Observations on Disks with Tropical Lagrangian Boundary

2021 ◽  
pp. 603-607
Author(s):  
Jeff Hicks
Keyword(s):  
Lagrangian Boundary

scholarly journals Impact of environmental moisture on tropical cyclone intensification

2015 ◽  
Vol 15 (11) ◽  
pp. 16111-16139 ◽  
Author(s):  
L. Wu ◽  
H. Su ◽  
R. G. Fovell ◽  
T. J. Dunkerton ◽  
Z. Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Tropical Cyclone ◽  
Inner Core ◽  
Wrf Model ◽  
Weather Research And Forecasting ◽  
Convective Activity ◽  
Dry Air ◽  
Moving Storm ◽  
Lagrangian Boundary ◽  
Moisture Increase

Abstract. The impacts of environmental moisture on the intensification of a tropical cyclone (TC) are investigated in the Weather Research and Forecasting (WRF) model, with a focus on the azimuthal asymmetry of the moisture impacts. A series of sensitivity experiments with varying moisture perturbations in the environment are conducted and the Marsupial Paradigm framework is employed to understand the different moisture impacts. We find that modification of environmental moisture has insignificant impacts on the storm in this case unless it leads to convective activity in the environment, which deforms the quasi-Lagrangian boundary of the storm. By facilitating convection and precipitation outside the storm, enhanced environmental moisture ahead of the northwestward-moving storm induces a dry air intrusion to the inner core and limits TC intensification. However, increased moisture in the rear quadrants favors intensification by providing more moisture to the inner core and promoting storm symmetry, with primary contributions coming from moisture increase in the boundary layer. The different impacts of environmental moisture on TC intensification are governed by the relative locations of moisture perturbations and their interactions with the storm Lagrangian structure.

scholarly journals Impact of environmental moisture on tropical cyclone intensification

2015 ◽  
Vol 15 (24) ◽  
pp. 14041-14053 ◽  
Author(s):  
L. Wu ◽  
H. Su ◽  
R. G. Fovell ◽  
T. J. Dunkerton ◽  
Z. Wang ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Moisture Transport ◽  
Inner Core ◽  
Wrf Model ◽  
Weather Research And Forecasting ◽  
Convective Activity ◽  
Dry Air ◽  
Moving Storm ◽  
Lagrangian Boundary ◽  
Moisture Increase

Abstract. The impacts of environmental moisture on the intensification of a tropical cyclone (TC) are investigated in the Weather Research and Forecasting (WRF) model, with a focus on the azimuthal asymmetry of the moisture impacts relative to the storm path. A series of sensitivity experiments with varying moisture perturbations in the environment are conducted and the Marsupial Paradigm framework is employed to understand the different moisture impacts. We find that modification of environmental moisture has insignificant impacts on the storm in this case unless it leads to convective activity that deforms the quasi-Lagrangian boundary of the storm and changes the moisture transport into the storm. By facilitating convection and precipitation outside the storm, enhanced environmental moisture ahead of the northwestward-moving storm induces a dry air intrusion to the inner core and limits TC intensification. In contrast, increased moisture in the rear quadrants favors intensification by providing more moisture to the inner core and promoting storm symmetry, with primary contributions coming from moisture increase in the boundary layer. The different impacts of environmental moisture on TC intensification are governed by the relative locations of moisture perturbations and their interactions with the storm Lagrangian structure.

scholarly journals The Competing Effects of Stability and Humidity on Subtropical Stratocumulus Entrainment and Cloud Evolution from a Lagrangian Perspective

2018 ◽  
Vol 75 (8) ◽  
pp. 2563-2578 ◽  
Author(s):  
Ryan Eastman ◽  
Robert Wood
Keyword(s):  
Boundary Layer ◽  
Cloud Cover ◽  
Reanalysis Data ◽  
Radiation Balance ◽  
Stratocumulus Clouds ◽  
Primary Driver ◽  
Inversion Strength ◽  
Cloud Evolution ◽  
Lagrangian Boundary ◽  
Daily Time

Abstract The evolution of subtropical stratocumulus clouds and the boundary layer is studied on daily time scales from the Lagrangian perspective, following the flow. Measures of humidity above the boundary layer and of inversion strength are obtained from reanalysis data, and their effects on the Lagrangian evolution of cloud cover and the boundary layer are compared. An analysis that disentangles these variables and tests their effects independently is developed. Increased inversion strength and increased humidity above the boundary layer lead to anomalously persistent cloud cover and slower Lagrangian deepening of the boundary layer. These parameters affect the stratocumulus boundary layer in different ways: inversion strength controls the buoyancy difference across the inversion, while humidity differences affect both the radiation balance and rate of cloud drop evaporation at cloud top. The relative strengths of the two effects of humidity are compared using two products: the entraining humidity in the layer directly above the inversion and the radiating humidity, which is the mean humidity in the column above the entraining humidity. Results show that the variability in the radiating humidity is the primary driver of Lagrangian boundary layer depth changes, but entraining humidity variation is mostly responsible for altering cloud lifetime.

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