scholarly journals Toward a Global Climatology of Severe Hailstorms as Estimated by Satellite Passive Microwave Imagers

2012 ◽  
Vol 25 (2) ◽  
pp. 687-703 ◽  
Author(s):  
Daniel J. Cecil ◽  
Clay B. Blankenship
Keyword(s):  
United States ◽  
Indian Subcontinent ◽  
Central Africa ◽  
Tropical Rainfall Measuring Mission ◽  
The United States ◽  
Early Morning ◽  
Northern Pakistan ◽  
Diurnal Variability ◽  
Late Night ◽  
Early Afternoon

Abstract An 8-yr climatology of storms producing large hail is estimated from satellite measurements using Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E). This allows a unique, consistent comparison between regions that cannot be consistently compared using ground-based records because of varying data collection standards. Severe hailstorms are indicated most often in a broad region of northern Argentina and southern Paraguay and a smaller region in Bangladesh and eastern India. Numerous hailstorms are also estimated in the central and southeastern United States, northern Pakistan and northwestern India, central and western Africa, and southeastern Africa (and adjacent waters). Fewer hailstorms are estimated for other regions over land and scattered across subtropical oceans. Very few are estimated in the deep tropics other than in Africa. Most continental regions show seasonality with hailstorms peaking in late spring or summer. The South Asian monsoon alters the hailstorm climatology around the Indian subcontinent. About 75% of the hailstorms on the eastern side (around Bangladesh) occur from April through June, generally before monsoon onset. Activity shifts northwest to northern India in late June and July. An arc along the foothills in northern Pakistan becomes particularly active from mid-June through mid-August. The AMSR-E measurements are limited to early afternoon and late night. Tropical Rainfall Measuring Mission (TRMM) measurements are used to investigate diurnal variability in the tropics and subtropics. All of the prominent regions have hailstorm peaks in late afternoon and early evening. The United States and central Africa have the fewest overnight and early morning storms, while subtropical South America and Bangladesh have the most.

scholarly journals Constructing a Multifrequency Passive Microwave Hail Retrieval and Climatology in the GPM Domain

2019 ◽  
Vol 58 (9) ◽  
pp. 1889-1904 ◽  
Author(s):  
Sarah D. Bang ◽  
Daniel J. Cecil
Keyword(s):  
United States ◽  
Brightness Temperature ◽  
Microwave Radiometer ◽  
Central Africa ◽  
Tropical Rainfall Measuring Mission ◽  
The United States ◽  
Low Earth Orbit ◽  
Passive Microwave ◽  
Central United States ◽  
Microwave Data

AbstractLarge hail is a primary contributor to damages and loss around the world, in both agriculture and infrastructure. The sensitivity of passive microwave radiometer measurements to scattering by hail led to the development of proxies for severe hail, most of which use brightness temperature thresholds from 37-GHz and higher-frequency microwave channels on board weather satellites in low-Earth orbit. Using 16+ years of data from the Tropical Rainfall Measuring Mission (TRMM; 36°S–36°N), we pair TRMM brightness temperature–derived precipitation features with surface hail reports in the United States to train a hail retrieval on passive microwave data from the 10-, 19-, 37-, and 85-GHz channels based on probability curves fit to the microwave data. We then apply this hail retrieval to features in the Global Precipitation Measurement (GPM) domain (from 69°S to 69°N) to develop a nearly global passive microwave–based climatology of hail. The extended domain of the GPM satellite into higher latitudes requires filtering out features that we believe are over icy and snowy surface regimes. We also normalize brightness temperature depression by tropopause height in an effort to account for differences in storm depth between the tropics and higher latitudes. Our results show the highest hail frequencies in the region of northern Argentina through Paraguay, Uruguay, and southern Brazil; the central United States; and a swath of Africa just south of the Sahel. Smaller hot spots include Pakistan, eastern India, and Bangladesh. A notable difference between these results and many prior satellite-based studies is that central Africa, while still active in our climatology, does not rival the aforementioned regions in retrieved hailstorm frequency.

scholarly journals Convective Storm Life Cycle and Environments near the Sierras de Córdoba, Argentina

2018 ◽  
Vol 146 (8) ◽  
pp. 2541-2557 ◽  
Author(s):  
Jake P. Mulholland ◽  
Stephen W. Nesbitt ◽  
Robert J. Trapp ◽  
Kristen L. Rasmussen ◽  
Paola V. Salio
Keyword(s):  
United States ◽  
Life Cycle ◽  
Vertical Wind Shear ◽  
Austral Summer ◽  
Tropical Rainfall Measuring Mission ◽  
Radar Data ◽  
The United States ◽  
Reanalysis Data ◽  
Austral Spring ◽  
Early Afternoon

Abstract Satellite observations have revealed that some of the world’s most intense deep convective storms occur near the Sierras de Córdoba, Argentina, South America. A C-band, dual-polarization Doppler weather radar recently installed in the city of Córdoba in 2015 is now providing a high-resolution radar perspective of this intense convection. Radar data from two austral spring and summer seasons (2015–17) are used to document the convective life cycle, while reanalysis data are utilized to construct storm environments across this region. Most of the storms in the region are multicellular and initiate most frequently during the early afternoon and late evening hours near and just east of the Sierras de Córdoba. Annually, the peak occurrence of these storms is during the austral summer months of December, January, and February. These Córdoba radar-based statistics are shown to be comparable to statistics derived from Tropical Rainfall Measuring Mission Precipitation Radar data. While generally similar to storm environments in the United States, storm environments in central Argentina tend to be characterized by larger CAPE and weaker low-level vertical wind shear. One of the more intriguing results is the relatively fast transition from first storms to larger mesoscale convective systems, compared with locations in the central United States.

Searching and Making Meaning of the COVID-19 Pandemic: Perspectives of African Immigrants in the United States

2021 ◽  
pp. 002216782110224
Author(s):  
Angela U. Ekwonye ◽  
Nina Truong
Keyword(s):  
United States ◽  
Health Care Providers ◽  
Meaning Making ◽  
Democratic Republic Of Congo ◽  
Central Africa ◽  
African Immigrants ◽  
The United States ◽  
Care Providers ◽  
Making Meaning ◽  
The Impact

African immigrants continue to be disproportionately affected by the COVID-19 pandemic. It is unclear how they are searching for and finding meaning in the face of this adversity. This study sought to understand how African immigrants in the United States are searching for and making meaning of the COVID-19 pandemic. We conducted in-depth interviews remotely with 20 immigrants from West Africa (Nigeria and Ghana), East Africa (Somali and Rwanda), and Central Africa (Democratic Republic of Congo). The meaning-making model was used as a framework to understand the processes of coping during a significant, adverse life event. The study found that some participants attempted to reduce the impact of the COVID-19 pandemic on their global meaning by seeking answers as to why the pandemic occurred and creating positive illusions. Some redefined their priorities and reframed the pandemic in a positive light. Participants found meaning in the form of accepting the pandemic as a reality of life, appreciating events previously taken for granted, and making positive changes in their lives. This study’s findings can inform health care providers of the meaning-making processes of African immigrants’ and the need to assist them in their search for meaning.

Smoking Among Immigrant Groups in the United States: Prevalence, Education Gradients, and Male-to-Female Ratios

2019 ◽  
Vol 22 (4) ◽  
pp. 532-538 ◽  
Author(s):  
Fred Pampel ◽  
Myriam Khlat ◽  
Damien Bricard ◽  
Stéphane Legleye
Keyword(s):  
United States ◽  
Indian Subcontinent ◽  
The United States ◽  
Sub Saharan Africa ◽  
Foreign Born ◽  
Current Cigarette Smoking ◽  
World Region ◽  
Duration Of Residence ◽  
Low Prevalence ◽  
Male To Female

Abstract Introduction Immigrants in the United States are less likely to smoke than those born in the United States, but studies have not fully described the diversity of their smoking patterns. We investigate smoking by world region of birth and duration of residence in the United States, with a comprehensive approach covering current prevalence levels, education gradients, and male-to-female ratios. Methods The data originate from the National Health Interview Surveys, 2000–2015, and the sample of 365 404 includes both US-born and foreign-born respondents aged 25–70 years. World region of birth and duration of residence in the United States measure immigrant characteristics. Current cigarette smoking was analyzed using logistic regression. Results Immigrant groups were protected from smoking and had weaker education gradients in smoking and larger male-to-female smoking ratios than the US-born population. However, large differences emerged among the immigrant groups for region of birth but less so for duration of residence in the United States. For example, immigrants from sub-Saharan Africa and the Indian subcontinent have low prevalence, weak education gradients, and high male-to-female ratios. Immigrants from Europe have the opposite pattern, and immigrants from Latin America fall between those two extremes. Conclusion The stage of the cigarette epidemic in the region of birth helps explain the diverse group profiles. Duration of residence in the United States does less to account for the differences in smoking than region of birth. The findings illustrate the heterogeneity of immigrant populations originating from diverse regions across the world and limited convergence with the host population after immigration. Implications The study identifies immigrant groups that, because of high smoking prevalence related to levels in the host country, should be targeted for cessation efforts. It also identifies immigrant groups with low prevalence for which anti-smoking programs should encourage maintenance of healthy habits. Many immigrant groups show strong education disparities in smoking, further suggesting that smokers with lower levels of education be targeted by public health programs.

scholarly journals Nephrology Fellows’ and Program Directors’ Perceptions of Hospital Rounds in the United States

2020 ◽  
Vol 15 (4) ◽  
pp. 474-483
Author(s):  
Suzanne M. Boyle ◽  
Keshab Subedi ◽  
Kurtis A. Pivert ◽  
Meera Nair Harhay ◽  
Jaime Baynes-Fields ◽  
...  
Keyword(s):  
United States ◽  
Patient Care ◽  
Training Programs ◽  
Clinical Skills ◽  
Care Delivery ◽  
Clinical Skill ◽  
Program Directors ◽  
The United States ◽  
Early Morning ◽  
Attending Rounds

Background and objectivesHospital rounds are a traditional vehicle for patient-care delivery and experiential learning for trainees. We aimed to characterize practices and perceptions of rounds in United States nephrology training programs.Design, setting, participants, & measurementsWe conducted a national survey of United States nephrology fellows and program directors. Fellows received the survey after completing the 2019 National Board of Medical Examiners Nephrology In-Training Exam. Program directors received the survey at the American Society of Nephrology’s 2019 Nephrology Training Program Directors’ Retreat. Surveys assessed the structure and perceptions of rounds, focusing on workload, workflow, value for patient care, and fellows’ clinical skill-building. Directors were queried about their expectations for fellow prerounds and efficiency of rounds. Responses were quantified by proportions.ResultsFellow and program director response rates were 73% (n=621) and 70% (n=55). Most fellows (74%) report a patient census of >15, arrive at the hospital before 7:00 am (59%), and complete progress notes after 5:00 pm (46%). Among several rounding activities, fellows most valued bedside discussions for building their clinical skills (34%), but only 30% examine all patients with the attending at the bedside. Most directors (71%) expect fellows to both examine patients and collect data before attending-rounds. A majority (78%) of directors commonly complete their documentation after 5:00 pm, and for 36%, after 8:00 pm. Like fellows, directors most value bedside discussion for development of fellows’ clinical skills (44%). Lack of preparedness for the rigors of nephrology fellowship was the most-cited barrier to efficient rounds (31%).ConclusionsHospital rounds in United States nephrology training programs are characterized by high patient volumes, early-morning starts, and late-evening clinical documentation. Fellows use a variety of prerounding styles and examine patients at the beside with their attendings at different frequencies.PodcastThis article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_03_17_CJN.10190819.mp3

The Voice of Paranoia: Norman Mailer's The Executioner's Song

Prospects ◽  
1992 ◽  
Vol 17 ◽  
pp. 459-473
Author(s):  
Patrick O'Donnell
Keyword(s):  
United States ◽  
Civil Liberties ◽  
The United States ◽  
Early Morning ◽  
The State ◽  
Armed Robbery ◽  
Firing Squad ◽  
Public Execution ◽  
American Civil Liberties Union ◽  
The Voice

The facts are these: some time on the early morning of July 20, 1976, Gary Gilmore, barely three months after his release from a twelveyear sentence for armed robbery served in the federal penitentiary at Marion, Illinois, drove into a gas station in Provo, Utah, robbed Max Jensen, the station attendant, and demanded that he lie facedown on the ground. Gilmore then fired twice into Jensen's head at point-blank range with an automatic pistol; Jensen died immediately. In the evening, fourteen or fifteen hours after the first murder, Gilmore drove into a motel situated next door to the house of his relatives, Vern and Ida Damico, who had given Gilmore refuge and found him a job upon his release from prison. Gilmore demanded money from Benny Bushnell, the owner of the motel, asked him to lie face-down on the floor, and then pumped one bullet into his head; Gilmore had intended to shoot him twice, but his gun jammed, and it was several hours before Bushnell would die of his wounds. One day later, Gilmore was arrested for the murder of Benny Bushnell. He was tried and found guilty of murder in the first degree and sentenced to death: his choice of death was by firing squad. Though his mother and the American Civil Liberties Union attempted to block the execution, Gilmore demanded that the state of Utah carry out the sentence. On January 17, 1977, he was shot to death by a team of four handpicked riflemen, in the first public execution to have taken place in the United States in over a decade.

Cloud Properties and Their Seasonal and Diurnal Variability from TOVS Path-B

2006 ◽  
Vol 19 (21) ◽  
pp. 5531-5553 ◽  
Author(s):  
C. J. Stubenrauch ◽  
A. Chédin ◽  
G. Rädel ◽  
N. A. Scott ◽  
S. Serrar
Keyword(s):  
South America ◽  
Diurnal Cycle ◽  
Cloud Amount ◽  
Early Morning ◽  
Infrared Observation ◽  
Relevant Variable ◽  
Diurnal Variability ◽  
Cloud Properties ◽  
Early Afternoon ◽  
The Tropics

Abstract Eight years of cloud properties retrieved from Television Infrared Observation Satellite-N (TIROS-N) Observational Vertical Sounder (TOVS) observations aboard the NOAA polar orbiting satellites are presented. The relatively high spectral resolution of these instruments in the infrared allows especially reliable cirrus identification day and night. This dataset therefore provides complementary information to the International Satellite Cloud Climatology Project (ISCCP). According to this dataset, cirrus clouds cover about 27% of the earth and 45% of the Tropics, whereas ISCCP reports 19% and 25%, respectively. Both global datasets agree within 5% on the amount of single-layer low clouds, at 30%. From 1987 to 1995, global cloud amounts remained stable to within 2%. The seasonal cycle of cloud amount is in general stronger than its diurnal cycle and it is stronger than the one of effective cloud amount, the latter the relevant variable for radiative transfer. Maximum effective low cloud amount over ocean occurs in winter in SH subtropics in the early morning hours and in NH midlatitudes without diurnal cycle. Over land in winter the maximum is in the early afternoon, accompanied in the midlatitudes by thin cirrus. Over tropical land and in the other regions in summer, the maximum of mesoscale high opaque clouds occurs in the evening. Cirrus also increases during the afternoon and persists during night and early morning. The maximum of thin cirrus is in the early afternoon, then decreases slowly while cirrus and high opaque clouds increase. TOVS extends information of ISCCP during night, indicating that high cloudiness, increasing during the afternoon, persists longer during night in the Tropics and subtropics than in midlatitudes. A comparison of seasonal and diurnal cycle of high cloud amount between South America, Africa, and Indonesia during boreal winter has shown strong similarities between the two land regions, whereas the Indonesian islands show a seasonal and diurnal behavior strongly influenced by the surrounding ocean. Deeper precipitation systems over Africa than over South America do not seem to be directly reflected in the horizontal coverage and mesoscale effective emissivity of high clouds.

scholarly journals Relating Passive 37-GHz Scattering to Radar Profiles in Strong Convection

2011 ◽  
Vol 50 (1) ◽  
pp. 233-240 ◽  
Author(s):  
Daniel J. Cecil
Keyword(s):  
Central Africa ◽  
Tropical Rainfall Measuring Mission ◽  
The United States ◽  
Phase Layer ◽  
Tropical Ocean ◽  
Convective Systems ◽  
Freezing Level ◽  
Brightness Temperatures ◽  
Microwave Imager ◽  
Ice Water

Abstract Tropical Rainfall Measuring Mission (TRMM) Microwave Imager and precipitation radar measurements are examined for strong convective systems. Storms having similar values of minimum 37-GHz polarization-corrected temperature (PCT) are grouped together, and their vertical profiles of maximum radar reflectivity are composited. Lower 37-GHz PCT corresponds to stronger radar profiles (high reflectivity through a deep layer), but characteristic profiles for a given 37-GHz PCT are different for deep tropical ocean, deep tropical land, subtropical ocean, and subtropical land regions. Tropical oceanic storms have a sharper decrease of reflectivity just above the freezing level than storms from other regions with the same brightness temperature. Storms from subtropical land regions have the slowest decrease of reflectivity with height and the greatest mixed-phase-layer ice water content (IWC). Linear fits of 37-GHz PCT versus IWC for each region are used to scale the brightness temperatures. Counts of storms with these scaled brightness temperatures below certain thresholds suggest that not as many of the strongest storms occur in central Africa as in subtropical parts of South America, the United States, and central Asia.

scholarly journals Impact of Assimilating Dropsonde Observations from MPEX on Ensemble Forecasts of Severe Weather Events

2016 ◽  
Vol 144 (10) ◽  
pp. 3799-3823 ◽  
Author(s):  
Glen S. Romine ◽  
Craig S. Schwartz ◽  
Ryan D. Torn ◽  
Morris L. Weisman
Keyword(s):  
United States ◽  
Initial Conditions ◽  
Positive Impact ◽  
The United States ◽  
Early Morning ◽  
Severe Weather ◽  
Synoptic Scale ◽  
Ensemble Forecasts ◽  
Forecast Performance ◽  
Weather Events

Over the central Great Plains, mid- to upper-tropospheric weather disturbances often modulate severe storm development. These disturbances frequently pass over the Intermountain West region of the United States during the early morning hours preceding severe weather events. This region has fewer in situ observations of the atmospheric state compared with most other areas of the United States, contributing toward greater uncertainty in forecast initial conditions. Assimilation of supplemental observations is hypothesized to reduce initial condition uncertainty and improve forecasts of high-impact weather. During the spring of 2013, the Mesoscale Predictability Experiment (MPEX) leveraged ensemble-based targeting methods to key in on regions where enhanced observations might reduce mesoscale forecast uncertainty. Observations were obtained with dropsondes released from the NSF/NCAR Gulfstream-V aircraft during the early morning hours preceding 15 severe weather events over areas upstream from anticipated convection. Retrospective data-denial experiments are conducted to evaluate the value of dropsonde observations in improving convection-permitting ensemble forecasts. Results show considerable variation in forecast performance from assimilating dropsonde observations, with a modest but statistically significant improvement, akin to prior targeted observation studies that focused on synoptic-scale prediction. The change in forecast skill with dropsonde information was not sensitive to the skill of the control forecast. Events with large positive impact sampled both the disturbance and adjacent flow, akin to results from past synoptic-scale targeting studies, suggesting that sampling both the disturbance and adjacent flow is necessary regardless of the horizontal scale of the feature of interest.

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