This study develops nudging methods of data assimilation that will expand the utility of the forthcoming GOES-R satellite
series by including data from the Geostationary Lightning Mapper (GLM) and Advanced Baseline Imager (ABI). We develop a method to help
trigger storms where lightning is observed, but no storm in simulated. Another method suppresses spurious simulated storms based on
estimates of satellite-derived cloud top height (CTH) that will be improved due to the increased number of infrared channels on the ABI.
In lieu of GOES-R data, Earth Networks Total Lightning Network (ENTLN) observations and GOES-13 10.7-micron observations are used in the
current research. The assimilation methods are developed and evaluated using the Weather Research and Forecasting (WRF) model at
convection-permitting scales (3-km horizontal grid spacing). We verify precipitation simulations against NCEP Stage IV hourly
precipitation observations by computing fraction skill score (FSS; a neighborhood approach) and frequency bias for three case days.
Simulated temperature, winds, humidity, and surface pressure are also verified against METAR surface observations. Our new method of
assimilating lightning observations nudges low-level vertical velocity to trigger storms. This method is compared to a previous method
that nudges low-level temperature (MU). Both lightning assimilation methods then are combined with the assimilation of CTH. CTH
assimilation removes hydrometeors above the CTH estimate and applies an amount of cooling that is proportional to the latent heat of the
removed hydrometeors to suppress spurious convection. Without applying CTH assimilation, the MU method produces better precipitation
forecasts in terms of FSS than our optimal configuration of the vertical velocity nudging (WNO) method. However, if WNO is applied
together with CTH assimilation, WNO produces FSS during the forecast period similar to MU applied with CTH assimilation. MU generally
produces stronger storms than WNO that cause more mesoscale subsidence and indirect suppression of spurious storms. Direct suppression
during CTH assimilation diminishes the impact of the indirect suppression. CTH assimilation also provides greater convective available
potential energy that supports the weaker WNO storms. Regardless of whether CTH assimilation is applied, WNO generally produces superior
forecasts of surface fields relative to MU and a control that employs no assimilation. This improvement is 1-6% of root mean square error
during a 12-h forecast period subsequent to assimilation. Lightning assimilation (WNO or MU) combined with CTH assimilation typically
provides the best precipitation forecasts. These are better than the control during the first 6-12 h of the forecast period for 1-mm and
10-mm precipitation thresholds. This combined assimilation method with the operation of GOES-R enables assimilation of clouds and storms
over areas devoid of quality radar, including mountainous terrain, ocean basins, and Central and South America. / A Dissertation submitted to the Department of Earth, Atmospheric, and Ocean Sciences in partial
fulfillment of the Doctor of Philosophy. / Fall Semester 2016. / October 13, 2016. / Includes bibliographical references. / Henry E. Fuelberg, Professor Directing Dissertation; James B. Elsner, University Representative;
Robert E. Hart, Committee Member; Guosheng Liu, Committee Member; Vasubandhu Misra, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_405604 |
| Contributors | Marchand, Max (authoraut), Fuelberg, Henry E. (professor directing dissertation), Elsner, James B. (university representative), Hart, Robert E. (Robert Edward), 1972- (committee member), Liu, Guosheng (committee member), Misra, Vasubandhu, 1970- (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting departmentdgg) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource (97 pages), computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
Page generated in 0.0018 seconds