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Articles 901 - 930 of 1402

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Metr 323: Physical Meteorology—A Peer Review Of Teaching Project Benchmark Portfolio, Jun Wang Jan 2013

Metr 323: Physical Meteorology—A Peer Review Of Teaching Project Benchmark Portfolio, Jun Wang

UNL Faculty Course Portfolios

Hands-on out-door activities are added into a course that is designed to teach students atmospheric physics ranging form solar light transfer to cloud and precipitation formation in the atmosphere. Statistical analysis and anonymous survey are conducted to benchmark the improvement in students' learning. Results show that these hands-on activities increase the student's interest and understanding in the course materials, and also improve the overall students' satisfaction for the course.


An Examination Of Physical And Empirical Approaches In Forecasting Nonconvective Wind Gusts, Jeramie Lippman Dec 2012

An Examination Of Physical And Empirical Approaches In Forecasting Nonconvective Wind Gusts, Jeramie Lippman

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Nonconvective winds can be a dangerous and costly weather hazard. For example, over a ten year span from 2002 to 2011, there were over 200 fatalities and nearly 1,000 injuries, as well as over 6.4 billion dollars in monetary losses due to high, nonconvective winds. An important subset to nonconvective winds is the nonconvective wind gust. When winds are already relatively strong, a sudden wind gust can magnify already existing hazards. Three different methods were evaluated to determine if either of two physically based algorithms can outperform an empirical algorithm. The two physically based methods were the Wind Gust Estimate …


The Use Of Tree Rings To Study The Impacts Of Stream Flow And Climate Variability On Native And Invasive Woody Species Along A Semi-Arid Riparian Ecosystem In The Great Plains, Usa, Kristen M. Skolaut Dec 2012

The Use Of Tree Rings To Study The Impacts Of Stream Flow And Climate Variability On Native And Invasive Woody Species Along A Semi-Arid Riparian Ecosystem In The Great Plains, Usa, Kristen M. Skolaut

School of Natural Resources: Dissertations, Theses, and Student Research

Forested riparian areas of the Northern Great Plains have historically been dominated by the native Populus deltoides L. vegetation type. Changes in climate, stream flow, groundwater, and management practices in the past few decades have promoted the expansion of the upland native woody species Juniperus virginiana L. and the invasion of the non-native Elaeagnus angustifolia L. into these riparian ecosystems. This study aims at using dendrochronology, or the study of tree rings, to assess the impacts of intra- and inter- annual climatic variability and stream flow over the past decades, on the annual tree ring growth, oxygen and carbon isotopic …


Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor Dec 2012

Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor

United States Geological Survey: Staff Publications

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for .1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The …


Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm Nov 2012

Agricultural Advisors: A Receptive Audience For Weather And Climate Information?, Linda Stalker Prokopy, Tonya Haigh, Amber Saylor Mase, Jim Angel, Chad Hart, Cody Knutson, Maria Carmen Lemos, Yun Jia Lo, Jean Mcguire, Lois Wright Morton, Jennifer Perron, Dennis Todey, Melissa Widhalm

National Drought Mitigation Center: Faculty Publications

As the climate in the midwestern United States becomes increasingly variable because of global climate change, it is critical to provide tools to the agricultural community to ensure adaptability and profitability of agricultural cropping systems. When used by farmers and their advisors, agricultural decision support tools can reduce uncertainty and risks in the planning, operation, and management decisions of the farm enterprise. Agricultural advisors have historically played a key role in providing information and guidance in these decisions. However, little is known about what these advisors know or think about weather and climate information and their willingness to incorporate this …


An Analysis Of Deep Convection Initiation Environments, Noah Lock Nov 2012

An Analysis Of Deep Convection Initiation Environments, Noah Lock

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Initiation is the part of the convective life cycle which is currently least understood and least well forecast. The inability to properly forecast the timing and/or location of deep convection initiation degrades forecast skill, especially during the warm season. The goals of this research are examine the spatiotemporal distribution of thunderstorm initiation points and to determine which atmospheric parameters (and ultimately processes) are most important for the initiation of thunderstorms. The spatiotemporal distribution of thunderstorm initiation points shows the expected peaks during summer and during the afternoon. The warm season also produces significant concentrations of initiation points near mountains, mainly …


Droughtscape, Fall 2012, National Drought Mitigation Center Oct 2012

Droughtscape, Fall 2012, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s report

Updated resources

Drought outlook and review

2012 and past droughters

Summer impacts summary

Urban planners and drought

USDM wins CLEAN seal

Meixiu Yu's Chinese SPEI

Ethiopian project

Mexican VegDRI

Drought monitor sculpture


Catching Air - Those Magnificent Jumping Suwannee Sturgeons, Ken Sulak Oct 2012

Catching Air - Those Magnificent Jumping Suwannee Sturgeons, Ken Sulak

United States Geological Survey: Staff Publications

It starts deep at the bottom of the dark silent river, three to four powerful tail beats and three sharp acoustic clicks. Then, a sudden upturn of the body and the fish explodes upward, 100 pounds going vertical, catching air, lots of air. A good jump can power a big fish, six to nine feet into the air. You have to be quick to get a photo, hang time is only about a second, but an accomplished jump by a big old Suwannee River Gulf Sturgeon is impressive; a magnificent display of power. The exit is almost vertical. The tail …


Impacts Of Climate Change On The Surface Water Balance Of The Central United States, 1984–2007, Bo Dong Oct 2012

Impacts Of Climate Change On The Surface Water Balance Of The Central United States, 1984–2007, Bo Dong

School of Natural Resources: Dissertations, Theses, and Student Research

The climate system and the hydrologic cycle are strongly connected with each other. Understanding the interactions between these two systems is important, since variations in climate can trigger extensive changes in the hydrologic cycle, with significant impacts on agriculture, ecosystems, and society. Observations over the central U.S. in recent decades show numerous changes in climatic variables. This includes decreases in cloud cover and wind speed, increases in air temperature, and seasonal shifts in precipitation rate and rain/snow fraction. To assess the impacts of these variations in climate on the regional water cycle, a terrestrial ecosystem/land surface hydrologic model (Agro-IBIS) is …


The Geologic Records Of Dust In The Quaternary, Daniel R. Muhs Sep 2012

The Geologic Records Of Dust In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Study of geologic records of dust composition, sources and deposition rates is important for understanding the role of dust in the overall planetary radiation balance, fertilization of organisms in the world’s oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic reconstructions. Both glacial and non-glacial processes produce fine-grained particles that can be transported by the wind. Geologic records of dust flux occur in a number of depositional archives for sediments: (1) loess deposits; (2) lake sediments; (3) soils; (4) deep-ocean basins; and (5) ice sheets and smaller glaciers. These archives have several characteristics that make them highly …


Retrieval Of Sub-Pixel-Based Fire Intensity And Its Application For Characterizing Smoke Injection Heights And Fire Weather In North America, David Peterson Sep 2012

Retrieval Of Sub-Pixel-Based Fire Intensity And Its Application For Characterizing Smoke Injection Heights And Fire Weather In North America, David Peterson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

For over two decades, satellite sensors have provided the locations of global fire activity with ever-increasing accuracy. However, the ability to measure fire intensity, know as fire radiative power (FRP), and its potential relationships to meteorology and smoke plume injection heights, are currently limited by the pixel resolution. This dissertation describes the development of a new, sub-pixel-based FRP calculation (FRPf) for fire pixels detected by the MODerate Resolution Imaging Spectroradiometer (MODIS) fire detection algorithm (Collection 5), which is subsequently applied to several large wildfire events in North America. The methodology inherits an earlier bi-spectral algorithm for retrieving sub-pixel …


Accuracy Assessment Of Aqua-Modis Aerosol Optical Depth Over Coastal Regions: Importance Of Quality Flag And Sea Surface Wind Speed, Jacob Anderson Jul 2012

Accuracy Assessment Of Aqua-Modis Aerosol Optical Depth Over Coastal Regions: Importance Of Quality Flag And Sea Surface Wind Speed, Jacob Anderson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Using data collected from 62 coastal stations worldwide from the Aerosol Robotic Network (AERONET) from 2002-2011, accuracy assessments are made for coastal aerosol optical depth (AOD) retrieved from MODIS aboard the Aqua satellite. It is found that coastal AODs (at 550 nm) characterized respectively by the MODIS Dark Land (Land) surface algorithm, the Open Ocean (Ocean) algorithm, and AERONET all exhibit a log-normal distribution. After filtering by quality flags, the coastal MODIS AODs retrieved from the Land and Ocean algorithms are highly correlated with AERONET (with R2≈0.8), but only the Land algorithm AODs fall within the expected error …


A Climatological Analysis Of The Warm-Season Wind Regimes Of The Beaufort/Chukchi Seas Coasts, William J. Baule Jul 2012

A Climatological Analysis Of The Warm-Season Wind Regimes Of The Beaufort/Chukchi Seas Coasts, William J. Baule

School of Natural Resources: Dissertations, Theses, and Student Research

Climate records for wind speed, wind direction, and temperature are analyzed for the period from 1979-2009 for the Beaufort/Chukchi Seas region of the Arctic. Wind records have historically been subject to far fewer analyses than other meteorological variables, such as temperature or precipitation. This is particularly true for data sparse regions. Data were collected for a large area in the Beaufort/Chukchi Seas region, which includes portions of Russia, the United States, and Canada. Data from 250 stations were collected from a variety of networks throughout the region and uniformly quality controlled. Eight long-term stations were identified for data completeness and …


Droughtscape, Summer 2012, National Drought Mitigation Center Jul 2012

Droughtscape, Summer 2012, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s report 1

Drought expanse 1

Upcoming ranch workshops. 3

Drought outlook and review 4

Spring impacts summary 6

Hawaii impact workshops 9

Remote sensing of drought. 10

China workshop . 12


Life Cycle Boundaries And Greenhouse Gas Emissions From Beef Cattle, Quentin M. Dudley Jul 2012

Life Cycle Boundaries And Greenhouse Gas Emissions From Beef Cattle, Quentin M. Dudley

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Beef cattle are estimated to directly contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy may target reducing these emissions. Life cycle assessment (LCA) of GHG emissions from U.S. feedlot beef cattle was conducted to compare methods of the U.S. Environmental Protection Agency (EPA) with a more complete evaluation of emissions. The inclusion of emissions from crop production for feed, associated land use change, and other minor factors nearly doubled GHG emissions associated with beef feedlots from the EPA Annual Inventory estimate of 1611 kgCO2e hd-1 yr-1 to 3182 ± 167 …


Climate's Role In Polar Bear Past [Letters], Kurt E. Galbreath, Joseph A. Cook, Eric P. Hoberg Jun 2012

Climate's Role In Polar Bear Past [Letters], Kurt E. Galbreath, Joseph A. Cook, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Striking temporal concordance between the new date for divergence of polar bears and persistent freezing of the Arctic Ocean suggests that this may be one of relatively few instances in which a specific paleoclimatological episode can be convincingly linked to a specific evolutionary event, and it provides vivid demonstration of climatic forcing as a determinant of diversification in biological systems.


Periodicities Of Peak Current And Flash Multiplicity In Cloud To Ground Lightning, Alexander R. Gibbs Apr 2012

Periodicities Of Peak Current And Flash Multiplicity In Cloud To Ground Lightning, Alexander R. Gibbs

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Research on lightning has been conducted on various topics including thunderstorm electrification and climatology of lightning strikes however; there are still some characteristics of lightning that are not well known, such as flash multiplicity and peak current as a function of individual thunderstorms. These characteristics are the leading cause of injuries and damage each year. This study examines a severe weather event in Minnesota on 16 September 2006, in order to determine what may cause peak current and flash multiplicity. Cycles in peak current and flash multiplicity are identified and then associated with CAPE to determine if a thunderstorm’s updraft …


Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui Apr 2012

Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, …


Droughtscape, Spring 2012, National Drought Mitigation Center Apr 2012

Droughtscape, Spring 2012, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Director’s report.

Climate Masters 1

Ranch plan workshop . 3

Winter climate summary 4

Winter impacts summary . 6

Zhao research.

Getachew research 0

Other international news

Wardlow move 13

IPCC disaster report .


Water And Energy Balance Response Of A Riparian Wetland To The Removal Of Phragmites Australis, Phillip Mykleby Apr 2012

Water And Energy Balance Response Of A Riparian Wetland To The Removal Of Phragmites Australis, Phillip Mykleby

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Vegetation and climate both play integral roles in water availability, particularly for arid to semi-arid regions. Changes in these variables can lead to extreme shortages in water for regions that rely on water for crop irrigation (i.e., the Great Plains). The objective of this study is to evaluate the impacts of vegetation on water availability in the Republican River basin in central Nebraska. Decreases in streamflow have been observed in the river basin for many years and, as a result, an invasive riparian plant species (Phragmites australis) is being removed in an effort to reduce evapotranspiration and reclaim …


Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall Mar 2012

Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall

United States Geological Survey: Staff Publications

Stable 13C, 15N, and 34S isotopes were analyzed to define the feeding habitats of Acipenser oxyrinchus desotoi in the Suwannee and Yellow River populations. For the majority (93.9%) of Suwannee sub adults and adults, 13C and 34S signatures indicate use of nearshore marine waters as primary winter feeding habitat, probably due to the limiting size of the Suwannee Sound estuary. In the Yellow River population, 13C isotope signatures indicate that adults remain primarily within Pensacola Bay estuary to feed in winter, rather than immigrating to the open Gulf of Mexico. A minor Suwannee River subset (6% of …


Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs, Joshua T. Schloesser, Craig P. Paukert, Wyatt J. Doyle, Tracy D. Hill, Kirk D. Steffensen, Vince H. Travnichek Mar 2012

Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs, Joshua T. Schloesser, Craig P. Paukert, Wyatt J. Doyle, Tracy D. Hill, Kirk D. Steffensen, Vince H. Travnichek

United States Geological Survey: Staff Publications

Occupancy modeling was used to determine (1) if detection probabilities (p) for 7 regionally imperiled Missouri River fishes (Scaphirhynchus albus, Scaphirhynchus platorynchus, Cycleptus elongatus, Sander canadensis, Macrhybopsis aestivalis, Macrhybopsis gelida, and Macrhybopsis meeki) differed among gear types (i.e. stationary gill nets, drifted trammel nets, and otter trawls), and (2) how detection probabilities were affected by habitat (i.e. pool, bar, and open water), longitudinal position (five 189 to 367 rkm long segments), sampling year (2003 to 2006), and season (July 1 to October 30 and October 31 to June 30). Adult, large-bodied fishes were …


Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa, Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly Mar 2012

Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa, Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly

United States Geological Survey: Staff Publications

The pallid sturgeon Scaphirhynchus albus is a federally endangered species native to the Missouri and lower Mississippi Rivers, USA. As part of recovery efforts, over 360 000 pallid sturgeon have been stocked into the Missouri River since 1994, and a standardized, long-term monitoring program was initiated in 2003. Understanding the distribution and habitat requirements of juvenile and early adult pallid sturgeon (fork length <720 mm, age <10 yr) is an important goal of the monitoring and recovery programs. In this study, we collected information on habitat characteristics and prey availability from the upper Missouri River along the Nebraska-South Dakota border and compared these attributes between capture (present) and non-capture (absent) locations (N = 59). To evaluate the relative influence of habitat and prey availability on pallid sturgeon occurrence, we examined several candidate models using an informationtheoretic approach. A prey availability model had the most support and included site-specific information on Diptera and Ephemeroptera abundance. A habitat-based model showed that juveniles and early adults were found in relatively deeper water and avoided areas where bottom velocities were greater than 1.2 m s−1. Although not as well supported as the prey-effects model (evidence ratio = 6.4), habitat features also provided a plausible model for predicting occurrence. The models developed here could be used to evaluate pallid sturgeon habitat potential in the Missouri River basin and help guide future monitoring and conservation management of this endangered species.


The Response Of Calcareous Nannofossil Communities To Environmental Variation During The Late Middle Eocene At Blake Nose, Western North Atlantic, Odp Leg 171b, Johnathon P. Kell Mar 2012

The Response Of Calcareous Nannofossil Communities To Environmental Variation During The Late Middle Eocene At Blake Nose, Western North Atlantic, Odp Leg 171b, Johnathon P. Kell

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Ocean Drilling Program Leg 171B Hole 1051B penetrated a continuous sequence of upper middle Eocene pelagic sediment dominated by rich calcareous nannofossil assemblages. Samples were taken at 10 cm spacing from a 20.2 meter section of the upper middle Eocene. This interval of pelagic sediment had previously been interpreted to represent ~500ky. Our revised age model, using additional data, indicates this section represents ~842ky.

The Eocene Epoch was characterized by one of the most dramatic climatic transitions in the last 65 my, changing the greenhouse earth of the early Eocene to the icehouse world of early Oligocene. Here changes in …


Fragilariopsis Diatom Evolution In Pliocene And Pleistocene Antarctic Shelf Sediments, Charlotte Sjunneskog, Christina R. Riesselman, Diane Winter, Reed Scherer Jan 2012

Fragilariopsis Diatom Evolution In Pliocene And Pleistocene Antarctic Shelf Sediments, Charlotte Sjunneskog, Christina R. Riesselman, Diane Winter, Reed Scherer

ANDRILL Research and Publications

The late Pliocene – early Pleistocene sediment record in the AND-1B core from the McMurdo Sound, Ross Sea, Antarctica, displays a rich diversity and high abundance of diatoms, including several new morphologies within the genus Fragilariopsis. These new morphologies exhibit similarities to the extinct late Miocene/early Pliocene species Fragilariopsis aurica Gersonde and Fragilariopsis praecurta Gersonde, as well as to the modern sea ice-associated species Fragilariopsis ritscheri Hustedt and Fragilariopsis obliquecostata van Heurck. From the diverse morphologies present, we use light microscopy and scanning electron microscopy to identify and describe the characteristics of three new taxa, Fragilariopsis laqueata Riesselman, Fragilariopsis …


Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright Jan 2012

Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright

United States Geological Survey: Staff Publications

Epidemiologic surveillance is defined by the Centers for Disease Control and Prevention (CDC) as the "ongoing systematic and continuous collection, analysis, and interpretation of health data': The objective of surveillance is to generate data for rapid response to the detection of a disease of concern to apply prevention, control, or eradication measures as well as to evaluate such interventions. This is distinct from disease monitoring, which usually does not involve a particular response to disease detection.

Surveillance for wildlife diseases has increased in importance due to the emergence and re-emergence of wildlife diseases that are threats to human, animal, and …


Working Trees For Water Quality Jan 2012

Working Trees For Water Quality

Working Trees (USDA-NAC)

Working trees for water quality

Working Trees: a partner in watershed management. Agroforestry helps to protect water quality while achieving both landowner and community objectives.


Climate Divisions For Alaska Based On Objective Methods, Peter A. Bieniek, Uma S. Bhatt, Richard L. Thoman, Heather Angeloff, James Partain, John Papineau, Frederick Fritsch, Eric Holloway, John E. Walsh, Christopher Daly, Martha Shulski, Gary Hufford, David F. Hill, Stavros Calos, Rudiger Gens Jan 2012

Climate Divisions For Alaska Based On Objective Methods, Peter A. Bieniek, Uma S. Bhatt, Richard L. Thoman, Heather Angeloff, James Partain, John Papineau, Frederick Fritsch, Eric Holloway, John E. Walsh, Christopher Daly, Martha Shulski, Gary Hufford, David F. Hill, Stavros Calos, Rudiger Gens

National Drought Mitigation Center: Faculty Publications

Alaska encompasses several climate types because of its vast size, high-latitude location, proximity to oceans, and complex topography. There is a great need to understand how climate varies regionally for climatic research and forecasting applications. Although climate-type zones have been established for Alaska on the basis of seasonal climatological mean behavior, there has been little attempt to construct climate divisions that identify regions with consistently homogeneous climatic variability. In this study, cluster analysis was applied to monthly-average temperature data from 1977 to 2010 at a robust set of weather stations to develop climate divisions for the state. Mean-adjusted Advanced Very …


Drought Monitoring: Historical And Current Perspectives, Michael J. Hayes, Mark D. Svoboda, Brian D. Wardlow, Martha C. Anderson, Felix Kogan Jan 2012

Drought Monitoring: Historical And Current Perspectives, Michael J. Hayes, Mark D. Svoboda, Brian D. Wardlow, Martha C. Anderson, Felix Kogan

National Drought Mitigation Center: Faculty Publications

Drought is a normal, recurring feature of climate throughout the world, with characteristics and impacts that can vary from region to region. Figure 1.1 illustrates the regular occurrence of drought within the United States between 1895 and 2010 with approximately 14% of the country, on average (plotted by black dotted line), experiencing severe to extreme drought conditions during any given year. Drought conditions can persist in a region for several years, as occurred in the United States in the 1930s, 1950s, and early 2000s, and tree ring and other proxy records confirm that multiple-year droughts are part of the long-term …


Future Opportunities And Challenges In Remote Sensing Of Drought, Brian D. Wardlow, Martha C. Anderson, Justin Sheffield, Bradley D. Doorn, James P. Verdin, Xiwu Zhan, Matthew Rodell Jan 2012

Future Opportunities And Challenges In Remote Sensing Of Drought, Brian D. Wardlow, Martha C. Anderson, Justin Sheffield, Bradley D. Doorn, James P. Verdin, Xiwu Zhan, Matthew Rodell

National Drought Mitigation Center: Faculty Publications

The value of satellite remote sensing for drought monitoring was first realized more than two decades ago with the application of Normalized Difference Vegetation Index (NDVI) data from the Advanced Very High Resolution Radiometer (AVHRR) for assessing the effect of drought on vegetation, as summarized by Anyamba and Tucker (2012, Chapter 2). Other indices such as the Vegetation Health Index (VHI) (Kogan, 1995) were also developed during this time period and applied to AVHRR NDVI and brightness temperature data for routine global monitoring of drought conditions. These early efforts demonstrated the unique perspective that global imagers like AVHRR could provide …