Modulation of tropical convective systems by environmental conditions as observed from multiple satellite measurements

2003 ◽  
Author(s):  
Michel Desbois ◽  
Remy Roca ◽  
Michel Viollier ◽  
Kusuma G. Rao ◽  
Jean-Louis Monge
Keyword(s):  
Environmental Conditions ◽  
Satellite Measurements ◽  
Convective Systems

scholarly journals Synoptic Control of Convective Rainfall Rates and Cloud-to-Ground Lightning Frequencies in Warm-Season Mesoscale Convective Systems over North China

2018 ◽  
Vol 146 (3) ◽  
pp. 813-831 ◽  
Author(s):  
Rudi Xia ◽  
Da-Lin Zhang ◽  
Cuihong Zhang ◽  
Yongqing Wang
Keyword(s):  
Environmental Conditions ◽  
North China ◽  
Convective Available Potential Energy ◽  
Cloud Microphysics ◽  
Small Sample ◽  
Mesoscale Convective Systems ◽  
Convective Rainfall ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Cg Lightning

Abstract This study examines whether environmental conditions can control convective rainfall rates and cloud-to-ground (CG) lightning frequencies in mesoscale convective systems (MCSs) over north China (NC). A total of 60 identified MCSs over NC during June–August of 2008–13 were classified into 4 categories based on their high/low convective rainfall rates (HR/LR) and high/low CG lightning frequencies (HL/LL) (i.e., HRHL, HRLL, LRHL, and LRLL MCSs). MCSs with HR (HL) occurred most frequently in July (August), while those with LR or LL occurred most frequently in June; they followed closely seasonal changes. All MCSs were apt to form during afternoon hours. HRLL MCSs also formed during evening hours while HRHL MCSs could occur at any time of a day. A composite analysis of environmental conditions shows obvious differences and similarities among the HRHL, HRLL, and LRLL categories, while the LRHL MCSs exhibited little differences from the climatological mean because of its small sample size. Both the HRHL and HRLL MCSs occurred in the presence of upper-level anomalous divergence, a midlevel trough, and the lower-tropospheric southwesterly transport of tropical moist air. In contrast, LRLL MCSs took place as a result of daytime heating over mountainous regions, with little midlevel forcing over NC. The HRHL, HRLL, LRHL, and LRLL categories exhibited orders of the highest-to-smallest convective available potential energy and precipitable water but the smallest-to-largest convective inhibition and lifted indices. It is concluded that environmental conditions determine to some extent convective rainfall rates and CG lightning activity, although some other processes (e.g., cloud microphysics) also play certain roles, especially in CG lightning production.

Dependence of Ice Microphysical Properties On Environmental Parameters: Results from HAIC-HIWC Cayenne Field Campaign

2021 ◽  
Author(s):  
Yachao Hu ◽  
Greg M. McFarquhar ◽  
Wei Wu ◽  
Yongjie Huang ◽  
Alfons Schwarzenboeck ◽  
...  
Keyword(s):  
Water Content ◽  
Environmental Conditions ◽  
Environmental Parameters ◽  
Surface Characteristics ◽  
Ice Crystal ◽  
Convective Systems ◽  
Microphysical Properties ◽  
Ice Water Content ◽  
Deposition Processes ◽  
Ice Water

AbstractHigh Ice Water Content (HIWC) regions above tropical mesoscale convective systems are investigated using data from the second collaboration of the High Altitude Ice Crystals and High Ice Water Content projects (HAIC-HIWC) based in Cayenne, French Guiana in 2015. Observations from in-situ cloud probes on the French Falcon 20 determine the microphysical and thermodynamic properties of such regions. Data from a 2-D stereo probe and precipitation imaging probe show how statistical distributions of ice crystal mass median diameter (MMD), ice water content (IWC), and total number concentration (Nt) for particles with maximum dimension (Dmax) > 55 μm vary with environmental conditions, temperature (T), and convective properties such as vertical velocity (w), MCS age, distance away from convective peak (L), and surface characteristics. IWC is significantly correlated with w, whereas MMD decreases and Nt increases with decreasing T consistent with aggregation, sedimentation and vapor deposition processes at lower altitudes. MMD typically increases with IWC when IWC < 0.5 g m-3, but decreases with IWC when IWC > 0.5 g m-3 for -15 °C ≤ T ≤ -5 °C. Trends also depend on environmental conditions, such as presence of convective updrafts that are the ice crystal source, MMD being larger in older MCSs consistent with aggregation and less injection of small crystals into anvils, and IWCs decrease with increasing L at lower T. The relationship between IWC and MMD depends on environmental conditions, with correlations decreasing with decreasing T. The strength of correlation between IWC and Nt increases as T decreases.

Environmental Distinctions between Cellular and Slabular Convective Lines

2005 ◽  
Vol 133 (9) ◽  
pp. 2669-2691 ◽  
Author(s):  
Richard P. James ◽  
J. Michael Fritsch ◽  
Paul M. Markowski
Keyword(s):  
Environmental Conditions ◽  
Dynamic Pressure ◽  
Level Line ◽  
Cold Pool ◽  
Two Dimensional ◽  
Low Level ◽  
Convective Systems ◽  
Cold Pools ◽  
Pool Model ◽  
Wind Profiles

Abstract The organizational mode of quasi-linear convective systems often falls within a spectrum of modes described by a line of discrete cells on one end (“cellular”) and an unbroken two-dimensional swath of ascent on the other (“slabular”). Convective events exhibiting distinctly cellular or slabular characteristics over the continental United States were compiled, and composite soundings of the respective inflow environments were constructed. The most notable difference between the environments of slabs and cells occurred in the wind profiles; lines organized as slabs existed in much stronger low-level line-relative inflow and stronger low-level shear. A compressible model with high resolution (Δx = 500 m) was used to investigate the effects of varying environmental conditions on the nature of the convective overturning. The numerical results show that highly cellular convective lines are favored when the environmental conditions and initiation procedure allow the convectively generated cold pools to remain separate from one another. The transition to a continuous along-line cold pool and gust front leads to the generation of a more “solid” line of convection, as dynamic pressure forcing above the downshear edge of the cold outflow creates a swath of quasi-two-dimensional ascent. Using both full-physics simulations and a simplified cold-pool model, it is demonstrated that the magnitude of the two-dimensional ascent in slabular convective systems is closely related to the integrated cold-pool strength. It is concluded that slabular organization tends to occur under conditions that favor the development of a strong, contiguous cold pool. The tendency to produce slabular convection is therefore enhanced by environmental conditions such as large CAPE, weak convective inhibition, strong along-line winds, and moderately strong cross-line wind shear.

scholarly journals Impacts of Aerosol and Environmental Conditions on Maritime and Continental Deep Convective Systems Using a Bin Microphysical Model

2020 ◽  
Vol 125 (12) ◽  
Author(s):  
Takamichi Iguchi ◽  
Steven A. Rutledge ◽  
Wei‐Kuo Tao ◽  
Toshi Matsui ◽  
Brenda Dolan ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Convective Systems ◽  
Deep Convective Systems

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

The influence of external conditions on sound pressure in the pistonphone at the infrasound frequency range

2020 ◽  
pp. 67-72
Author(s):  
A. V. Konkov ◽  
D. V. Golovin
Keyword(s):  
Environmental Conditions ◽  
Sound Pressure ◽  
Primary Method ◽  
Frequency Range ◽  
External Conditions ◽  
Numerical Estimations

The influence of environmental conditions on a sound pressure reproduced by the primary method in the measuring chambers of the Pistonphone in the frequency range from 1 mHz to 250 Hz is estimated. Numerical estimations of influence of environmental conditions on sound pressure in pistonphone measuring chambers are given and special requirements to system of maintenance of required external conditions are specified.

Sign in / Sign up

Export Citation Format

Share Document