The Evolution and Extratropical Transition of Tropical Cyclones from a GPM, ISS LIS and GLM Perspective

Not much is known about the evolution of lightning within extra-tropical cyclones traversing the mid-latitudes, especially its oceans. To facilitate such studies we combine a recently constructed precipitation features (PF) database obtained from the Global Precipitation Measurement (GPM) mission constellation of satellites with lightning observations from the Geostationary Lightning Mapper (GLM) onboard GOES-16 and the Lightning Imaging Sensor (LIS) onboard the International Space Station (ISS). The goal of this study is to provide a new observationally-based view of the tropical to extra-tropical transition and its impact on lightning production. Such data fusion approaches, as presented here, will also be important in future satellite studies of convective precipitation

The Extratropical Transition of Tropical Storm Cindy From a GLM, ISS LIS and GPM Perspective

The distribution of lightning with respect to tropical convective precipitation systems has been well established in previous studies and more recently by the successful Tropical Rainfall Measuring Mission (TRMM). However, TRMM did not provide information about precipitation features poleward of +/-38 deg latitude. Hence we focus on the evolution of lightning within extra-tropical cyclones traversing the mid-latitudes, especially its oceans. To facilitate such studies, lightning data from the Geostationary Lightning Mapper (GLM) onboard GOES-16 was combined with precipitation features obtained from the Global Precipitation Measurement (GPM) mission constellation of satellites

Lightning Enriched Global Precipitation Feature Database

The Tropical Rainfall Measurement Mission (TRMM) has provided a wealth of insight about lightning and precipitation in the tropics. However TRMM did not provide coverage outside the tropics and sub-tropics (i.e., beyond 38latitude), and hence it was unable to sample the lightning activity and precipitation features over a large fraction of mid-latitude continents and oceans, including extratropical cyclone storm tracks. The Global Precipitation Measurement (GPM) mission picks up where TRMM left off in that it provides information on precipitation features in the mid-and high latitudes (up to 65N/S). However, GPM lacks a lightning instrument that can provide additional insights into mid-latitude thunderstorm activity and distribution. Hence we integrate observations from coincident the ISS Lightning Imaging Sensor (LIS) and the World Wide Lightning Location Network (WWLLN) observations with measurements from the GPM constellation of satellites, in particular to extend the existing GPM Precipitation Feature (PF) database so its data parameters are similar to that of the TRMM PF database (i.e., precipitation + lighting). Currently, WWLLN and ISS-LIS lightning have been collocated into precipitation features defined from GPM core satellite and constellation satellites observations

MS

thesisStratigraphic, sedimentologic, and field mapping data from the Pecos River Canyon of northern New Mexico are used to interpret Pennsylvanian depositional systems, their relation to Ancestral Rocky Mountain paleoGeography;, the general geologic history, and Cenozoic geomorphic processes. The Pennsylvanian La Pasada and Alamitos Formations record primarily subtidal and shallow water marine sedimentation on the Pecos platform at the edge of an actively subsiding tectonic basin. The 203 m of strata in the study area consist of 59% siltstone, sandstone, and conglomerate, 25% carbonate, and 16% shale. Seven shoaling upward cycles and eight gravity flow pulses observed in the studied section reflect an interplay of intrabasinal and extrabasinal controls. Using existing stratigraphic data, subsidence history calculation based on an estimate of isostatic subsidence indicates that ~450 m of tectonic subsidence occurred at the Pecos platform throughout the Pennsylvanian (~165 m during the Desmoinesian). The large amount of tectonic subsidence during deposition of the studied interval and decrease in number of shallowing upward cycles proximal to the basin bounding fault show that tectonics had an influence on the succession of strata at Pecos. East to southeast lateral thinning of strata and south directed paleocurrents indicate that the Ancestral Rocky highland was located northwest of the study area. This highland location supports the idea that the Pecos-Picuris fault, a major fault approximately 6 km northwest of the study area, may have been an active Pennsylvanian basin-bounding fault. Paleocurrents show bidirectional north and south transport in tabular and trough crossbedded mixed carbonate-siliciclastic sediment with mud drapes and reactivation surfaces indicating reworking by tidal currents. Stacked channels and large clasts in conglomerates indicate high-energy sediment pulses from flood plumes and rapidly shifting channels in close proximity to the Uncompahgre Uplift. However, the presence of open marine Pennsylvanian invertebrate fossils and trace fossils in many of these conglomeratic deposits and interbedded carbonates shows deposition on a carbonate shelf. The arkosic composition of sandstones and abundance of granitic and metamorphic clasts in the conglomerates reveal basement uplift of igneous and metamorphic provenance. Thus, the clastic sediments are interpreted as tidal influenced fan-delta deposits on the carbonate Pecos platform, southeast of the Uncompahgre highlands of the Ancestral Rocky Mountains. Geologic mapping revealed previously unmapped faults, folds, and surficial deposits. The folding and faulting are likely associated with the Laramide Orogeny and Rio Grande Rift respectively. A large anticline and smaller superimposed folds show northwest to southeast crustal shortening. Northeast striking steep normal faults with an average offset of ~9 m parallel major normal faults associated with formation of the Rio Grande Rift. Geologic structure exerts important controls on geomorphology of the Pecos River Canyon and surrounding area. The canyon is asymmetric with the east rim higher than the west rim due to a southwest structural dip across the canyon. Because the east rim of the canyon is ~60-150 m higher than the west rim, the east side of the canyon is subject to a higher rate of physical weathering. A large area (~1.9 km2) below the east rim contains a combination of landslide, rockfall, and colluvial material. This study enhances our understanding of the sedimentology and stratigraphy of the Pennsylvanian Pecos shelf adjacent to the Ancestral Rocky Mountains in northern New Mexico and provides insight into geomorphic and structural styles of the Pecos River Canyon and the surrounding region

Hail Variability in Supercell Storms and Response to Environmental Variables

Severe weather events in the United States including tornadoes, hail, and wind are often produced by supercell thunderstorms. These storms are characterized by complex hydrometeor distributions which can be influenced by environmental distributions of wind and moisture. Since the Weather Surveillance Radar-1988 Doppler (WSR-88D) network was fully upgraded to dual-polarimetric capabilities in 2013, dominant hydrometeor species such as hail have been inferable using fuzzy logic. In this study, time series of areal extent of the inferred hail signature at base scan level have been estimated for 145 supercell storms, including both tornadic and non-tornadic cases, across a variety of environments from February 2012-December 2014. Proximity soundings were gathered for environments representative of the supercells (e.g., on the same side of mesoscale boundaries, in a region representative of storm-relative inflow) using archived Rapid Update Cycle (RUC) and Rapid Refresh (RAP) model output from the National Operational Model Archive and Distribution System (NOMADS). Model sounding points were within ~80 km and the midpoint of the analysis period in order to spatiotemporally represent environments during the period in which storms were analyzed. Previous modeling and observational studies have shown that thermodynamic, moisture, and shear parameters influence the mean areal extent of hail at the base scan level and the temporal variability of inferred hail areal extent (HAE). Significant relationships were determined in this study between mean HAE/variability and several environmental parameters. Hail polarimetric radar signatures were also compared across environments; results showed that certain environments produce distinctive mean hail areal extent and hail variability. Correlations between HAE and environment variables are generally higher when the storm has a mean altitude greater than 1 km. An increase in some thermodynamic parameters is observed to produce an increase in mean HAE, while an increase in shear produces an increase in hail variability. Predictive equations for HAE and hail variability are also developed from the analyzed environmental variables. Advisor: Matthew Van Den Broek

The Evolution and ET Transition of Tropical Cyclones during the 2017 Hurricane Seasonfrom a Lightning and Precipitation Perspective

https://louis.uah.edu/vbs-posters/1298/thumbnail.jp

Hierarchical Multimodel Ensemble Estimates of Soil Water Retention with Global Coverage

A correct quantification of mass and energy exchange processes among land surface and atmosphere requires an accurate description of unsaturated soil hydraulic properties. Soil pedotransfer functions (PTFs) have been widely used to predict soil hydraulic parameters. Here, 13 PTFs were grouped according to input data requirements and evaluated against a well-documented soil database with global coverage. Weighted ensembles (calibrated by four groups and the full 13-member set of PTFs) were shown to have improved performance over individual PTFs in terms of root mean square error and other model selection criteria. Global maps of soil water retention data from the ensemble models as well as their uncertainty were provided. These maps demonstrate that five PTF ensembles tend to have different estimates, especially in middle and high latitudes in the Northern Hemisphere. Our full 13-member ensemble model provides more accurate estimates than PTFs that are currently being used in earth system models

PEDO-TRANSFER FUNCTIONS FOR ESTIMATING SOIL BULK DENSITY IN CENTRAL AMAZONIA

Under field conditions in the Amazon forest, soil bulk density is difficult to measure. Rigorous methodological criteria must be applied to obtain reliable inventories of C stocks and soil nutrients, making this process expensive and sometimes unfeasible. This study aimed to generate models to estimate soil bulk density based on parameters that can be easily and reliably measured in the field and that are available in many soil-related inventories. Stepwise regression models to predict bulk density were developed using data on soil C content, clay content and pH in water from 140 permanent plots in terra firme (upland) forests near Manaus, Amazonas State, Brazil. The model results were interpreted according to the coefficient of determination (R2) and Akaike information criterion (AIC) and were validated with a dataset consisting of 125 plots different from those used to generate the models. The model with best performance in estimating soil bulk density under the conditions of this study included clay content and pH in water as independent variables and had R2 = 0.73 and AIC = -250.29. The performance of this model for predicting soil density was compared with that of models from the literature. The results showed that the locally calibrated equation was the most accurate for estimating soil bulk density for upland forests in the Manaus region