You searched for +publisher:"Colorado State University" +contributor:("Chiu, Christine").
Showing records 1 – 6 of
6 total matches.
No search limiters apply to these results.
Colorado State University
1.
Trabing, Benjamin.
Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The.
Degree: MS(M.S.), Atmospheric Science, 2018, Colorado State University
URL: http://hdl.handle.net/10217/191282 
► Potential intensity (PI) theory predicts that the tropopause temperature acts as a powerful constraint on tropical cyclone (TC) intensity and structure. The physical mechanisms by…
(more)
▼ Potential intensity (PI) theory predicts that the tropopause temperature acts as a powerful constraint on tropical cyclone (TC) intensity and structure. The physical mechanisms by which the upper tropospheric thermal structure and radiative forcing impact TC intensity and structure have not been fully explored however, due in part to limited observations and the complex interactions between clouds, radiation, and storm dynamics. Idealized Weather Research and Forecasting (WRF) ensembles were conducted using a combination of three different tropopause temperatures (196, 199, and 202 K) with different radiation schemes (full diurnal radiation, longwave only, and no radiation) on weather timescales. The simulated TC intensity and structure were strongly sensitive to colder tropopause temperatures using only longwave radiation, but were less sensitive using full-radiation and no radiation. The maximum intensity of the longwave only simulations were more sensitive to small boundary layer moisture perturbations in the initial conditions. Colder tropopause temperatures resulted in deeper convection, increased ice mass aloft, and when radiation was included more intense storms on average. Deeper convection led to increased local longwave cooling rates but reduced top of atmosphere outgoing longwave radiation, such that from a Carnot engine perspective, the radiative heat sink is reduced in the stronger storms. It is hypothesized that a balanced response in the secondary circulation described by the Eliassen equation arises from upper troposphere radiative cooling/heating anomalies that leads to stronger tangential winds. The results of this study further suggest that cloud-radiative feedbacks have a non-negligible impact on weather timescales.
Advisors/Committee Members: Bell, Michael (advisor), Chiu, Christine (committee member), Suryanarayanan, Siddharth (committee member).
Subjects/Keywords: radiation; upper troposphere; tropical cyclones; potential intensity
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Trabing, B. (2018). Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/191282
Chicago Manual of Style (16th Edition):
Trabing, Benjamin. “Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The.” 2018. Masters Thesis, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/191282.
MLA Handbook (7th Edition):
Trabing, Benjamin. “Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The.” 2018. Web. 07 Mar 2021.
Vancouver:
Trabing B. Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The. [Internet] [Masters thesis]. Colorado State University; 2018. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/191282.
Council of Science Editors:
Trabing B. Impact of upper tropospheric temperatures and radiation on idealized tropical cyclones, The. [Masters Thesis]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/191282
Colorado State University
2.
Morin, Alexander.
System design and development of Front-X: an X-band dual-polarization phased array weather radar.
Degree: MS(M.S.), Electrical and Computer Engineering, 2019, Colorado State University
URL: http://hdl.handle.net/10217/195313
► The electronic beam steering capability of phased array weather radars has the potential to improve the temporal resolution of meteorological data and enable the development…
(more)
▼ The electronic beam steering capability of phased array weather radars has the potential to improve the temporal resolution of meteorological data and enable the development of multifunction radars, yet questions about their dual-polarimetric performance remain an ongoing topic of research. This thesis presents the system design and development of Front-X, an X-band dual-polarization phased array weather radar capable of both electronic and mechanical beam steering, whose purpose is to serve as a test-bed for implementing adaptive scan strategies, developing phased array radar calibration techniques, and exploring the efficacy of electronic scanning for weather applications. The design, development, calibration, and configuration of a system controller, antenna positioner, and signal processor are discussed. Furthermore, the system is demonstrated through a comparison of polarimetric electronic and mechanical scan weather data, including various electronic scan correction methods, and visually verified through a comparison to data collected with the proven CHILL X-band radar.
Advisors/Committee Members: Chandrasekar, V. (advisor), Cheney, Margaret (committee member), Chiu, Christine (committee member).
Subjects/Keywords: mechanical beam steering; system control; electronic beam steering; weather radar; phased array
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Morin, A. (2019). System design and development of Front-X: an X-band dual-polarization phased array weather radar. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/195313
Chicago Manual of Style (16th Edition):
Morin, Alexander. “System design and development of Front-X: an X-band dual-polarization phased array weather radar.” 2019. Masters Thesis, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/195313.
MLA Handbook (7th Edition):
Morin, Alexander. “System design and development of Front-X: an X-band dual-polarization phased array weather radar.” 2019. Web. 07 Mar 2021.
Vancouver:
Morin A. System design and development of Front-X: an X-band dual-polarization phased array weather radar. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/195313.
Council of Science Editors:
Morin A. System design and development of Front-X: an X-band dual-polarization phased array weather radar. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195313
Colorado State University
3.
Gonzalez, Ryan L.
Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm.
Degree: MS(M.S.), Atmospheric Science, 2019, Colorado State University
URL: http://hdl.handle.net/10217/199801
► Snow is an important wintertime property because it is a source of freshwater, regulates land-atmosphere exchanges, and increases the surface albedo of snow-covered regions. Unfortunately,…
(more)
▼ Snow is an important wintertime property because it is a source of freshwater, regulates land-atmosphere exchanges, and increases the surface albedo of snow-covered regions. Unfortunately, in-situ observations of both snowfall and snow water equivalent (SWE) are globally sparse and point measurements are not representative of the surrounding area, especially in mountainous regions. The total amount of land covered by snow, which is climatologically important, is fairly straightforward to measure using satellite remote sensing. The total SWE is hydrologically more useful, but significantly more difficult to measure. Accurately measuring snowfall and SWE is an important first step toward a better understanding of the impacts snow has for hydrological and climatological purposes. Satellite passive microwave retrievals of snow offer potential due to consistent overpasses and the capability to make measurements during the day, night, and cloudy conditions. However, passive microwave snow retrievals are less mature than precipitation retrievals and have been an ongoing area of research. Exacerbating the problem, communities that remotely sense snowfall and SWE from passive microwave sensors have historically operated independently while the accuracy of the products has suffered because of the physical and radiometric dependency between the two. In this study, we assessed the relationship between the Northern Hemisphere snowfall and SWE products from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). This assessment provides insight into regimes that can be used as a starting point for future improvements using coupled snowfall and SWE algorithm. SnowModel, a physically-based snow evolution modeling system driven by the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis, was employed to consistently compare snowfall and SWE by accounting for snow evolution. SnowModel has the ability to assimilate observed SWE values to scale the amount of snow that must have fallen to match the observed SWE. Assimilation was performed using AMSR-E, Canadian Meteorological Centre (CMC) Snow Analysis, and Snow Data Assimilation System (SNODAS) SWE to infer the required snowfall for each dataset. Observed AMSR-E snowfall and SWE were then compared to the MERRA-2 snowfall and SnowModel-produced SWE as well as SNODAS and CMC inferred snowfall and observed SWE. Results from the study showed significantly different snowfall and SWE bias patterns observed by AMSR-E. Specifically, snowfall was underestimated nearly globally and SWE had pronounced regions of over and underestimation. Snowfall and SWE biases were found to differ as a function of surface temperature, snow class, and elevation.
Advisors/Committee Members: Kummerow, Christian (advisor), Liston, Glen (committee member), Chiu, Christine (committee member), Notaros, Branislav (committee member).
Subjects/Keywords: satellite; snowfall; SWE; snow; remote sensing; snow water equivalent
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Gonzalez, R. L. (2019). Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/199801
Chicago Manual of Style (16th Edition):
Gonzalez, Ryan L. “Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm.” 2019. Masters Thesis, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/199801.
MLA Handbook (7th Edition):
Gonzalez, Ryan L. “Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm.” 2019. Web. 07 Mar 2021.
Vancouver:
Gonzalez RL. Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/199801.
Council of Science Editors:
Gonzalez RL. Consistency in the AMSR-E snow products: groundwork for a coupled snowfall and SWE algorithm. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/199801
Colorado State University
4.
Trabing, Benjamin.
On intensity change and the effects of shortwave radiation on tropical cyclone rainbands.
Degree: PhD, Atmospheric Science, 2020, Colorado State University
URL: http://hdl.handle.net/10217/219626
► In this dissertation, the effects of shortwave radiation and the diurnal cycle of radiation on tropical cyclone rainbands are explored. In order to improve short…
(more)
▼ In this dissertation, the effects of shortwave radiation and the diurnal cycle of radiation on tropical cyclone rainbands are explored. In order to improve short term forecasts of tropical cyclone intensity and size, a better understanding of the processes that affect the inner rainbands of tropical cyclones is warranted. In Chapter 2, the distribution of intensity forecast errors from the National Hurricane Center (NHC) are characterized in the Atlantic and East Pacific basins. Analysis of the forecast error distributions and the relationship between the thermodynamic environments in which those errors occur leads to the conclusion that improvements need to be made to our understanding and prediction of inner-core processes, particularly to predict rapid changes in intensification and weakening. The effect of shortwave radiation on tropical cyclone rainbands during an eyewall replacement cycle (ERC) is examined in Chapter 3. In the idealized experiments we vary the amount of incoming solar radiation to change the magnitude of the response and assess the sensitivity of the timing of the ERC. Shortwave radiation has a delaying effect on the ERC primarily through its modifications of the distribution of convective and stratiform heating profiles in the rainbands. Shortwave radiation reduces the amount and strength of convective heating profiles by stabilizing the thermodynamic profiles and reducing convective available potential energy. The idealized modeling study shows that the coupled interactions between the shortwave radiation and the cloud microphysics is at the crux of the experiment and requires further verification by observations. Chapter 4 explores the diurnal cycle of convection in the rainbands of Typhoon Kong-rey (2018) using a suite of novel observations from the Propagation of Intraseasonal Tropical Oscillations (PISTON) field campaign. Convection in the rainbands of Typhoon Kong-rey had a more pronounced diurnal cycle compared to the rest of PISTON where shortwave heating in the upper-levels increased the static stability during the day. Pronounced diurnal oscillations in the brightness temperatures, which are out of phase with those documented in Dunion et al. (2014), are found to be coupled with outflow jets below the tropopause and radially outward propagating convective rainbands approximately ∼6 hours later. In Chapter 5 an attempt is made to simulate the diurnal variations in the rainbands of Typhoon Kong-rey that were observed during PISTON. Four experiments are conducted using commonly used shortwave radiation and cloud microphysics schemes to determine the extent to which previous and future studies can reproduce diurnal variability. Of the four experiments, only one realistically simulated Typhoon Kong-rey's rapid intensification and none of the experiments reproduce the diurnal oscillations in the infrared brightness temperatures. The interactions between the shortwave radiation and cloud microphysics schemes cause variations in the distribution of convective and stratiform pre- cipitation…
Advisors/Committee Members: Bell, Michael (advisor), Chiu, Christine (committee member), Knaff, John (committee member), Windom, Bret (committee member), van den Heever, Sue (committee member).
Subjects/Keywords: tropical cyclones; radiation
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Trabing, B. (2020). On intensity change and the effects of shortwave radiation on tropical cyclone rainbands. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/219626
Chicago Manual of Style (16th Edition):
Trabing, Benjamin. “On intensity change and the effects of shortwave radiation on tropical cyclone rainbands.” 2020. Doctoral Dissertation, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/219626.
MLA Handbook (7th Edition):
Trabing, Benjamin. “On intensity change and the effects of shortwave radiation on tropical cyclone rainbands.” 2020. Web. 07 Mar 2021.
Vancouver:
Trabing B. On intensity change and the effects of shortwave radiation on tropical cyclone rainbands. [Internet] [Doctoral dissertation]. Colorado State University; 2020. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/219626.
Council of Science Editors:
Trabing B. On intensity change and the effects of shortwave radiation on tropical cyclone rainbands. [Doctoral Dissertation]. Colorado State University; 2020. Available from: http://hdl.handle.net/10217/219626
5.
Kilmer, Braxton.
Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats.
Degree: MS(M.S.), Electrical and Computer Engineering, 2019, Colorado State University
URL: http://hdl.handle.net/10217/195412
► Global observations of ice cloud particle size and ice water content are needed to improve weather forecasting and climate prediction. The interaction between ice particles…
(more)
▼ Global observations of ice cloud particle size and ice water content are needed to improve weather forecasting and climate prediction. The interaction between ice particles and upwelling radiation at sub-millimeter-wavelengths strongly depends on ice particle size and observation frequency. Sub-millimeter-wavelength radiometry provides the capability to fill an observational gap by allowing the detection and sizing of ice particles with diameters between 50 μm and 1 mm. Atmospheric temperature and water vapor profiles can also be yielded at sub-millimeter-wavelengths. The Tropospheric Water and Cloud ICE (TWICE) millimeter- and sub-millimeter-wave radiometer instrument is currently under development for 6U CubeSats in a joint effort among
Colorado State University (lead), NASA/Caltech Jet Propulsion Laboratory, and Northrop Grumman Corporation. The TWICE radiometer instrument is designed to provide global measurements of cloud ice, as well as temperature and water vapor profiles in the upper troposphere/lower stratosphere. The TWICE radiometer instrument has 16 frequency channels near 118 GHz for temperature profiling, near 183 and 380 GHz for water vapor profiling, and centered on 240, 310, 670, and 850 GHz quasi-window channels for ice particle sizing. The TWICE radiometer instrument uses a conical scanning strategy to observe the Earth's atmosphere and surface. The complete TWICE scan is designed to sweep out a 200° arc once per second, and the scan direction reverses every second interval. The TWICE scanning system is designed to fit inside a 6U CubeSat in terms of volume and mass, while meeting the torque and acceleration requirements of the scanning radiometer instrument. A stepper motor and gearbox mechanism were selected for the TWICE scanning system. Precisely placed position sensors, in combination with stepper motor step calculation, provide sufficient angular position data, in place of a traditional encoder. The TWICE scanning system has been tested, and angular position analysis has been performed. The TWICE instrument performs end-to-end, two-point radiometric calibration by observing an ambient temperature calibration target and cosmic microwave background reflector during each conical scan. The ambient calibration target is designed to enable simultaneous blackbody measurements at all TWICE millimeter- and sub-millimeter-wave channels. Calibration target design parameters, including size, geometry, thermal and electromagnetic properties, have been chosen to meet the performance requirements of the ambient target and to minimize temperature gradients. Reflection coefficient measurements have been performed in the millimeter to sub-millimeter wavelength range of the TWICE channels. Thermal analysis of the ambient calibration target has been performed using ANSYS software. The resulting ambient calibration target design meets functional requirements as well as size and weight constraints to fit into a 6U CubeSat. The TWICE radiometer instrument employs several subsystems that need to communicate during…
Advisors/Committee Members: Reising, Steven C. (advisor), Chandrasekar, V. (committee member), Chiu, Christine (committee member).
…Reising at the Colorado State University (CSU) Microwave Systems Laboratory (MSL…
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kilmer, B. (2019). Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/195412
Chicago Manual of Style (16th Edition):
Kilmer, Braxton. “Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats.” 2019. Masters Thesis, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/195412.
MLA Handbook (7th Edition):
Kilmer, Braxton. “Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats.” 2019. Web. 07 Mar 2021.
Vancouver:
Kilmer B. Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/195412.
Council of Science Editors:
Kilmer B. Development, fabrication and testing of the scanning and calibration subsystems for the Tropospheric Water and Cloud ICE instrument for 6U CubeSats. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/195412
6.
Hicks, Adam.
Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera.
Degree: MS(M.S.), Electrical and Computer Engineering, 2019, Colorado State University
URL: http://hdl.handle.net/10217/197252
► Recent developments in machine learning are applied to in-situ data collected by a Multi-Angle Snowflake Camera (MASC), incorporating convolutional and residual networks in big data…
(more)
▼ Recent developments in machine learning are applied to in-situ data collected by a Multi-Angle Snowflake Camera (MASC), incorporating convolutional and residual networks in big data environments. These networks provide the following benefits: require little initial preparation and automatic feature extraction, high accuracy and through transfer learning techniques, and relatively small training sets. The networks have large supporting communities and are popular for image processing and classification tasks specifically. In this paper, a convolutional neural network (CNN) is adapted and tasked with classifying images captured from two storm events in December 2014 and February 2015 in Greeley,
Colorado. A training data set containing 1400 MASC images was developed by visual inspection of recognizable snowflake geometries and sorted into six distinct classes. The network trained on this data set achieved a mean accuracy of 93.4% and displayed excellent generality. A separate training data set was developed sorting flakes into three classes showcasing distinct degrees of riming. The network was then tasked with classifying images and estimating where flakes fell within this riming scale. The riming degree estimator yields promising initial results but would benefit from larger training sets. Future applications are discussed.
Advisors/Committee Members: Notaros, Branislav (advisor), Chiu, Christine (committee member), Pezeshki, Ali (committee member).
Subjects/Keywords: machine learning; in-situ measurement
…common focal center distances of 10 cm. The system used at Colorado State University, Figure
2… …Colorado State
University, Fort Collins. Feb. 2nd – April 30th 2018.
24. Murphy, K. P… …State University. The network
architecture is the ResNet-50, which was chosen over AlexNet… …implemented using Matlab™ 2018b, with
the Deep Learning and Machine Learning Toolboxes at Colorado…
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hicks, A. (2019). Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/197252
Chicago Manual of Style (16th Edition):
Hicks, Adam. “Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera.” 2019. Masters Thesis, Colorado State University. Accessed March 07, 2021.
http://hdl.handle.net/10217/197252.
MLA Handbook (7th Edition):
Hicks, Adam. “Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera.” 2019. Web. 07 Mar 2021.
Vancouver:
Hicks A. Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera. [Internet] [Masters thesis]. Colorado State University; 2019. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10217/197252.
Council of Science Editors:
Hicks A. Utilization of convolutional neural networks in the classification of snowflakes based on images by a multi-angle snowflake camera. [Masters Thesis]. Colorado State University; 2019. Available from: http://hdl.handle.net/10217/197252
. 
Open Access Theses and Dissertations
