THE WAY TO DETERMINE THE APPROXIMATELY HAIL'S DIMENSIONS

To determine those storms associated with the convective clouds is necessary a good knowledge of the vertical profile of the troposphere. To determine this parameter, it's essential to make the Skew-T diagrams. From these, we can extract useful information relating to the level of free convection (LFC), the equilibrium level (EL), and the maximum speed of the updraft. The parameter brought in the discussion is handy to hail's forecast. Therefore, based on this parameter, of the ascendant airflow flux, it can determine the dimension of the hail. Besides to determine the hail's sizes, from Skew-T diagram we can find other parameters, such as the Total Totals Index (TTI), this being useful to decide on the coverage rate of the storms, the K Index (KI) - helpful in the case of convections who occur in the same air-mass. The Skew-T diagrams are useful to determine the conductor flux's speed and direction; this is situated between 700 to 500 hPa geopotential heights. Noteworthy are the synoptically materials, by analyzing the way of disposing of the isobars who can be a good indicator of the severity of the storm. Also, the synoptically materials examine at the 500 hPa, 300 hPa, and 200 hPa geopotential to notice if occur the 'cut-off low' areas in the high troposphere. To see if a cloud system is dangerous of hail will be following the cloud's top temperature.

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An objective method for predicting occurrence of pre-monsoon (March-May) thunderstorm events over Delhi using stability indices

MAUSAM ◽

10.54302/mausam.v62i3.312 ◽

2021 ◽

Vol 62 (3) ◽

pp. 329-338

Author(s):

M. DURAISAMY ◽

S.K.ROY BHOWMIK ◽

B.K. BANDYOPADHYAY

Keyword(s):

Free Convection ◽

Precipitable Water ◽

Critical Values ◽

Objective Method ◽

K Index ◽

Equilibrium Level ◽

Stability Indices

In this paper an attempt has been made to investigate different stability indices in relation to the occurrence of thunderstorms in order to determine the critical values of these indices for Delhi (28.35° N / 77.12° E) using pre monsoon data for the years 1999 - 2004. The study shows that the critical values of Showalter Index (SI), Lifted Index (LI), K Index (KI), Total Totals Index (TTI), and Sweat Index (SWI) are respectively < 2 °C, < 0 °C, > 24 °C, > 44.5 °C and > 100 for the thunderstorm to occur over Delhi. The corresponding common critical ranges of Lifted Condensation Level (LCL), Level of Free Convection (LFC), Equilibrium Level (EL) and Precipitable Water (PW) are respectively 923 hPa – 695 hPa, 856 hPa – 504 hPa, 545 hPa – 109 hPa and 18 mm – 54 mm. Testing of critical values of indices and the corresponding common critical ranges of LCL, LFC, EL and PW during pre-monsoon seasons of the years 2005 and 2006 shows that they are matching well with the respective critical values/ranges in most of the thunderstorm days.

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How do changes in warm-phase microphysics affect deep convective clouds?

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-9585-2017 ◽

2017 ◽

Vol 17 (15) ◽

pp. 9585-9598 ◽

Cited By ~ 19

Author(s):

Qian Chen ◽

Ilan Koren ◽

Orit Altaratz ◽

Reuven H. Heiblum ◽

Guy Dagan ◽

...

Keyword(s):

Rain Rate ◽

Convective Cloud ◽

Cloud Fraction ◽

Marshall Islands ◽

Cloud System ◽

Main Question ◽

Convective Clouds ◽

Deep Convective Clouds ◽

Aerosol Effects ◽

Deep Convective Cloud

Abstract. Understanding aerosol effects on deep convective clouds and the derived effects on the radiation budget and rain patterns can largely contribute to estimations of climate uncertainties. The challenge is difficult in part because key microphysical processes in the mixed and cold phases are still not well understood. For deep convective clouds with a warm base, understanding aerosol effects on the warm processes is extremely important as they set the initial and boundary conditions for the cold processes. Therefore, the focus of this study is the warm phase, which can be better resolved. The main question is: How do aerosol-derived changes in the warm phase affect the properties of deep convective cloud systems? To explore this question, we used a weather research and forecasting (WRF) model with spectral bin microphysics to simulate a deep convective cloud system over the Marshall Islands during the Kwajalein Experiment (KWAJEX). The model results were validated against observations, showing similarities in the vertical profile of radar reflectivity and the surface rain rate. Simulations with larger aerosol loading resulted in a larger total cloud mass, a larger cloud fraction in the upper levels, and a larger frequency of strong updrafts and rain rates. Enlarged mass both below and above the zero temperature level (ZTL) contributed to the increase in cloud total mass (water and ice) in the polluted runs. Increased condensation efficiency of cloud droplets governed the gain in mass below the ZTL, while both enhanced condensational and depositional growth led to increased mass above it. The enhanced mass loading above the ZTL acted to reduce the cloud buoyancy, while the thermal buoyancy (driven by the enhanced latent heat release) increased in the polluted runs. The overall effect showed an increased upward transport (across the ZTL) of liquid water driven by both larger updrafts and larger droplet mobility. These aerosol effects were reflected in the larger ratio between the masses located above and below the ZTL in the polluted runs. When comparing the net mass flux crossing the ZTL in the clean and polluted runs, the difference was small. However, when comparing the upward and downward fluxes separately, the increase in aerosol concentration was seen to dramatically increase the fluxes in both directions, indicating the aerosol amplification effect of the convection and the affected cloud system properties, such as cloud fraction and rain rate.

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Vertical Characteristics of Reflectivity in Intense Convective Clouds using TRMM PR Data

Environment and Natural Resources Research ◽

10.5539/enrr.v7n2p58 ◽

2017 ◽

Vol 7 (2) ◽

pp. 58 ◽

Cited By ~ 7

Author(s):

Shailendra Kumar

Keyword(s):

Vertical Profile ◽

Regional Differences ◽

Vertical Structure ◽

Convective Cloud ◽

Convective Precipitation ◽

Vertical Profiles ◽

Gangetic Plain ◽

Convective Clouds ◽

Trmm Pr ◽

Precipitation Area

Tropical Rainfall Measuring Mission Precipitation Radar (TRMM-PR) based vertical structure in intense convective precipitation is presented here for Indian and Austral summer monsoon seasons. TRMM 2A23 data is used to identify the convective echoes in PR data. Two types of cloud cells are constructed here, namely intense convective cloud (ICC) and most intense convective cloud (MICC). ICC consists of PR radar beams having Ze>=40 dBZ above 1.5 km in convective precipitation area, whereas MICC, consists of maximum reflectivity at each altitude in convective precipitation area, with at least one radar pixel must be higher than 40 dBZ or more above 1.5 km within the selected areas. We have selected 20 locations across the tropics to see the regional differences in the vertical structure of convective clouds. One of the important findings of the present study is identical behavior in the average vertical profiles in intense convective precipitation in lower troposphere across the different areas. MICCs show the higher regional differences compared to ICCs between 5-12 km altitude. Land dominated areas show higher regional differences and Southeast south America (SESA) has the strongest vertical profile (higher Ze at higher altitude) followed by Indo-Gangetic plain (IGP), Africa, north Latin America whereas weakest vertical profile occurs over Australia. Overall SESA (41%) and IGP (36%) consist higher fraction of deep convective clouds (>10 km), whereas, among the tropical oceanic areas, Western (Eastern) equatorial Indian ocean consists higher fraction of low (high) level of convective clouds. Nearly identical average vertical profiles over the tropical oceanic areas, indicate the similarity in the development of intense convective clouds and useful while considering them in model studies.

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Quantification of the effect of modeled lightning NO<sub>2</sub> on UV–visible air mass factors

Atmospheric Measurement Techniques ◽

10.5194/amt-10-4403-2017 ◽

2017 ◽

Vol 10 (11) ◽

pp. 4403-4419 ◽

Cited By ~ 10

Author(s):

Joshua L. Laughner ◽

Ronald C. Cohen

Keyword(s):

United States ◽

A Priori ◽

Early Summer ◽

Lightning Flash ◽

Eastern United States ◽

Ozone Monitoring Instrument ◽

Reanalysis Dataset ◽

Near Surface ◽

Air Mass ◽

Convective Clouds

Abstract. Space-borne measurements of tropospheric nitrogen dioxide (NO2) columns are up to 10x more sensitive to upper tropospheric (UT) NO2 than near-surface NO2 over low-reflectivity surfaces. Here, we quantify the effect of adding simulated lightning NO2 to the a priori profiles for NO2 observations from the Ozone Monitoring Instrument (OMI) using modeled NO2 profiles from the Weather Research and Forecasting–Chemistry (WRF-Chem) model. With observed NO2 profiles from the Deep Convective Clouds and Chemistry (DC3) aircraft campaign as observational truth, we quantify the bias in the NO2 column that occurs when lightning NO2 is not accounted for in the a priori profiles. Focusing on late spring and early summer in the central and eastern United States, we find that a simulation without lightning NO2 underestimates the air mass factor (AMF) by 25 % on average for common summer OMI viewing geometry and 35 % for viewing geometries that will be encountered by geostationary satellites. Using a simulation with 500 to 665 mol NO flash−1 produces good agreement with observed NO2 profiles and reduces the bias in the AMF to <  ±4 % for OMI viewing geometries. The bias is regionally dependent, with the strongest effects in the southeast United States (up to 80 %) and negligible effects in the central US. We also find that constraining WRF meteorology to a reanalysis dataset reduces lightning flash counts by a factor of 2 compared to an unconstrained run, most likely due to changes in the simulated water vapor profile.

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A high-resolution and observationally constrained OMI NO<sub>2</sub> satellite retrieval

10.5194/acp-2017-219 ◽

2017 ◽

Cited By ~ 1

Author(s):

Daniel L. Goldberg ◽

Lok N. Lamsal ◽

Christopher P. Loughner ◽

Zifeng Lu ◽

David G. Streets

Keyword(s):

United States ◽

High Resolution ◽

Urban Areas ◽

Vertical Profile ◽

Model Simulation ◽

New Product ◽

Eastern United States ◽

Shape Factors ◽

Air Mass ◽

Tropospheric No2

Abstract. This work presents a new high resolution NO2 dataset derived from the standard NASA Ozone Monitoring Instrument (OMI) NO2 version 3.0 retrieval that can be used to estimate surface level concentrations. The standard NASA product uses NO2 vertical profile shape factors from a 1.25° × 1° (~ 110 × 110 km) resolution Global Model Initiative (GMI) model simulation to calculate air mass factors, a critical value used to determine observed tropospheric NO2 vertical columns. To better estimate vertical profile shape factors, we use a high resolution Community Multi-scale Air Quality (CMAQ) model simulation (1.33 × 1.33 km) to generate tropospheric air mass factors and tropospheric NO2 columns during summertime in the eastern United States. Results show OMI NO2 tropospheric columns in this new product increase by up to 160 % in city centers, and decrease by 20–50 % in the rural areas outside of urban areas when compared to the operational product. This new product shows much better agreement with the Pandora NO2 spectrometer measurements acquired during the DISCOVER-AQ Maryland field campaign. Furthermore, the correlation between this satellite product and EPA NO2 monitors in urban areas has improved dramatically: r2 = 0.60 in new product, r2 = 0.39 in operational product, signifying that this new product is a better indicator of surface concentrations than the operational product. Our work emphasizes the need to use high resolution models to re-calculate satellite data in areas with large spatial heterogeneities in NOx emissions. Although the current work is focused on the eastern United States, the methodology developed in this work can be applied to other world regions to produce high-quality region-specific NO2 satellite retrievals.

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Tip Growing Actuator with the Hose-Like Structure Aiming for Inspection on Narrow Terrain

International Journal of Automation Technology ◽

10.20965/ijat.2011.p0516 ◽

2011 ◽

Vol 5 (4) ◽

pp. 516-522 ◽

Cited By ~ 14

Author(s):

Hideyuki Tsukagoshi ◽

◽

Nobuyuki Arai ◽

Ichiro Kiryu ◽

Ato Kitagawa

Keyword(s):

Plant Growth ◽

Growth Process ◽

Maximum Speed ◽

Flexible Hose ◽

Head Unit ◽

Flat Tubes ◽

Outer Environment ◽

The Way

This paper proposes a flexible hose-like fluid actuator to inspect narrow curved or bumpy terrain. The tip alone moves forward and the rest remains stationary, enabling the actuator to move smoothly without interfering with the outer environment – a concept based on the plant growth process. The actuator consists of multiple flexible flat tubes bent in the skin, whose bending point is involved in preventing fluid from passing through. The actuator can also steer the direction in which the tip lengthens, while the shape of the rest remains unchanged. Our Grow-hose-I prototype is 62 mm in diameter and grows at a maximum speed of 500 mm/s while producing a 45 N drive. The way of carrying a head unit equipped with a camera is discussed and feasibility of the actuator’s inspection on narrow terrain is demonstrated.

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Development and characterisation of a state-of-the-art GOME-2 formaldehyde air-mass factor algorithm

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-1109-2015 ◽

2015 ◽

Vol 8 (1) ◽

pp. 1109-1150 ◽

Cited By ~ 1

Author(s):

W. Hewson ◽

M. P. Barkley ◽

G. Gonzalez Abad ◽

H. Bösch ◽

T. Kurosu ◽

...

Keyword(s):

Radiative Transfer ◽

Vertical Profile ◽

Trace Gas ◽

Satellite Line ◽

Air Mass ◽

Volatile Organic ◽

Weight Calculation ◽

Transfer Error ◽

Mass Factor ◽

The University

Abstract. Space-borne observations of formaldehyde (HCHO) are frequently used to derive surface emissions of isoprene, an important biogenic volatile organic compound. The conversion of retrieved HCHO slant column concentrations from satellite line of sight measurements to vertical columns is determined through application of an air mass factor (AMF), accounting for instrument viewing geometry, radiative transfer, and vertical profile of the absorber in the atmosphere. This step in the trace gas retrieval is subject to large errors. This work presents the AMF algorithm in use at the University of Leicester (UoL), which introduces scene specific variables into a per-observation full radiative transfer AMF calculation, including increasing spatial resolution of key environmental parameter databases, input variable area weighting, instrument specific scattering weight calculation, and inclusion of an ozone vertical profile climatology. Application of these updates to HCHO slant columns from the GOME-2 instrument is shown to typically adjust the AMF by ±10%, compared to a~reference algorithm without these advanced parameterisations. Furthermore, the new UoL algorithm also incorporates a full radiative transfer error calculation for each scene to help characterise AMF uncertainties. Global median AMF errors are typically 50–60%, and are dominated by uncertainties in the HCHO profile shape and its corresponding seasonal variation.

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Characteristics of vertical air motion in isolated convective clouds

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-10159-2016 ◽

2016 ◽

Vol 16 (15) ◽

pp. 10159-10173 ◽

Cited By ~ 9

Author(s):

Jing Yang ◽

Zhien Wang ◽

Andrew J. Heymsfield ◽

Jeffrey R. French

Keyword(s):

Vertical Velocity ◽

Mass Flux ◽

Convective Precipitation ◽

Small Scale ◽

High Plains ◽

Air Mass ◽

Convective Clouds ◽

Field Campaigns ◽

Air Motion

Abstract. The vertical velocity and air mass flux in isolated convective clouds are statistically analyzed using aircraft in situ data collected from three field campaigns: High-Plains Cumulus (HiCu) conducted over the midlatitude High Plains, COnvective Precipitation Experiment (COPE) conducted in a midlatitude coastal area, and Ice in Clouds Experiment-Tropical (ICE-T) conducted over a tropical ocean. The results show that small-scale updrafts and downdrafts (<  500 m in diameter) are frequently observed in the three field campaigns, and they make important contributions to the total air mass flux. The probability density functions (PDFs) and profiles of the observed vertical velocity are provided. The PDFs are exponentially distributed. The updrafts generally strengthen with height. Relatively strong updrafts (>  20 m s−1) were sampled in COPE and ICE-T. The observed downdrafts are stronger in HiCu and COPE than in ICE-T. The PDFs of the air mass flux are exponentially distributed as well. The observed maximum air mass flux in updrafts is of the order 104 kg m−1 s−1. The observed air mass flux in the downdrafts is typically a few times smaller in magnitude than that in the updrafts. Since this study only deals with isolated convective clouds, and there are many limitations and sampling issues in aircraft in situ measurements, more observations are needed to better explore the vertical air motion in convective clouds.

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Comparing Airborne and Satellite Retrievals of Optical and Microphysical Properties of Cirrus and Deep Convective Clouds using a Radiance Ratio Technique

10.5194/acp-2017-758 ◽

2017 ◽

Cited By ~ 1

Author(s):

Trismono C. Krisna ◽

Manfred Wendisch ◽

André Ehrlich ◽

Evelyn Jäkel ◽

Frank Werner ◽

...

Keyword(s):

Vertical Profile ◽

Effective Radius ◽

In Situ Measurements ◽

Spectral Radiance ◽

Retrieval Algorithm ◽

Mean Absolute Deviation ◽

Absolute Deviation ◽

Convective Clouds ◽

Deep Convective Clouds

Abstract. Solar radiation reflected by cirrus and deep convective clouds (DCCs) was measured by the Spectral Modular Airborne Radiation Measurement System (SMART) installed on the German HALO (High Altitude and Long Range Research Aircraft) during the ML-CIRRUS and the ACRIDICON-CHUVA campaigns. In particular flights, HALO performed closely collocated measurements with overpasses of the Moderate Resolution Imaging Spectroradiometer (MODIS) on board of Aqua satellite. Based on the nadir upward radiance, the optical thickness τ and bulk particle effective radius reff of cirrus and DCC are retrieved using a radiance ratio algorithm which considers the cloud thermodynamic phase, the cloud vertical profile, multi layer clouds, and heterogeneity of the surface albedo. For the cirrus case, the comparison of τci and reff,ci retrieved on the basis of SMART and MODIS upward radiances yields a normalized mean absolute deviation of 0.5 % for τci and 2.5 % for reff,ci. While for the DCC case, the respective deviation is 5.9 % for τdcc and 13.2 % for reff,dcc. The larger deviations in case of DCC are mainly attributed to the fast cloud evolution and three-dimensional radiative effects. Measurements of spectral radiance at near-infrared wavelengths with different absorption by cloud particles are employed to investigate the vertical profile of cirrus effective radius. The retrieved values of cirrus effective radius are further compared with corresponding in situ measurements using a vertical weighting method. Compared to the MODIS observation, spectral measurements of SMART provide an increased amount of information on the vertical distribution of particle sizes at cloud top, and therefore allow to reconstruct the profile of effective radius at cloud top. The retrieved effective radius differs to in situ measurements with a normalized mean absolute deviation between 4–19 %, depending on the wavelength chosen in the retrieval algorithm. While, the MODIS cloud product underestimates the in situ measurements by 48 %. The presence of liquid water clouds below the cirrus, the variability of particle size distributions, and the simplification in the retrieval algorithm assuming vertically homogeneous cloud are identified as the potential error contributors.

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Perceptions of Medieval Settlement

10.1093/oxfordhb/9780198744719.013.10 ◽

2018 ◽

Author(s):

Mark Gardiner ◽

Susan Kilby

Keyword(s):

Historical Context ◽

Phenomenological Approach ◽

Good Knowledge ◽

Archaeological Remains ◽

Place Names ◽

The Past ◽

The World ◽

Competing Ideas ◽

The Way

Medieval archaeologists, possessing elements of the landscape and the buildings of the past, together with a good knowledge of the historical context, can recover many aspects of the way that space was perceived in the past. A phenomenological approach has been applied not only to castles, but also to the mundane world of peasants. Phenomenology emphasizes the experience of the world whereas archaeologists have been no less interested in the way in which that experience was manipulated and also in the competing ideas of space. Examples of encultured landscapes examined include natural places, gentry houses, village tofts, liminal places, and sites of pilgrimage. Drawing upon the evidence of place-names and documents, as well as the archaeological remains, it has been possible to reconstruct how people conceived of and experienced the world around them.

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