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Articles 31 - 60 of 69

Full-Text Articles in Remote Sensing

Linkages Between Atmospheric Circulation, Weather, Climate, Land Cover And Social Dynamics Of The Tibetan Plateau, Shobha Kumari Yadav Jan 2023

Linkages Between Atmospheric Circulation, Weather, Climate, Land Cover And Social Dynamics Of The Tibetan Plateau, Shobha Kumari Yadav

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Tibetan Plateau (TP) is an important landmass that plays a significant role in both regional and global climates. In recent decades, the TP has undergone significant changes due to climate and human activities. Since the 1980s anthropogenic activities, such as the stocking of livestock, land cover change, permafrost degradation, urbanization, highway construction, deforestation and desertification, and unsustainable land management practices, have greatly increased over the TP. As a result, grasslands have undergone rapid degradation and have altered the land surface which in turn has altered the exchange of heat and moisture properties between land and the atmosphere. But gaps …


Systematic Review Of A Ramsar Wetland And Unesco Biosphere Reserve In A Climate Change Hotspot (Ichkeul Lake, Tunisia), Sabrine Sahbani, Béchir Béjaoui, Sihem Benabdalla, Rachid Toujani, Afef Fathalli, Noureddine Zaaboub, Jalel Aouissi, Zeineb Kassouk, Nabil Hamdi, Nabiha Ben Mbarek, Hechmi Missaoui, Leila Basti, Reginald Blake, Hamidreza Norouzi Dec 2022

Systematic Review Of A Ramsar Wetland And Unesco Biosphere Reserve In A Climate Change Hotspot (Ichkeul Lake, Tunisia), Sabrine Sahbani, Béchir Béjaoui, Sihem Benabdalla, Rachid Toujani, Afef Fathalli, Noureddine Zaaboub, Jalel Aouissi, Zeineb Kassouk, Nabil Hamdi, Nabiha Ben Mbarek, Hechmi Missaoui, Leila Basti, Reginald Blake, Hamidreza Norouzi

Publications and Research

Tunisia's Ichkeul Lake is among the most productive ecosystems in the Mediterranean, with a great regional value thanks to its diversity of habitats. It is an important overwintering area for waterfowl species. It is a RAMSAR wetland, a National Park, a UNESCO World Heritage, and a Biosphere Reserve. This review paper provides a broad overview of the climatic, hydraulic, biogeochemical features, bio-resources, and bio-productivity of the Lake. The interconnectivity between the different environmental components of the lake is presented, highlighting the main characteristics of this vital ecosystem. Its ecosystem consists of a permanent lake bordered by temporary marshes. It is …


Spatio-Temporal Changes In Vegetation In The Last Two Decades (2001–2020) In The Beijing–Tianjin–Hebei Region, Yuan Zou, Wei Chen, Siliang Li, Tiejun Wang, Le Yu, Min Xu, Ramesh P. Singh, Cong-Qiang Liu Aug 2022

Spatio-Temporal Changes In Vegetation In The Last Two Decades (2001–2020) In The Beijing–Tianjin–Hebei Region, Yuan Zou, Wei Chen, Siliang Li, Tiejun Wang, Le Yu, Min Xu, Ramesh P. Singh, Cong-Qiang Liu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In terrestrial ecosystems, vegetation is sensitive to climate change and human activities. Its spatial-temporal changes also affect the ecological and social environment. In this paper, we considered the Beijing–Tianjin–Hebei region to study the spatio-temporal vegetation patterns. The detailed analysis of a moderate-resolution imaging spectroradiometer (MODIS) data were carried out through the Google Earth Engine (GEE) platform. Our results show a slow and tortuous upward trend in the average leaf area index (LAI) in the study region for the periods 2001–2020. Specifically, Beijing had the highest LAI value, with an average of 1.64 over twenty years, followed by Hebei (1.30) and …


Remote Sensing & Land Surface Temperature From Satellite Observations, Isatu Jollah May 2022

Remote Sensing & Land Surface Temperature From Satellite Observations, Isatu Jollah

Publications and Research

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument is designed and developed in 1995. • It is a critical instrument aboard Terra and Aqua satellites. Terra's orbit around the Earth is timed so that it crosses the equator from north to south in the morning, while Aqua crosses the equator from south to north in the afternoon. • Every 1 to 2 days, Terra MODIS and Aqua MODIS scan the entire Earth's surface, collecting data in groups of wavelengths. • In this research, a whole month of MODIS Land Surface Temperature data from both Aqua and Terra were explored and investigated.


Lake Satellite Temperature Data Validation, Mamadou Balde, Pascal Kouogang May 2022

Lake Satellite Temperature Data Validation, Mamadou Balde, Pascal Kouogang

Publications and Research

In environmental remote sensing, satellite data isn't absolutely conclusive, for that reason, there is a natural need to verify the data acquired from the satellite. The most suitable tool to achieve such verification is on ground sensors that have the advantage of proximity. Addressing any possible discrepancies between the satellite data and the ground sensor data is sure to yield ways to come up with improvements of satellite band calibration and sensing capabilities. This research focused on correlating temperature data from the MODIS satellite with the data obtained from the In Situ sensor located in Lake Sunapee. Doing the latter …


Spatial Downscaling Of Goes-R Land Surface Temperature Over Urban Regions: A Case Study For New York City, Abdou Bah, Hamidreza Norouzi, Satya Prakash, Reginald Blake, Reza Khanbilvardi, Cynthia Rosenzweig Feb 2022

Spatial Downscaling Of Goes-R Land Surface Temperature Over Urban Regions: A Case Study For New York City, Abdou Bah, Hamidreza Norouzi, Satya Prakash, Reginald Blake, Reza Khanbilvardi, Cynthia Rosenzweig

Publications and Research

The surface urban heat island (SUHI) effect is among the major environmental issues encountered in urban regions. To better predict the dynamics of the SUHI and its impacts on extreme heat events, an accurate characterization of the surface energy balance in urban regions is needed. However, the ability to improve understanding of the surface energy balance is limited by the heterogeneity of surfaces in urban areas. This study aims to enhance the understanding of the urban surface energy budget through an innovation in the use of land surface temperature (LST) observations from remote sensing satellites. A LST database with 5–min …


Snow Cover Variability And Trend Over The Hindu Kush Himalayan Region Using Modis And Srtm Data, Nirasindhu Desinayak, Anup K. Prasad, Hesham El-Askary, Menas Kafatos, Ghassem R. Asrar Jan 2022

Snow Cover Variability And Trend Over The Hindu Kush Himalayan Region Using Modis And Srtm Data, Nirasindhu Desinayak, Anup K. Prasad, Hesham El-Askary, Menas Kafatos, Ghassem R. Asrar

Mathematics, Physics, and Computer Science Faculty Articles and Research

Snow cover changes have a direct bearing on the regional and global energy and water cycles and the change in the Earth's climate conditions. We studied the relatively long-term (2000–2017) altitudinal spatiotemporal changes in the coverage of snow and glaciers in one of the world's largest mountainous regions, the Hindu Kush Himalayan (HKH) region, including Tibet, using remote sensing data (5 km grid resolution) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite. This dataset provided a unique opportunity to study zonal and hypsographic changes in the intra-annual (accumulating season and melting season) and interannual variations in …


Fire Emissions In The Tropical Indonesia: Improved Estimation And Driving Forces Investigation, Xiaoman Lu Jan 2022

Fire Emissions In The Tropical Indonesia: Improved Estimation And Driving Forces Investigation, Xiaoman Lu

Electronic Theses and Dissertations

Indonesia has experienced frequent fires since the 1970s due to large-scale peatland conversion and extensive drainage for agricultural development. Fire emissions released from these fires have led to Indonesia being the world’s 3rd largest emitter of greenhouse gases in certain years. Given that fire emissions severely affect climate, weather, and the human environment, numerous approaches have been developed to estimate fire emissions. However, existing emission estimates differ largely by a factor of four in this tropical country because of frequent cloud interferences and low-temperature smoldering fires. Therefore, this dissertation aims to improve the quantification of Indonesian fire emissions through enhanced …


Characterization Of Site-Specific Vegetation Activity In Alaskan Wet And Dry Tundra As Related To Climate And Soil State, Michael Gregory Brown, Kyle C. Mcdonald, Reiner Zimmermann, Nicholas Steiner, Stephanie Devries, Laura Bourgeau-Chavez Jan 2022

Characterization Of Site-Specific Vegetation Activity In Alaskan Wet And Dry Tundra As Related To Climate And Soil State, Michael Gregory Brown, Kyle C. Mcdonald, Reiner Zimmermann, Nicholas Steiner, Stephanie Devries, Laura Bourgeau-Chavez

Advanced Science Research Center

We present discrete (2-h resolution) multi-year (2008–2017) in situ measurements of seasonal vegetation growth and soil biophysical properties from two sites on Alaska's North Slope, USA, representing dry and wet sedge tundra. We examine measurements of vertical active soil layer temperature and soil moisture profiles (freeze/thaw status), woody shrub vegetation physiological activity, and meteorological site data to assess interrelationships within (and between) these two study sites. Vegetation phenophases (cold de-hardening start, physiological function start, stem growth start, stem growth end, physiological function end, cold hardening completion) were found to have greater interannual day of year (DOY) occurrence variability at the …


Progressive Destabilization And Triggering Mechanism Analysis Using Multiple Data For Chamoli Rockslide Of 7 February 2021, Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li Dec 2021

Progressive Destabilization And Triggering Mechanism Analysis Using Multiple Data For Chamoli Rockslide Of 7 February 2021, Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A catastrophic rockslide occurred on 7 February 2021 in Chamoli area in the high Himalaya. In the absence of field data, multiple satellites data of decade span have been used to investigate and understand the progressive destabilization of rockslide body. A 3D geometric model was developed using geospatial information about geology, terrain, and ice cover to understand the triggering mechanism. Several causes are uncovered as: the pronounced long-term change of land surface temperature facilitated local permafrost degradation and led to ice cover shrinking since 2010; the occurrence of ice avalanche nearby in 2016 accompanying with sidewall-to-bedrock fracturing enhanced the ice …


Changes In The Flood Plains And Water Quality Along The Himalayan Rivers After The Chamoli Disaster Of 7 February 2021, Sansar Raj Meena, Kushanav Bhuyan, Akshansa Chauhan, Ramesh P. Singh Aug 2021

Changes In The Flood Plains And Water Quality Along The Himalayan Rivers After The Chamoli Disaster Of 7 February 2021, Sansar Raj Meena, Kushanav Bhuyan, Akshansa Chauhan, Ramesh P. Singh

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The Himalayan regions are vulnerable to all kinds of natural hazards. On 7 February 2021, a deadly disaster occurred near the Tapovan, in Uttarakhand, Himalayas. During the event, large volume of debris along with broken glacial fragments flooded the Rishi Ganga River and washed away the nearby hydropower plants (Rishi Ganga and Tapovan), which was revealed from detailed analysis of multi spectral and bi-temporal satellite data. We present the impact of the Chamoli disaster on the flood plains and water quality of Himalayan rivers, Rishi Ganga near Tapovan, Alaknanda near Srinagar and Ganga near Haridwar and Bijnor. We used four …


Examining Melt Pond Dynamics And Light Availability In The Arctic Ocean Via High Resolution Satellite Imagery, Austin Wesley Abbott Jul 2021

Examining Melt Pond Dynamics And Light Availability In The Arctic Ocean Via High Resolution Satellite Imagery, Austin Wesley Abbott

OES Theses and Dissertations

As the Arctic experiences consequences of climate change, a shift from thicker, multi-year ice to thinner, first-year ice has been observed. First-year ice is prone to extensive pools of meltwater (“melt ponds”) forming on its surface, which enhance light transmission to the ocean. Changes in the timing and distribution of melt pond formation and associated increases in under-ice light availability are the primary drivers for seasonal progression of water column primary production and warming. Observations of melt pond development and distribution require meter scale resolution and have traditionally been limited to airborne images. However, recent advances in high spatial resolution …


Investigating Water Usage Patterns Tied To California State Water Project, Xiaoqing Wu May 2021

Investigating Water Usage Patterns Tied To California State Water Project, Xiaoqing Wu

Publications and Research

California (USA) is the largest agricultural producer and one of the populous states in the United State. As the population and agriculture grows, water consumption patterns become crucial to keep track of especially surface water. In this research project, we studied possible changes in water consumption patterns in different counties and water rights holders who obtain surface water supply from the State Water Project (SWP) in California. We conducted a time series analysis on the California Monthly Diverted Surface Water dataset through two different time series forecasting models. Our analysis indicates that the total diverted surface water presents a periodic …


Downscaling Methodology For Satellite Land Surface Temperatures Over Urban Environments, Naved Khan, Ruben Vecino May 2021

Downscaling Methodology For Satellite Land Surface Temperatures Over Urban Environments, Naved Khan, Ruben Vecino

Publications and Research

The objective of this study is to develop high spatial and temporal resolution Land Surface Temperature (LST) data using a combination of Landsat 8, infrared satellite sensors such as the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Geostationary Operational Environmental Satellite-R Series (GOES-16). The Landsat 8 Thermal Infrared Sensor (TIRS) provides higher spatial resolution (30 m) estimates of skin temperature every 16 days. MODIS makes daytime and nighttime observations of the Earth’s thermal emission at a coarser spatial resolution (1000 m), while GOES-16, which has lower spatial resolution (2 km), measures the skin temperature at a much higher temporal resolution …


Understanding The Effect Of Internal Climate Variability On 20th Century Indian Ocean Sea Level: Results From Newly Reconstructed Sea Level Data, Praveen Kumar Apr 2021

Understanding The Effect Of Internal Climate Variability On 20th Century Indian Ocean Sea Level: Results From Newly Reconstructed Sea Level Data, Praveen Kumar

OES Theses and Dissertations

Densely populated low-lying coastal zones of countries that border the Indian Ocean are at risk due to sea level rise. However, sea level change in the Indian Ocean is poorly understood primarily due to short and sparse tide gauge observations. Although satellite altimetry provides accurate basin-wide sea level measurements, trends computed from its relatively short (~27-year) data record are heavily influenced by interannual to multi-decadal variability. To accurately project future Indian Ocean sea level trends using altimeter data it is imperative that trends associated with fluctuating internal variability (interannual-decadal) be identified and extracted, which in turn requires long (~100-year) data. …


Investigating Decadal Changes Of Multiple Hydrological Products And Land-Cover Changes In The Mediterranean Region For 2009–2018, Wenzhao Li, Sachi Perera, Erik Linstead, Rejoice Thomas, Hesham El-Askary, Thomas Piechota, Daniele Struppa Mar 2021

Investigating Decadal Changes Of Multiple Hydrological Products And Land-Cover Changes In The Mediterranean Region For 2009–2018, Wenzhao Li, Sachi Perera, Erik Linstead, Rejoice Thomas, Hesham El-Askary, Thomas Piechota, Daniele Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Land-cover change is a critical concern due to its climatic, ecological, and socioeconomic consequences. In this study, we used multiple variables including precipitation, vegetation index, surface soil moisture, and evapotranspiration obtained from different satellite sources to study their association with land-cover changes in the Mediterranean region. Both observational and modeling data were used for climatology and correlation analysis. Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) and Global Land Data Assimilation System (GLDAS) were used to extract surface soil moisture and evapotranspiration data. Intercomparing the results of FLDAS and GLDAS suggested that FLDAS data had better …


Diurnal Cycle Of Passive Microwave Brightness Temperatures Over Land At A Global Scale, Zahra Sharifnezhad, Hamid Norouzi, Satya Prakash, Reginald Blake, Reze Khanbilvard Feb 2021

Diurnal Cycle Of Passive Microwave Brightness Temperatures Over Land At A Global Scale, Zahra Sharifnezhad, Hamid Norouzi, Satya Prakash, Reginald Blake, Reze Khanbilvard

Publications and Research

Satellite-borne passive microwave radiometers provide brightness temperature (TB) measurements in a large spectral range which includes a number of frequency channels and generally two polarizations: horizontal and vertical. These TBs are widely used to retrieve several atmospheric and surface variables and parameters such as precipitation, soil moisture, water vapor, air temperature profile, and land surface emissivity. Since TBs are measured at different microwave frequencies with various instruments and at various incidence angles, spatial resolutions, and radiometric characteristics, a mere direct integration of them from different microwave sensors would not necessarily provide consistency. However, when appropriately harmonized, they can provide a …


Time Lags: Insights From The U.S. Long Term Ecological Research Network, Edward B. Rastetter, Mark D. Ohman, Katherine J. Elliott, J. S. Rehage, Victor H. Rivera-Monroy, R. E. Boucek, Edward Castañeda-Moya, Tess M. Danielson, Laura Gough, Peter M. Groffman, C. Rhett Jackson, Chelcy Ford Miniat, Gaius R. Shaver Jan 2021

Time Lags: Insights From The U.S. Long Term Ecological Research Network, Edward B. Rastetter, Mark D. Ohman, Katherine J. Elliott, J. S. Rehage, Victor H. Rivera-Monroy, R. E. Boucek, Edward Castañeda-Moya, Tess M. Danielson, Laura Gough, Peter M. Groffman, C. Rhett Jackson, Chelcy Ford Miniat, Gaius R. Shaver

Advanced Science Research Center

Ecosystems across the United States are changing in complex ways that are difficult to predict. Coordinated long-term research and analysis are required to assess how these changes will affect a diverse array of ecosystem services. This paper is part of a series that is a product of a synthesis effort of the U.S. National Science Foundation’s Long Term Ecological Research (LTER) network. This effort revealed that each LTER site had at least one compelling scientific case study about “what their site would look like” in 50 or 100 yr. As the site results were prepared, themes emerged, and the case …


Long Term Air Quality Analysis In Reference To Thermal Power Plants Using Satellite Data In Singrauli Region, India, H. K. Romana, Ramesh P. Singh, D. P. Shukla Aug 2020

Long Term Air Quality Analysis In Reference To Thermal Power Plants Using Satellite Data In Singrauli Region, India, H. K. Romana, Ramesh P. Singh, D. P. Shukla

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The exponentially growing population and related anthropogenic activities have led to modifications in local environment. The change in local environment, evolving pattern of land use, concentrations of greenhouse gases and aerosols alter the energy balance of our climate system. This alteration in climate is leading to pre-mature deaths worldwide. This study analyses the air quality of Singrauli region, Madhya Pradesh, India for the past 15 years. Otherwise known as Urjanchal “the energy capital” of India has been declared as critically polluted by CPCB. The study provides an updated list of thermal power plants in the study area and their emission …


Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus Aug 2020

Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus

Theses and Dissertations

This paper investigates how the snow-albedo feedback mechanism of the arctic is changing in response to rising climate temperatures. Specifically, the interplay of vegetation and snowmelt, and how these two variables can be correlated. This has the potential to refine climate modelling of the spring transition season. Research was conducted at the ecoregion scale in northern Alaska from 2000 to 2020. Each ecoregion is defined by distinct topographic and ecological conditions, allowing for meaningful contrast between the patterns of spring albedo transition across surface conditions and vegetation types. The five most northerly ecoregions of Alaska are chosen as they encompass …


Long-Term Ndvi And Recent Vegetation Cover Profiles Of Major Offshore Island Nesting Sites Of Sea Turtles In Saudi Waters Of The Northern Arabian Gulf, Rommel H. Maneja, Jeffrey D. Miller, Wenzhao Li, Hesham El-Askary, Ace Vincent B. Flandez, Joshua J. Dagoy, Joselito Francis A. Alcaria, Abdullajid U. Basali, Khaled A. Al-Abdulkader, Ronald A. Loughland, Mohamed A. Qurban Jun 2020

Long-Term Ndvi And Recent Vegetation Cover Profiles Of Major Offshore Island Nesting Sites Of Sea Turtles In Saudi Waters Of The Northern Arabian Gulf, Rommel H. Maneja, Jeffrey D. Miller, Wenzhao Li, Hesham El-Askary, Ace Vincent B. Flandez, Joshua J. Dagoy, Joselito Francis A. Alcaria, Abdullajid U. Basali, Khaled A. Al-Abdulkader, Ronald A. Loughland, Mohamed A. Qurban

Mathematics, Physics, and Computer Science Faculty Articles and Research

Vegetation is an important ecological component of offshore islands in the Arabian Gulf (AG), which maintains long-term resilience of these islands. This is achieved by influencing sediment retention and moisture acquisition via condensation during periods of high humidity and by providing a variety of microhabitats for island fauna. The resilience of offshore islands’ ecosystems in the Saudi waters is important because they host the largest number of nesting hawksbill and green turtles in the AG. This study defines the characteristics and the long-term trends in vegetation cover of the offshore islands used by sea turtles as nesting grounds in the …


Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa May 2020

Synergistic Use Of Remote Sensing And Modeling For Estimating Net Primary Productivity In The Red Sea With Vgpm, Eppley-Vgpm, And Cbpm Models Intercomparison, Wenzhao Li, Surya Prakash Tiwari, Hesham El-Askary, Mohamed Ali Qurban, Vassilis Amiridis, K. P. Manikandan, Michael J. Garay, Olga V. Kalashnikova, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Primary productivity (PP) has been recently investigated using remote sensing-based models over quite limited geographical areas of the Red Sea. This work sheds light on how phytoplankton and primary production would react to the effects of global warming in the extreme environment of the Red Sea and, hence, illuminates how similar regions may behave in the context of climate variability. study focuses on using satellite observations to conduct an intercomparison of three net primary production (NPP) models--the vertically generalized production model (VGPM), the Eppley-VGPM, and the carbon-based production model (CbPM)--produced over the Red Sea domain for the 1998-2018 time period. …


Analysis Of Land Surface Temperature Over Urban Landcover Types Using Satellite Remote Sensing And Ground-Based Applications, Makini Valentine, Justine Ginchereau Dec 2018

Analysis Of Land Surface Temperature Over Urban Landcover Types Using Satellite Remote Sensing And Ground-Based Applications, Makini Valentine, Justine Ginchereau

Publications and Research

Urban areas have discrete differences in their land surface temperatures (LST) compared to rural areas. These regions are covered with impermeable materials with less vegetation and moisture. Consequently, this phenomenon causes major thermal intensities of different land surfaces, negatively impact people and environment. The objective of this project is to examine and to compare land surface temperature obtained from in-situ data and satellite-based observations in order to understand the diurnal variation and heat transfer at each surface type. The study utilizes series of hand held thermal infrared cameras and one Unmanned Aerial Vehicle (UAV) infrared camera to find land surface …


Large Scale Climate Oscillation Impacts On Temperature, Precipitation And Land Surface Phenology In Central Asia, Kirsten M. De Beurs, Geoffrey Henebry, Braden C. Owsley, Irina N. Sokolik Jun 2018

Large Scale Climate Oscillation Impacts On Temperature, Precipitation And Land Surface Phenology In Central Asia, Kirsten M. De Beurs, Geoffrey Henebry, Braden C. Owsley, Irina N. Sokolik

GSCE Faculty Publications

Central Asia has been rapidly changing in multiple ways over the past few decades. Increases in temperature and likely decreases in precipitation in Central Asia as the result of global climate change are making one of the most arid regions in the world even more susceptible to large-scale droughts. Global climate oscillations, such as the El Ni ̃no–Southern Oscillation, have previously been linked to observed weather patterns in Central Asia. However, until now it has been unclear how the different climate oscillations act simultaneously to affect the weather and subsequently the vegetated land surface in Central Asia.We fit well-established land …


Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry May 2018

Changing Snow Seasonality In The Highlands Of Kyrgyzstan, Monika Tomaszewska, Geoffrey Henebry

GSCE Faculty Publications

Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2). We focused on three metrics of snow seasonality—first date of snow, last date of snow, and duration of snow season—and used nonparametric trends tests to assess the significance and direction of trends. We evaluated trends at three administration scales and across elevation. We used two techniques to assure that our identification of significant trends was …


The Role Of Sulfur Dioxide In Stratospheric Aerosol Formation Evaluated By Using In Situ Measurements In The Tropical Lower Stratosphere, A. W. Rollins, T. D. Thornberry, L. A. Watts, P. Yu, K. H. Rosenlof, M. Mills, E. Baumann, F. R. Giorgetta, T. V. Bui, M. Höpfner, P. F. Bernath May 2017

The Role Of Sulfur Dioxide In Stratospheric Aerosol Formation Evaluated By Using In Situ Measurements In The Tropical Lower Stratosphere, A. W. Rollins, T. D. Thornberry, L. A. Watts, P. Yu, K. H. Rosenlof, M. Mills, E. Baumann, F. R. Giorgetta, T. V. Bui, M. Höpfner, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in the future to offset greenhouse gases (geoengineering). The role of tropospheric-sourced sulfur dioxide (SO2) in maintaining background SAs has been debated for decades without in situ measurements of SO2 at the tropical tropopause to inform this issue. Here we clarify the role of SO2 in maintaining SAs by using new in situ SO2 measurements to evaluate climate models and satellite retrievals. We then use the observed tropical tropopause SO2 mixing ratios to estimate the global flux of …


Grand Challenges In Understanding The Interplay Of Climate And Land Changes, Shuguang Liu, Ben Bond-Lamberty, Lena R. Boysen, James D. Ford, Andrew Fox, Kevin Gallo, Jerry Hatfield, Geoffrey M. Henebry, Thomas G. Huntington, Zhihua Liu, Thomas R. Loveland, Richard J. Norby, Terry Sohl, Allison L. Steiner, Wenping Yuan, Zhao Zhang, Shuqing Zhao Apr 2017

Grand Challenges In Understanding The Interplay Of Climate And Land Changes, Shuguang Liu, Ben Bond-Lamberty, Lena R. Boysen, James D. Ford, Andrew Fox, Kevin Gallo, Jerry Hatfield, Geoffrey M. Henebry, Thomas G. Huntington, Zhihua Liu, Thomas R. Loveland, Richard J. Norby, Terry Sohl, Allison L. Steiner, Wenping Yuan, Zhao Zhang, Shuqing Zhao

GSCE Faculty Publications

Half of Earth’s land surface has been altered by human activities, creating various consequences on the climate and weather systems at local to global scales, which in turn affect a myriad of land surface processes and the adaptation behaviors. This study reviews the status and major knowledge gaps in the interactions of land and atmospheric changes and present 11 grand challenge areas for the scientific research and adaptation community in the coming decade. These land-cover and land-use change (LCLUC)-related areas include 1) impacts on weather and climate, 2) carbon and other biogeochemical cycles, 3) biospheric emissions, 4) the water cycle, …


Urban Heat Islands As Viewed By Microwave Radiometers And Thermal Time Indices, Lan H. Nguyen, Geoffrey M. Henebry Oct 2016

Urban Heat Islands As Viewed By Microwave Radiometers And Thermal Time Indices, Lan H. Nguyen, Geoffrey M. Henebry

GSCE Faculty Publications

Urban heat islands (UHIs) have been long studied using both ground-based observations of air temperature and remotely sensed thermal infrared (TIR) data. While ground-based observations lack spatial detail even in the occasional “dense” urban network, skin temperature retrievals using TIR data have lower temporal coverage due to revisit frequency, limited swath width, and cloud cover. Algorithms have recently been developed to retrieve near-surface air temperatures using microwave radiometer data, which enables characterization of UHIs in metropolitan areas, major conurbations, and global megacities at regional to continental scales using temporally denser time series than those that have been available from TIR …


A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo Aug 2016

A Comparison Of Tropical Rainforest Phenology Retrieved From Geostationary (Seviri) And Polar-Orbiting (Modis) Sensors Across The Congo Basin, Dong Yan, Xiaoyang Zhang, Yunyue Yu, Wei Guo

GSCE Faculty Publications

The seasonal and interannual dynamics of tropical rainforests play a critical role in the global carbon cycle and climate change. This paper retrieved and compared land surface phenology from observations acquired by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard geostationary satellites and the Moderate Resolution Imaging Spectroradiometer (MODIS) on polar-orbiting satellites over the Congo Basin. To achieve this,we first retrieved canopy greenness cycles (CGCs) and their transition timing from two-band enhanced vegetation index (EVI2) derived from SEVIRI and MODIS data between 2006 and 2013.We then assessed the influences of SEVIRI and MODIS data quality on the reconstruction of …


A Model Of The Effects Of Deforestation On Local Climate In The North Cascades, Monica R. H. Jasper Mar 2016

A Model Of The Effects Of Deforestation On Local Climate In The North Cascades, Monica R. H. Jasper

Geography and the Environment: Graduate Student Capstones

Changes in areal extent of land cover types may lead to alterations in the surface energy budget that contribute to anthropogenic climate forcing. This study examines the effects of deforestation in the Cascade Range on local temperature. Temperature sensors were installed in 14 forest stands, taking measurements for one year. Estimated tree age, circumference, and species were recorded to calculate stand density index. Satellite imagery was used to calculate shade fraction from spectral mixture analysis, which is a proxy for canopy structure and density. These data were used to construct seasonal cycles of temperature to model variation with stand density …