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Full-Text Articles in Engineering

Interannual Variability And Seasonal Predictability Of Wind And Solar Resources, Nir Krakauer, Daniel S. Cohen Jul 2017

Interannual Variability And Seasonal Predictability Of Wind And Solar Resources, Nir Krakauer, Daniel S. Cohen

Publications and Research

Solar and wind resources available for power generation are subject to variability due to meteorological factors. Here, we use a new global climate reanalysis product, Version 2 of the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA-2), to quantify interannual variability of monthly-mean solar and wind resource from 1980 to 2016 at a resolution of about 0.5 degrees. We find an average coefficient of variation (CV) of 11% for monthly-mean solar radiation and 8% for wind speed. Mean CVs were about 25% greater over ocean than over land and, for land areas, were greatest at high latitude. The correlation …


Development Of Geospatial And Temporal Characteristics For Hispaniola’S Lake Azuei And Enriquillo Using Landsat Imagery, Mahrokh Moknatian, Michael Piasecki, Jorge Gonzalez May 2017

Development Of Geospatial And Temporal Characteristics For Hispaniola’S Lake Azuei And Enriquillo Using Landsat Imagery, Mahrokh Moknatian, Michael Piasecki, Jorge Gonzalez

Publications and Research

In this paper, we used Landsat imagery for water body identification to create a novel 36-year surface area extent time series for lakes Azuei (Haiti) and Enriquillo (Dominican Republic) aimed at illuminating the dramatic temporal changes of these two lakes not just at yearly but at monthly or even sub-monthly scales. We used the Normalized Difference Water Index (NDWI) to extract water features and we also used spatial differentiation and thresholding techniques to remove clouds and associated shadows from the scene that were then passed through gap filling algorithms to complete and extract the lake extent polygons. We also explored …


Proof Of Concept: Development Of Snow Liquid Water Content Profiler Using Cs650 Reflectometers At Caribou, Me, Usa, Carlos L. Pérez Díaz, Jonathan Muñoz, Tarendra Lakhankar, Reza Khanbilvardi, Peter Romanov Mar 2017

Proof Of Concept: Development Of Snow Liquid Water Content Profiler Using Cs650 Reflectometers At Caribou, Me, Usa, Carlos L. Pérez Díaz, Jonathan Muñoz, Tarendra Lakhankar, Reza Khanbilvardi, Peter Romanov

Publications and Research

The quantity of liquid water in the snowpack defines its wetness. The temporal evolution of snow wetness’s plays a significant role in wet-snow avalanche prediction, meltwater release, and water availability estimations and assessments within a river basin. However, it remains a difficult task and a demanding issue to measure the snowpack’s liquid water content (LWC) and its temporal evolution with conventional in situ techniques. We propose an approach based on the use of time-domain reflectometry (TDR) and CS650 soil water content reflectometers to measure the snowpack’s LWC and temperature profiles. For this purpose, we created an easily-applicable, low-cost, automated, and …


A Comparison Of Modis/Viirs Cloud Masks Over Ice-Bearing River: On Achieving Consistent Cloud Masking And Improved River Ice Mapping, Simon Kraatz, Reza Khanbilvardi, Peter Romanov Mar 2017

A Comparison Of Modis/Viirs Cloud Masks Over Ice-Bearing River: On Achieving Consistent Cloud Masking And Improved River Ice Mapping, Simon Kraatz, Reza Khanbilvardi, Peter Romanov

Publications and Research

The capability of frequently and accurately monitoring ice on rivers is important, since it may be possible to timely identify ice accumulations corresponding to ice jams. Ice jams are dam-like structures formed from arrested ice floes, and may cause rapid flooding. To inform on this potential hazard, the CREST River Ice Observing System (CRIOS) produces ice cover maps based on MODIS and VIIRS overpass data at several locations, including the Susquehanna River. CRIOS uses the respective platform’s automatically produced cloud masks to discriminate ice/snow covered grid cells from clouds. However, since cloud masks are produced using each instrument’s data, and …


Ocean–Atmosphere Interactions Modulate Irrigation’S Climate Impacts, Nir Y. Krakauer, Michael J. Puma, Benjamin I. Cook, Pierre Gentine, Larisa Nazarenko Nov 2016

Ocean–Atmosphere Interactions Modulate Irrigation’S Climate Impacts, Nir Y. Krakauer, Michael J. Puma, Benjamin I. Cook, Pierre Gentine, Larisa Nazarenko

Publications and Research

Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean– atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity.We find that ocean–atmosphere interaction does impact the magnitude of globalmean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, …


Bathymetric Survey For Lakes Azuei And Enriquillo, Hispaniola, Michael Piasecki, Mahrokh Moknatian, Fred Moshary, Joseph Cleto, Yolanda Leon, Jorge Gonzalez, Daniel Comarazamy Jun 2016

Bathymetric Survey For Lakes Azuei And Enriquillo, Hispaniola, Michael Piasecki, Mahrokh Moknatian, Fred Moshary, Joseph Cleto, Yolanda Leon, Jorge Gonzalez, Daniel Comarazamy

Publications and Research

The two largest lakes on the Caribbean Island of Hispaniola, Lake Azuei in Haiti and Lake Enriquillo in the Dominican Republic, have experienced dramatic growth and surface area expansion over the past few years leading to severe flooding and loss of arable land around the lake perimeters. In order to better understand the reasons for this unprecedented rate of expansion and the resulting consequences a multi-disciplinary team comprised of researchers from Haiti, the DR, and the US have embarked on an extensive data collecting and hydrologic and climatological modeling campaign. While the sensor deployment entails stations that measure climatological data …


Historical Trends In Mean And Extreme Runoff And Streamflow Based On Observations And Climate Models, Behzad Asadieh, Nir Y. Krakauer, Balázs M. Fekete May 2016

Historical Trends In Mean And Extreme Runoff And Streamflow Based On Observations And Climate Models, Behzad Asadieh, Nir Y. Krakauer, Balázs M. Fekete

Publications and Research

To understand changes in global mean and extreme streamflow volumes over recent decades, we statistically analyzed runoff and streamflow simulated by the WBM-plus hydrological model using either observational-based meteorological inputs from WATCH Forcing Data (WFD), or bias-corrected inputs from five global climate models (GCMs) provided by the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP). Results show that the bias-corrected GCM inputs yield very good agreement with the observation-based inputs in average magnitude of runoff and streamflow. On global average, the observation-based simulated mean runoff and streamflow both decreased about 1.3% from 1971 to 2001. However, GCM-based simulations yield increasing trends over …


Estimating The Probability Of Vegetation To Be Groundwater Dependent Based On The Evaluation Of Tree Models, Isabel C. Pérez Hoyos, Nir Y. Krakauer, Reza Khanbilvardi Apr 2016

Estimating The Probability Of Vegetation To Be Groundwater Dependent Based On The Evaluation Of Tree Models, Isabel C. Pérez Hoyos, Nir Y. Krakauer, Reza Khanbilvardi

Publications and Research

Groundwater Dependent Ecosystems (GDEs) are increasingly threatened by humans’ rising demand for water resources. Consequently, it is imperative to identify the location of GDEs to protect them. This paper develops a methodology to identify the probability of an ecosystem to be groundwater dependent. Probabilities are obtained by modeling the relationship between the known locations of GDEs and factors influencing groundwater dependence, namely water table depth and climatic aridity index. Probabilities are derived for the state of Nevada, USA, using modeled water table depth and aridity index values obtained from the Global Aridity database. The model selected results from the performance …


Ensemble Forecasts: Probabilistic Seasonal Forecasts Based On A Model Ensemble, Hannah Aizenman, Michael D. Grossberg, Nir Y. Krakauer, Irina Gladkova Mar 2016

Ensemble Forecasts: Probabilistic Seasonal Forecasts Based On A Model Ensemble, Hannah Aizenman, Michael D. Grossberg, Nir Y. Krakauer, Irina Gladkova

Publications and Research

Ensembles of general circulation model (GCM) integrations yield predictions for meteorological conditions in future months. Such predictions have implicit uncertainty resulting from model structure, parameter uncertainty, and fundamental randomness in the physical system. In this work, we build probabilistic models for long-term forecasts that include the GCM ensemble values as inputs but incorporate statistical correction of GCM biases and different treatments of uncertainty. Specifically, we present, and evaluate against observations, several versions of a probabilistic forecast for gridded air temperature 1 month ahead based on ensemble members of the National Centers for Environmental Prediction (NCEP) Climate Forecast System Version 2 …


A Review Of Advances In The Identification And Characterization Of Groundwater Dependent Ecosystems Using Geospatial Technologies, Isabel C. Pérez Hoyos, Nir Y. Krakauer, Reza Khanbilvardi, Roy A. Armstrong Mar 2016

A Review Of Advances In The Identification And Characterization Of Groundwater Dependent Ecosystems Using Geospatial Technologies, Isabel C. Pérez Hoyos, Nir Y. Krakauer, Reza Khanbilvardi, Roy A. Armstrong

Publications and Research

Groundwater Dependent Ecosystem (GDE) protection is increasingly being recognized as essential for the sustainable management and allocation of water resources. GDE services are crucial for human well-being and for a variety of flora and fauna. However, the conservation of GDEs is only possible if knowledge about their location and extent is available. Several studies have focused on the identification of GDEs at specific locations using ground-based measurements. However, recent progress in remote sensing technologies and their integration with Geographic Information Systems (GIS) has provided alternative ways to map GDEs at a much larger spatial extent. This paper presents a review …


Sefo: A Package For Generating Probabilistic Forecasts From Nmme Predictive Ensembles, Nir Krakauer Mar 2016

Sefo: A Package For Generating Probabilistic Forecasts From Nmme Predictive Ensembles, Nir Krakauer

Publications and Research

Long-range weather forecasts based on output from ensembles of computer simulations are attracting increasing interest. A variety of methods have been proposed to convert the ensemble outputs to calibrated probabilistic forecasts. The package presented here (SeFo, for Seasonal Forecasting) implements a number of methods for producing forecasts of monthly surface air temperature anomalies up to 9 months in advance using output from the North American Multi-Model Ensemble (NMME). The package contains modules for downloading and reading past observations and ensemble output; producing forecast probability distributions; and verifying and calibrating a user-determined subset of methods using arbitrary past periods. By changing …


Impact Of Irrigation Method On Water Use Efficiency And Productivity Of Fodder Crops In Nepal, Ajay K. Jha, Razan Malla, Mohan Sharma, Jeeban Panthi, Tarendra Lakhankar, Nir Y. Krakauer, Soni M. Pradhanang, Piyush Dahal, Madan Lall Shrestha Jan 2016

Impact Of Irrigation Method On Water Use Efficiency And Productivity Of Fodder Crops In Nepal, Ajay K. Jha, Razan Malla, Mohan Sharma, Jeeban Panthi, Tarendra Lakhankar, Nir Y. Krakauer, Soni M. Pradhanang, Piyush Dahal, Madan Lall Shrestha

Publications and Research

Improved irrigation use efficiency is an important tool for intensifying and diversifying agriculture in Nepal, resulting in higher economic yield from irrigated farmlands with a minimum input of water. Research was conducted to evaluate the effect of irrigation method (furrow vs. drip) on the productivity of nutritious fodder species during off-monsoon dry periods in different elevation zones of central Nepal. A split-block factorial design was used. The factors considered were treatment location, fodder crop, and irrigation method. Commonly used local agronomical practices were followed in all respects except irrigation method. Results revealed that location effect was significant (p < 0.01) with highest fodder productivity seen for the middle elevation site, Syangja. Species effects were also significant, with teosinte (Euchlaena mexicana) having higher yield than cowpea (Vigna unguiculata). Irrigation method impacted green biomass yield (higher with furrow irrigation) but both methods yielded similar dry biomass, while water use was 73% less under drip irrigation. Our findings indicated that the controlled application of water through drip irrigation is able to produce acceptable yields of nutritionally dense fodder species during dry seasons, leading to more effective utilization and resource conservation of available land, fertilizer and water. Higher productivity of these nutritional fodders resulted in higher milk productivity for livestock smallholders. The ability to grow fodder crops year-round in lowland and hill regions of Nepal with limited water storages using low-cost, water-efficient drip irrigation may greatly increase livestock productivity and, hence, the economic security of smallholder farmers.


Evaluation Of Viirs Land Surface Temperature Using Crest-Safe Air, Snow Surface, And Soil Temperature Data, Carlos L. Pérez Díaz, Tarendra Lakhankar, Peter Romanov, Reza Khanbilvardi, Yunyue Yu Dec 2015

Evaluation Of Viirs Land Surface Temperature Using Crest-Safe Air, Snow Surface, And Soil Temperature Data, Carlos L. Pérez Díaz, Tarendra Lakhankar, Peter Romanov, Reza Khanbilvardi, Yunyue Yu

Publications and Research

In this study, the Visible Infrared Imager Radiometer Suite (VIIRS) Land Surface Temperature (LST) Environmental Data Record (EDR) was evaluated against snow surface (T-skin) and near-surface air temperature (T-air) ground observations recorded at the Cooperative Remote Sensing Science and Technology Center—Snow Analysis and Field Experiment (CREST-SAFE), located in Caribou, ME, USA during the winters of 2013 and 2014. The satellite LST corroboration of snow-covered areas is imperative because high-latitude regions are often physically inaccessible and there is a need to complement the data from the existing meteorological station networks. T-skin is not a standard meteorological parameter commonly observed at synoptic …


Evaluation Of The Snow Thermal Model (Sntherm) Through Continuous In Situ Observations Of Snow’S Physical Properties At The Crest-Safe Field Experiment, José Alberto Infante Corona, Jonathan Muñoz, Tarendra Lakhankar, Peter Romanov, Reza Khanbilvardi Nov 2015

Evaluation Of The Snow Thermal Model (Sntherm) Through Continuous In Situ Observations Of Snow’S Physical Properties At The Crest-Safe Field Experiment, José Alberto Infante Corona, Jonathan Muñoz, Tarendra Lakhankar, Peter Romanov, Reza Khanbilvardi

Publications and Research

Snowpack properties like temperature or density are the result of a complex energy and mass balance process in the snowpack that varies temporally and spatially. The Snow Thermal Model (SNTHERM) is a 1-dimensional model, energy and mass balance-driven, that simulates these properties. This article analyzes the simulated snowpack properties using SNTHERM forced with two datasets, namely measured meteorological data at the Cooperative Remote Sensing Science and Technology-Snow Analysis and Field Experiment (CREST-SAFE) site and the National Land Data Assimilation System (NLDAS). The study area is located on the premises of Caribou Municipal Airport at Caribou (ME, USA). The model evaluation …


Probabilistic Precipitation Estimation With A Satellite Product, Nir Y. Krakauer, Soni M. Pradhanang, Jeeban Panthi, Tarendra Lakhankar, Ajay K. Jha Apr 2015

Probabilistic Precipitation Estimation With A Satellite Product, Nir Y. Krakauer, Soni M. Pradhanang, Jeeban Panthi, Tarendra Lakhankar, Ajay K. Jha

Publications and Research

Satellite-based precipitation products have been shown to represent precipitation well over Nepal at monthly resolution, compared to ground-based stations. Here, we extend our analysis to the daily and subdaily timescales, which are relevant for mapping the hazards caused by storms as well as drought. We compared the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) 3B42RT product with individual stations and with the gridded APHRODITE product to evaluate its ability to retrieve different precipitation intensities. We find that 3B42RT, which is freely available in near real time, has reasonable correspondence with ground-based precipitation products on a daily timescale; rank …


National Livestock Policy Of Nepal: Needs And Opportunities, Upendra B. Pradhanang, Soni M. Pradhanang, Arhan Sthapit, Nir Y. Krakauer, Ajay K. Jha, Tarendra Lakhankar Mar 2015

National Livestock Policy Of Nepal: Needs And Opportunities, Upendra B. Pradhanang, Soni M. Pradhanang, Arhan Sthapit, Nir Y. Krakauer, Ajay K. Jha, Tarendra Lakhankar

Publications and Research

This paper describes Nepal’s national livestock policies and considers how they can be improved to help meet the pressing national challenges of economic development, equity, poverty alleviation, gender mainstreaming, inclusion of marginalized and underprivileged communities, and climate vulnerability. Nepal is in the process of transforming its government from a unitary system to a federal democratic structure through the new constitution expected by 2015, offering the opportunity to bring a new set of priorities and stakeholders to policymaking. Nepal’s livestock subsector comes most directly within the purview of the National Agricultural Policy 2004, Agro-Business Policy, 2006 and Agricultural Sectoral Operating Policies …


Spatial And Temporal Variability Of Rainfall In The Gandaki River Basin Of Nepal Himalaya, Jeeban Panthi, Piyush Dahal, Madan Lall Shrestha, Suman Aryal, Nir Y. Krakauer, Soni M. Pradhanang, Tarendra Lakhankar, Ajay K. Jha, Mohan Sharma, Ramchandra Karki Mar 2015

Spatial And Temporal Variability Of Rainfall In The Gandaki River Basin Of Nepal Himalaya, Jeeban Panthi, Piyush Dahal, Madan Lall Shrestha, Suman Aryal, Nir Y. Krakauer, Soni M. Pradhanang, Tarendra Lakhankar, Ajay K. Jha, Mohan Sharma, Ramchandra Karki

Publications and Research

Landslides, floods, and droughts are recurring natural disasters in Nepal related to too much or too little water. The summer monsoon contributes more than 80% of annual rainfall, and rainfall spatial and inter-annual variation is very high. The Gandaki River, one of the three major rivers of Nepal and one of the major tributaries of the Ganges River, covers all agro-ecological zones in the central part of Nepal. Time series tests were applied for different agro-ecological zones of the Gandaki River Basin (GRB) for rainfall trends of four seasons (pre-monsoon, monsoon, post-monsoon and winter) from 1981 to 2012. The non-parametric …


A Critical Review Of Research On Reuse Of Mechanically Recycled Frp Production And End-Of-Life Waste For Construction, Ardavan Yazdanbakhsh, Lawrence C. Bank Jun 2014

A Critical Review Of Research On Reuse Of Mechanically Recycled Frp Production And End-Of-Life Waste For Construction, Ardavan Yazdanbakhsh, Lawrence C. Bank

Publications and Research

For the last three decades, fiber reinforced polymer (FRP) composite materials have been widely used in major engineering industries. Managing FRP waste is becoming an important issue due to the growth in the production of FRP composite materials. In this article, the issue of FRP waste management is discussed and the commonly used methods for the handling of FRP waste are reviewed. One potentially viable use of FRP waste is in the partial replacement of fillers or aggregates in cementitious materials (particularly portland cement mortar and concrete). A number of important prior investigations performed on the use of FRP waste …


Economic Growth Assumptions In Climate And Energy Policy, Nir Y. Krakauer Mar 2014

Economic Growth Assumptions In Climate And Energy Policy, Nir Y. Krakauer

Publications and Research

The assumption that the economic growth seen in recent decades will continue has dominated the discussion of future greenhouse gas emissions and the mitigation of and adaptation to climate change. Given that long-term economic growth is uncertain, the impacts of a wide range of growth trajectories should be considered. In particular, slower economic growth would imply that future generations will be relatively less able to invest in emissions controls or adapt to the detrimental impacts of climate change. Taking into consideration the possibility of economic slowdown therefore heightens the urgency of reducing greenhouse gas emissions now by moving to renewable …


Assessing The Performance Of A Northern Gulf Of Mexico Tidal Model Using Satellite Imagery, Stephen C. Medeiros, Scott C. Hagen, Naira Chaouch, Jesse Feyen, Marouane Temimi, John F. Weishampel, Yuji Funakoshi, Reza Khanbilvardi Nov 2013

Assessing The Performance Of A Northern Gulf Of Mexico Tidal Model Using Satellite Imagery, Stephen C. Medeiros, Scott C. Hagen, Naira Chaouch, Jesse Feyen, Marouane Temimi, John F. Weishampel, Yuji Funakoshi, Reza Khanbilvardi

Publications and Research

Tidal harmonic analysis simulations along with simulations spanning four specific historical time periods in 2003 and 2004 were conducted to test the performance of a northern Gulf of Mexico tidal model. A recently developed method for detecting inundated areas based on integrated remotely sensed data (i.e., Radarsat-1, aerial imagery, LiDAR, Landsat 7 ETM+) was applied to assess the performance of the tidal model. The analysis demonstrates the applicability of the method and its agreement with traditional performance assessment techniques such as harmonic resynthesis and water level time series analysis. Based on the flooded/non-flooded coastal areas estimated by the integrated remotely …


Evaluating Satellite Products For Precipitation Estimation In Mountain Regions: A Case Study For Nepal, Nir Y. Krakauer, Soni M. Pradhanang, Tarendra Lakhankar, Ajay K. Jha Aug 2013

Evaluating Satellite Products For Precipitation Estimation In Mountain Regions: A Case Study For Nepal, Nir Y. Krakauer, Soni M. Pradhanang, Tarendra Lakhankar, Ajay K. Jha

Publications and Research

Precipitation in mountain regions is often highly variable and poorly observed, limiting abilities to manage water resource challenges. Here, we evaluate remote sensing and ground station-based gridded precipitation products over Nepal against weather station precipitation observations on a monthly timescale. We find that the Tropical Rainfall Measuring Mission (TRMM) 3B-43 precipitation product exhibits little mean bias and reasonable skill in giving precipitation over Nepal. Compared to station observations, the TRMM precipitation product showed an overall Nash-Sutcliffe efficiency of 0.49, which is similar to the skill of the gridded station-based product Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of Water …


Crest-Snow Field Experiment: Analysis Of Snowpack Properties Using Multi-Frequency Microwave Remote Sensing Data, Tarendra Lakhankar, J. Munoz, A.M. Powell, N.Y. Krakauer, W.B. Rossow, Reza Khanbilvardi Jan 2013

Crest-Snow Field Experiment: Analysis Of Snowpack Properties Using Multi-Frequency Microwave Remote Sensing Data, Tarendra Lakhankar, J. Munoz, A.M. Powell, N.Y. Krakauer, W.B. Rossow, Reza Khanbilvardi

Publications and Research

The CREST-Snow Analysis and Field Experiment (CREST-SAFE) was carried out during January–March 2011 at the research site of the National Weather Service office, Caribou, ME, USA. In this experiment dual-polarized microwave (37 and 89 GHz) observations were accompanied by detailed synchronous observations of meteorology and snowpack physical properties. The objective of this long-term field experiment was to improve understanding of the effect of changing snow characteristics (grain size, density, temperature) under various meteorological conditions on the microwave emission of snow and hence to improve retrievals of snow cover properties from satellite observations. In this paper we present an overview of …


Potential Significance Of Photoexcited No2 On Global Air Quality With The Nmmb/Bsc Chemical Transport Model, O. Jorba, D. Dabdub, Christopher S. Blaszczak-Boxe, C. Pérez, Z. Janjic, J. M. Baldasano, M. Spada, A. Badia, M. Gonçalves Jul 2012

Potential Significance Of Photoexcited No2 On Global Air Quality With The Nmmb/Bsc Chemical Transport Model, O. Jorba, D. Dabdub, Christopher S. Blaszczak-Boxe, C. Pérez, Z. Janjic, J. M. Baldasano, M. Spada, A. Badia, M. Gonçalves

Publications and Research

Atmospheric chemists have recently focused on the relevance of the NO2* + H2O → OH + HONO reaction to local air quality. This chemistry has been considered not relevant for the troposphere from known reaction rates until nowadays. New experiments suggested a rate constant of 1.7 × 10−13 cm3 molecule−1 s−1, which is an order of magnitude faster than the previously estimated upper limit of 1.2 × 10−14 cm3 molecule−1 s−1, determined by Crowley and Carl (1997). Using the new global model, NMMB/BSC Chemical Transport Model (NMMB/BSC-CTM), simulations are presented that assess the potential significance of this chemistry on global …


Validation Of Noaa-Interactive Multisensor Snow And Ice Mapping System (Ims) By Comparison With Ground-Based Measurements Over Continental United States, Christine Chen, Tarendra Lakhankar, Peter Romanov, Sean Helfrich, Al Powell, Reza Khanbilvardi Apr 2012

Validation Of Noaa-Interactive Multisensor Snow And Ice Mapping System (Ims) By Comparison With Ground-Based Measurements Over Continental United States, Christine Chen, Tarendra Lakhankar, Peter Romanov, Sean Helfrich, Al Powell, Reza Khanbilvardi

Publications and Research

In this study, daily maps of snow cover distribution and sea ice extent produced by NOAA’s interactive multisensor snow and ice mapping system (IMS) were validated using in situ snow depth data from observing stations obtained from NOAA’s National Climatic Data Center (NCDC) for calendar years 2006 to 2010. IMS provides daily maps of snow and sea ice extent within the Northern Hemisphere using data from combination of geostationary and polar orbiting satellites in visible, infrared and microwave spectrums. Statistical correspondence between the IMS and in situ point measurements has been evaluated assuming that ground measurements are discrete and continuously …


Using Avhrr-Based Vegetation Health Indices For Estimation Of Potato Yield In Bangladesh, Rahman A., Kaiser Khan, Nir Y. Krakauer, Leonid Roytman, Kogan F. Mar 2012

Using Avhrr-Based Vegetation Health Indices For Estimation Of Potato Yield In Bangladesh, Rahman A., Kaiser Khan, Nir Y. Krakauer, Leonid Roytman, Kogan F.

Publications and Research

We developed a model correlating Advanced Very High Resolution Radiometer (AVHRR)-based Temperature Condition Index (TCI) and Vegetation Condition Index (VCI) with potato yield in Bangladesh. Weekly TCI and VCI Indices for 1993–2005 along with official potato yield statistics were used for model development. We found a strong correlation between inter annual variation in potato yield and TCI and VCI during the critical period of potato growth (vegetative phase and tuber initiation), mid-December to mid-January. Principal component regression (PCR) was used to construct a model to predict potato yield as function of TCI and VCI. The model explained about 75% of …


Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi Jan 2012

Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi

Publications and Research

To retrieve microwave land emissivity, infrared surface skin temperatures have been used as surface physical temperature since there is no global information on physical vegetation/soil temperature profiles. However, passive microwave emissions originate fromdeeper layerswith respect to the skin temperature. So, this inconsistency in sensitivity depths between skin temperatures and microwave temperaturesmay introduce a discrepancy in the determined emissivity. Previous studies showed that this inconsistency can lead to significant differences between day and night retrievals of land emissivity which can exceed 10%. This study proposes an approach to address this inconsistency and improve the retrieval of land emissivity using microwave observations …


Analysis Of The Effects Of Snowpack Properties On Satellite Microwave Brightness Temperature And Emissivity Data, Tarendra Lakhankar, Amir E. Azar, Narges Shahroudi, Alfred Powell, Reza Khanbilvardi Jan 2012

Analysis Of The Effects Of Snowpack Properties On Satellite Microwave Brightness Temperature And Emissivity Data, Tarendra Lakhankar, Amir E. Azar, Narges Shahroudi, Alfred Powell, Reza Khanbilvardi

Publications and Research

Spatial variations of snowpack properties are an essential component in flood predictions and water resource management. Satellite microwave remote sensing has shown great potential in retrieving snowpack properties such as: snow depth, snow grain size, and snow density. In this research, we investigate the potential of microwave emissivity which is highly influenced by snowpack properties. Brightness temperature and emissivity data generated from HUT (Helsinki University of Technology) microwave emission of snow model were evaluated with satellite microwave measurements. The comparison of the real measurements (in-situ and satellite) with the modeled results shows that the scattering signature (19GHz-37GHz and 19GHz-85GHz) shows …


Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott Oct 2011

Dissemination Of Geological Information In Avoiding Geotechnical Risks Associated With Tunnel Construction: Lessons Learned From Deep Voids In Marble In Lower Manhattan, New York City, Nazrul I. Khandaker, Stanley Schleifer, Masud Ahmed, Leah Scott

Publications and Research

Test boring associated with the recently accomplished City Water Tunnel # 3 in Manhattan, New York City revealed moderately to highly weathered marble with insoluble silicate residues composed mostly of phlogopite, chlorite, and tremolite. Apparent control on the weatherability of the marble was in response to original mineral constituents dominating this lithology. Encountered marble samples ranged between pure calcitic to mixed dolomitic/siliceous types. Fresh marble samples collected from adjacent boring locations revealed characteristic geochemical data: Lime (25-45%), Silica (4-7%), Alumina (1-3%), MgO (5-20%), and LOI (35-42%); compressive strength of unweathered marble varied between 2000-3000 Kg/cm2. Relict foliations with …


Brooklyn's Thirst, Long Island's Water: Consolidation, Local Control, And The Aquifer, Jeffrey A. Kroessler Jan 2011

Brooklyn's Thirst, Long Island's Water: Consolidation, Local Control, And The Aquifer, Jeffrey A. Kroessler

Publications and Research

The creation of greater New York City in 1898 promised a solution to the problem of supplying Brooklyn and Queens with water. In the 1850s, the City of Brooklyn tapped ponds and streams on the south side of Queens County, and in the 1880s, dug wells for additional supply. This lowered the water table and caused problems for farmers and oystermen, many of whom sued the city for damages. Ultimately, salt water seeped into some wells from over-pumping. By 1896, Brooklyn’s system had reached its limit. Prevented by the state legislature from tapping the aquifer beneath Suffolk’s Pine Barrens, the …


A Multi-Temporal Analysis Of Amsr-E Data For Flood And Discharge Monitoring During The 2008 Flood In Iowa, Marouane Temimi, Teodosio Lacava, Tarendra Lakhankar, Valerio Tramutoli, Hosni Ghedira, Riadh Ata, Reza Khanbilvardi Jan 2011

A Multi-Temporal Analysis Of Amsr-E Data For Flood And Discharge Monitoring During The 2008 Flood In Iowa, Marouane Temimi, Teodosio Lacava, Tarendra Lakhankar, Valerio Tramutoli, Hosni Ghedira, Riadh Ata, Reza Khanbilvardi

Publications and Research

The objective of this work is to demonstrate the potential of using passive microwave data to monitor flood and discharge conditions and to infer watershed hydraulic and hydrologic parameters. The case study is the major flood in Iowa in summer 2008. A new Polarisation Ratio Variation Index (PRVI) was developed based on a multi-temporal analysis of 37 GHz satellite imagery from the Advanced Microwave Scanning Radiometer (AMSR-E) to calculate and detect anomalies in soil moisture and/or inundated areas. The Robust Satellite Technique (RST) which is a change detection approach based on the analysis of historical satellite records was adopted. A …