Physical Sciences and Mathematics Commons^™

Incorporating Animal Movement Into Distance Sampling, R. Glennie, S. T. Buckland, R. Langrock, Tim Gerrodette, Susan Chivers, M. D. Scott

United States Department of Commerce: Staff Publications

Distance sampling is a popular statistical method to estimate the density of wild animal populations. Conventional distance sampling represents animals as fixed points in space that are detected with an unknown probability that depends on the distance between the observer and the animal. Animal movement can cause substantial bias in density estimation. Methods to correct for responsive animal movement exist, but none account for nonresponsive movement independent of the observer. Here, an explicit animal movement model is incorporated into distance sampling, combining distance sampling survey data with animal telemetry data. Detection probability depends on the entire unobserved path the animal …

Heat Stored In The Earth System: Where Does The Energy Go?, Karina Von Schuckmann, Lijing Cheng, Matthew D. Palmer, James Hansen, Caterina Tassone, Valentin Aich, Susheel Adusumilli, Hugo Beltrami, Tim Boyer, Francisco José Cuesta-Valero, Damien Desbruyères, Catia Domingues, Almudena García-García, Pierre Gentine, John Gilson, Maximillian Gorfer, Leopold Haimberger, Masayoshi Ishii, Gregory C. Johnson, Rachel Killick, Brian A. King, Gottfried Kirchengast, Nicolas Kolodziejczyk, John Lyman, Ben Marzeion, Michael Mayer, Maeva Monier, Didier Paolo Monselesan, Sarah Purkey, Dean Roemmich, Axel Schweiger, Sonia I. Seneviratne, Andrew Shepherd, Donald A. Slater, Andrea K. Steiner, Fiammetta Straneo, Mary-Louise Timmermans, Susan E. Wijffels

United States Department of Commerce: Staff Publications

Human-induced atmospheric composition changes cause a radiative imbalance at the top of the atmosphere which is driving global warming. This Earth energy imbalance (EEI) is the most critical number defining the prospects for continued global warming and climate change. Understanding the heat gain of the Earth system—and particularly how much and where the heat is distributed—is fundamental to understanding how this affects warming ocean, atmosphere and land; rising surface temperature; sea level; and loss of grounded and floating ice, which are fundamental concerns for society. This study is a Global Climate Observing System (GCOS) concerted international effort to update the …

Incorporating Uh Occurrence Time To Ensemble-Derived Tornado Probabilities, Burkely T. Gallo, Adam J. Clark, Bryan T. Smith, Richard L. Thompson, Israel Jirak, Scott R. Dembek

United States Department of Commerce: Staff Publications

Probabilistic ensemble-derived tornado forecasts generated from convection-allowing models often use hourly maximum updraft helicity (UH) alone or in combination with environmental parameters as a proxy for right-moving (RM) supercells. However, when UH occurrence is a condition for tornado probability generation, false alarm areas can occur from UH swaths associated with nocturnal mesoscale convective systems, which climatologically produce fewer tornadoes than RM supercells. This study incorporates UH timing information with the forecast near-storm significant tornado parameter (STP) to calibrate the forecast tornado probability. To generate the probabilistic forecasts, three sets of observed climatological tornado frequencies given an RM supercell and STP …

Precipitation And Growth Of Barite Within Hydrothermal Vent Deposits From The Endeavour Segment, Juan De Fuca Ridge, John William Jamieson, Mark D. Hannington, Margaret K. Tivey, Thor Hansteen, Nicole M.-B. Williamson, Margaret Stewart, Jan Fietzke, David Butterfield, Matthias Frische, Leigh Allen, Brian Cousens, Julia Langer

United States Department of Commerce: Staff Publications

Hydrothermal vent deposits form on the seafloor as a result of cooling and mixing of hot hydrothermal fluids with cold seawater. Amongst the major sulfide and sulfate minerals that are preserved at vent sites, barite (BaSO₄) is unique because it requires the direct mixing of Ba-rich hydrothermal fluid with sulfate-rich seawater in order for precipitation to occur. Because of its extremely low solubility, barite crystals preserve geochemical fingerprints associated with conditions of formation. Here, we present data from petrographic and geochemical analyses of hydrothermal barite from the Endeavour Segment of the Juan de Fuca Ridge, northeast Pacific Ocean, …

Decadal Variability Of Net Water Flux At The Mediterranean Sea Gibraltar Strait, L. Fenoglio-Marc, A. Mariotti, G. Sannino, B. Meyssignac, A. Carillo, M. V. Struglia, M. Rixen

United States Department of Commerce: Staff Publications

Long-term variability of the net water flux into the Mediterranean Sea at the Gibraltar Strait over the period 1960–2009 is explored based on an approach combining multiple observational datasets and results from a regional climate model simulation. The approach includes deriving Gibraltar net inflow from the application of the Mediterranean Sea water budget equation using observationally based estimates of mass variation, evaporation, precipitation and simulated river discharge and Bosphorus Strait water fluxes. This derivation is compared with results from a simulation using the PROTHEUS regional ocean–atmosphere coupled model considering both individual water cycle terms and overall Gibraltar water flux.

Results …

Metabolite Profiles In Starved Diporeia Spp. Using Liquid Chromatography-Mass Spectrometry (Lc-Ms) Based Metabolomics, Suman Maity, Amber Jannasch, Jiri Adamec, Michael Gribskov, Thomas F. Nalepa, Tomas O. Höök, Maria S. Sepúlveda

United States Department of Commerce: Staff Publications

The holarctic amphipod Diporeia spp. was historically the most abundant benthic macroinvertebrate in the offshore region of the Laurentian Great Lakes basin. However, since the 1990’s, the numbers of Diporeia have declined precipitously throughout the region. Competition for food with introduced dreissenid mussels may be partly to blame for this decline. Thus, a better understanding of how Diporeia responds and adjust to starvation is needed. For this purpose, we used liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOFMS) to study the metabolite profiles of Diporeia during starvation. Diporeia were collected from Lake Michigan, brought to the laboratory and starved …

Identification Of Ovarian Gene Expression Patterns During Vitellogenesis In Atlantic Cod (Gadus Morhua), Timothy S. Breton, Janet L. Anderson, Frederick W. Goetz, David L. Berlinsky

United States Department of Commerce: Staff Publications

Follicular maturational competence and ovulatory competence in teleost fish refer to the ability of the ovarian follicle to undergo final oocyte maturation and ovulation, respectively, in response to gonadotropin stimulation and other external cues. Some gene products related to competence acquisition are likely synthesized during vitellogenic growth, as these follicles gain in vivo responsiveness to exogenous gonadotropin stimulation and can be induced to undergo maturation and ovulation. In Atlantic cod (Gadus morhua), gonadotropin responsiveness has been shown to be oocyte size-dependent, and only ovaries containing late-stage vitellogenic follicles can be induced to ovulate. The purpose of the present …

Land Surface Temperature Product Validation Using Noaa's Surface Climate Observation Networks—Scaling Methodology For The Visible Infrared Imager Radiometer Suite (Viirs), Pierre C. Guillevic, Jeffrey L. Privette, Benoit Coudert, Michael A. Palecki, Jerome Demarty, Catherine Ottlé, John A. Augustine

United States Department of Commerce: Staff Publications

NOAA will soon use the new Visible Infrared Imager Radiometer Suite (VIIRS) on the Joint Polar Satellite System (JPSS) as its primary polar-orbiting satellite imager. Employing a near real-time processing system, NOAA will generate a series of Environmental Data Records (EDRs) from VIIRS data. For example, the VIIRS Land Surface Temperature (LST) EDR will estimate the surface skin temperature over all global land areas and provide key information for monitoring Earth surface energy and water fluxes. Because both VIIRS and its processing algorithms are new, NOAA is conducting a rigorous calibration and validation program to understand and improve product quality. …

Estimation Of Surface Albedo And Directional Reflectance From Moderate Resolution Imaging Spectroradiometer (Modis) Observations, Tao He, Shunlin Liang, Dongdong Wang, Hongyi Wu, Yunyue Yu, Jindi Wang

United States Department of Commerce: Staff Publications

Land surface albedo is one of the key geophysical variables controlling the surface radiation budget. In recent years, land surface albedo products have been generated using data from various satellites. However, some problems exist in those products due to either the failure of the current retrieving procedures resulting from persistent clouds and/or abrupt surface changes, or the reduced temporal or spatial coverage, which may limit their applications. Rapidly generated albedo products that help reduce the impacts of cloud contamination and improve the capture of events such as ephemeral snow and vegetation growth are in demand.

In this study, we propose …

Arctic Cloud Macrophysical Characteristics From Cloudsat And Calipso, Yinghui Liu, Jeffrey R. Key, Steven A. Ackerman, Gerald G. Mace, Qiuqing Zhang

United States Department of Commerce: Staff Publications

The lidar and radar profiling capabilities of the CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder (CALIPSO) satellites provide opportunities to improve the characterization of cloud properties. An Arctic cloud climatology based on their observations may be fundamentally different from earlier Arctic cloud climatologies based on passive satellite observations, which have limited contrast between the cloud and underlying surface. Specifically, the Radar–Lidar Geometrical Profile product (RL-GEOPROF) provides cloud vertical profiles fromthe combination of active lidar and radar. Based on this data product for the period July 2006 to March 2011, this paper presents a new cloud macrophysical property characteristic analysis for …

Starvation Causes Disturbance In Amino Acid And Fatty Acid Metabolism In Diporeia, Suman Maity, Amber Jannasch, Jiri Adamec, Thomas Nalepa, Tomas O. Höök, Maria S. Sepúlveda

United States Department of Commerce: Staff Publications

The benthic amphipod Diporeia spp. was once the predominant macroinvertebrate in deep, offshore regions of the Laurentian Great Lakes. However, since the early 1990s, Diporeia populations have steadily declined across the area. It has been hypothesized that this decline is due to starvation from increasing competition for food with invasive dreissenid mussels. In order to gain a better understanding of the changes in Diporeia physiology during starvation, we applied two-dimensional gas chromatography coupled with time of flight mass spectrometry (GCXGC/TOF-MS) for investigating the responses in Diporeia metabolome during starvation. We starved Diporeia for 60 days and collected five organisms every …

Social Network Correlates Of Food Availability In An Endangered Population Of Killer Whales, Orcinus Orca, Emma A. Foster, Daniel W. Franks, Lesley J. Morrell, Ken C. Balcomb, Kim M. Parsons, Astrid Van Ginneken, Darren P. Croft

United States Department of Commerce: Staff Publications

For the majority of social species, group composition is dynamic, and individuals are interconnected in a heterogeneous social network. Social network structure has far-reaching implications for the ecology of individuals and populations. However, we have little understanding of how ecological variables shape this structure. We used a long-term data set (1984e2007) to examine the relationship between food availability and social network structure in the endangered southern resident killer whales. During the summer months individuals in this population feed primarily on chinook salmon, Oncorhynchus tshawytscha, which show annual variation in abundance. We tested the hypothesis that temporal variation in chinook …

Reconstructing Disturbance History Using Satellite-Based Assessment Of The Distribution Of Land Cover In The Russian Far East, T.V. Loboda, Z. Zhang, K.J. O'Neal, G. Sun, I.A. Csiszar, H.H. Shugart, N.J. Sherman

United States Department of Commerce: Staff Publications

Russian boreal forests are the largest forested zone on Earth and a tremendous pool of organic carbon. Current limited records on forest structure, composition, successional stage and disturbances contribute to large uncertainties in estimates of carbon stocks and fluxes in this zone. Our ability to monitor ongoing changes in forest cover has improved with the influx of remotely sensed data products since 2000 from multiple satellite platforms. Here we present a method aimed at reconstructing disturbance history from a known distribution of land cover. We developed and tested the method over a biologically and topographically diverse region of the Russian …

Linking Ciguatera Poisoning To Spatial Ecology Of Fish: A Novel Approach To Examining The Distribution Of Biotoxin Levels In The Great Barracuda By Combining Non-Lethal Blood Sampling And Biotelemetry, Amanda C. O'Toole, Marie-Yasmine Dechraoui Bottein, Andy J. Danylchuk, John S. Ramsdell, Steven J. Cooke

United States Department of Commerce: Staff Publications

Ciguatera in humans is typically caused by the consumption of reef fish that have accumulated Ciguatoxins (CTXs) in their flesh. Over a six month period, we captured 38 wild adult great barracuda (Sphyraena barracuda), a species commonly associated with ciguatera in The Bahamas. We sampled three tissues (i.e.,muscle, liver, and blood) and analysed them for the presence of ciguatoxins using a functional in vitro N2A bioassay. Detectable concentrations of ciguatoxins found in the three tissue types ranged from 2.51 to 211.74 pg C-CTX-1 equivalents/ g. Blood and liver toxin concentrations were positively correlated (ρ=0.86, P=0.003), indicating …

State Of The Art Satellite And Airborne Marine Oil Spill Remote Sensing: Application To The Bp Deepwater Horizon Oil Spill, Ira Leifer, William J. Lehr, Debra Simecek-Beatty, Eliza Bradley, Roger Clark, Philip Dennison, Yongxiang Hu, Scott Matheson, Cathleen E. Jones, Benjamin Holt, Molly Reif, Dar A. Roberts, Jan Svejkovsky, Gregg Swayze, Jennifer Wozencraft

United States Department of Commerce: Staff Publications

The vast and persistent Deepwater Horizon (DWH) spill challenged response capabilities, which required accurate, quantitative oil assessment at synoptic and operational scales. Although experienced observers are a spill response's mainstay, few trained observers and confounding factors including weather, oil emulsification, and scene illumination geometry present challenges. DWH spill and impact monitoring was aided by extensive airborne and spaceborne passive and active remote sensing.

Oil slick thickness and oil-to-water emulsion ratios are key spill response parameters for containment/cleanup and were derived quantitatively for thick (>0.1 mm) slicks from AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data using a spectral library approach based …

A Pollen-Based Reconstruction Of Summer Temperature In Central North America And Implications For Circulation Patterns During Medieval Times, Eugene R. Wahl, Henry F. Diaz, Christian Ohlwein

United States Department of Commerce: Staff Publications

We present a reconstruction of mean summer temperature for the northern Midwest of the USA based on lacustrine pollen records from three different lakes in Wisconsin. The results suggest a relatively warm period during the earlier part of the record (~1200–1500 CE) followed by a cooler Little Ice Age (~1500–1900) and a subsequent warming to modern conditions. The reconstructed modern summer mean temperature is in good agreement with observations, and the decades of the 1930s to 1950s appear to be the warmest such period in the proxy record (through 1974).

Analyses of circulation features associated with the warmest summers in …

View Angle Effects On Modis Snow Mapping In Forests, Qinchuan Xin, Curtis E. Woodcock, Jicheng Liu, Bin Tan, Rae A. Melloh, Robert E. Davis

United States Department of Commerce: Staff Publications

Binary snow maps and fractional snow cover data are provided routinely from MODIS (Moderate Resolution Imaging Spectroradiometer). This paper investigates how the wide observation angles of MODIS influence the current snow mapping algorithm in forested areas. Theoretical modeling results indicate that large view zenith angles (VZA) can lead to underestimation of fractional snow cover (FSC) by reducing the amount of the ground surface that is viewable through forest canopies, and by increasing uncertainties during the gridding of MODIS data. At the end of the MODIS scan line, the total modeled error can be as much as 50% for FSC. Empirical …

Prototype For Monitoring And Forecasting Fall Foliage Coloration In Real Time From Satellite Data, Xiaoyang Zhang, Mitchell D. Goldberg, Yunyue Yu

United States Department of Commerce: Staff Publications

While determining vegetation phenology from the time series of historical satellite data has been widely investigated throughout the last decade, little effort has been devoted to real-time monitoring and shortterm forecasting. The latter is more important for numerical weather modeling, ecosystem forecasting, forest and crop management, and health risk warning. In this study we developed a prototype approach for the real-time monitoring and short-term forecasting of fall foliage status (including low coloration, moderate coloration, near-peak coloration, peak coloration, and post-peak coloration) using temporal satellite observations. The algorithm combined the climatology of vegetation phenology and temporally available satellite observations to establish …

Comparison Of Methods For The Detection Of Coliphages In Recreational Water At Two California, United States Beaches, Roberto A. Rodríguez, David C. Love, Jill R. Stewart, Julianne Tajuba, Jacqueline Knee, Jerold W. Dickerson Jr., Laura F. Webster, Mark D. Sobsey

United States Department of Commerce: Staff Publications

Methods for detection of two fecal indicator viruses, F+ and somatic coliphages, were evaluated for application to recreational marine water. Marine water samples were collected during the summer of 2007 in Southern California, United States from transects along Avalon Beach (n = 186 samples) and Doheny Beach (n = 101 samples). Coliphage detection methods included EPA method 1601 – two-step enrichment (ENR), EPA method 1602 – single agar layer (SAL), and variations of ENR. Variations included comparison of two incubation times (overnight and 5-h incubation) and two final detection steps (lysis zone assay and a rapid latex agglutination …

The Effect Of Soil Surface Litter Residue On Energy And Carbon Fluxes In A Deciduous Forest, T.B. Wilson, T.P. Meyers, J. Kochendorfer, M. C. Anderson, M. Heuer

United States Department of Commerce: Staff Publications

The Atmosphere–Land Exchange Surface Energy (ALEX) balance model is an analytical formulation of the energy and mass transport within the soil and the vegetation canopy used for simulating energy, evapotranspiration, and CO2 fluxes in a wide range of vegetation environments. The objective of this study was to evaluate the ability of ALEX to simulate the effect of soil-surface leaf litter residue on soil heat conduction (G), sensible heat (H), evapotranspiration (ET) (or latent heat (LE) when expressed as rate of energy loss) and CO₂ fluxes in a deciduous forest. The model was evaluated in a deciduous forest in Oak …

Spatial Complexity In Fragmenting Amazonian Rainforests: Do Feedbacks From Edge Effects Push Forests Towards An Ecological Threshold?, Graeme S. Cumming, Jane Southworth, Xanic J. Rondon, Matthew Marsik

United States Department of Commerce: Staff Publications

Deforestation and resulting landscape fragmentation are important concerns in many tropical areas. Deforestation is a complex process with many potential feedback loops, many of which are ignored in models that attempt to interpolate forest loss based on past deforestation rates. In addition, most ecological studies of the impacts of deforestation have focused on landscapes that are already fragmented. These studies ignore the fact that edge effects, such as anthropogenic fire, reach their maximum well before habitat connectivity is lost and may create positive feedbacks that result in further fragmentation. We developed a simple model to explore the potential influence of …

Immunomodulation In Eastern Oysters, Crassostrea Virginica, Exposed To A Pah-Contaminated, Microphytobenthic Diatom, April N. Croxton, Gary H. Wikfors, Richard D. Schulterbrandt-Gragg

United States Department of Commerce: Staff Publications

The trophic transfer of sediment-associated pollutants is a growing concern in shellfish harvesting areas. Previous studies have examined the role of phytoplankton in the transport of organic contaminants to bivalve species, but little information on microphytobenthic communities and their role as contaminant vectors exists. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds formed during natural and industrial processes; they are termed “persistent organic pollutants” because they are only slowly degraded by natural processes. This study examined the transfer of PAH compounds (naphthalene, pyrene, and benzo(a)pyrene) by a microphytobenthic diatom to the eastern oyster, a commercially important shellfish species, to determine if …

A Multi-Beach Study Of Staphylococcus Aureus, Mrsa, And Enterococci In Seawater And Beach Sand, Kelly D. Goodwin, Melody Mcnay, Yiping Cao, Darcy Ebentier, Melissa Madison, John F. Griffith

United States Department of Commerce: Staff Publications

Incidences of Staphylococcus aureus and methicillin resistant S. aureus (MRSA) have risen worldwide prompting a need to better understand routes of human exposure and whether standard bacterial water quality monitoring practices adequately account for this potential threat. Beach water and sand samples were analyzed during summer months for S. aureus, enterococci, and MRSA at three southern California beaches (Avalon, Doheny, Malibu Surfrider). S. aureus frequently was detected in samples of seawater (59%, n = 328) and beach sand (53%, n = 358). MRSA sometimes was detected in seawater (1.6%, n = 366) and sand (2.7%, n = 366) at …

North American Carbon Program (Nacp) Regional Interim Synthesis: Terrestrial Biospheric Model Intercomparison, D.N. Huntzinger, W.M. Post, Y. Wei, A.M. Michalak, T.O. West, A.R. Jacobson, I.T. Baker, J.M. Chen, K. J. Davis, D.J. Hayes, F.M. Hoffman, A.K. Jain, S. Liu, A.D. Mcguire, R.P. Neilson, Chris Potter, B. Poulter, David T. Price, B.M. Raczka, H.Q. Tian, P. Thornton, E. Tomelleri, N. Viovy, J. Xiao, W. Yuan, N. Zeng, M. Zhao, R. Cook

United States Department of Commerce: Staff Publications

Understanding of carbon exchange between terrestrial ecosystems and the atmosphere can be improved through direct observations and experiments, as well as through modeling activities. Terrestrial biosphere models (TBMs) have become an integral tool for extrapolating local observations and understanding to much larger terrestrial regions. Although models vary in their specific goals and approaches, their central role within carbon cycle science is to provide a better understanding of the mechanisms currently controlling carbon exchange. Recently, the North American Carbon Program (NACP) organized several interim-synthesis activities to evaluate and inter-compare models and observations at local to continental scales for the years 2000–2005. …

Analysis Of Inconsistencies In Multi-Year Gridded Quantitative Precipitation Estimate Over Complex Terrain And Its Impact On Hydrologic Modeling, Naoki Mizukami, Michael B. Smith

United States Department of Commerce: Staff Publications

It is common that bias trends of long term precipitation data change over time due to various factors such as gauge relocation and changes in data processing methods. Temporal consistency of this error characteristic of precipitation data is as important as accuracy itself for reliable streamflow prediction with a hydrologic model. The main goal of this paper is to illustrate the detection and adverse effect of inconsistent precipitation data on distributed hydrologic model simulations over a mountainous basin in the Sierra Nevada Mountains of California. We used 1-h 4 km gridded precipitation time series intended for the second phase of …

Health Status, Infection And Disease In California Sea Lions (Zalophus Californianus) Studied Using A Canine Microarray Platform And Machine-Learning Approaches, Annalaura Mancia, James C. Ryan, Robert W. Chapman, Qingzhong Wu, Gregory W. Warr, Frances M.D. Gulland, Frances M. Van Dolah

United States Department of Commerce: Staff Publications

Conservation biologists face many challenges in assessing health, immune status and infectious diseases in protected species. These challenges include unpredictable sample populations, diverse genetic and environmental backgrounds of the animals, as well as the practical, legal and ethical issues involved in experimentation. The use of whole genome scale transcriptomics with animal samples obtained in a minimally invasive manner is an approach that shows promise for health assessment. In this study we assessed the utility of a microarray to identify changes in gene expression predictive of health status by interrogating blood samples from California sea lions (Zalophus californianus) in …

Groundwater Pumping And Spatial Externalities In Agriculture, Lisa Pfeiffer, C.-Y. Cynthia Lin

United States Department of Commerce: Staff Publications

We investigate the behavior of farmers who share an underground aquifer. In the case where seepage may occur the resource is nonexclusive, giving rise to a spatial externality whereby pumping by one user affects others nearby. Theoretically, these externalities are potentially important causes of welfare loss. Using a unique spatial data set of groundwater users in western Kansas, we are able to empirically measure the physical and behavioral effects of groundwater pumping by neighbors. To address the simultaneity of neighbors’ pumping, we use the neighbors’ permitted water allocation as an instrument for their pumping. We estimate that 2.5% of the …

Disease Will Limit Future Food Supply From The Global Crustacean Fishery And Aquaculture Sectors, G.D. Stentiford, D.M. Neil, E.J. Peeler, J.D. Shields, H.J. Small, T.W. Flegel, J.M. Vlak, B. Jones, F. Morado, S. Moss, J. Lotz, L. Bartholomay, D.C. Behringer, C. Hauton, D.V. Lightner

United States Department of Commerce: Staff Publications

Seafood is a highly traded food commodity. Farmed and captured crustaceans contribute a significant proportion with annual production exceeding 10 M metric tonnes with first sale value of $40bn. The sector is dominated by farmed tropical marine shrimp, the fastest growing sector of the global aquaculture industry. It is significant in supporting rural livelihoods and alleviating poverty in producing nations within Asia and Latin America while forming an increasing contribution to aquatic food supply in more developed countries. Nations with marine borders often also support important marine fisheries for crustaceans that are regionally traded as live animals and commodity products. …

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

United States Department of Commerce: Staff Publications

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 …

Water Properties In Chesapeake Bay From Modis-Aqua Measurements, Seunghyun Son, Menghua Wang

United States Department of Commerce: Staff Publications

This study evaluates the performance of ocean color products derived from measurements of the Moderate Resolution Imaging Spectro-radiometer (MODIS) on the satellite Aqua using the standard near-infrared (NIR) and the shortwave infrared (SWIR)-based atmospheric correction algorithms in the Chesapeake Bay. The MODIS-Aquaderived normalized water-leaving radiances, nL_w(λ), and chlorophyll-a (Chl-a) data are comparedwith in situ radiometric measurements fromtheNASA SeaWiFS Bio-opticalArchive and Storage System(SeaBASS) database and Chl-a data from the Chesapeake Bay Water Quality Database. Results show that, using the NIR-SWIR combined ocean color data processing, improved nL_w(λ) and Chl-a data products can be produced in …