week intensive campaign over the Valencia basin, in order to understand how mesoscale circulations develop over complex terrain and affect the atmospheric transport of tracers. A high-resolution version of the RAMS model was run to simulate the campaign and characterize the diurnal patterns of the flow regime: night-time katabatic drainage, morning seabreeze development and its subsequent coupling with mountain up-slopes, and evening flow-veering under larger-scale interactions. An application of this mesoscale model to the transport of CO 2 is given in a companion paper. A careful evaluation of the model performances against diverse meteorological observations is carried out. Despite the complexity of the processes interacting with each other, and the uncertainties on modeled soil moisture boundary conditions and turbulence parameterizations, we show that it is possible to simulate faithfully the contrasted flow regimes during the course of one day, especially the inland progression and organization of the sea breeze. This gives confidence with respect to future applicability of mesoscale models to establish a reliable link between surface sources of tracers and their atmospheric concentration signals over complex terrain.

show abstract

Sensitivity of the Great Plains Severe-Storm Environment to Soil-Moisture Distribution

Cited by 91 publications

References 0 publications

A Numerical Study of the Hydrometeorological Dryline in Northwest India During the Monsoon

A Numerical Study of the Hydrometeorological Dryline in Northwest India During the Monsoon

Sensitivity of Forecast Rainfall in a Texas Convective System to Soil Moisture and Convective Parameterization

Mesoscale circulations over complex terrain in the Valencia coastal region, Spain – Part 1: Simulation of diurnal circulation regimes

Contact Info

Product

Resources

About