116 research outputs found
Nowcasting lightning occurrence from commonly available meteorological parameters using machine learning techniques
No full textArticle Open Access Published: 08 November 2019 Nowcasting lightning occurrence from commonly available meteorological parameters using machine learning techniques Amirhossein Mostajabi, Declan L. Finney, Marcos Rubinstein & Farhad Rachidi npj Climate and Atmospheric Science volume 2, Article number: 41 (2019) Cite this article Article metrics 71 Altmetric Metrics details Abstract Lightning discharges in the atmosphere owe their existence to the combination of complex dynamic and microphysical processes. Knowledge discovery and data mining methods can be used for seeking characteristics of data and their teleconnections in complex data clusters. We have used machine learning techniques to successfully hindcast nearby and distant lightning hazards by looking at single-site observations of meteorological parameters. We developed a four-parameter model based on four commonly available surface weather variables (air pressure at station level (QFE), air temperature, relative humidity, and wind speed). The produced warnings are validated using the data from lightning location systems. Evaluation results show that the model has statistically considerable predictive skill for lead times up to 30 min. Furthermore, the importance of the input parameters fits with the broad physical understanding of surface processes driving thunderstorms (e.g., the surface temperature and the relative humidity will be important factors for the instability and moisture availability of the thunderstorm environment). The model also improves upon three competitive baselines for generating lightning warnings: (i) a simple but objective baseline forecast, based on the persistence method, (ii) the widely-used method based on a threshold of the vertical electrostatic field magnitude at ground level, and, finally (iii) a scheme based on CAPE threshold. Apart from discussing the prediction skill of the model, data mining techniques are also used to compare the patterns of data distribution, both spatially and temporally among the stations. The results encourage further analysis on how mining techniques could contribute to further our understanding of lightning dependencies on atmospheric parameters.SCI-STI-F
Present-day and future lightning, and its impact on tropospheric chemistry
No full textLightning represents a key interaction with climate through its production of
nitrogen oxides (NOx) which lead to ozone production. These NOx emissions are
generally calculated interactively in chemistry-climate models but there has been
little development of the representation of the lightning processes since the 1990s.
In most models the parametrisation of lightning is based upon simulated cloud-top
height. The aims of the thesis are: to explore existing schemes, and develop
a new process-based scheme, to parametrise lightning; to use a new process-based
lightning scheme to give insights regarding the role of lightning NOx in
tropospheric chemistry; and to use alternative lightning schemes to improve the
understanding of the response of lightning to climate change, and the consequent
impacts on tropospheric chemistry.
First, a new lightning parametrisation is developed using reanalysis data and
satellite lightning observations which is based on upward cloud ice flux. This
parametrisation is more closely linked to thunderstorm charging theory. It greatly
improves the simulated zonal distribution of lightning compared to the cloud-top
height approach, which overestimates lightning in the tropics. The new lightning
scheme is then implemented in a chemistry-climate model, the UK Chemistry
and Aerosol model (UKCA). It is evaluated against ozone sonde measurements
with broad global coverage and improves the simulation of the annual cycle of
upper tropospheric ozone concentration, compared to ozone simulated with the
cloud-top height approach. This improvement in simulated ozone is attributed to
the change in ozone production associated with the improved zonal distribution
of simulated lightning.
Subsequently, data from a chemistry-climate model intercomparison project (ACCMIP)
are used to study the state-of-the-art in lightning NOx parametrisation
along with its response to climate change. It is found that the models using the
cloud-top height approach produce a very similar response of lightning NOx to
changes in global mean surface temperature of +0.44± 0.05 TgNK-1, for a baseline
emission of 5 TgN yr-1. However, two models using two alternative lightning
schemes produce a weaker and a negative response of lightning to climate change.
Finally, simulations in a future climate scenario for year 2100 in the UKCA model
were performed with the cloud-top height and the ice flux parametrisations. The
lightning response to climate change when using the cloud-top height scheme is
in good agreement with the positive response found in the multi-model results
of the cloud-top height approach. However, the new ice flux approach suggests
that lightning will decrease in future. These opposing responses introduce large
uncertainty into the projections of tropospheric ozone and methane lifetime in the
future scenario. An analysis of the radiative forcing from these two species also
shows the large uncertainty in the individual methane and ozone radiative forcings
in the future. Due to the opposite effect that lightning NOx has on methane (loss)
and ozone (production) the net radiative forcing effect of lightning in present-day
and future is found to be close to zero. However, there is a small positive feedback
suggested by the results of the cloud-top height approach, whereas no feedback is
evident with the ice flux approach.
These results show there are large and crucial uncertainties introduced by
lightning parametrisation choice, not only in terms of the actual lightning
distribution but also atmospheric composition and radiative forcing. The new
ice-based parametrisation developed here offers a good alternative to the widely-used
approach and can be used in future to model lightning and develop the
understanding of associated uncertainties
Land use map, Finney County, Kansas
No full textThe author has identified the following significant results. Methods for the mapping of land use in agricultural regions are developed and applied to preparation of a land use map of Finney County, Kanas. Six land use categories were identified from an MSS-5 image. These categories are: (1) large field irrigation; (2) small field irrigation; (3) dryland cultivation; (4) rangeland; (5) cultural features; and (6) riverine land. The map is composed of basically homogeneous regions with definable mixtures of the six categories. Each region is bounded by an ocularly evident change in land use
Discrimination of winter wheat on irrigated land in southern Finney County, Kansas
No full textThe author has identified the following significant results. Winter wheat in the large field irrigated landscape of southern Finney County, Kansas was successfully discriminated by use of 4 ERTS-1 images. These images were acquired 16 August 1972, 21 September 1972, and 2 December 1972. MSS-5 images from each date and the MSS-7 image from 2 December 1972 were used. Human interpretation of the four images resulted in a classification scheme which produced 98% correct estimation of the number of wheat fields in the training sample and 100% correct estimation in the test sample. Overall correct separation of wheat from non-wheat fields was 93% and 86%, respectively. Offsetting errors resulted in the estimation accuracy for wheat
A History of Irrigation in the Arkansas River Valley in Western Kansas, 1880-1910
No full textOne of the important adjustments made by the settlers of the High Plains to their new environment was the introduction of irrigation agriculture. Among the earliest and most important centers of this development was the Arkansas River Valley of western Kansas, in particular the community around Garden City, Kansas. This history attempts to relate the development of irrigation in the Arkansas Valley through its formative years, 1880-1910. The term "Arkansas River Valley" as used here refers to that portion of the valley of the Arkansas in the Counties of Hamilton, Kearny, Finney, Gray, and Ford, and the adjacent uplands which were influenced by the practice of irrigation. Statistitcs generally refer to those counties unless otherwise stated. The author is indebted to his advisor, Dr. George L. Anderson, who suggested the topic and provided guidance and encouragement toward its completion. Most of the research was done in the Kansas State Historical Society whose staff was most understanding and helpful. Among the many friends of irrigation in western Kansas special thanks are due to Mr. Clyde Beymer of Lakin who furnished abstracts to the South Side, Great Eastern, and Amazon Ditches, Mr. Edward Dekeiser of Deerfield who loaned a large plat of the Amazon Canal, the Garden City law firm of Calahan, Green, Calahan, and High and to their secretary Mrs. Luava Golightly (who is also secretary of the Finney County Water Users' Association) who provided free access to the Records of the Water Users' Association. Thanks are also due to the county officials in Hamilton, Kearny, Finney, Gray, and Ford Counties who provided assistance in locating and copying local records
Lipids in the storage organs of three mermithid nematodes and in the hemolymph of their hosts
No full textTrophosomes of the mosquito parasitic mermithid Romanomermis culicivorax and two strains of the simuliid parasitic mermithid Mesomermis flumenalis (Neomesomermis flumenalis) contained in order of prevalence: triacylglycerols, phospholipids, sterols and sterol esters. Triacylglycerols in the trophosomes comprised a wide array of fatty acids, sterol esters a smaller variety. The degree of unsaturation of triacylglycerols and sterol esters was greater for M. flumenalis than R. culicivorax. The haemolymph of the 3 host species (Aedes aegypti (L.), Prosimulium mixtum Syme & Davis/S. fuscum Syme & Davis and Simulium venustum Say) contained an assortment of fatty acids, with a higher degree of unsaturation in the simuliids than in the culicid. The overall lipid concentration of the blood of A. aegypti was unaltered by parasitism, but the mermithid caused an increase in the myristic acid: palmitic acid ratio in the free fatty acid fraction of the host's haemolymph.ADDITIONAL ABSTRACT:Analysis of the trophosomes of Romanomermis culicivorax and Neomesomermis flumenalis showed the presence, in decreasing order of concentration, of triacylglycerols, phospholipids, sterols and sterol esters. The degree of unsaturation of triacylglycerols and sterol esters was larger in N. flumenalis than R. culicivorax. Parasitism of Aedes aegypti resulted in an increase in the myristic acid: palmitic acid ratio in the free fatty acid fraction of the mosquito haemolymph..RE: 36 ref.; RN: 544-63-8; 57-10-3; SC: ZA; HE; CA; BE; PE; PA; VE; 0J; 0T; 0H; 0NSource type: Electronic(1
Review of \u3ci\u3eThe Great Kansas Bond Scandal\u3c/i\u3e By Robert Smith Bader
No full textIn 1933 Kansas was mired in the Great Depression, ravaged by the Dust Bowl, and afflicted by human cupidity. The biggest public scandal in Kansas history is the subject of this thorough and well-written monograph.
Ronald and Warren Finney, son and father, were the principal malefactors in the bond scandal. The state reverberated from the exposure of the freewheeling, charismatic Ronald\u27s forging and deposit of bonds in the state treasury, brokerage houses, and banks to finance high living and business ventures. Even more disquieting was the knowledge of the culpability of his father, a respected, civic-spirited, influential businessman and banker of Emporia, and a friend of William Allen White and Governor Alfred Mossman Landon.
The integrity of state government was questioned when the public learned of the scandal\u27s repercussions on state finances and that a few high office holders abetted the Finney machinations through negligence and complicity. Acting decisively and without fear or favor, Governor Landon sustained confidence in his administration through the vigorous prosecution of the offenders, including his friend and the state treasurer. This was, the author asserts, the prerequisite to Landon\u27s reelection and the 1936 Republican presidential nomination.
The disposition of the culprits receives substantial attention, and some interesting chapters are included on the impeachment and trials of the attorney general and auditor (both were acquitted), and the protracted and complicated criminal proceedings against the principals, which ended in convictions and three of the longest prison sentences in state history. Warren Finney committed suicide before imprisonment.
The final chapters focus on the reform of Ronald Finney, his release from prison, and his life as a responsible citizen. A model prisoner at Lansing, Finney developed his literary aptitude, with the assistance of Kathrine and William L. White, and earned a modest income. The active intercession of the White family helped Finney obtain a parole, and his last years were spent with his second wife as a writer for trade journals.
A strong secondary theme of the book involves the study in conflict between friendship and principle. Because the Whites were close friends of the Finneys, their position was especially poignant. They refused either to abandon friends or to compromise principles, and the author shows the strain and occasional impossibility of reconciling the two.
Inured to malfeasance and chicanery, this generation will find Bader\u27s book instructive on the effect of public corruption on an earlier and less sophisticated society shocked to the depths of its puritanical soul. The author concludes that the total financial, political, psychological, and personal cost of the tragic affairs became almost impossible to calculate, but he has convincingly probed human wreckage and public despair from cover to cover
Center pivot irrigation in Finney County, Kansas: An ERTS-1 interpretation procedure
No full textThere are no author-identified significant results in this report
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Cloud feedback uncertainty in the equatorial Pacific across CMIP6 models
No full textCloud feedback is the largest uncertainty in estimating Equilibrium Climate Sensitivity. In this study we focus on the equatorial Pacific, where CMIP6 model cloud feedback spread is notably large. Cloud radiative effects in this region are relevant for the global climate. Our findings show that models predict a consistent shift towards the ascent regime in response to El Nino‐like sea surface warming. Models diverge in terms of the radiative impact due to differences in cloud characteristics in ascent and subsidence regimes. Using the observed relationship between circulation regime and cloud radiative effect, we find a reduction in the regional mean cloud feedback estimate from 0.77 to 0.22 W m− 2 K− 1, though this does not substantially lessen the model spread in total feedback. Pathways to reduce this spread include: improving confidence in the regional ocean warming pattern, and using observations and models to understand cloud type and circulation interactions
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