Meteorology Commons^™

Finite Element Modeling Of Macro Fiber Composite Actuators With Application To Wing De-Icing, Boutros Youssef Azizi

Doctoral Dissertations and Master's Theses

Icing can have a profound impact on aircraft performance during inclement weather conditions. Aircraft icing primarily occurs on the leading edge of wings, tails and engines. The de-icing/anti-icing technologies currently in use are typically bulky, heavy, cover the entire airfoil surface and consume high energy. These drawbacks highlight the need for a de-icing technique that can overcome some or all of the aforementioned problems. Therefore, in this thesis, a proposed de-icing technique is studied in which lightweight Macro Fiber Composite (MFC) actuators are used to break the adhesive bond between the leading edge of a wing and an accumulated ice …

Cloud-Scale Ice-Supersaturated Regions Spatially Correlate With High Water Vapor Heterogeneities, Minghui Diao, Mark Zondlo, Andrew Heymsfield, L. Avallone, M. Paige, Stuart Beaton, T. Campos, D. Rogers

Faculty Publications, Meteorology and Climate Science

Cirrus clouds have large yet uncertain impacts on Earth's climate. Ice supersaturation (ISS) – where the relative humidity with respect to ice (RHi) is greater than 100% – is the prerequisite condition of ice nucleation. Here we use 1 Hz (~230 m) in situ, aircraft-based observations from 87° N to 67° S to analyze the spatial characteristics of ice-supersaturated regions (ISSRs). The median length of 1-D horizontal ISSR segments is found to be very small (~1 km), which is 2 orders of magnitude smaller than previously reported. To understand the conditions of these small-scale ISSRs, we compare individual ISSRs with …

Validation Of The Air Force Weather Agency Ensemble Prediction Systems, William B. Clements

Theses and Dissertations

Air Force Weather Agency's (AFWA) Ensemble Prediction Systems (EPS), Global Ensemble Prediction System (GEPS), 20km Mesoscale Ensemble Prediction System (MEPS20) and 4km Mesoscale Prediction System (MEPS4), were evaluated from April to October 2013 for 10 locations around the world to determine how accurately forecast probabilities for wind and precipitation thresholds and lightning occurrence match observed frequencies using Aerodrome Routine Meteorological Reports (METARs) and Aerodrome Special Meteorological Reports (SPECIs). Reliability diagrams were created for each forecast hour detailing the Brier skill score (BSS) to depict EPS performance compared to climatology for each site and score composition through reliability, resolution and uncertainty. …

Day/Night Visible Satellite Images, Frederick R. Mosher

Frederick R. Mosher

Visible satellite images are very helpful for a wide variety of users. In particular, they are helpful in identifying areas of clouds and fog for general aviation pilots who must fly within sight of ground. However, visible satellite images have several major drawbacks, such as at night the visible pictures are black. Another problem is that it is sometimes difficult to distinguish between high clouds and low clouds. While the infrared channel can be used at night, frequently the low clouds and fog are near the temperature of the ground, so low clouds do not show up well on infrared …

Analysis Of Causes Of Icing Conditions Which Contributed To The Crash Of Continental Flight 3407, Frederick R. Mosher, Debbie Schaum, Chris Herbster, Tom Guinn

Frederick R. Mosher

On February 12, 2009, at 10:20 p.m. EST, Continental Connection Flight 3407 from Newark to Buffalo crashed 5 miles short of the runway at Buffalo, killing all 49 people on board and one person on the ground. The National Transportation Safety Board (NTSB) is still investigating the crash, but preliminary reports show the airplane was experiencing icing conditions before the crash. Preliminary reports indicate that the pilot did not respond properly to the icing conditions, which contributed to the crash. However, the presence of the icing conditions which were significant enough to cause aircraft problems needs further investigation to determine …

Attempting To Turn Night Into Day; Development Of Visible Like Nighttime Satellite Images, Frederick R. Mosher

Frederick R. Mosher

Visible satellite images have long been used in aviation flight planning. The visible satellite images show a variety of phenomena of interest to aviation, including fog, low clouds, thunderstorms, etc. Since one’s eyes detect visible light, the visible satellite image is easier for untrained personnel to interpret than other bands. The biggest problem with the visible images is that they are not available at night. However, other channels on the satellites can be used to develop a derived satellite product which looks very much like a visible satellite image. This derived product can then be inserted into the nighttime portions …

Global Satellite Images For Aviation Operations, Frederick R. Mosher, James Block

Frederick R. Mosher

Flight planning and flight following dispatch operations require information on potential flight hazards. Hazards such as thunderstorms, turbulence, icing, fog, volcanic ash, etc., are potential problems which are not always forecast adequately by numerical models. Satellite images are used to monitor the weather conditions causing existing flight hazards, as well as being used to identify the development of new hazards.

Umphlett Qci March 2014, Natalie Umphlett

HPRCC Personnel Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Mountain Snowpack

Agriculture

Tourism and Recreation

Missouri Basin Flood Outlook

U.S. Seasonal Drought Outlook

Sfa Weather Station-March 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Day/Night Visible Satellite Images, Frederick R. Mosher

Frederick R. Mosher

Visible satellite images are very helpful for a wide variety of users. In particular, they are helpful in identifying areas of clouds and fog for general aviation pilots who must fly within sight of ground. However, visible satellite images have several major drawbacks, such as at night the visible pictures are black. Another problem is that it is sometimes difficult to distinguish between high clouds and low clouds. While the infrared channel can be used at night, frequently the low clouds and fog are near the temperature of the ground, so low clouds do not show up well on infrared …

Sfa Weather Station-February 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Reducing Wave-Induced Microwave Water-Level Measurement Error With A Least Squares-Designed Digital Filter, John D. Boon

VIMS Articles

A microwave water-level sensor, the Design Analysis model H-3611i, will soon enter service at tide stations operated by the National Oceanic and Atmospheric Administration's Center for Operational Oceanographic Products and Services (CO-OPS) as part of the National Water Level Observation Network. CO-OPS tests include a multisensor deployment at the U.S. Army Corps of Engineers Field Research Facility at Duck, North Carolina, to evaluate microwave water-level measurement error over a wide range of Atlantic Ocean sea states. In situ precision and accuracy of processed (6-min average) water level is found to depend on sea state in addition to data processing methods …

Local Meteorological Modeling To Support Flight Training Operations, Austin D. Wardall, Melanie A. Wetzel

Aviation / Aeronautics / Aerospace International Research Conference

Spatial and temporal variability in atmospheric conditions directly impact pilot safety and training objectives. Specific conditions of frequent concern to the ERAU Prescott flight training operations include boundary layer wind shear and turbulence. These conditions are most common during spring and summer months due to vertical wind shear, unstable air temperature profiles and thunderstorm-produced gust fronts. Case study comparisons of a high resolution meteorological forecasting model can demonstrate the value of operational modeling in support of a flight training program.

Prescribed Burning Of Logging Slash In The Boreal Forest Of Finland: Emissions And Effects On Meteorological Quantities And Soil Properties, A. Virkkula, J. Levula, T. Pohja, P. Aalto, P. Keronen, S. Schobesberger, Craig Clements, L. Pirjola, A. Kieloaho, L. Kulmala, H. Aaltonen, J. Patoskoski, J. Pumpanen, J. Rinne, T. Ruuskanen, M. Pihlatie, H. Mannien, V. Aaltonen, H. Junninen, T. Petaja, J. Backman, M. Dal Maso, T. Nieminen, T. Olsson, T. Grönholm, J. Aalto, T. Virtanen, M. Kajos, V. Kerminen, D. Shultz, J. Kukkonen, M. Sofiev, G. De Leeuw, J. Back, P. Hari, M. Kulmala

Faculty Publications, Meteorology and Climate Science

A prescribed fire experiment was conducted on 26 June 2009 in Hyytiälä, Finland, to study aerosol and trace gas emissions from prescribed fires of slash fuels and the effects of fire on soil properties in a controlled environment. A 0.8 ha forest near the SMEAR II measurement station (Station for Measuring Ecosystem-Atmosphere Relations) was cut clear; some tree trunks, all tree tops and branches were left on the ground and burned. The amount of burned organic material was ~46.8 tons (i.e., ~60 tons ha−1). The flaming phase lasted 2 h 15 min, the smoldering phase 3 h. Measurements were conducted …

Airborne Measurements Of Aerosols And Carbon Dioxide During A Prescribed Fire Experiment At A Boreal Forest Site, Aki Virkkula, Toivo Pohja, Pasi Aalto, Petri Keronen, Siegfried Schobesberger, Craig Clements, Tuukka Petäjä, Juha Nikmo, Markku Kulmala

Faculty Publications, Meteorology and Climate Science

During a prescribed fire experiment, CO2 and particle number concentrations, light scattering and absorption coefficients were measured from a Cessna 172 airplane. Peak number concentrations were (3 ± 1) x 106 cm–3 and they decreased faster than what can be explained by coagulation alone. The single-scattering albedo of particles grew from the values of 0.4 ± 0.1 closest to the emissions to the values of 0.8 ± 0.1 at the distance of 400 m from the emissions. The mean Ângström exponent of absorption, 1.70 ± 0.24, is in line with the published spectral absorption values of wood-smoke aerosol. The estimated …

Sfa Weather Station-January 2014, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Winter Wind Chill Climatology For The High Plains Region, Holly B. Lussenden, Natalie A. Umphlett, Martha D. Shulski, Daniel Ebert

HPRCC Personnel Publications

During the winter months in the High Plains region of the United States, wind chill temperatures can reach dangerous levels for humans and animals. Knowing the frequency in which extreme wind chill temperatures occur could help forecasters know when to issue wind chill advisories and also the general public understand just how rare, or common, certain wind chill temperatures are. A climatology spanning a 37-year period was created using data from 57 stations in and around the plains portion of the High Plains region from the Integrated Surface Hourly Database at National Climatic Data Center (NCDC). These climatologies were completed …

Global Meteorological Drought – Part 1: Probabilistic Monitoring, Will Pozzi

Will Pozzi

Near-real-time drought monitoring can provide decision-makers with valuable information for use in se- veral areas, such as water resources management, or inter- national aid. One of the main constrains of assessing the current drought situation is associated with the lack of re- liable sources of observed precipitation on a global scale available in near-real time. Furthermore, monitoring sys- tems also need a long record of past observations to pro- vide mean climatological conditions. To address these prob- lems, a novel probabilistic drought monitoring methodology based on ECMWF probabilistic forecasts is presented, where probabilistic monthly means of precipitation were derived from …

Climatic Changes In Mountain Regions Of The American Cordillera And The Tropics: Historical Changes And Future Outlook, Henry F. Diaz, Raymond S. Bradley, Liang Ning

Raymond S Bradley

We review some recent work regarding climatic changes in selected mountain regions, with particular attention to the tropics and the American Cordillera. Key aspects of climatic variability and trends in these regions are the amplification of surface warming trends with height, and the strong modulation of tempera¬ture trends by tropical sea surface temperature, largely controlled by changes in El Niño–Southern Oscillation on multiple time scales. Corollary aspects of these climate trends include the increase in a critical plant growth temperature threshold, a rise in the freezing level surface, and the possibility of enhanced subtropical drying. Anthropogenic global warming projections indicate …

Winter Precipitation Variability And Corresponding Teleconnections Over The Northeastern United States, Liang Ning, Raymond S. Bradley

Raymond S Bradley

The variability of winter precipitation over the northeastern United States and the corresponding teleconnections with five dominant large-scale modes of climate variability (Atlantic Multidecadal Oscillation, AMO; North Atlantic Oscillation, NAO; Pacific-North American pattern, PNA; Pacific Decadal Oscillation, PDO; and El Niño–Southern Oscillation, ENSO) were systemically analyzed in this study. Three leading patterns of winter precipitation were first generated by empirical orthogonal function (EOF) analysis. The correlation analysis shows that the first pattern is significantly correlated with PNA and PDO, the second pattern is significantly correlated with NAO and AMO, and the third pattern is significantly correlated with ENSO, PNA, and …

Representation Of Ethiopian Wet Spells In Global And Nested Models, Mark Jury, Sen Chiao

Faculty Publications, Meteorology and Climate Science

Weather forecast and reanalysis models exhibit different performance in daily rainfall estimation over the Ethiopian highlands, 2000–2012, with ECMWF closer to observations than other models. Background is given to illustrate the Hadley circulation and easterly jets over Ethiopia, using sections on 37°E in July–August 2011. ECMWF reanalysis has a narrow band of rainfall >15 mm/day on 10°N, consistent with TRMM satellite estimates, associated with a steep gradient in meridional wind. MERRA and GFS models have a wider band of rainfall and weaker gradients in meridional winds. The contrasting background states influence a nested WRF model simulation of heavy rain in …

Droughtscape- Winter 2014, Kelly Smith

Droughtscape, Quarterly Newsletter of NDMC, 2007-

CONTENTS

Director’s report...........................1

Outlook & quarterly review .......... 2

Drought in 2013 review................3

Quarterly impacts review ............. 5

Impacts in 2013 review................8

Belmont Forum research...........10

USDM change maps ................. 11

Central Asia drought planning ....... 12

Kansas RC&D planning.............13

Publication compares plans.......13

Drought for planners webinar .... 14

Soil moisture networks .............. 14

KS farm & ranch planning..........15

$500 to develop leadership ....... 15

Kids seek solutions....................16

Plains symposium April 1-4 ....... 17

Investigating The Effect Of The ‘‘Land Between The Lakes’’ On Storm Patterns, Joshua D. Durkee, Ahmed M. Degu, Faisal Hossain, Rezaul Mahmood, Jesse Winchester, Themis Chronis

HPRCC Personnel Publications

The artificially created region around the ‘‘Land between the Lakes’’ (LBL) in Kentucky represents unique land use and land cover (LULC) heterogeneities. Over a distance of 100 km, the LULC comprises artificially created open water bodies (i.e., two parallel large run-on-river dams separated by the LBL), mountainous terrain, forest cover, and extensive agricultural land. Such heterogeneities increase (decrease) moisture supply and sensible heat, resulting in a differential air mass boundary that helps to initiate (inhibit) convection. Hence, the LBL can potentially modify precipitation formation. Historical anecdotes reveal a tendency for storms to dissipate or reintensify near the LBL. The specific …

Climate Masters Of Nebraska: An Innovative Action-Based Approach For Climate Change Education, Tapan Pathak, Tonya Bernadt, Natalie A. Umphlett

HPRCC Personnel Publications

Climate Masters of Nebraska is an innovative educational program that strategically trains community volunteers about climate change science and corresponding ways to reduce greenhouse gas emissions in an interactive and action-based teaching environment. As a result of the program, 91% of participants indicated that they made informed changes in their lives to reduce greenhouse gas emissions. Approximately 500 hours of volunteer work was reported by participants as an outreach for greenhouse gas emission reduction. The program can be easily replicated to other locales with an effective planning and with small leadership team.

A Comparison Of The Mm5 And The Regional Atmospheric Modeling System Simulations For Land--Atmosphere Interactions Under Varying Soil Moisture, Astrid Suarez, Rezaul Mamood, Arturo I. Quintanar, Adriana Beltran-Prezekurat, Roger Pielke Sr.

HPRCC Personnel Publications

A comparison between two mesoscale models, Colorado State University Regional Atmospheric Modeling System (RAMS) version 4.4 coupled with the Land-Ecosystem--Atmosphere Feedback Model (LEAF2) and Penn State/NCAR’s Mesoscale Model (MM5) coupled with NOAH Land Surface Model, was conducted in order to assess the sensitivity of forecasted planetary boundary layer (PBL) variables to anomalous initial volumetric soil moisture conditions. The experiments were conducted using three synoptic events: June 11, 17 and 22, 2006. For each event, one control run and six additional simulations were completed using RAMS and MM5. In each of the events, initial volumetric soil moisture was increased and decreased …

A Molecular-Level Approach For Characterizing Water-Insoluble Components Of Ambient Organic Aerosol Particulates Using Ultrahigh-Resolution Mass Spectrometry, A. S. Willoughby, A. S. Wozniak, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The chemical composition of organic aerosols in the atmosphere is strongly influenced by human emissions. The effect these have on the environment, human health, and climate change is determined by the molecular nature of these chemical species. The complexity of organic aerosol samples limits the ability to study the chemical composition, and therefore the associated properties and the impacts they have. Many studies have addressed the watersoluble fraction of organic aerosols and have had much success in identifying specific molecular formulas for thousands of compounds present. However, little attention is given to the water-insoluble portion, which can contain most of …

Distinguishing Molecular Characteristics Of Aerosol Water Soluble Organic Matter From The 2011 Trans-North Atlantic Us Geotraces Cruise, A. S. Wozniak, A. S. Willoughby, S. C. Gurganus, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The molecular characteristics of aerosol organic matter (OM) determines to a large extent its impacts on the atmospheric radiative budget and ecosystem function in terrestrial and aquatic environments, yet the OM molecular details of aerosols from different sources are not well established. Aerosol particulate samples with North American-influenced, North African-influenced, and marine (minimal recent continental influence) air mass back trajectories were collected as part of the 2011 trans-North Atlantic US GEOTRACES cruise and analyzed for their water soluble OM (WSOM) molecular characteristics using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Principal component analysis (PCA) separated the samples into …

Derivation Of Tropospheric Methane From Tccon Ch4 And Hf Total Column Observations, K. M. Saad, D. Wunch, P. Bernath, C. Boone, B. Connor, N. M. Deutscher, D.W.T. Griffith, R. Kivi, J. Notholt, C. Roehl, M. Schneider, V. Sherlock, P. O. Wennberg

Chemistry & Biochemistry Faculty Publications

The Total Carbon Column Observing Network (TCCON) is a global ground-based network of Fourier transform spectrometers that produce precise measurements of column-averaged dry-air mole fractions of atmospheric methane (CH₄). Temporal variability in the total column of CH₄ due to stratospheric dynamics obscures fluctuations and trends driven by tropospheric transport and local surface fluxes that are critical for understanding CH₄ sources and sinks. We reduce the contribution of stratospheric variability from the total column average by subtracting an estimate of the stratospheric CH₄ derived from simultaneous measurements of hydrogen fluoride (HF). HF provides a proxy for …

Global Stratospheric Fluorine Inventory For 2004-2009 From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements And Slimcat Model Simulations, A. T. Brown, M. P. Chipperfield, N. A. D. Richards, C. Boone, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Fluorine-containing species can be extremely effective atmospheric greenhouse gases. We present fluorine budgets using organic and inorganic species retrieved by the ACE-FTS satellite instrument supplemented with output from the SLIMCAT 3-D chemical transport model. The budgets are calculated between 2004 and 2009 for a number of latitude bands: 70-30 °N, 30-00 °N, 00 °N-30 °S, and 30-70°S. At lower altitudes total fluorine profiles are dominated by the contribution from CFC-12, up to an altitude of 20 km in the extra-tropics and 29 km in the tropics; above these altitudes the profiles are dominated by hydrogen fluoride (HF). Our data show …

Horizontal Divergence Of Typhoon-Generated Gravity Waves In The Upper Troposphere And Lower Stratosphere (Utls) And Its Influence On Typhoon Evolution, Seung Hee Kim, H.-Y. Chun, W. Jang

Mathematics, Physics, and Computer Science Faculty Articles and Research

The characteristics of horizontal divergence induced by typhoon-generated gravity waves (HDTGWs) and the influence of HDTGW on typhoon evolution are investigated based on the simulation results of Typhoon Saomai (2006) using the Weather Research and Forecasting (WRF) model. The power spectral density of HDTGW shows dominant powers at horizontal wavelengths of 20-30 km and at periods of less than 1 h. This is associated with gravity waves generated by vigorous convective clouds in an inner core region of the typhoon. However, the domain-averaged HDTGW in the upper troposphere and lower stratosphere had a spectral peak at 24 h, which is …