Showing papers in "Journal of Applied Meteorology and Climatology in 2018"
TL;DR: In this paper, a Clausius-Clapeyron equation was used to calculate the saturation vapor pressure of water and of ice in a wide range of temperatures from −100° to 100°C.
Abstract: It is necessary to calculate the saturation vapor pressure of water and of ice for some purposes in many disciplines. A number of formulas are available for this calculation. These formulas either are tedious or are not very accurate. In this study, a new formula has been developed by integrating the Clausius–Clapeyron equation. This new formula is simple and easy to remember. In comparison with the International Association for the Properties of Water and Steam reference dataset, the mean relative errors from this new formula are only 0.001% and 0.006% for the saturation vapor pressure of water and of ice, respectively, within a wide range of temperatures from −100° to 100°C. In addition, this new formula yields a mean relative error of 0.0005% within the commonly occurring temperature range (10°–40°C). Therefore, this new formula has significant advantages over the improved Magnus formula and can be used to calculate the saturation vapor pressure of water and of ice in a wide variety of disciplines.
70 citations
TL;DR: The properties of clouds derived using a suite of remote sensors on board the Australian research vessel (R/V) Investigator during the 5-week Clouds, Aerosols, Precipitation, Radiation, and... as discussed by the authors.
Abstract: The properties of clouds derived using a suite of remote sensors on board the Australian research vessel (R/V) Investigator during the 5-week Clouds, Aerosols, Precipitation, Radiation, and...
49 citations
TL;DR: In this article, a novel method for snow quantification that is based on the joint use of radar reflectivity Z and specific differential phase KDP is introduced, and an extensive dataset of 2D-video-disdrometer measurements of snow in central Oklahoma is used to derive polarimetric relations for liquid-equivalent snowfall rate S and ice water content IWC in the forms of bivariate power-law relations S = and along with similar relations for the intercept N0s and slope Λs of the exponential snow size distribution.
Abstract: Accurate measurements of snow amounts by radar are very difficult to achieve. The inherent uncertainty in radar snow estimates that are based on the radar reflectivity factor Z is caused by the variability of snow particle size distributions and snow particle density as well as the large diversity among snow growth habits. In this study, a novel method for snow quantification that is based on the joint use of radar reflectivity Z and specific differential phase KDP is introduced. An extensive dataset of 2D-video-disdrometer measurements of snow in central Oklahoma is used to derive polarimetric relations for liquid-equivalent snowfall rate S and ice water content IWC in the forms of bivariate power-law relations S = and along with similar relations for the intercept N0s and slope Λs of the exponential snow size distribution. The physical basis of these relations is explained. Their multipliers are sensitive to variations in the width of the canting angle distribution and to a lesser extent the par...
48 citations
TL;DR: The higher temperature in cities relative to their rural surroundings, known as the urban heat island (UHI), is one of the most well documented and severe anthropogenic modifications of the UHI as discussed by the authors.
Abstract: The higher temperature in cities relative to their rural surroundings, known as the urban heat island (UHI), is one of the most well documented and severe anthropogenic modifications of the...
47 citations
TL;DR: In 2006, NCDC (now NCEI) Storm Data, from the contiguous United States were classified as severe at 50 kt (58 mi h−1, or 26 m s−1), whether measured or estimated as discussed by the authors.
Abstract: Convective surface winds in the contiguous United States are classified as severe at 50 kt (58 mi h−1, or 26 m s−1), whether measured or estimated. In 2006, NCDC (now NCEI) Storm Data, from...
46 citations
TL;DR: In this paper, a quasi-vertical profile (QVP) methodology was implemented to investigate the microphysical evolution and significance of intriguing winter polarimetric signatures and their statistical correlations.
Abstract: This study implements a new quasi-vertical profile (QVP) methodology to investigate the microphysical evolution and significance of intriguing winter polarimetric signatures and their statistical correlations. QVPs of transitional stratiform and pure snow precipitation are analyzed using WSR-88D S-band data, alongside their corresponding environmental thermodynamic High-Resolution Rapid Refresh model analyses. QVPs of KDP and ZDR are implemented to demonstrate their value in interpreting elevated ice processes. Several fascinating and repetitive signatures are observed in the QVPs for differential reflectivity ZDR and specific differential phase KDP, in the dendritic growth layer (DGL), and at the tops of clouds. The most striking feature is maximum ZDR (up to 6 dB) in the DGL occurring near the −10-dBZ ZH contour within low KDP and during shallower and warmer cloud tops. Conversely, maximum KDP (up to 0.3° km−1) in the DGL occurs within low ZDR and during taller and colder cloud tops. Essentially...
44 citations
TL;DR: In this paper, an understanding of the atmospheric drivers of rain on snow (ROS) events is required, and an analysis of the ice formed by cold-season rainfall or rain-on-snow is presented.
Abstract: The ice formed by cold-season rainfall or rain on snow (ROS) has striking impacts on the economy and ecology of Alaska. An understanding of the atmospheric drivers of ROS events is required...
43 citations
TL;DR: In this paper, the authors report on measurements of drop size distributions (DSD) using collocated instruments (a Droplet Measurement Technologies, Inc., Meteorological Particle Spectrometer and a 2D-video disdrometer) from two locations with different rainfall climates.
Abstract: We report on measurements of drop size distributions (DSD) using collocated instruments (a Droplet Measurement Technologies, Inc., Meteorological Particle Spectrometer and a 2D-video disdrometer) from two locations with different rainfall climates (Greeley, Colorado, and Huntsville, Alabama, with measurements from the latter that include the outer rainbands of Hurricane Irma). The combination of the two instruments gives what we term as the “full” DSD spectra, the shape of which generally cannot be represented by the standard gamma model, but instead requires the additional flexibility of the generalized gamma model, which includes two shape parameters (μ and c). The double-moment normalization of DSDs using the third and fourth moments is used to arrive at the intrinsic shapes of the DSD with two shape parameters that are shown to capture simultaneously the drizzle mode as well as the precipitation mode, together with a “plateau” region between the two. The estimation of μ and c is done with a g...
41 citations
TL;DR: In this paper, the ability of cool roofs and vegetation to reduce urban temperatures and improve human thermal stress during heat wave conditions was investigated for the city of Melbourne, Australia, and the results showed that cooling roofs can reduce urban temperature and improve thermal stress.
Abstract: The ability of cool roofs and vegetation to reduce urban temperatures and improve human thermal stress during heat wave conditions is investigated for the city of Melbourne, Australia. The ...
40 citations
TL;DR: In this paper, the authors present an application of the method of factor separation to assess combined impacts of a synoptic-scale heat wave, urban land cover, and urban energy and momentum fluxes on temperatures and winds over New York City, New York, via use of high-resolution simulations (1-km grid spacing) with an urbanized version of the Weather Research and Forecasting (WRF) Model Results showed that factors behaved different throughout the day, withsynoptic conditions dominating afternoon temperature contributions (>7°C) At night, combined urban surface factors contributed
Abstract: Heat waves are projected to increase in magnitude and frequency throughout this century because of increasing global temperatures, making it critically important to acquire improved understanding of their genesis and interactions with large cities This study presents an application of the method of factor separation to assess combined impacts of a synoptic-scale heat wave, urban land cover, and urban energy and momentum fluxes on temperatures and winds over New York City, New York, via use of high-resolution simulations (1-km grid spacing) with an urbanized version of the Weather Research and Forecasting (WRF) Model Results showed that factors behaved different throughout the day, with synoptic conditions dominating afternoon temperature contributions (>7°C) At night, combined urban surface factors contributed over 5°C during the heat wave and up to 15°C on non-heat-wave days Positive interactions among all factors during morning and nighttime indicate an amplification of the urban heat islan
38 citations
TL;DR: This research evaluates the ability of image-processing and select machine-learning algorithms to identify midlatitude mesoscale convective systems (MCSs) in radar-reflectivity images for the conterminous United States and suggests that machine learning can add value by limiting the amount of false-positive samples that are not removed by segmentation alone.
Abstract: This research evaluates the ability of image-processing and select machine-learning algorithms to identify midlatitude mesoscale convective systems (MCSs) in radar-reflectivity images for t...
TL;DR: In this article, the severity of tree-caused outages in Connecticut is estimated under future-climate Hurricane Sandy simulations, each exhibiting strengthened winds and heavier rain accumulation over the study area from large-scale thermodynamic changes in the atmosphere and track changes, referred to as Future Sandy.
Abstract: Hurricane Sandy (2012, referred to as Current Sandy) was among the most devastating storms to impact Connecticut’s overhead electric distribution network, resulting in over 15 000 outage locations that affected more than 500 000 customers. In this paper, the severity of tree-caused outages in Connecticut is estimated under future-climate Hurricane Sandy simulations, each exhibiting strengthened winds and heavier rain accumulation over the study area from large-scale thermodynamic changes in the atmosphere and track changes in the year ~2100 (referred to as Future Sandy). Three machine-learning models used five weather simulations and the ensemble mean of Current and Future Sandy, along with land-use and overhead utility infrastructure data, to predict the severity and spatial distribution of outages across the Eversource Energy service territory in Connecticut. To assess the influence of increased precipitation from Future Sandy, two approaches were compared: an outage model fit with a full set of...
TL;DR: A 17-yr "climatology" of tropical-system activity, track, size, and 24-h intensity change in the southwest Indian Ocean (SWIO) is developed and analyzed in comparison with other intensively as mentioned in this paper.
Abstract: A 17-yr “climatology” of tropical-system activity, track, size, and 24-h intensity change in the southwest Indian Ocean (SWIO) is developed and analyzed in comparison with other intensively
TL;DR: In this article, both hail occurrence and maximum hail diameter (MHD) data from more than 2000 surface stations were released by the National Meteorological Information Center of China (NMCIC) for the period of 1980 to 2015.
Abstract: The hail day climatology from 1961 to 2005 was previously studied based on hundreds of surface stations in China Recently, both hail occurrence and maximum hail diameter (MHD) data from more than 2000 surface stations were released by the National Meteorological Information Center of China These data enable hail climatology to be explored using both hail frequency (HF), which is defined as annual mean hail occurrence, and MHD records from more stations over the entire country Following quality control, hail data from 2254 stations were selected for the period of 1980–2015 In general, HF increased with station topography height, with a maximum of more than 30 events per year in the Tibetan Plateau and a minimum of less than 1 event per year in southern China, whereas the station mean MHD decreased with topography height The highest peak of the 80th-percentile cumulative distribution function of the annual MHD cycle in southern China occurred in May but was delayed to July in the north Severe
TL;DR: In this article, the authors studied the influence of El Nino-Southern Oscillation (ENSO) and the Gulf of Mexico (GoM) on winter tornado variability and significant EF2+ environments.
Abstract: El Nino–Southern Oscillation (ENSO) and the Gulf of Mexico (GoM) influence winter tornado variability and significant tornado (EF2+, where EF is the enhanced Fujita scale) environments. Inc...
TL;DR: The urban heat island (UHI) has a negative impact on the health of urban residents by increasing average temperatures and the intensity of the UHI effect is influenced by urban geometry and urban geometry.
Abstract: The urban heat island (UHI) has a negative impact on the health of urban residents by increasing average temperatures. The intensity of the UHI effect is influenced by urban geometry and th...
TL;DR: A 2-yr cloud microphysical property dataset derived from ground-based remote sensors at the Atmospheric Radiation Measurement site near Barrow, Alaska, was used as input into a radiative tracer as mentioned in this paper.
Abstract: A 2-yr cloud microphysical property dataset derived from ground-based remote sensors at the Atmospheric Radiation Measurement site near Barrow, Alaska, was used as input into a radiative tr...
TL;DR: In this article, the authors investigated the wind stress formulation in an atmospheric model over shallow waters using year-long observations of the wind profile within the first 100 m of the atmosphere and mesoscale simulations.
Abstract: The wind stress formulation in an atmospheric model over shallow waters is investigated using year-long observations of the wind profile within the first 100 m of the atmosphere and mesoscale simulations. The model experiments use a range of planetary boundary layer parameterizations to quantify the uncertainty related to the turbulent closure assumptions and thus to isolate the dominant influence of the surface roughness formulation. Results indicate that a positive wind speed bias exists when common open-ocean formulations for roughness are adopted for a region with a water depth of 30 m. Imposition of a wind stress formulation that is consistent with previous shallow-water estimates is necessary to reconcile model wind speeds with observations, providing modeling evidence that supports the increase of surface drag over shallow waters. The possibility of including water depth in the parameterization of roughness length is examined.
TL;DR: The properties of clouds derived from measurements collected using a suite of remote sensors on board the Australian R/V Investigator during a 5-week voyage into the Southern Ocean during M....
Abstract: The properties of clouds derived from measurements collected using a suite of remote sensors on board the Australian R/V Investigator during a 5-week voyage into the Southern Ocean during M...
TL;DR: In this paper, the authors studied regional-scale carbon dioxide transport, temporal variability, and budget over the Southern California Air Basin (SoCAB) during the California Research at the Nexus of Air Qu...
Abstract: To study regional-scale carbon dioxide (CO2) transport, temporal variability, and budget over the Southern California Air Basin (SoCAB) during the California Research at the Nexus of Air Qu...
TL;DR: The present work adopts the peak-over-threshold method of classifying points as extreme if they exceed a pre-specified threshold, which eliminates much of the noise that was produced by the existing models due to a short data record, producing more reasonable ARI maps when compared with NOAA's long-term Climate Prediction Center ground-based observations.
Abstract: This paper improves upon an existing extreme precipitation monitoring system based on the Tropical Rainfall Measuring Mission (TRMM) daily product (3B42) using new statistical models. The proposed system utilizes a regional modeling approach, where data from similar locations are pooled to increase the quality of the resulting model parameter estimates to compensate for the short data record. The regional analysis is divided into two stages. First, the region defined by the TRMM measurements is partitioned into approximately 28,000 non-overlapping clusters using a recursive k-means clustering scheme. Next, a statistical model is used to characterize the extreme precipitation events occurring in each cluster. Instead of applying the block-maxima approach used in the existing system, where the Generalized Extreme Value probability distribution is fit to the annual precipitation maxima at each site separately, the present work adopts the peak-over-threshold method of classifying points as extreme if they exceed a pre-specified threshold. Theoretical considerations motivate using the Point Process framework for modeling extremes. The fitted parameters are used to estimate trends and to construct simple and intuitive average recurrence interval (ARI) maps which reveal how rare a particular precipitation event is. This information could be used by policy makers for disaster monitoring and prevention. The new methodology eliminates much of the noise that was produced by the existing models due to a short data record, producing more reasonable ARI maps when compared with NOAA's long-term Climate Prediction Center ground-based observations. Furthermore, the proposed methodology can be applied to other extreme climate records.
TL;DR: In this article, self-organizing maps (SOMs) are employed to objectively classify the 500-hPa geopotential height patterns for 33 years of reanalysis fields (ERA-Interim) into pretrough, trough, posttrough, ridge, and zonal flow categories.
Abstract: Marine boundary layer clouds are modified by processes at different spatial and temporal scales. To isolate the processes governing aerosol–cloud–precipitation interactions, multiday synoptic variability of the environment must be accounted for. Information on the location of low clouds relative to the ridge–trough pattern gives insight into how cloud properties vary as a function of environmental subsidence and stability. The technique of self-organizing maps (SOMs) is employed to objectively classify the 500-hPa geopotential height patterns for 33 years of reanalysis fields (ERA-Interim) into pretrough, trough, posttrough, ridge, and zonal-flow categories. The SOM technique is applied to a region of prevalent marine low cloudiness over the eastern North Atlantic Ocean that is centered on the Azores island chain, the location of a long-term U.S. Department of Energy observation site. The Azores consistently lie in an area of substantial variability in synoptic configuration, thermodynamic environ...
TL;DR: For example, high mixing ratios of ozone along the shores of Lake Michigan have been a recurring theme over the last 40 years and models continue to have difficulty in replicating ozone behavior in the reg...
Abstract: High mixing ratios of ozone along the shores of Lake Michigan have been a recurring theme over the last 40 years. Models continue to have difficulty in replicating ozone behavior in the reg...
TL;DR: Stall warnings at flight level 410 (125 km) occurred unexpectedly during a research flight of the High Altitude and Long Range Research Aircraft (HALO) over Italy on 12 January 2016 as discussed by the authors.
Abstract: Stall warnings at flight level 410 (125 km) occurred unexpectedly during a research flight of the High Altitude and Long Range Research Aircraft (HALO) over Italy on 12 January 2016 The d
TL;DR: A 10-yr geostationary (GEO) overshooting cloud-top (OT) detection database using Multifunction Transport Satellite (MTSAT) Japanese Advanced Meteorological Imager (JAMI) observations has been developed over the Australian region as mentioned in this paper.
Abstract: A 10-yr geostationary (GEO) overshooting cloud-top (OT) detection database using Multifunction Transport Satellite (MTSAT) Japanese Advanced Meteorological Imager (JAMI) observations has been developed over the Australian region. GEO satellite imagers collect spatially and temporally detailed observations of deep convection, providing insight into the development and evolution of hazardous storms, particularly where surface observations of hazardous storms and deep convection are sparse and ground-based radar or lightning sensor networks are limited. Hazardous storms often produce one or more OTs that indicate the location of strong updrafts where weather hazards are typically concentrated, which can cause substantial impacts on the ground such as hail, damaging winds, tornadoes, and lightning and to aviation such as turbulence and in-flight icing. The 10-yr OT database produced using an automated OT detection algorithm is demonstrated for analysis of storm frequency, diurnally, spatially, and sea...
TL;DR: The authors showed that the Weather Research and Forecasting (WRF) model often underpredicts the strength of the Great Plains nocturnal low-level jet (NLLJ), which has implications.
Abstract: Previous studies have shown that the Weather Research and Forecasting (WRF) Model often underpredicts the strength of the Great Plains nocturnal low-level jet (NLLJ), which has implications...
TL;DR: The sea-breeze circulations are a prominent source of diurnal wind variability along coastlines throughout the world as mentioned in this paper, and the sea breeze is the largest source of variability in the co...
Abstract: Sea-breeze circulations are a prominent source of diurnal wind variability along coastlines throughout the world. For Delaware, the sea breeze is the largest source of variability in the co...
TL;DR: Coefficients for computing the polarization-corrected temperature (PCT) for 10-, 19-, 37- and 89-GHz frequencies with applicability to satellites in the Global Positioning System (GPS) were derived in this article.
Abstract: Coefficients are derived for computing the polarization-corrected temperature (PCT) for 10-, 19-, 37- and 89-GHz (and similar) frequencies, with applicability to satellites in the Global Pr...
TL;DR: The Wyoming Weather Modification Pilot Project randomized cloud seeding experiment was a crossover statistical experiment conducted over two mountain ranges in eastern Wyoming and lasted for two weeks as mentioned in this paper. But the experiment was not conducted in the wild.
Abstract: The Wyoming Weather Modification Pilot Project randomized cloud seeding experiment was a crossover statistical experiment conducted over two mountain ranges in eastern Wyoming and lasted fo...
TL;DR: Met Eireann, the Irish Meteorological Service, has generated a very high resolution (25km horizontal grid) regional climate reanalysis for Ireland called the MET EireANN Reanalysis (MERA) as mentioned in this paper.
Abstract: Met Eireann, the Irish Meteorological Service, has generated a very high resolution (25-km horizontal grid) regional climate reanalysis for Ireland called the Met Eireann Reanalysis (MERA)