Hurricanes Frances and Ivan

Atmospheric Science Data Center

2014-05-15

... Image NASA's Multi-angle Imaging SpectroRadiometer (MISR) captured these images and cloud-top height retrievals of Hurricane ... especially on the 24 to 48 hour timescale vital for disaster planning. To improve the operational models used to make hurricane ...

Arizona Fires

Atmospheric Science Data Center

2014-05-15

... Image This image and accompanying animation from NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument on the Terra ... and is currently the second largest fire in Arizona history. More than 2,000 people are working to contain the fire, which is being ...

Mystery #14

Atmospheric Science Data Center

2013-04-22

... play geographical detective! This natural-color image from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on the Terra ... type of clouds pictured here are often associated with lightning and sustained rainstorms lasting several hours or more. 5. ...

Hurricane Earl Multi-level Winds

NASA Image and Video Library

2010-09-02

NASA Multi-angle Imaging SpectroRadiometer instrument captured this image of Hurricane Earl Aug. 30, 2010. At this time, Hurricane Earl was a Category 3 storm. The hurricane eye is just visible on the right edge of the MISR image swath.

Where on Earth...? MISR Mystery Image Quiz #13: Western Uzbekistan and Northeastern Turkmenistan

NASA Image and Video Library

2003-03-19

Acquired by the Multi-angle Imaging SpectroRadiometer instrument aboard NASA Terra spacecraft, this image is from the MISR Where on Earth...? Mystery Quiz #13. The location is Western Uzbekistan and Northeastern Turkmenistan.

California: San Joaquin Valley

Atmospheric Science Data Center

2014-05-15

...     View Larger Image This illustration features Multi-angle Imaging SpectroRadiometer ... quadrant is a map of haze amount determined from automated processing of the MISR imagery. Low amounts of haze are shown in blue, and a ...

MISR High-Resolution, Cross-Track Winds for Hurricane Ida

NASA Image and Video Library

2009-11-10

This image shows JPL Multi-angle Imaging SpectroRadiometer instrument onboard NASA Terra satellite on Sunday, Nov. 8, 2009 as it passed over Hurricane Ida while situated between western Cuba and the Yucatan Peninsula.

Ash from Kilauea Eruption Viewed by NASA's MISR

Atmospheric Science Data Center

2018-06-07

... title:  Ash from Kilauea Eruption Viewed by NASA's MISR View Larger Image   Ash ... Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite captured this view of the island as it passed overhead. ...

Eyjafjallajökull Ash Plume Particle Properties

NASA Image and Video Library

2010-04-21

As NASA Terra satellite flew over Iceland erupting Eyjafjallajökull volcano, its Multi-angle Imaging SpectroRadiometer instrument acquired 36 near-simultaneous images of the ash plume, covering nine view angles in each of four wavelengths.

Mystery #16 Answer

Atmospheric Science Data Center

2013-04-22

... were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) during October and November 2003. The two images represent about 310 ... obtain calcium from the seawater and carbon dioxide from cell respiration, and bring these products into the internal tissues of the ...

Colorado

Atmospheric Science Data Center

2014-05-15

... the Multi-angle Imaging SpectroRadiometer (MISR). On the left, a natural-color view acquired by MISR's vertical-viewing (nadir) camera ... Gunnison River at the city of Grand Junction. The striking "L" shaped feature in the lower image center is a sandstone monocline known as ...

Texas Fires

Atmospheric Science Data Center

2014-05-15

... one-year drought on record and the warmest month in Texas history. The Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft passed over the wildfires at 12:05 p.m. CDT on ...

Mystery #21 Answer

Atmospheric Science Data Center

2013-04-22

article title:  MISR Mystery Image Quiz #21: Actinoform Clouds ... This mystery concerns a particular type of cloud, one example of which was imaged by the Multi-angle Imaging SpectroRadiometer (MISR) ... ) These clouds are commonly tracked using propeller-driven research aircraft. Answer: C is True. The weather satellite, TIROS ...

Mystery #21

Atmospheric Science Data Center

2013-04-22

article title:  MISR Mystery Image Quiz #21   ... This mystery concerns a particular type of cloud, one example of which was imaged by the Multi-angle Imaging SpectroRadiometer (MISR) ... ) These clouds are commonly tracked using propeller-driven research aircraft. 3.   Two of these statements are false. Which one is ...

Hawaii

Atmospheric Science Data Center

2014-05-15

article title:  Big Island, Hawaii     View Larger ... Multi-angle Imaging SpectroRadiometer (MISR) images of the Big Island of Hawaii, April - June 2000. The images have been rotated so that ... NASA's Goddard Space Flight Center, Greenbelt, MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science ...

Morocco and Algeria

Atmospheric Science Data Center

2013-04-15

... mosaic of southwestern Europe and northwestern Morocco and Algeria. The image extends from 48°N, 16°W in the northwest to 32°N, 8°E in ... corner. The rugged Atlas Mountain ranges traverse northern Algeria and Morocco. The Multi-angle Imaging SpectroRadiometer (MISR) ...

MISR INTEX-B Products

Atmospheric Science Data Center

2016-11-25

... scales and assess their impact on air quality and climate. Phase B will be performed March 1-31, 2006 and it will focus on Mexico City pollution outflow. The Multi-angle Imaging SpectroRadiometer (MISR) team ...

MISR: protection from ourselves

NASA Technical Reports Server (NTRS)

Nolan, T.; Varanasi, P.

2004-01-01

Outlines lessons learned by the Instrument Operations Team of NASA/JPL Terra's Multi-angle Imaging SpectroRadiometer mission. It narrates a story of MISR: Protection from Ourselves! and describes, in detail, how the MISR instrument survived operator errors.

Level 2 Ancillary Products and Datasets Algorithm Theoretical Basis

NASA Technical Reports Server (NTRS)

Diner, D.; Abdou, W.; Gordon, H.; Kahn, R.; Knyazikhin, Y.; Martonchik, J.; McDonald, D.; McMuldroch, S.; Myneni, R.; West, R.

1999-01-01

This Algorithm Theoretical Basis (ATB) document describes the algorithms used to generate the parameters of certain ancillary products and datasets used during Level 2 processing of Multi-angle Imaging SpectroRadiometer (MIST) data.

Hurricane Katrina

Atmospheric Science Data Center

2014-05-15

... Katrina is one of the most powerful and destructive storms on record for the Atlantic Basin. The animation progresses from ... tops" are also characteristic of strong and rapidly growing storms. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth ...

Comparison of Coincident Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer Aerosol Optical Depths over Land and Ocean Scenes Containing Aerosol Robotic Network Sites

NASA Technical Reports Server (NTRS)

Abdou, Wedad A.; Diner, David J.; Martonchik, John V.; Bruegge, Carol J.; Kahn, Ralph A.; Gaitley, Barbara J.; Crean, Kathleen A.; Remer, Lorraine A.; Holben, Brent

2005-01-01

The Multiangle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), launched on 18 December 1999 aboard the Terra spacecraft, are making global observations of top-of-atmosphere (TOA) radiances. Aerosol optical depths and particle properties are independently retrieved from these radiances using methodologies and algorithms that make use of the instruments corresponding designs. This paper compares instantaneous optical depths retrieved from simultaneous and collocated radiances measured by the two instruments at locations containing sites within the Aerosol Robotic Network (AERONET). A set of 318 MISR and MODIS images, obtained during the months of March, June, and September 2002 at 62 AERONET sites, were used in this study. The results show that over land, MODIS aerosol optical depths at 470 and 660 nm are larger than those retrieved from MISR by about 35% and 10% on average, respectively, when all land surface types are included in the regression. The differences decrease when coastal and desert areas are excluded. For optical depths retrieved over ocean, MISR is on average about 0.1 and 0.05 higher than MODIS in the 470 and 660 nm bands, respectively. Part of this difference is due to radiometric calibration and is reduced to about 0.01 and 0.03 when recently derived band-to-band adjustments in the MISR radiometry are incorporated. Comparisons with AERONET data show similar patterns.

Low Clouds

Atmospheric Science Data Center

2013-04-19

article title:  Indian Ocean Clouds     View Larger ... Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's polar-orbiting Terra spacecraft. The area covered by the image is 247.5 ... during the last decade. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission ...

Appalachia Snow

Atmospheric Science Data Center

2014-05-15

... 7, 2002. The Appalachians are bounded by the Blue Ridge mountain belt along the east and the Appalachian Plateau along the west. ... tip, near the Great Smoky Mountains (the dark-colored range at lower right). The Multi-angle Imaging SpectroRadiometer observes ...

Closed Large Cell Clouds

Atmospheric Science Data Center

2013-04-19

article title:  Closed Large Cell Clouds in the South Pacific ... the Multi-angle Imaging SpectroRadiometer (MISR) provide an example of very large scale closed cells, and can be contrasted with the  ... MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image ...

Global Albedo

Atmospheric Science Data Center

2013-04-19

... the albedo. Bright surfaces have albedo near unity, and dark surfaces have albedo near zero. The DHR refers to the amount of spectral ... Atmospheric Science Data Center's  MISR Level 3 Imagery web site . The Multi-angle Imaging SpectroRadiometer observes the daylit ...

A data base of ASAS digital imagery. [Advanced Solid-state Array Spectroradiometer

NASA Technical Reports Server (NTRS)

Irons, James R.; Meeson, Blanche W.; Dabney, Philip W.; Kovalick, William M.; Graham, David W.; Hahn, Daniel S.

1992-01-01

The Advanced Solid-State Array Spectroradiometer (ASAS) is an airborne, off-nadir tilting, imaging spectroradiometer that acquires digital image data for 29 spectral bands in the visible and near-infrared. The sensor is used principally for studies of the bidirectional distribution of solar radiation scattered by terrestial surfaces. ASAS has acquired data for a number of terrestial ecosystem field experiments and investigators have received over 170 radiometrically corrected, multiangle, digital image data sets. A database of ASAS digital imagery has been established in the Pilot Land Data System (PLDS) at the NASA/Goddard Space Flight Center to provide access to these data by the scientific community. ASAS, its processed data, and the PLDS are described, together with recent improvements to the sensor system.

Spatial Statistical Data Fusion for Remote Sensing Applications

NASA Technical Reports Server (NTRS)

Nguyen, Hai

2010-01-01

Data fusion is the process of combining information from heterogeneous sources into a single composite picture of the relevant process, such that the composite picture is generally more accurate and complete than that derived from any single source alone. Data collection is often incomplete, sparse, and yields incompatible information. Fusion techniques can make optimal use of such data. When investment in data collection is high, fusion gives the best return. Our study uses data from two satellites: (1) Multiangle Imaging SpectroRadiometer (MISR), (2) Moderate Resolution Imaging Spectroradiometer (MODIS).

MISR - Science Data Validation Plan

NASA Technical Reports Server (NTRS)

Conel, J.; Ledeboer, W.; Ackerman, T.; Marchand, R.; Clothiaux, E.

2000-01-01

This Science Data Validation Plan describes the plans for validating a subset of the Multi-angle Imaging SpectroRadiometer (MISR) Level 2 algorithms and data products and supplying top-of-atmosphere (TOA) radiances to the In-flight Radiometric Calibration and Characterization (IFRCC) subsystem for vicarious calibration.

Calibration Plans for the Multi-angle Imaging SpectroRadiometer (MISR)

NASA Astrophysics Data System (ADS)

Bruegge, C. J.; Duval, V. G.; Chrien, N. L.; Diner, D. J.

1993-01-01

The EOS Multi-angle Imaging SpectroRadiometer (MISR) will study the ecology and climate of the Earth through acquisition of global multi-angle imagery. The MISR employs nine discrete cameras, each a push-broom imager. Of these, four point forward, four point aft and one views the nadir. Absolute radiometric calibration will be obtained pre-flight using high quantum efficiency (HQE) detectors and an integrating sphere source. After launch, instrument calibration will be provided using HQE detectors in conjunction with deployable diffuse calibration panels. The panels will be deployed at time intervals of one month and used to direct sunlight into the cameras, filling their fields-of-view and providing through-the-optics calibration. Additional techniques will be utilized to reduce systematic errors, and provide continuity as the methodology changes with time. For example, radiation-resistant photodiodes will also be used to monitor panel radiant exitance. These data will be acquired throughout the five-year mission, to maintain calibration in the latter years when it is expected that the HQE diodes will have degraded. During the mission, it is planned that the MISR will conduct semi-annual ground calibration campaigns, utilizing field measurements and higher resolution sensors (aboard aircraft or in-orbit platforms) to provide a check of the on-board hardware. These ground calibration campaigns are limited in number, but are believed to be the key to the long-term maintenance of MISR radiometric calibration.

A Spectralon BRF Data Base for MISR Calibration Application

NASA Technical Reports Server (NTRS)

Bruegge, C.; Chrien, N.; Haner, D.

1999-01-01

The Multi-angle Imaging SpectroRadiometer (MISR) is an Earth observing sensor which will provide global retrievals of aerosols, clouds, and land surface parameters. Instrument specifications require high accuracy absolute calibration, as well as accurate camera-to-camera, band-to-band and pixel-to-pixel relative response determinations.

ESTIMATING GROUND LEVEL PM 2.5 IN THE EASTERN UNITED STATES USING SATELLITE REMOTE SENSING

EPA Science Inventory

An empirical model based on the regression between daily average final particle (PM2.5) concentrations and aerosol optical thickness (AOT) measurements from the Multi-angle Imaging SpectroRadiometer (MISR) was developed and tested using data from the eastern United States during ...

A strategy for compression and analysis of massive geophysical data sets

NASA Technical Reports Server (NTRS)

Braverman, A.

2001-01-01

This paper describes a method for summaraizing data in a way that approximately preserves high-resolution data structure while reducing data volume and maintaining global integrity of very large, remote sensing data sets. The method is under development for one of Terra's instruments, the Multi-angle Imaging SpectroRadiometer (MISR).

MISR Multi-angle Views of Sunday Morning Fires

NASA Technical Reports Server (NTRS)

2007-01-01

Hot, dry Santa Ana winds began blowing through the Los Angeles and San Diego areas on Sunday October 21, 2007. Wind speeds ranging from 30 to 50 mph were measured in the area, with extremely low relative humidities. These winds, coupled with exceptionally dry conditions due to lack of rainfall resulted in a number of fires in the Los Angeles and San Diego areas, causing the evacuation of more than 250,000 people.

These two images show the Southern California coast from Los Angeles to San Diego from two of the nine cameras on the Multi-angle Imaging SpectroRadiometer (MISR) instrument on the NASA EOS Terra satellite. These images were obtained around 11:35 a.m. PDT on Sunday morning, October 21, 2007 and show a number of plumes extending out over the Pacific ocean. In addition, locations identified as potential hot spots from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the same satellite are outlined in red.

The left image is from MISR's nadir looking camera and the plumes appear very faint. The image on the right is from MISR's 60o forward looking camera, which accentuates the amount of light scattered by aerosols in the atmosphere, including smoke and dust. Both these images are false color and contain information from MISR's red, green, blue and near-infrared wavelengths, which makes vegetated land appear greener than it would naturally. Notice in the right hand image that the color of the plumes associated with the MODIS hot spots is bluish, while plumes not associated with hot spots appear more yellow. This is because the latter plumes are composed of dust kicked up by the strong Santa Ana winds. In some locations along Interstate 5 on this date, visibility was severely reduced due to blowing dust. MISR's multiangle and multispectral capability give it the ability to distinguish smoke from dust in this situation.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These images were generated from a portion of the imagery acquired during Terra orbit 41713, and use data from blocks 63 to 66 within World Reference System-2 path 40.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. JPL is a division of the California Institute of Technology.

MISR Where on Earth...? MISR Mystery Image Quiz #28

NASA Image and Video Library

2016-11-16

Are you ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA's MISR (Multi-angle Imaging SpectroRadiometer) instrument onboard the Terra satellite. Prize submissions for perfect scores accepted until Wednesday, November 23, at 4:00 p.m. PST. Happy sleuthing! Take the quiz here http://climate.nasa.gov/quizzes/misr_quiz_28. http://photojournal.jpl.nasa.gov/catalog/PIA15375

MISR Where on Earth ...? MISR Mystery Image Quiz #29

NASA Image and Video Library

2017-06-21

Are you ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA's MISR Multi-angle Imaging SpectroRadiometer (MISR) instrument onboard the Terra satellite. Prize submissions for perfect scores accepted until Wednesday, June 28, at 4:00 p.m. PDT. Happy sleuthing! Take the quiz here http://climate.nasa.gov/quizzes/misr_quiz_29. https://photojournal.jpl.nasa.gov/catalog/PIA21762

An evaluation of modeled plume injection height with satellite-derived observed plume height

Treesearch

Sean M. Raffuse; Kenneth J. Craig; Narasimhan K. Larkin; Tara T. Strand; Dana Coe Sullivan; Neil J.M. Wheeler; Robert Solomon

2012-01-01

Plume injection height influences plume transport characteristics, such as range and potential for dilution. We evaluated plume injection height from a predictive wildland fire smoke transport model over the contiguous United States (U.S.) from 2006 to 2008 using satellite-derived information, including plume top heights from the Multi-angle Imaging SpectroRadiometer (...

Advances in Satellite Remote Sensing of Particulate Air Pollution: From MISR to MAIA

NASA Astrophysics Data System (ADS)

Diner, D. J.; Burke, K.; Xu, F.; Garay, M. J.; Kalashnikova, O. V.; Liu, Y.; Meng, X.; Wang, J.; Martin, R.; Ostro, B.

2017-12-01

Airborne particulate matter (PM) is a well-known cause of cardiovascular and respiratory disease. To estimate human exposure to PM pollution, satellite instruments such as the Terra Multi-angle Imaging SpectroRadiometer (MISR) and the Moderate resolution Imaging Spectroradiometer (MODIS) have been used in conjunction with surface monitors to map near-surface PM concentrations. The relative toxicity of different size and compositional mixtures of PM is not well understood. To address this, we are developing the Multi-Angle Imager for Aerosols (MAIA) investigation. The satellite instrument extends MISR's multiangular visible and near-infrared (VNIR) spectral coverage to 14 bands in the ultraviolet, VNIR, and shortwave IR; three of the bands are polarimetric to enhance sensitivity to aerosol size and composition. To constrain the retrievals, the observations will be combined with data from surface monitors and the WRF-Chem and GEOS-Chem chemical transport models. Existing surface PM speciation monitors will be supplemented by adding new stations to the Surface PARTiculate mAtter Network (SPARTAN). Unlike MISR, MAIA is a targeting instrument. Primary areas of interest include metropolitan areas in North and South America, Europe, the Middle East, Africa, India, and East Asia. PM retrieval algorithms are being developed using data from MISR and the high-altitude Airborne Multiangle SpectroPolarimetric Imager (AirMSPI). Epidemiologists on the MAIA science team will use the derived PM data products and birth, death, and hospital records to investigate adverse health impacts of different types of airborne particulates. MAIA's earliest possible launch date is mid-2020, making it possible for the data to be complemented by global observations from Terra as well as high temporal resolution atmospheric chemistry measurements from TEMPO (Tropospheric Emissions: Monitoring Pollution), GEMS (Geostationary Environment Monitoring Spectrometer), and Sentinel-4.

Distinguishing remobilized ash from erupted volcanic plumes using space-borne multi-angle imaging.

PubMed

Flower, Verity J B; Kahn, Ralph A

2017-10-28

Volcanic systems are comprised of a complex combination of ongoing eruptive activity and secondary hazards, such as remobilized ash plumes. Similarities in the visual characteristics of remobilized and erupted plumes, as imaged by satellite-based remote sensing, complicate the accurate classification of these events. The stereo imaging capabilities of the Multi-angle Imaging SpectroRadiometer (MISR) were used to determine the altitude and distribution of suspended particles. Remobilized ash shows distinct dispersion, with particles distributed within ~1.5 km of the surface. Particle transport is consistently constrained by local topography, limiting dispersion pathways downwind. The MISR Research Aerosol (RA) retrieval algorithm was used to assess plume particle microphysical properties. Remobilized ash plumes displayed a dominance of large particles with consistent absorption and angularity properties, distinct from emitted plumes. The combination of vertical distribution, topographic control, and particle microphysical properties makes it possible to distinguish remobilized ash flows from eruptive plumes, globally.

Snowstorm Along the China-Mongolia-Russia Borders

NASA Technical Reports Server (NTRS)

2004-01-01

Heavy snowfall on March 12, 2004, across north China's Inner Mongolia Autonomous Region, Mongolia and Russia, caused train and highway traffic to stop for several days along the Russia-China border. This pair of images from the Multi-angle Imaging SpectroRadiometer (MISR) highlights the snow and surface properties across the region on March 13. The left-hand image is a multi-spectral false-color view made from the near-infrared, red, and green bands of MISR's vertical-viewing (nadir) camera. The right-hand image is a multi-angle false-color view made from the red band data of the 46-degree aftward camera, the nadir camera, and the 46-degree forward camera.

About midway between the frozen expanse of China's Hulun Nur Lake (along the right-hand edge of the images) and Russia's Torey Lakes (above image center) is a dark linear feature that corresponds with the China-Mongolia border. In the upper portion of the images, many small plumes of black smoke rise from coal and wood fires and blow toward the southeast over the frozen lakes and snow-covered grasslands. Along the upper left-hand portion of the images, in Russia's Yablonovyy mountain range and the Onon River Valley, the terrain becomes more hilly and forested. In the nadir image, vegetation appears in shades of red, owing to its high near-infrared reflectivity. In the multi-angle composite, open-canopy forested areas are indicated by green hues. Since this is a multi-angle composite, the green color arises not from the color of the leaves but from the architecture of the surface cover. The green areas appear brighter at the nadir angle than at the oblique angles because more of the snow-covered surface in the gaps between the trees is visible. Color variations in the multi-angle composite also indicate angular reflectance properties for areas covered by snow and ice. The light blue color of the frozen lakes is due to the increased forward scattering of smooth ice, and light orange colors indicate rougher ice or snow, which scatters more light in the backward direction.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire Earth between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 22525. The panels cover an area of about 355 kilometers x 380 kilometers, and utilize data from blocks 50 to 52 within World Reference System-2 path 126.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

New 4.4 km-resolution aerosol product from NASA's Multi-angle Imaging SpectroRadiometer: A user's guide

NASA Astrophysics Data System (ADS)

Nastan, A.; Garay, M. J.; Witek, M. L.; Seidel, F.; Bull, M. A.; Kahn, R. A.; Diner, D. J.

2017-12-01

The NASA Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite has provided an 18-year-and-growing aerosol data record. MISR's V22 aerosol product has been used extensively in studies of regional and global climate and the health effects of particulate air pollution. The MISR team recently released a new version of this product (V23), which increases the spatial resolution from 17.6 km to 4.4 km, improves performance versus AERONET, and provides better spatial coverage, more accurate cloud screening, and improved radiometric conditioning relative to V22. The product formatting was also completely revamped to improve clarity and usability. Established and prospective users of the MISR aerosol product are invited to learn about the features and performance of the new product and to participate in one-on-one demonstrations of how to obtain, visualize, and analyze the new product. Because the aerosol product is used in generating atmospherically-corrected surface bidirectional reflectance factors, improvements in MISR's 1.1 km resolution land surface product are a by-product of the updated aerosol retrievals. Illustrative comparisons of the V22 and V23 aerosol and surface products will be shown.

Radiometric stability of the Multi-angle Imaging SpectroRadiometer (MISR) following 15 years on-orbit

NASA Astrophysics Data System (ADS)

Bruegge, Carol J.; Val, Sebastian; Diner, David J.; Jovanovic, Veljko; Gray, Ellyn; Di Girolamo, Larry; Zhao, Guangyu

2014-09-01

The Multi-angle Imaging SpectroRadiometer (MISR) has successfully operated on the EOS/ Terra spacecraft since 1999. It consists of nine cameras pointing from nadir to 70.5° view angle with four spectral channels per camera. Specifications call for a radiometric uncertainty of 3% absolute and 1% relative to the other cameras. To accomplish this, MISR utilizes an on-board calibrator (OBC) to measure camera response changes. Once every two months the two Spectralon panels are deployed to direct solar-light into the cameras. Six photodiode sets measure the illumination level that are compared to MISR raw digital numbers, thus determining the radiometric gain coefficients used in Level 1 data processing. Although panel stability is not required, there has been little detectable change in panel reflectance, attributed to careful preflight handling techniques. The cameras themselves have degraded in radiometric response by 10% since launch, but calibration updates using the detector-based scheme has compensated for these drifts and allowed the radiance products to meet accuracy requirements. Validation using Sahara desert observations show that there has been a drift of ~1% in the reported nadir-view radiance over a decade, common to all spectral bands.

Multi-Angle View of the Canary Islands

NASA Technical Reports Server (NTRS)

2000-01-01

A multi-angle view of the Canary Islands in a dust storm, 29 February 2000. At left is a true-color image taken by the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite. This image was captured by the MISR camera looking at a 70.5-degree angle to the surface, ahead of the spacecraft. The middle image was taken by the MISR downward-looking (nadir) camera, and the right image is from the aftward 70.5-degree camera. The images are reproduced using the same radiometric scale, so variations in brightness, color, and contrast represent true variations in surface and atmospheric reflectance with angle. Windblown dust from the Sahara Desert is apparent in all three images, and is much brighter in the oblique views. This illustrates how MISR's oblique imaging capability makes the instrument a sensitive detector of dust and other particles in the atmosphere. Data for all channels are presented in a Space Oblique Mercator map projection to facilitate their co-registration. The images are about 400 km (250 miles)wide, with a spatial resolution of about 1.1 kilometers (1,200 yards). North is toward the top. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Airborne Sea of Dust over China

NASA Technical Reports Server (NTRS)

2002-01-01

TDust covered northern China in the last week of March during some of the worst dust storms to hit the region in a decade. The dust obscuring China's Inner Mongolian and Shanxi Provinces on March 24, 2002, is compared with a relatively clear day (October 31, 2001) in these images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera aboard NASA's Terra satellite. Each image represents an area of about 380 by 630 kilometers (236 by 391 miles). In the image from late March, shown on the right, wave patterns in the yellowish cloud liken the storm to an airborne ocean of dust. The veil of particulates obscures features on the surface north of the Yellow River (visible in the lower left). The area shown lies near the edge of the Gobi desert, a few hundred kilometers, or miles, west of Beijing. Dust originates from the desert and travels east across northern China toward the Pacific Ocean. For especially severe storms, fine particles can travel as far as North America. The Multi-angle Imaging SpectroRadiometer, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is one of five Earth-observing instruments aboard the Terra satellite, launched in December 1999. The instrument acquires images of Earth at nine angles simultaneously, using nine separate cameras pointed forward, downward and backward along its flight path. The change in reflection at different view angles affords the means to distinguish different types of atmospheric particles, cloud forms and land surface covers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team

JMISR INteractive eXplorer

NASA Technical Reports Server (NTRS)

Nelson, David L.; Diner, David J.; Thompson, Charles K.; Hall, Jeffrey R.; Rheingans, Brian E.; Garay, Michael J.; Mazzoni, Dominic

2010-01-01

MISR (Multi-angle Imaging SpectroRadiometer) INteractive eXplorer (MINX) is an interactive visualization program that allows a user to digitize smoke, dust, or volcanic plumes in MISR multiangle images, and automatically retrieve height and wind profiles associated with those plumes. This innovation can perform 9-camera animations of MISR level-1 radiance images to study the 3D relationships of clouds and plumes. MINX also enables archiving MISR aerosol properties and Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power along with the heights and winds. It can correct geometric misregistration between cameras by correlating off-nadir camera scenes with corresponding nadir scenes and then warping the images to minimize the misregistration offsets. Plots of BRF (bidirectional reflectance factor) vs. camera angle for points clicked in an image can be displayed. Users get rapid access to map views of MISR path and orbit locations and overflight dates, and past or future orbits can be identified that pass over a specified location at a specified time. Single-camera, level-1 radiance data at 1,100- or 275- meter resolution can be quickly displayed in color using a browse option. This software determines the heights and motion vectors of features above the terrain with greater precision and coverage than previous methods, based on an algorithm that takes wind direction into consideration. Human interpreters can precisely identify plumes and their extent, and wind direction. Overposting of MODIS thermal anomaly data aids in the identification of smoke plumes. The software has been used to preserve graphical and textural versions of the digitized data in a Web-based database.

Evaluation of AirMSPI photopolarimetric retrievals of smoke properties with in-situ observations collected during the ImPACT-PM field campaign

NASA Astrophysics Data System (ADS)

Kalashnikova, O. V.; Garay, M. J.; Xu, F.; Seidel, F.; Diner, D. J.; Seinfeld, J.; Bates, K. H.; Kong, W.; Kenseth, C.; Cappa, C. D.

2017-12-01

We introduce and evaluate an approach for obtaining closure between in situ and polarimetric remote sensing observations of smoke properties obtained during the collocated CIRPAS Twin Otter and ER-2 aircraft measurements of the Lebec fire event on July 8, 2016. We investigate the utility of multi-angle, spectropolarimetric remote sensing imagery to evaluate the relative contribution of organics, non-organic and black carbon particles to smoke particulate composition. The remote sensing data were collected during the Imaging Polarimetric and Characterization of Tropospheric Particular Matter (ImPACT-PM) field campaign by the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI), which flew on NASA's high-altitude ER-2 aircraft. The ImPACT-PM field campaign was a joint JPL/Caltech effort to combine measurements from the Terra Multi-angle Imaging SpectroRadiometer (MISR), AirMSPI, in situ airborne measurements, and a chemical transport model to validate remote sensing retrievals of different types of airborne particulate matter with a particular emphasis on carbonaceous aerosols. The in-situ aerosol data were collected with a suite of Caltech instruments on board the CIRPAS Twin Otter aircraft and included the Aerosol Mass Spectrometer (AMS), the Differential Mobility Analyzer (DMA), and the Single Particle Soot Photometer (SP-2). The CIRPAS Twin Otter aircraft was also equipped with the Particle Soot Absorption Photometer (PSAP), nephelometer, a particle counter, and meteorological sensors. We found that the multi-angle polarimetric observations are capable of fire particulate emission monitoring by particle type as inferred from the in-situ airborne measurements. Modeling of retrieval sensitivities show that the characterization of black carbon is the most challenging. The work aims at evaluating multi-angle, spectropolarimetric capabilities for particulate matter characterization in support of the Multi-Angle Imager for Aerosols (MAIA) satellite investigation, which is currently in development under NASA's third Earth Venture Instrument Program.

Gravity Waves Ripple over Marine Stratocumulus Clouds

NASA Technical Reports Server (NTRS)

2004-01-01

In this natural-color image from the Multi-angle Imaging SpectroRadiometer (MISR), a fingerprint-like gravity wave feature occurs over a deck of marine stratocumulus clouds. Similar to the ripples that occur when a pebble is thrown into a still pond, such 'gravity waves' sometimes appear when the relatively stable and stratified air masses associated with stratocumulus cloud layers are disturbed by a vertical trigger from the underlying terrain, or by a thunderstorm updraft or some other vertical wind shear. The stratocumulus cellular clouds that underlie the wave feature are associated with sinking air that is strongly cooled at the level of the cloud-tops -- such clouds are common over mid-latitude oceans when the air is unperturbed by cyclonic or frontal activity. This image is centered over the Indian Ocean (at about 38.9o South, 80.6o East), and was acquired on October 29, 2003.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 20545. The image covers an area of 245 kilometers x 378 kilometers, and uses data from blocks 121 to 122 within World Reference System-2 path 134.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Aerosol and Surface Parameter Retrievals for a Multi-Angle, Multiband Spectrometer

NASA Technical Reports Server (NTRS)

Broderick, Daniel

2012-01-01

This software retrieves the surface and atmosphere parameters of multi-angle, multiband spectra. The synthetic spectra are generated by applying the modified Rahman-Pinty-Verstraete Bidirectional Reflectance Distribution Function (BRDF) model, and a single-scattering dominated atmosphere model to surface reflectance data from Multiangle Imaging SpectroRadiometer (MISR). The aerosol physical model uses a single scattering approximation using Rayleigh scattering molecules, and Henyey-Greenstein aerosols. The surface and atmosphere parameters of the models are retrieved using the Lavenberg-Marquardt algorithm. The software can retrieve the surface and atmosphere parameters with two different scales. The surface parameters are retrieved pixel-by-pixel while the atmosphere parameters are retrieved for a group of pixels where the same atmosphere model parameters are applied. This two-scale approach allows one to select the natural scale of the atmosphere properties relative to surface properties. The software also takes advantage of an intelligent initial condition given by the solution of the neighbor pixels.

Eyjafjallajokull Volcano Plume Particle-Type Characterization from Space-Based Multi-angle Imaging

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.; Limbacher, James

2012-01-01

The Multi-angle Imaging SpectroRadiometer (MISR) Research Aerosol algorithm makes it possible to study individual aerosol plumes in considerable detail. From the MISR data for two optically thick, near-source plumes from the spring 2010 eruption of the Eyjafjallaj kull volcano, we map aerosol optical depth (AOD) gradients and changing aerosol particle types with this algorithm; several days downwind, we identify the occurrence of volcanic ash particles and retrieve AOD, demonstrating the extent and the limits of ash detection and mapping capability with the multi-angle, multi-spectral imaging data. Retrieved volcanic plume AOD and particle microphysical properties are distinct from background values near-source, as well as for overwater cases several days downwind. The results also provide some indication that as they evolve, plume particles brighten, and average particle size decreases. Such detailed mapping offers context for suborbital plume observations having much more limited sampling. The MISR Standard aerosol product identified similar trends in plume properties as the Research algorithm, though with much smaller differences compared to background, and it does not resolve plume structure. Better optical analogs of non-spherical volcanic ash, and coincident suborbital data to validate the satellite retrieval results, are the factors most important for further advancing the remote sensing of volcanic ash plumes from space.

Climatology of the Aerosol Optical Depth by Components from the Multi-Angle Imaging Spectroradiometer (MISR) and Chemistry Transport Models

NASA Technical Reports Server (NTRS)

Lee, Huikyo; Kalashnikova, Olga V.; Suzuki, Kentaroh; Braverman, Amy; Garay, Michael J.; Kahn, Ralph A.

2016-01-01

The Multi-angle Imaging Spectroradiometer (MISR) Joint Aerosol (JOINT_AS) Level 3 product has provided a global, descriptive summary of MISR Level 2 aerosol optical depth (AOD) and aerosol type information for each month over 16+ years since March 2000. Using Version 1 of JOINT_AS, which is based on the operational (Version 22) MISR Level 2 aerosol product, this study analyzes, for the first time, characteristics of observed and simulated distributions of AOD for three broad classes of aerosols: spherical nonabsorbing, spherical absorbing, and nonspherical - near or downwind of their major source regions. The statistical moments (means, standard deviations, and skew-nesses) and distributions of AOD by components derived from the JOINT_AS are compared with results from two chemistry transport models (CTMs), the Goddard Chemistry Aerosol Radiation and Transport (GOCART) and SPectral RadIatioN-TrAnSport (SPRINTARS). Overall, the AOD distributions retrieved from MISR and modeled by GOCART and SPRINTARS agree with each other in a qualitative sense. Marginal distributions of AOD for each aerosol type in both MISR and models show considerable high positive skewness, which indicates the importance of including extreme AOD events when comparing satellite retrievals with models. The MISR JOINT_AS product will greatly facilitate comparisons between satellite observations and model simulations of aerosols by type.

EOSDIS Terra Data Sampler #1: Western US Wildfires 2000. 1.1

NASA Technical Reports Server (NTRS)

Perkins, Dorothy C. (Technical Monitor)

2000-01-01

This CD-ROM contains sample data in HDF-EOS format from the instruments on board the Earth Observing System (EOS) Terra satellite: (1) Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER); (2) Clouds and the Earth's Radiant Energy System (CERES); (3) Multi-angle Imaging Spectroradiometer (MISR); and (4) Moderate Resolution Imaging Spectroradiometer (MODIS). Data from the Measurements of Pollution in the Troposphere (MOPITT) instrument were not available for distribution (as of October 17, 2000). The remotely sensed, coincident data for the Western US wildfires were acquired August 30, 2000. This CD-ROM provides information about the Terra mission, instruments, data, and viewing tools. It also provides the Collage tool for viewing data, and links to Web sites containing other digital data processing software. Full granules of the data on this CD-ROM and other EOS Data and Information System (EOSDIS) data products are available from the NASA Distributed Active Archive Centers (DAACs).

Nicaraguan Volcanoes, 26 February 2000

NASA Image and Video Library

2000-04-19

The true-color image at left is a downward-looking (nadir) view of the area around the San Cristobal volcano, which erupted the previous day. This image is oriented with east at the top and north at the left. The right image is a stereo anaglyph of the same area, created from red band multi-angle data taken by the 45.6-degree aftward and 70.5-degree aftward cameras on the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite. View this image through red/blue 3D glasses, with the red filter over the left eye. A plume from San Cristobal (approximately at image center) is much easier to see in the anaglyph, due to 3 effects: the long viewing path through the atmosphere at the oblique angles, the reduced reflection from the underlying water, and the 3D stereoscopic height separation. In this image, the plume floats between the surface and the overlying cumulus clouds. A second plume is also visible in the upper right (southeast of San Cristobal). This very thin plume may originate from the Masaya volcano, which is continually degassing at as low rate. The spatial resolution is 275 meters (300 yards). http://photojournal.jpl.nasa.gov/catalog/PIA02600

Greenland's Coast in Holiday Colors

NASA Technical Reports Server (NTRS)

2003-01-01

Vibrant reds, emerald greens, brilliant whites, and pastel blues adorn this view of the area surrounding the Jakobshavn Glacier on the western coast of Greenland. The image is a false-color (near-infrared, green, blue) view acquired by the Multi-angle Imaging SpectroRadiometer's nadir camera. The brightness of vegetation in the near-infrared contributes to the reddish hues; glacial silt gives rise to the green color of the water; and blue-colored melt ponds are visible in the bright white ice. A scattering of small icebergs in Disco Bay adds a touch of glittery sparkle to the scene.

The large island in the upper left is called Qeqertarsuaq. To the east of this island, and just above image center, is the outlet of the fast-flowing Jakobshavn (or Ilulissat) glacier. Jakobshavn is considered to have the highest iceberg production of all Greenland glaciers and is a major drainage outlet for a large portion of the western side of the ice sheet. Icebergs released from the glacier drift slowly with the ocean currents and pose hazards for shipping along the coast.

The Multi-angle Imaging SpectroRadiometer views the daylit Earth continuously and the entire globe between 82 degrees north and 82 degrees south latitude is observed every 9 days. These data products were generated from a portion of the imagery acquired on June 18, 2003 during Terra orbit 18615. The image cover an area of about 254 kilometers x 210 kilometers, and use data from blocks 34 to 35 within World Reference System-2 path 10.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Scandinavia and the Baltic Region

NASA Technical Reports Server (NTRS)

2003-01-01

Data from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera were combined to create this cloud-free natural-color mosaic of Scandinavia and the Baltic region. The image extends from 64oN, 0oE in the northwest to 56oN, 32oE in the southeast, and has been draped over a shaded relief Digital Terrain Elevation Model from the United States Geological Survey. It is displayed in an equidistant conic projection.

The image area includes southern Norway, Sweden and Finland, northern Denmark, Estonia, Latvia and part of western Russia. Norway's rugged western coastline is deeply indented by fjords. Elongated lakes, formed by glacial erosion and deposition, are characteristic of the entire region, and are particularly dense throughout Finland and Sweden. Numerous islands are present, and a virtually continuous chain of small, scattered islands occur between Sweden and Finland. The northern and eastern waters of the Baltic Sea are almost fresh, since the Baltic receives saltwater only from the narrow and shallow sounds between Denmark and Sweden that connect it to the North Sea. Most of the major cities within the image area are coastal, including St. Petersburg, Stockholm, Helsinki, Riga, and Oslo.

The Multi-angle Imaging SpectroRadiometer (MISR) observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

The 2010 Eyjafjallajokull Eruptions: The NASA Applied Sciences Perspective for Aviation

NASA Astrophysics Data System (ADS)

Murray, J. J.; Haynes, J. A.; Trepte, C. R.; Krotkov, N. A.; Krueger, A. J.

2010-12-01

The volcanic ash from the eruption of the Eyjafjallajokull volcano in Iceland which began on March 17, 2010 was closely monitored by NASA Earth Observing System satellites. A wide variety of applications and techniques developed by the NASA Science Mission Directorate’s Applied Science Program were employed. These included information from imager data obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua and Terra spacecraft. Horizontal distribution of the ash cloud and column amount of volcanic sufur dioxide gas was accurately mapped by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite. Highly precise retrievals of the vertical distribution of volcanic aerosols were obtained by the Caliop instrument onboard the Calipso satellite. The Multi-angle Imaging SpectroRadiometer (MISR) satellite also provided stereo-derived plume heights at 1km horizontal and ~0.5km vertical resolutions. All of this information was employed to assist in airspace management during the eruptive period. It will continue to be used to improve dispersion models and procedures for dealing with volcanic ash.

Impacts of Cross-Platform Vicarious Calibration on the Deep Blue Aerosol Retrievals for Moderate Resolution Imaging Spectroradiometer Aboard Terra

NASA Technical Reports Server (NTRS)

Jeong, Myeong-Jae; Hsu, N. Christina; Kwiatkowska, Ewa J.; Franz, Bryan A.; Meister, Gerhard; Salustro, Clare E.

2012-01-01

The retrieval of aerosol properties from spaceborne sensors requires highly accurate and precise radiometric measurements, thus placing stringent requirements on sensor calibration and characterization. For the Terra/Moderate Resolution Imaging Spedroradiometer (MODIS), the characteristics of the detectors of certain bands, particularly band 8 [(B8); 412 nm], have changed significantly over time, leading to increased calibration uncertainty. In this paper, we explore a possibility of utilizing a cross-calibration method developed for characterizing the Terral MODIS detectors in the ocean bands by the National Aeronautics and Space Administration Ocean Biology Processing Group to improve aerosol retrieval over bright land surfaces. We found that the Terra/MODIS B8 reflectance corrected using the cross calibration method resulted in significant improvements for the retrieved aerosol optical thickness when compared with that from the Multi-angle Imaging Spectroradiometer, Aqua/MODIS, and the Aerosol Robotic Network. The method reported in this paper is implemented for the operational processing of the Terra/MODIS Deep Blue aerosol products.

What We are Learning from (and About) the 10 Plus Year MISR Aerosol Data Record

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.

2010-01-01

Having a 10+ year data record from the Multi-angle Imaging SpectroRadiometer (MISR) significantly improves our opportunities to validate the retrieved aerosol optical depth (AOD) and especially particle microphysical property products. It also begins to raise the possibility of using the data to look for changes or even trends, at least on a regional basis. Further, we have had the opportunity to expand the database of wildfire smoke plume heights derived from the multiangle observations. This presentation will review the latest aerosol validation results and algorithm upgrades under consideration by the MISR team, and will summarize the current status of MISR global aerosol air mass type, and regional dust transport and smoke injection height products. The strengths and limitations of these data for constraining aerosol transport model simulations will receive special emphasis.

Multiangle Imaging Spectroradiometer (MISR) Global Aerosol Optical Depth Validation Based on 2 Years of Coincident Aerosol Robotic Network (AERONET) Observations

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.; Gaitley, Barbara J.; Martonchik, John V.; Diner, David J.; Crean, Kathleen A.; Holben, Brent

2005-01-01

Performance of the Multiangle Imaging Spectroradiometer (MISR) early postlaunch aerosol optical thickness (AOT) retrieval algorithm is assessed quantitatively over land and ocean by comparison with a 2-year measurement record of globally distributed AERONET Sun photometers. There are sufficient coincident observations to stratify the data set by season and expected aerosol type. In addition to reporting uncertainty envelopes, we identify trends and outliers, and investigate their likely causes, with the aim of refining algorithm performance. Overall, about 2/3 of the MISR-retrieved AOT values fall within [0.05 or 20% x AOT] of Aerosol Robotic Network (AERONET). More than a third are within [0.03 or 10% x AOT]. Correlation coefficients are highest for maritime stations (approx.0.9), and lowest for dusty sites (more than approx.0.7). Retrieved spectral slopes closely match Sun photometer values for Biomass burning and continental aerosol types. Detailed comparisons suggest that adding to the algorithm climatology more absorbing spherical particles, more realistic dust analogs, and a richer selection of multimodal aerosol mixtures would reduce the remaining discrepancies for MISR retrievals over land; in addition, refining instrument low-light-level calibration could reduce or eliminate a small but systematic offset in maritime AOT values. On the basis of cases for which current particle models are representative, a second-generation MISR aerosol retrieval algorithm incorporating these improvements could provide AOT accuracy unprecedented for a spaceborne technique.

Tomographic reconstruction of an aerosol plume using passive multiangle observations from the MISR satellite instrument

NASA Astrophysics Data System (ADS)

Garay, Michael J.; Davis, Anthony B.; Diner, David J.

2016-12-01

We present initial results using computed tomography to reconstruct the three-dimensional structure of an aerosol plume from passive observations made by the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite. MISR views the Earth from nine different angles at four visible and near-infrared wavelengths. Adopting the 672 nm channel, we treat each view as an independent measure of aerosol optical thickness along the line of sight at 1.1 km resolution. A smoke plume over dark water is selected as it provides a more tractable lower boundary condition for the retrieval. A tomographic algorithm is used to reconstruct the horizontal and vertical aerosol extinction field for one along-track slice from the path of all camera rays passing through a regular grid. The results compare well with ground-based lidar observations from a nearby Micropulse Lidar Network site.

Use of Spectralon as a diffuse reflectance standard for in-flight calibration of earth-orbiting sensors

NASA Technical Reports Server (NTRS)

Bruegge, Carol J.; Stiegman, Albert E.; Rainen, Richard A.; Springsteen, Arthur W.

1993-01-01

Spectralon, a commercially available diffuse reflectance material made from polytetrafluoroethylene (PTFE), is being evaluated for the multiangle imaging spectroradiometer (MISR), currently under development for the Earth Observing System. Results of a series of environmental exposure tests indicate that no degradation of the optical properties was apparent following proton bombardment, and stability through UV illumination was satisfactory, provided simple cleaning and handling procedures were implemented. A buildup of several thousand volts of static charge was found to develop while simulating a rare pass through an auroral storm.

Longwave Radiative Forcing of Saharan Dust Aerosols Estimated from MODIS, MISR and CERES Observations on Terra

NASA Technical Reports Server (NTRS)

Zhang, Jiang-Long; Christopher, Sundar A.

2003-01-01

Using observations from the Multi-angle Imaging Spectroradiometer (MISR), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Clouds and the Earth's Radiant Energy System (CERES) instruments onboard the Terra satellite; we present a new technique for studying longwave (LW) radiative forcing of dust aerosols over the Saharan desert for cloud-free conditions. The monthly-mean LW forcing for September 2000 is 7 W/sq m and the LW forcing efficiency' (LW(sub eff)) is 15 W/sq m. Using radiative transfer calculations, we also show that the vertical distribution of aerosols and water vapor are critical to the understanding of dust aerosol forcing. Using well calibrated, spatially and temporally collocated data sets, we have combined the strengths of three sensors from the same satellite to quantify the LW radiative forcing, and show that dust aerosols have a "warming" effect over the Saharan desert that will counteract the shortwave "cooling effect" of aerosols.

Remote Sensing of Aerosol and Aerosol Radiative Forcing of Climate from EOS Terra MODIS Instrument

NASA Technical Reports Server (NTRS)

Kaufman, Yoram; Tanre, Didier; Remer, Lorraine; Einaudi, Franco (Technical Monitor)

2000-01-01

The recent launch of EOS-Terra into polar orbit has begun to revolutionize remote sensing of aerosol and their effect on climate. Terra has five instruments, two of them,Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectro-Radiometer (MISR) are designed to monitor global aerosol in two different complementary ways. Here we shall discuss the use of the multispectral measurements of MODIS to derive: (1) the global distribution of aerosol load (and optical thickness) over ocean and land; (2) to measure the impact of aerosol on reflection of sunlight to space; and (3) to measure the ability of aerosol to absorb solar radiation. These measurements have direct applications on the understanding of the effect of aerosol on climate, the ability to predict climate change, and on the monitoring of dust episodes and man-made pollution. Principles of remote sensing of aerosol from MODIS will be discussed and first examples of measurements from MODIS will be provided.

Western United States and Southwestern Canada

NASA Technical Reports Server (NTRS)

2003-01-01

This natural-color image from the Multi-angle Imaging SpectroRadiometer (MISR) captures the beauty of the western United States and Canada. Data from 45 swaths from MISR's vertical-viewing (nadir) camera were combined to create this cloud-free mosaic. The image extends from 48o N 128o W in the northwest, to 32oN, 104o W in the southeast, and has been draped over a shaded relief Digital Terrain Elevation Model from the United States Geological Survey.

The image area includes much of British Columbia, Alberta and Saskatchewan in the north, and extends southward to California, Arizona and New Mexico. The snow-capped Rocky Mountains are a prominent feature extending through British Columbia, Montana, Wyoming, Colorado and New Mexico. Many major rivers originate in the Columbia Plateau region of Washington, Oregon and Idaho. The Colorado Plateau region is characterized by the vibrant red-colored rocks of the Painted Desert in Utah and Arizona, and in New Mexico, White Sands National Park is the large white feature in the Southeast corner of the image with the Malpais lava flow just to its North. The southwest is dominated by the Mojave Desert of California and Nevada, California's San Joaquin Valley, the Los Angeles basin and the Pacific Ocean.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during 2000-2002. The panels utilize data from blocks 45 to 65 within World Reference System-2 paths 31 to 53.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Tropical Cyclone Monty Strikes Western Australia

NASA Technical Reports Server (NTRS)

2004-01-01

The Multi-angle Imaging SpectroRadiometer (MISR) acquired these natural color images and cloud top height measurements for Monty before and after the storm made landfall over the remote Pilbara region of Western Australia, on February 29 and March 2, 2004 (shown as the left and right-hand image sets, respectively). On February 29, Monty was upgraded to category 4 cyclone status. After traveling inland about 300 kilometers to the south, the cyclonic circulation had decayed considerably, although category 3 force winds were reported on the ground. Some parts of the drought-affected Pilbara region received more than 300 millimeters of rainfall, and serious and extensive flooding has occurred.

The natural color images cover much of the same area, although the right-hand panels are offset slightly to the east. Automated stereoscopic processing of data from multiple MISR cameras was utilized to produce the cloud-top height fields. The distinctive spatial patterns of the clouds provide the necessary contrast to enable automated feature matching between images acquired at different view angles. The height retrievals are at this stage uncorrected for the effects of the high winds associated with cyclone rotation. Areas where heights could not be retrieved are shown in dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 22335 and 22364. The panels cover an area of about 380 kilometers x 985 kilometers, and utilize data from blocks 105 to 111 within World Reference System-2 paths 115 and 113.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

MISR Stereo-heights of Grassland Fire Smoke Plumes in Australia

NASA Astrophysics Data System (ADS)

Mims, S. R.; Kahn, R. A.; Moroney, C. M.; Gaitley, B. J.; Nelson, D. L.; Garay, M. J.

2008-12-01

Plume heights from wildfires are used in climate modeling to predict and understand trends in aerosol transport. This study examines whether smoke from grassland fires in the desert region of Western and central Australia ever rises above the relatively stable atmospheric boundary layer and accumulates in higher layers of relative atmospheric stability. Several methods for deriving plume heights from the Multi-angle Imaging SpectroRadiometer (MISR) instrument are examined for fire events during the summer 2000 and 2002 burning seasons. Using MISR's multi-angle stereo-imagery from its three near-nadir-viewing cameras, an automatic algorithm routinely derives the stereo-heights above the geoid of the level-of-maximum-contrast for the entire global data set, which often correspond to the heights of clouds and aerosol plumes. Most of the fires that occur in the cases studied here are small, diffuse, and difficult to detect. To increase the signal from these thin hazes, the MISR enhanced stereo product that computes stereo heights from the most steeply viewing MISR cameras is used. For some cases, a third approach to retrieving plume heights from MISR stereo imaging observations, the MISR Interactive Explorer (MINX) tool, is employed to help differentiate between smoke and cloud. To provide context and to search for correlative factors, stereo-heights are combined with data providing fire strength from the Moderate-resolution Imaging Spectroradiometer (MODIS) instrument, atmospheric structure from the NCEP/NCAR Reanalysis Project, surface cover from the Australia National Vegetation Information System, and forward and backward trajectories from the NOAA HYSPLIT model. Although most smoke plumes concentrate in the near-surface boundary layer, as expected, some appear to rise higher. These findings suggest that a closer examination of grassland fire energetics may be warranted.

WindCam and MSPI: two cloud and aerosol instrument concepts derived from Terra/MISR heritage

NASA Astrophysics Data System (ADS)

Diner, David J.; Mischna, Michael; Chipman, Russell A.; Davis, Ab; Cairns, Brian; Davies, Roger; Kahn, Ralph A.; Muller, Jan-Peter; Torres, Omar

2008-08-01

The Multi-angle Imaging SpectroRadiometer (MISR) has been acquiring global cloud and aerosol data from polar orbit since February 2000. MISR acquires moderately high-resolution imagery at nine view angles from nadir to 70.5°, in four visible/near-infrared spectral bands. Stereoscopic parallax, time lapse among the nine views, and the variation of radiance with angle and wavelength enable retrieval of geometric cloud and aerosol plume heights, height-resolved cloud-tracked winds, and aerosol optical depth and particle property information. Two instrument concepts based upon MISR heritage are in development. The Cloud Motion Vector Camera, or WindCam, is a simplified version comprised of a lightweight, compact, wide-angle camera to acquire multiangle stereo imagery at a single visible wavelength. A constellation of three WindCam instruments in polar Earth orbit would obtain height-resolved cloud-motion winds with daily global coverage, making it a low-cost complement to a spaceborne lidar wind measurement system. The Multiangle SpectroPolarimetric Imager (MSPI) is aimed at aerosol and cloud microphysical properties, and is a candidate for the National Research Council Decadal Survey's Aerosol-Cloud-Ecosystem (ACE) mission. MSPI combines the capabilities of MISR with those of other aerosol sensors, extending the spectral coverage to the ultraviolet and shortwave infrared and incorporating high-accuracy polarimetric imaging. Based on requirements for the nonimaging Aerosol Polarimeter Sensor on NASA's Glory mission, a degree of linear polarization uncertainty of 0.5% is specified within a subset of the MSPI bands. We are developing a polarization imaging approach using photoelastic modulators (PEMs) to accomplish this objective.

Informing Aerosol Transport Models With Satellite Multi-Angle Aerosol Measurements

NASA Technical Reports Server (NTRS)

Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.

2011-01-01

As the aerosol products from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the aerosol amount and type data products, and aerosol plume heights, to constrain aerosol transport models. We have demonstrated the ability to map aerosol air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the aerosol type information content, that varies depending upon retrieval conditions. We have shown that MISR aerosol type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution aerosol components in urban settings. We demonstrated the use of stereo imaging to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS aerosol optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining aerosol transport models, planet-wide.

Impacts of including forest understory brightness and foliage clumping information from multiangular measurements on leaf area index mapping over North America

NASA Astrophysics Data System (ADS)

Pisek, Jan; Chen, Jing M.; Alikas, Krista; Deng, Feng

2010-09-01

A new leaf area index (LAI) data set in 10 day intervals with consideration of the understory reflectance and foliage clumping effects over North America for 1 year is developed. The data set brings effectively together measurements from multiple sensors with complementary capabilities (SPOT-VEGETATION, Multiangle Imaging Spectroradiometer, POLDER). First, the temporal consistency analysis indicated the new product is on par with other available LAI data sets currently used by the community. Second, with the removal of the background (understory in forests, moss, litter, and soil) effect on the forest overstory LAI retrieval, slightly different LAI reductions were found between needleleaf and broadleaf forests. This is caused by the more clumped nature of needleleaf forests, especially at higher LAI values, which allows more light to penetrate through the overstory canopy, making the understory more visible for equal LAI as compared to broadleaf forests. This is found over a representative set of 105 CEOS Benchmark Land Multisite Analysis and Intercomparison of Products sites in North America used for indirect validation. Third, the data set was directly validated and compared with Moderate Resolution Imaging Spectroradiometer Collection 5 LAI product using results from the BigFoot project for available forest test sites. This study demonstrates that the fusion of data inputs between multiple sensors can indeed lead to improved products and that multiangle remote sensing can help us to address effectively the issues (separating the signal from the understory and overstory, foliage clumping) that could not be solved via the means of the conventional mono-angle remote sensing.

Icebergs Adrift in the Amundsen Sea

NASA Image and Video Library

2002-03-27

The Thwaites Ice Tongue is a large sheet of glacial ice extending from the West Antarctic mainland into the southern Amundsen Sea. A large crack in the Thwaites Tongue was discovered in imagery from Terra's Moderate Resolution Imaging SpectroRadiometer (MODIS). Subsequent widening of the crack led to the calving of a large iceberg. The development of this berg, designated B-22 by the National Ice Center, can be observed in these images from the Multi-angle Imaging SpectroRadiometer, also aboard Terra. The two views were acquired by MISR's nadir (vertical-viewing) camera on March 10 and 24, 2002. The B-22 iceberg, located below and to the left of image center, measures approximately 82 kilometers long x 62 kilometers wide. Comparison of the two images shows the berg to have drifted away from the ice shelf edge. The breakup of ice near the shelf edge, in the area surrounding B-22, is also visible in the later image. These natural-color images were acquired during Terra orbits 11843 and 12047, respectively. At the right-hand edge is Pine Island Bay, where the calving of another large iceberg (B-21) occurred in November 2001. B-21 subsequently split into two smaller bergs, both of which are visible to the right of B-22. http://photojournal.jpl.nasa.gov/catalog/PIA03700

Height and Motion of the Chikurachki Eruption Plume

NASA Technical Reports Server (NTRS)

2003-01-01

The height and motion of the ash and gas plume from the April 22, 2003, eruption of the Chikurachki volcano is portrayed in these views from the Multi-angle Imaging SpectroRadiometer (MISR). Situated within the northern portion of the volcanically active Kuril Island group, the Chikurachki volcano is an active stratovolcano on Russia's Paramushir Island (just south of the Kamchatka Peninsula).

In the upper panel of the still image pair, this scene is displayed as a natural-color view from MISR's vertical-viewing (nadir) camera. The white and brownish-grey plume streaks several hundred kilometers from the eastern edge of Paramushir Island toward the southeast. The darker areas of the plume typically indicate volcanic ash, while the white portions of the plume indicate entrained water droplets and ice. According to the Kamchatkan Volcanic Eruptions Response Team (KVERT), the temperature of the plume near the volcano on April 22 was -12o C.

The lower panel shows heights derived from automated stereoscopic processing of MISR's multi-angle imagery, in which the plume is determined to reach heights of about 2.5 kilometers above sea level. Heights for clouds above and below the eruption plume were also retrieved, including the high-altitude cirrus clouds in the lower left (orange pixels). The distinctive patterns of these features provide sufficient spatial contrast for MISR's stereo height retrieval to perform automated feature matching between the images acquired at different view angles. Places where clouds or other factors precluded a height retrieval are shown in dark gray.

The multi-angle 'fly-over' animation (below) allows the motion of the plume and of the surrounding clouds to be directly observed. The frames of the animation consist of data acquired by the 70-degree, 60-degree, 46-degree and 26-degree forward-viewing cameras in sequence, followed by the images from the nadir camera and each of the four backward-viewing cameras, ending with the view from the 70-degree backward camera.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 17776. The panels cover an area of approximately 296 kilometers x 216 kilometers (still images) and 185 kilometers x 154 kilometers (animation), and utilize data from blocks 50 to 51 within World Reference System-2 path 100.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

[figure removed for brevity, see original site

Burn Scar Near the Hanford Nuclear Reservation

NASA Technical Reports Server (NTRS)

2002-01-01

This Multi-angle Imaging Spectroradiometer (MISR) image pair shows 'before and after' views of the area around the Hanford Nuclear Reservation near Richland, Washington. On June 27, 2000, a fire in the dry sagebrush was sparked by an automobile crash. The flames were fanned by hot summer winds. By the day after the accident, about 100,000 acres had burned, and the fire's spread forced the closure of highways and loss of homes. These images were obtained by MISR's vertical-viewing (nadir) camera. Compare the area just above and to the right of the line of cumulus clouds in the May 15 image with the same area imaged on August 3. The darkened burn scar measures approximately 35 kilometers across. The Columbia River is seen wending its way around Hanford. Image courtesy NASA/GSFC/JPL, MISR Science Team

Ten Years of MISR Observations from Terra: Looking Back, Ahead, and in Between

NASA Technical Reports Server (NTRS)

Diner, David J.; Ackerman, Thomas P.; Braverman, Amy J.; Bruegge, Carol J.; Chopping, Mark J.; Clothiaux, Eugene E.; Davies, Roger; Di Girolamo, Larry; Kahn, Ralph A.; Knyazikhin, Yuri;

MISR Interactive Explorer (MINX) : Production Digitizing to Retrieve Smoke Plume Heights and Validating Heights Against Lidar Data

NASA Technical Reports Server (NTRS)

Dunst, Ben

2011-01-01

The height at which smoke from a wildfire is injected into the atmosphere is an important parameter for climatology, because it determines how far the smoke can be transported. Using the MINX program to analyze MISR (Multi-angle Imaging Spectro-Radiometer) data, I digitized wildfire smoke plumes to add to an existing database of these heights for use by scientists studying smoke transport and plume dynamics. In addition to using MINX to do production digitizing of heights, I assisted in gathering lidar data for an ongoing validation of MINX and helped evaluate those data.

A Summer View of Russia's Lena Delta and Olenek

NASA Technical Reports Server (NTRS)

2004-01-01

These views of the Russian Arctic were acquired by NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument on July 11, 2004, when the brief arctic summer had transformed the frozen tundra and the thousands of lakes, channels, and rivers of the Lena Delta into a fertile wetland, and when the usual blanket of thick snow had melted from the vast plains and taiga forests. This set of three images cover an area in the northern part of the Eastern Siberian Sakha Republic. The Olenek River wends northeast from the bottom of the images to the upper left, and the top portions of the images are dominated by the delta into which the mighty Lena River empties when it reaches the Laptev Sea. At left is a natural color image from MISR's nadir (vertical-viewing) camera, in which the rivers appear murky due to the presence of sediment, and photosynthetically-active vegetation appears green. The center image is also from MISR's nadir camera, but is a false color view in which the predominant red color is due to the brightness of vegetation at near-infrared wavelengths. The most photosynthetically active parts of this area are the Lena Delta, in the lower half of the image, and throughout the great stretch of land that curves across the Olenek River and extends northeast beyond the relatively barren ranges of the Volyoi mountains (the pale tan-colored area to the right of image center).

The right-hand image is a multi-angle false-color view made from the red band data of the 60o backward, nadir, and 60o forward cameras, displayed as red, green and blue, respectively. Water appears blue in this image because sun glitter makes smooth, wet surfaces look brighter at the forward camera's view angle. Much of the landscape and many low clouds appear purple since these surfaces are both forward and backward scattering, and clouds that are further from the surface appear in a different spot for each view angle, creating a rainbow-like appearance. However, the vegetated region that is darker green in the natural color nadir image, also appears to exhibit a faint greenish hue in the multi-angle composite. A possible explanation for this subtle green effect is that the taiga forest trees (or dwarf-shrubs) are not too dense here. Since the the nadir camera is more likly to observe any gaps between the trees or shrubs, and since the vegetation is not as bright (in the red band) as the underlying soil or surface, the brighter underlying surface results in an area that is relatively brighter at the nadir view angle. Accurate maps of vegetation structural units are an essential part of understanding the seasonal exchanges of energy and water at the Earth's surface, and of preserving the biodiversity in these regions.

The Multiangle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 24273. The panels cover an area of about 230 kilometers x 420 kilometers, and utilize data from blocks 30 to 34 within World Reference System-2 path 134.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Airborne Spectral Measurements of Ocean Directional Reflectance

NASA Technical Reports Server (NTRS)

Gatebe, Charles K.; King, Michael D.; Lyapustin, Alexei; Arnold, G. Thomas; Redemann, Jens

2004-01-01

During summer of 2001 NASA's Cloud Absorption Radiometer (CAR) obtained measurement of ocean angular distribution of reflected radiation or BRDF (bidirectional reflectance distribution function) aboard the University of Washington Convair CV-580 research aircraft under cloud-free conditions. The measurements took place aver the Atlantic Ocean off the eastern seaboard of the U.S. in the vicinity of the Chesapeake Light Tower and at nearby National Oceanic and Atmospheric Administration (NOAA) Buoy Stations. The measurements were in support of CLAMS, Chesapeake Lighthouse and Aircraft Measurements for Satellites, field campaign that was primarily designed to validate and improve NASA's Earth Observing System (EOS) satellite data products being derived from three sensors: MODIS (MODerate Resolution Imaging Spectro-Radiometer), MISR (Multi-angle Imaging Spectro-Radiometer) and CERES (Clouds and Earth s Radiant Energy System). Because of the high resolution of the CAR measurements and its high sensitivity to detect weak ocean signals against a noisy background, results of radiance field above the ocean are seen in unprecedented detail. The study also attempts to validate the widely used Cox-Munk model for predicting reflectance from a rough ocean surface.

AOD trends during 2001-2010 from observations and model simulations

NASA Astrophysics Data System (ADS)

Pozzer, A.; de Meij, A.; Yoon, J.; Tost, H.; Georgoulias, A. K.; Astitha, M.

2015-05-01

The aerosol optical depth (AOD) trend between 2001 and 2010 is estimated globally and regionally from observations and results from simulations with the EMAC (ECHAM5/MESSy Atmospheric Chemistry) model. Although interannual variability is applied only to anthropogenic and biomass-burning emissions, the model is able to quantitatively reproduce the AOD trends as observed by the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite sensor, while some discrepancies are found when compared to MISR (Multi-angle Imaging SpectroRadiometer) and SeaWIFS (Sea-viewing Wide Field-of-view Sensor) observations. Thanks to an additional simulation without any change in emissions, it is shown that decreasing AOD trends over the US and Europe are due to the decrease in the emissions, while over the Sahara Desert and the Middle East region, the meteorological changes play a major role. Over Southeast Asia, both meteorology and emissions changes are equally important in defining AOD trends. Additionally, decomposing the regional AOD trends into individual aerosol components reveals that the soluble components are the most dominant contributors to the total AOD, as their influence on the total AOD is enhanced by the aerosol water content.

On-Orbit Cross-Calibration of AM Satellite Remote Sensing Instruments using the Moon

NASA Technical Reports Server (NTRS)

Butler, James J.; Kieffer, Hugh H.; Barnes, Robert A.; Stone, Thomas C.

2003-01-01

On April 14,2003, three Earth remote sensing spacecraft were maneuvered enabling six satellite instruments operating in the visible through shortwave infrared wavelength region to view the Moon for purposes of on-orbit cross-calibration. These instruments included the Moderate Resolution Imaging Spectroradiometer (MODIS), the Multi-angle Imaging SpectroRadiometer (MISR), the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer on the Earth Observing System (EOS) Terra spacecraft, the Advanced Land Imager (ALI) and Hyperion instrument on Earth Observing-1 (EO-1) spacecraft, and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the SeaStar spacecraft. Observations of the Moon were compared using a spectral photometric mode for lunar irradiance developed by the Robotic Lunar Observatory (ROLO) project located at the United States Geological Survey in Flagstaff, Arizona. The ROLO model effectively accounts for variations in lunar irradiance corresponding to lunar phase and libration angles, allowing intercomparison of observations made by instruments on different spacecraft under different time and location conditions. The spacecraft maneuvers necessary to view the Moon are briefly described and results of using the lunar irradiance model in comparing the radiometric calibration scales of the six satellite instruments are presented here.

Fluctuations of Lake Eyre, South Australia

NASA Technical Reports Server (NTRS)

2002-01-01

Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. However, this low-lying lake attracts run-off from one of the largest inland drainage systems in the world. The drainage basin is very responsive to rainfall variations, and changes dramatically with Australia's inter-annual weather fluctuations. When Lake Eyre fills,as it did in 1989, it is temporarily Australia's largest lake, and becomes dense with birds, frogs and colorful plant life. The Lake responds to extended dry periods (often associated with El Nino events) by drying completely.

These four images from the Multi-angle Imaging SpectroRadiometer contrast the lake area at the start of the austral summers of 2000 and 2002. The top two panels portray the region as it appeared on December 9, 2000. Heavy rains in the first part of 2000 caused both the north and south sections of the lake to fill partially and the northern part of the lake still contained significant standing water by the time these data were acquired. The bottom panels were captured on November 29, 2002. Rainfall during 2002 was significantly below average ( http://www.bom.gov.au/ ), although showers occurring in the week before the image was acquired helped alleviate this condition slightly.

The left-hand panels portray the area as it appeared to MISR's vertical-viewing (nadir) camera, and are false-color views comprised of data from the near-infrared, green and blue channels. Here, wet and/or moist surfaces appear blue-green, since water selectively absorbs longer wavelengths such as near-infrared. The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree forward, nadir and 60-degree backward-viewing cameras, displayed as red, green and blue, respectively. In these multi-angle composites, color variations serve as a proxy for changes in angular reflectance, and indicate textural properties of the surface related to roughness and/or moisture content.Data from the two dates were processed identically to preserve relative variations in brightness between them. Wet surfaces or areas with standing water appear green due to the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have enhanced forward scattering, possibly as a result of surface moistness. Some variations exhibited by the multi-angle composites are not discernible in the nadir multi-spectral images and vice versa, suggesting that the combination of angular and spectral information is a more powerful diagnostic of surface conditions than either technique by itself.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 5194 and 15679. The panels cover an area of 146 kilometers x 122 kilometers, and utilize data from blocks 113 to 114 within World Reference System-2 path 100.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

The Earth Observing System AM Spacecraft - Thermal Control Subsystem

NASA Technical Reports Server (NTRS)

Chalmers, D.; Fredley, J.; Scott, C.

1993-01-01

Mission requirements for the EOS-AM Spacecraft intended to monitor global changes of the entire earth system are considered. The spacecraft is based on an instrument set containing the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multiangle Imaging Spectro-Radiometer (MISR), Moderate-Resolution Imaging Spectrometer (MODIS), and Measurements of Pollution in the Troposphere (MOPITT). Emphasis is placed on the design, analysis, development, and verification plans for the unique EOS-AM Thermal Control Subsystem (TCS) aimed at providing the required environments for all the onboard equipment in a densely packed layout. The TCS design maximizes the use of proven thermal design techniques and materials, in conjunction with a capillary pumped two-phase heat transport system for instrument thermal control.

Reflections on current and future applications of multiangle imaging to aerosol and cloud remote sensing

NASA Astrophysics Data System (ADS)

Diner, David

2010-05-01

The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its 9 along-track view angles, 4 spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. Multiangle imaging offers several tools for remote sensing of aerosol and cloud properties, including bidirectional reflectance and scattering measurements, stereoscopic pattern matching, time lapse sequencing, and potentially, optical tomography. Current data products from MISR employ several of these techniques. Observations of the intensity of scattered light as a function of view angle and wavelength provide accurate measures of aerosol optical depths (AOD) over land, including bright desert and urban source regions. Partitioning of AOD according to retrieved particle classification and incorporation of height information improves the relationship between AOD and surface PM2.5 (fine particulate matter, a regulated air pollutant), constituting an important step toward a satellite-based particulate pollution monitoring system. Stereoscopic cloud-top heights provide a unique metric for detecting interannual variability of clouds and exceptionally high quality and sensitivity for detection and height retrieval for low-level clouds. Using the several-minute time interval between camera views, MISR has enabled a pole-to-pole, height-resolved atmospheric wind measurement system. Stereo imagery also makes possible global measurement of the injection heights and advection speeds of smoke plumes, volcanic plumes, and dust clouds, for which a large database is now available. To build upon what has been learned during the first decade of MISR observations, we are evaluating algorithm updates that not only refine retrieval accuracies but also include enhancements (e.g., finer spatial resolution) that would have been computationally prohibitive just ten years ago. In addition, we are developing technological building blocks for future sensors that enable broader spectral coverage, wider swath, and incorporation of high-accuracy polarimetric imaging. Prototype cameras incorporating photoelastic modulators have been constructed. To fully capitalize on the rich information content of the current and next-generation of multiangle imagers, several algorithmic paradigms currently employed need to be re-examined, e.g., the use of aerosol look-up tables, neglect of 3-D effects, and binary partitioning of the atmosphere into "cloudy" or "clear" designations. Examples of progress in algorithm and technology developments geared toward advanced application of multiangle imaging to remote sensing of aerosols and clouds will be presented.

Oil Fire Plumes Over Baghdad

NASA Technical Reports Server (NTRS)

2003-01-01

Dark smoke from oil fires extend for about 60 kilometers south of Iraq's capital city of Baghdad in these images acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on April 2, 2003. The thick, almost black smoke is apparent near image center and contains chemical and particulate components hazardous to human health and the environment.

The top panel is from MISR's vertical-viewing (nadir) camera. Vegetated areas appear red here because this display is constructed using near-infrared, red and blue band data, displayed as red, green and blue, respectively, to produce a false-color image. The bottom panel is a combination of two camera views of the same area and is a 3-D stereo anaglyph in which red band nadir camera data are displayed as red, and red band data from the 60-degree backward-viewing camera are displayed as green and blue. Both panels are oriented with north to the left in order to facilitate stereo viewing. Viewing the 3-D anaglyph with red/blue glasses (with the red filter placed over the left eye and the blue filter over the right) makes it possible to see the rising smoke against the surface terrain. This technique helps to distinguish features in the atmosphere from those on the surface. In addition to the smoke, several high, thin cirrus clouds (barely visible in the nadir view) are readily observed using the stereo image.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 17489. The panels cover an area of about 187 kilometers x 123 kilometers, and use data from blocks 63 to 65 within World Reference System-2 path 168.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

A Strengthening Eastern Pacific Storm

NASA Technical Reports Server (NTRS)

2006-01-01

These July 11, 2006 images are from the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra Satellite. They show then Tropical Storm Bud as it was intensifying into a hurricane, which it became later that day. The true-color image at left is next to an image of cloud heights on the right. Two-dimensional maps of cloud heights such as these give scientists an opportunity to compare their models against actual hurricane observations.

At the time of these images, Bud was located near 14.4 degrees north latitude and 112.5 degrees west longitude, or about 620 miles (1000 kilometers) southwest of Cabo San Lucas, Baja California, Mexico.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena,Calif. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. JPL is a division of the California Institute of Technology.

Utility of BRDF Models for Estimating Optimal View Angles in Classification of Remotely Sensed Images

NASA Technical Reports Server (NTRS)

Valdez, P. F.; Donohoe, G. W.

1997-01-01

Statistical classification of remotely sensed images attempts to discriminate between surface cover types on the basis of the spectral response recorded by a sensor. It is well known that surfaces reflect incident radiation as a function of wavelength producing a spectral signature specific to the material under investigation. Multispectral and hyperspectral sensors sample the spectral response over tens and even hundreds of wavelength bands to capture the variation of spectral response with wavelength. Classification algorithms then exploit these differences in spectral response to distinguish between materials of interest. Sensors of this type, however, collect detailed spectral information from one direction (usually nadir); consequently, do not consider the directional nature of reflectance potentially detectable at different sensor view angles. Improvements in sensor technology have resulted in remote sensing platforms capable of detecting reflected energy across wavelengths (spectral signatures) and from multiple view angles (angular signatures) in the fore and aft directions. Sensors of this type include: the moderate resolution imaging spectroradiometer (MODIS), the multiangle imaging spectroradiometer (MISR), and the airborne solid-state array spectroradiometer (ASAS). A goal of this paper, then, is to explore the utility of Bidirectional Reflectance Distribution Function (BRDF) models in the selection of optimal view angles for the classification of remotely sensed images by employing a strategy of searching for the maximum difference between surface BRDFs. After a brief discussion of directional reflect ante in Section 2, attention is directed to the Beard-Maxwell BRDF model and its use in predicting the bidirectional reflectance of a surface. The selection of optimal viewing angles is addressed in Section 3, followed by conclusions and future work in Section 4.

Greener Pastures in Northern Queensland, Australia

NASA Technical Reports Server (NTRS)

2004-01-01

After a 19 month rainfall deficiency, heavy rainfall during January 2004 brought drought relief to much of northern Queensland. Local graziers hope for good long-term responses in pasture growth from the heavy rains. These images and maps from the Multi-angle Imaging SpectroRadiometer (MISR) portray part of Australia's Mitchell Grasslands bioregion before summer rainfall, on October 18, 2003 (left) and afterwards, on February 7, 2004 (right).

The top pair of images are natural color views from MISR's nadir camera. The green areas in the post-rainfall image highlight the growth of vegetation. The middle panels show the reflectivity of the surface over the photosynthetically active region (PAR) of visible light (400 - 700 nm), expressed as a directional-hemispherical reflectance (DHR-PAR), or albedo. That portion of the radiation that is not reflected back to the atmosphere or space is absorbed by either the vegetation or the soil. The fraction of PAR radiation absorbed by green vegetation, known as FPAR, is shown in the bottom panels. FPAR is one of the quantities that establishes the photosynthetic and carbon uptake efficiency of live vegetation. MISR's FPAR product makes use of aerosol retrievals to correct for atmospheric scattering and absorption effects, and uses plant canopy structural models to determine the partitioning of solar radiation. Both of these aspects are facilitated by the multiangular nature of the MISR measurements.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 20397 and 22028. The panels cover an area of about 290 kilometers x 228 kilometers, and utilize data from blocks 106 to 108 within World Reference System-2 path 96.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Summer Harvest in Saratov, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

Russia's Saratov Oblast (province) is located in the southeastern portion of the East-European plain, in the Lower Volga River Valley. Southern Russia produces roughly 40 percent of the country's total agricultural output, and Saratov Oblast is the largest producer of grain in the Volga region. Vegetation changes in the province's agricultural lands between spring and summer are apparent in these images acquired on May 31 and July 18, 2002 (upper and lower image panels, respectively) by the Multi-angle Imaging SpectroRadiometer (MISR).

The left-hand panels are natural color views acquired by MISR's vertical-viewing (nadir) camera. Less vegetation and more earth tones (indicative of bare soils) are apparent in the summer image (lower left). Farmers in the region utilize staggered sowing to help stabilize yields, and a number of different stages of crop maturity can be observed. The main crop is spring wheat, cultivated under non-irrigated conditions. A short growing season and relatively low and variable rainfall are the major limitations to production. Saratov city is apparent as the light gray pixels on the left (west) bank of the Volga River. Riparian vegetation along the Volga exhibits dark green hues, with some new growth appearing in summer.

The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree backward, nadir and 60-degree forward-viewing cameras displayed as red, green and blue respectively. In these images, color variations serve as a proxy for changes in angular reflectance, and the spring and summer views were processed identically to preserve relative variations in brightness between the two dates. Urban areas and vegetation along the Volga banks look similar in the two seasonal multi-angle composites. The agricultural areas, on the other hand, look strikingly different. This can be attributed to differences in brightness and texture between bare soil and vegetated land. The chestnut-colored soils in this region are brighter in MISR's red band than the vegetation. Because plants have vertical structure, the oblique cameras observe a greater proportion of vegetation relative to the nadir camera, which sees more soil. In spring, therefore, the scene is brightest in the vertical view and thus appears with an overall greenish hue. In summer, the soil characteristics play a greater role in governing the appearance of the scene, and the angular reflectance is now brighter at the oblique view angles (displayed as red and blue), thus imparting a pink color to much of the farmland and a purple color to areas along the banks of several narrow rivers. The unusual appearance of the clouds is due to geometric parallax which splits the imagery into spatially separated components as a consequence of their elevation above the surface.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. These images are a portion of the data acquired during Terra orbits 13033 and 13732, and cover an area of about 173 kilometers x 171 kilometers. They utilize data from blocks 49 to 50 within World Reference System-2 path 170.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Development and assessment of a higher-spatial-resolution (4.4 km) MISR aerosol optical depth product using AERONET-DRAGON data

NASA Astrophysics Data System (ADS)

Garay, Michael J.; Kalashnikova, Olga V.; Bull, Michael A.

2017-04-01

Since early 2000, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite has been acquiring data that have been used to produce aerosol optical depth (AOD) and particle property retrievals at 17.6 km spatial resolution. Capitalizing on the capabilities provided by multi-angle viewing, the current operational (Version 22) MISR algorithm performs well, with about 75 % of MISR AOD retrievals globally falling within 0.05 or 20 % × AOD of paired validation data from the ground-based Aerosol Robotic Network (AERONET). This paper describes the development and assessment of a prototype version of a higher-spatial-resolution 4.4 km MISR aerosol optical depth product compared against multiple AERONET Distributed Regional Aerosol Gridded Observations Network (DRAGON) deployments around the globe. In comparisons with AERONET-DRAGON AODs, the 4.4 km resolution retrievals show improved correlation (r = 0. 9595), smaller RMSE (0.0768), reduced bias (-0.0208), and a larger fraction within the expected error envelope (80.92 %) relative to the Version 22 MISR retrievals.

An Overview of SIMBIOS Program Activities and Accomplishments. Chapter 1

NASA Technical Reports Server (NTRS)

Fargion, Giulietta S.; McClain, Charles R.

2003-01-01

The SIMBIOS Program was conceived in 1994 as a result of a NASA management review of the agency's strategy for monitoring the bio-optical properties of the global ocean through space-based ocean color remote sensing. At that time, the NASA ocean color flight manifest included two data buy missions, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Earth Observing System (EOS) Color, and three sensors, two Moderate Resolution Imaging Spectroradiometers (MODIS) and the Multi-angle Imaging Spectro-Radiometer (MISR), scheduled for flight on the EOS-Terra and EOS-Aqua satellites. The review led to a decision that the international assemblage of ocean color satellite systems provided ample redundancy to assure continuous global coverage, with no need for the EOS Color mission. At the same time, it was noted that non-trivial technical difficulties attended the challenge (and opportunity) of combining ocean color data from this array of independent satellite systems to form consistent and accurate global bio-optical time series products. Thus, it was announced at the October 1994 EOS Interdisciplinary Working Group meeting that some of the resources budgeted for EOS Color should be redirected into an intercalibration and validation program (McClain et al., 2002).

Two Perspectives on Forest Fire

NASA Technical Reports Server (NTRS)

2002-01-01

Multi-angle Imaging Spectroradiometer (MISR) images of smoke plumes from wildfires in western Montana acquired on August 14, 2000. A portion of Flathead Lake is visible at the top, and the Bitterroot Range traverses the images. The left view is from MISR's vertical-viewing (nadir) camera. The right view is from the camera that looks forward at a steep angle (60 degrees). The smoke location and extent are far more visible when seen at this highly oblique angle. However, vegetation is much darker in the forward view. A brown burn scar is located nearly in the exact center of the nadir image, while in the high-angle view it is shrouded in smoke. Also visible in the center and upper right of the images, and more obvious in the clearer nadir view, are checkerboard patterns on the surface associated with land ownership boundaries and logging. Compare these images with the high resolution infrared imagery captured nearby by Landsat 7 half an hour earlier. Images by NASA/GSFC/JPL, MISR Science Team.

Desert Dust Aerosol Air Mass Mapping in the Western Sahara, Using Particle Properties Derived from Space-Based Multi-Angle Imaging

NASA Technical Reports Server (NTRS)

Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Esselborn, Michael; Fiebig, Marcus; Heese, Birgit; Knippertz, Peter; Mueller, Detlef;

Desert Dust Air Mass Mapping in the Western Sahara, using Particle Properties Derived from Space-based Multi-angle Imaging

NASA Technical Reports Server (NTRS)

Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Fiebig, Marcus; Schladitz, Alexander; von Hoyningen-Huene, Wolfgang

2008-01-01

Coincident observations made over the Moroccan desert during the SAhara Mineral dUst experiMent (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from Multi-angle Imaging SpectroRadiometer (MISR) observations, and to place the sub-orbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days for which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 to 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape, and single-scattering albedo. For the three study days, the satellite observations (a) highlight regional gradients in the mix of dust and background spherical particles, (b) identify a dust plume most likely part of a density flow, and (c) show an air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometers away.

Wildfires Rage in Southern California

NASA Technical Reports Server (NTRS)

2003-01-01

Large plumes of smoke rising from devastating wildfires burning near Los Angeles and San Diego on Sunday, October 26, 2003, are highlighted in this set of images from the Multi-angle Imaging SpectroRadiometer (MISR). These images include a natural color view from MISR's nadir camera (left) and an automated stereo height retrieval (right). The tops of the smoke plumes range in altitude from 500 - 3000 meters, and the stereo retrieval clearly differentiates the smoke from patches of high-altitude cirrus. Plumes are apparent from fires burning near the California-Mexico border, San Diego, Camp Pendleton, the foothills of the San Bernardino Mountains, and in and around Simi Valley. The majority of the smoke is coming from the fires near San Diego and the San Bernardino Mountains.

The Multiangle Imaging Spectro Radiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 20510. The panels cover an area of 329 kilometers x 543 kilometers, and utilize data from blocks 62 to 66 within World Reference System-2 path 40.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Vegetation Canopy Structure from NASA EOS Multiangle Imaging

NASA Astrophysics Data System (ADS)

Chopping, M.; Martonchik, J. V.; Bull, M.; Rango, A.; Schaaf, C. B.; Zhao, F.; Wang, Z.

2008-12-01

We used red band bidirectional reflectance data from the NASA Multiangle Imaging SpectroRadiometer (MISR) and the MODerate resolution Imaging Spectroradiometer (MODIS) mapped onto a 250 m grid in a multiangle approach to obtain estimates of woody plant fractional cover and crown height through adjustment of the mean radius and mean crown aspect ratio parameters of an hybrid geometric-optical (GO) model. We used a technique to rapidly obtain MISR surface reflectance estimates at 275 m resolution through regression on 1 km MISR land surface estimates previously corrected for atmospheric attenuation using MISR aerosol estimates. MISR data were used to make end of dry season maps from 2000-2007 for parts of southern New Mexico, while MODIS data were used to replicate previous results obtained using MISR for June 2002 over large parts of New Mexico and Arizona. We also examined the applicability of this method in Alaskan tundra and forest by adjusting the GO model against MISR data for winter (March 2000) and summer (August 2008) scenes. We found that the GO model crown aspect ratio from MISR followed dominant shrub species distributions in the USDA, ARS Jornada Experimental Range, enabling differentiation of the more spherical crowns of creosotebush (Larrea tridentata) from the more prolate crowns of honey mesquite (Prosopis glandulosa). The measurement limits determined from 2000-2007 maps for a large part of southern New Mexico are ~0.1 in fractional shrub crown cover and ~3 m in mean canopy height (results obtained using data acquired shortly after precipitation events that radically darkened and altered the structure and angular response of the background). Typical standard deviations over the period for 12 sites covering a range of cover types are on the order of 0.05 in crown cover and 2 m in mean canopy height. We found that the GO model can be inverted to retrieve reasonable distributions of canopy parameters in southwestern environments using MODIS V005 red band surface reflectance estimates at ~250 m spatial resolution accumulated over 16 day periods. The MODIS (N=895) and MISR (N=576) estimates of forest height and cover both showed agreement with USDA, Forest Service estimates, with MODIS mean absolute errors (MAE) of 0.09 and 8.4 m respectively; and MISR MAE of 0.10 and 2.2 m, respectively, noting that a sub-optimal background was used for the MODIS inversions. The MODIS and MISR MAE for estimates of aboveground woody biomass via regression against Forest Service estimates were both 10.1 Mg.ha-1. We found that red band MISR data for central Alaska can be used to obtain first-order estimates of forest cover and height using a snow-free summer scene and shrub cover using a winter scene with full snow cover. The GO model inversion results are often physically unrealistic but spatial distributions correspond to high resolution images and reflect the potential for the multiangle/GO method to retrieve meaningful information that is qualitatively different to that obtained using vegetation indices.

Multiangular Contributions for Discriminate Seasonal Structural Changes in the Amazon Rainforest Using MODIS MAIAC Data

NASA Astrophysics Data System (ADS)

Moura, Y. M.; Hilker, T.; Galvão, L. S.; Santos, J. R.; Lyapustin, A.; Sousa, C. H. R. D.; McAdam, E.

2014-12-01

The sensitivity of the Amazon rainforests to climate change has received great attention by the scientific community due to the important role that this vegetation plays in the global carbon, water and energy cycle. The spatial and temporal variability of tropical forests across Amazonia, and their phenological, ecological and edaphic cycles are still poorly understood. The objective of this work was to infer seasonal and spatial variability of forest structure in the Brazilian Amazon based on anisotropy of multi-angle satellite observations. We used observations from the Moderate Resolution Imaging Spectroradiometer (MODIS/Terra and Aqua) processed by a new Multi-Angle Implementation Atmospheric Correction Algorithm (MAIAC) to investigate how multi-angular spectral response from satellite imagery can be used to analyze structural variability of Amazon rainforests. We calculated differences acquired from forward and backscatter reflectance by modeling the bi-directional reflectance distribution function to infer seasonal and spatial changes in vegetation structure. Changes in anisotropy were larger during the dry season than during the wet season, suggesting intra-annual changes in vegetation structure and density. However, there were marked differences in timing and amplitude depending on forest type. For instance differences between reflectance hotspot and darkspot showed more anisotropy in the open Ombrophilous forest than in the dense Ombrophilous forest. Our results show that multi-angle data can be useful for analyzing structural differences in various forest types and for discriminating different seasonal effects within the Amazon basin. Also, multi-angle data could help solve uncertainties about sensitivity of different tropical forest types to light versus rainfall. In conclusion, multi-angular information, as expressed by the anisotropy of spectral reflectance, may complement conventional studies and provide significant improvements over approaches that are based on vegetation indices alone.

Fires in the Australian Capital Territory

NASA Technical Reports Server (NTRS)

2003-01-01

The height and extent of billowing smoke plumes from bushfires near Canberra, the Australian capital, are illustrated by these views from the Multi-angle Imaging SpectroRadiometer (MISR). The images were acquired on January 18, 2003. Never before had fires of this magnitude come so close to Australia's capital. Four people lost their lives and over 500 homes were destroyed, mostly in the southwestern suburbs. Australia's famous Mount Stromlo Observatory, located immediately west of the city, was also incinerated by the fires.

The top panel portrays a natural-color view from MISR's nadir camera, in which the eastern portion of the Australian Capital Territory is located south of a pale, ephemeral lake in the upper left-hand corner (Lake George). Several smoke plumes originate within the eastern part of the Australian Capital Territory, while the major plumes originate to the west of the image area. The Australian Capital Territory and much of New South Wales are completely obscured by the smoke, which is driven by fierce westerly winds and extends eastward to the coast and over the Pacific Ocean.

The lower panel provides a stereoscopically retrieved height field of the clouds and smoke plumes. The greenish areas indicate where smoke plumes extend several kilometers above a bank of patchy stratus clouds below. A few high clouds appear near the bottom of the image. Wind retrievals were excluded from this image in order to generate a smooth and continuous field. Although relative height variations are well-represented here, the inclusion of wind retrievals for this scene reduces the actual cloud height results by 1 to 2 kilometers. Areas where heights could not be retrieved are shown as dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuouslyand every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during Terra orbit 16421. The panels cover an area of 380 kilometers x 253 kilometers, and utilize data from blocks 118 to 120 within World Reference System-2 path 89.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Islands in the Midst of the World

NASA Technical Reports Server (NTRS)

2002-01-01

The Greek islands of the Aegean Sea, scattered across 800 kilometers from north to south and between Greece and western Turkey, are uniquely situated at the intersection of Europe, Asia and Africa. This image from the Multi-angle Imaging SpectroRadiometer includes many of the islands of the East Aegean, Sporades, Cyclades, Dodecanese and Crete, as well as part of mainland Turkey. Many sites important to ancient and modern history can be found here. The largest modern city in the Aegean coast is Izmir, situated about one quarter of the image length from the top, southeast of the large three-pronged island of Lesvos. Izmir can be located as a bright coastal area near the greenish waters of the Izmir Bay, about one quarter of the image length from the top, southeast of Lesvos. The coastal areas around this cosmopolitan Turkish city were a center of Ionian culture from the 11th century BC, and at the top of the image (north of Lesvos), once stood the ancient city of Troy.

The image was acquired before the onset of the winter rains, on September 30, 2001, but dense vegetation is never very abundant in the arid Mediterranean climate. The sharpness and clarity of the view also indicate dry, clear air. Some vegetative changes can be detected between the western or southern islands such as Crete (the large island along the bottom of the image) and those closer to the Turkish coast which appear comparatively green. Volcanic activities are evident by the form of the islands of Santorini. This small group of islands shaped like a broken ring are situated to the right and below image center. Santorini's Thera volcano erupted around 1640 BC, and the rim of the caldera collapsed, forming the shape of the islands as they exist today.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. This natural-color image was acquired by MISR's nadir (vertical-viewing) camera, and is a portion of the data acquired during Terra orbit 9495. The image covers an area of 369 kilometers x 567 kilometers, and utilizes data from blocks 58 to 64 within World Reference System-2 path 181.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Smoke Dispersion Modeling Over Complex Terrain Using High-Resolution Meteorological Data and Satellite Observations: The FireHub Platform

NASA Technical Reports Server (NTRS)

Solomos, S.; Amiridis, V.; Zanis, P.; Gerasopoulos, E.; Sofiou, F. I.; Herekakis, T.; Brioude, J.; Stohl, A.; Kahn, R. A.; Kontoes, C.

2015-01-01

A total number of 20,212 fire hot spots were recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite instrument over Greece during the period 2002e2013. The Fire Radiative Power (FRP) of these events ranged from 10 up to 6000 MW at 1 km resolution, and many of these fire episodes resulted in long-range transport of smoke over distances up to several hundred kilometers. Three different smoke episodes over Greece are analyzed here using real time hot-spot observations from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) satellite instrument as well as from MODIS hot-spots. Simulations of smoke dispersion are performed with the FLEXPART-WRF model and particulate matter emissions are calculated directly from the observed FRP. The modeled smoke plumes are compared with smoke stereo-heights from the Multiangle Imaging Spectroradiometer (MISR) instrument and the sensitivities to atmospheric and modeling parameters are examined. Driving the simulations with high resolution meteorology (4 4 km) and using geostationary satellite data to identify the hot spots allows the description of local scale features that govern smoke dispersion. The long-range transport of smoke is found to be favored over the complex coastline environment of Greece due to the abrupt changes between land and marine planetary boundary layers (PBL) and the decoupling of smoke layers from the surface.

Tropical Storms Bud and Dera

NASA Technical Reports Server (NTRS)

2002-01-01

Like dancers pirouetting in opposite directions, the rotational patterns of two different tropical storms are contrasted in this pair of Multi-angle Imaging Spectroradiometer (MISR) nadir-camera images. The left-hand image is of Tropical Storm Bud, acquired on June 17, 2000 (Terra orbit 2656) as the storm was dissipating. Bud was situated in the eastern Pacific Ocean between Socorro Island and the southern tip of Baja California. South of the storm's center is a vortex pattern caused by obstruction of the prevailing flow by tiny Socorro Island. Sonora, Mexico and Baja California are visible at the top of the image. The right-hand image is of Tropical Cyclone Dera, acquired on March 12, 2001. Dera was located in the Indian Ocean, south of Madagascar. The southern end of this large island is visible in the top portion of this image. Northern hemisphere tropical storms, like Bud, rotate in a counterclockwise direction, whereas those in the southern hemisphere, such as Dera, rotate clockwise. The opposite spins are a consequence of Earth's rotation. Each image covers a swath approximately 380 kilometers wide. Image courtesy NASA/JPL/GSFC/LaRC, MISR Team

Where Europe meets Africa

NASA Technical Reports Server (NTRS)

2005-01-01

Data from a portion of the imagery acquired by the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera during 2000-2002 were combined to create this cloud-free natural-color mosaic of southwestern Europe and northwestern Morocco and Algeria. The image extends from 48oN, 16oW in the northwest to 32oN, 8oE in the southeast. It is displayed in Albers conic equal-area projection (a projection which is frequently used for equal-area maps of regions that are predominantly east-west in extent).

From the northeast, the image traverses a portion of the Swiss Alps (partially snow-covered) and a small part of Italy's Po Valley. The northern portion of the image also includes the western coast of France and much of southern and southwestern France's undulating terrain, which continues until reaching the hills of the Pyrenees. The Pyrenees act as the natural frontier to the Iberian Peninsula -- a landmass comprised of Spain and Portugal. The Peninsular landscapes are extremely varied, with some almost desert-like, others green and fertile. About half of Spain is situated atop a high plain, known as the Central Plateau, and many mountain ranges, rivers, geological basement rock and vegetation types are found across this great plateau. The largest alluvial plain is Andalusia in the south, where the valley of the Guadalquivir River is shut in by mountain ranges on every side except the southwest, where the valley descends to the Atlantic. The islands of Mallorca, Menorca and Ibiza are Spanish territories in the western Mediterranean. At the Strait of Gibralter, Spain and Morocco very nearly kiss, and Morocco appears relatively verdant along its northern coastal corner. The rugged Atlas Mountain ranges traverse northern Algeria and Morocco.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during 2000-2002. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Seasonal Bias of Retrieved Ice Cloud Optical Properties Based on MISR and MODIS Measurements

NASA Astrophysics Data System (ADS)

Wang, Y.; Hioki, S.; Yang, P.; Di Girolamo, L.; Fu, D.

2017-12-01

The precise estimation of two important cloud optical and microphysical properties, cloud particle optical thickness and cloud particle effective radius, is fundamental in the study of radiative energy budget and hydrological cycle. In retrieving these two properties, an appropriate selection of ice particle surface roughness is important because it substantially affects the single-scattering properties. At present, using a predetermined ice particle shape without spatial and temporal variations is a common practice in satellite-based retrieval. This approach leads to substantial uncertainties in retrievals. The cloud radiances measured by each of the cameras of the Multi-angle Imaging SpectroRadiometer (MISR) instrument are used to estimate spherical albedo values at different scattering angles. By analyzing the directional distribution of estimated spherical albedo values, the degree of ice particle surface roughness is estimated. With an optimal degree of ice particle roughness, cloud optical thickness and effective radius are retrieved based on a bi-spectral shortwave technique in conjunction with two Moderate Resolution Imaging Spectroradiometer (MODIS) bands centered at 0.86 and 2.13 μm. The seasonal biases of retrieved cloud optical and microphysical properties, caused by the uncertainties in ice particle roughness, are investigated by using one year of MISR-MODIS fused data.

Quantitative assessment of AOD from 17 CMIP5 models based on satellite-derived AOD over India

DOE Office of Scientific and Technical Information (OSTI.GOV)

Misra, Amit; Kanawade, Vijay P.; Tripathi, Sachchida Nand

Aerosol optical depth (AOD) values from 17 CMIP5 models are compared with Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) derived AODs over India. The objective is to identify the cases of successful AOD simulation by CMIP5 models, considering satellite-derived AOD as a benchmark. Six years of AOD data (2000–2005) from MISR and MODIS are processed to create quality-assured gridded AOD maps over India, which are compared with corresponding maps of 17 CMIP5 models at the same grid resolution. Intercomparison of model and satellite data shows that model-AOD is better correlated with MISR-derived AOD than MODIS. The correlation between model-AOD andmore » MISR-AOD is used to segregate the models into three categories identifying their performance in simulating the AOD over India. Maps of correlation between model-AOD and MISR-/MODIS-AOD are generated to provide quantitative information about the intercomparison. The two sets of data are examined for different seasons and years to examine the seasonal and interannual variation in the correlation coefficients. In conclusion, latitudinal and longitudinal variations in AOD as simulated by models are also examined and compared with corresponding variations observed by satellites.« less

Quantitative assessment of AOD from 17 CMIP5 models based on satellite-derived AOD over India

DOE PAGES

Misra, Amit; Kanawade, Vijay P.; Tripathi, Sachchida Nand

2016-08-03

Aerosol optical depth (AOD) values from 17 CMIP5 models are compared with Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) derived AODs over India. The objective is to identify the cases of successful AOD simulation by CMIP5 models, considering satellite-derived AOD as a benchmark. Six years of AOD data (2000–2005) from MISR and MODIS are processed to create quality-assured gridded AOD maps over India, which are compared with corresponding maps of 17 CMIP5 models at the same grid resolution. Intercomparison of model and satellite data shows that model-AOD is better correlated with MISR-derived AOD than MODIS. The correlation between model-AOD andmore » MISR-AOD is used to segregate the models into three categories identifying their performance in simulating the AOD over India. Maps of correlation between model-AOD and MISR-/MODIS-AOD are generated to provide quantitative information about the intercomparison. The two sets of data are examined for different seasons and years to examine the seasonal and interannual variation in the correlation coefficients. In conclusion, latitudinal and longitudinal variations in AOD as simulated by models are also examined and compared with corresponding variations observed by satellites.« less

Appraising city-scale pollution monitoring capabilities of multi-satellite datasets using portable pollutant monitors

NASA Astrophysics Data System (ADS)

Aliyu, Yahaya A.; Botai, Joel O.

2018-04-01

The retrieval characteristics for a city-scale satellite experiment was explored over a Nigerian city. The study evaluated carbon monoxide and aerosol contents in the city atmosphere. We utilized the MSA Altair 5× gas detector and CW-HAT200 particulate counter to investigate the city-scale monitoring capabilities of satellite pollution observing instruments; atmospheric infrared sounder (AIRS), measurement of pollution in the troposphere (MOPITT), moderate resolution imaging spectroradiometer (MODIS), multi-angle imaging spectroradiometer (MISR) and ozone monitoring instrument (OMI). To achieve this, we employed the Kriging interpolation technique to collocate the satellite pollutant estimations over 19 ground sample sites for the period of 2015-2016. The portable pollutant devices were validated using the WHO air filter sampling model. To determine the city-scale performance of the satellite datasets, performance indicators: correlation coefficient, model efficiency, reliability index and root mean square error, were adopted as measures. The comparative analysis revealed that MOPITT carbon monoxide (CO) and MODIS aerosol optical depth (AOD) estimates are the appropriate satellite measurements for ground equivalents in Zaria, Nigeria. Our findings were within the acceptable limits of similar studies that utilized reference stations. In conclusion, this study offers direction to Nigeria's air quality policy organizers about available alternative air pollution measurements for mitigating air quality effects within its limited resource environment.

Analysis of fine-mode aerosol retrieval capabilities by different passive remote sensing instrument designs.

PubMed

Knobelspiesse, Kirk; Cairns, Brian; Mishchenko, Michael; Chowdhary, Jacek; Tsigaridis, Kostas; van Diedenhoven, Bastiaan; Martin, William; Ottaviani, Matteo; Alexandrov, Mikhail

2012-09-10

Remote sensing of aerosol optical properties is difficult, but multi-angle, multi-spectral, polarimetric instruments have the potential to retrieve sufficient information about aerosols that they can be used to improve global climate models. However, the complexity of these instruments means that it is difficult to intuitively understand the relationship between instrument design and retrieval success. We apply a Bayesian statistical technique that relates instrument characteristics to the information contained in an observation. Using realistic simulations of fine size mode dominated spherical aerosols, we investigate three instrument designs. Two of these represent instruments currently in orbit: the Multiangle Imaging SpectroRadiometer (MISR) and the POLarization and Directionality of the Earths Reflectances (POLDER). The third is the Aerosol Polarimetry Sensor (APS), which failed to reach orbit during recent launch, but represents a viable design for future instruments. The results show fundamental differences between the three, and offer suggestions for future instrument design and the optimal retrieval strategy for current instruments. Generally, our results agree with previous validation efforts of POLDER and airborne prototypes of APS, but show that the MISR aerosol optical thickness uncertainty characterization is possibly underestimated.

Seasonal Surface Changes in Namibia and Central Angola

NASA Technical Reports Server (NTRS)

2003-01-01

Brightness variations in the terrain along a portion of southwestern Africa are displayed in these views from the Multi-angle Imaging SpectroRadiometer (MISR). The panels portray an area that includes Namibia's Skeleton Coast and Etosha National Park as well as Angola's Cuando Cubango. The top panels were acquired on March 6, 2001, during the region's wet season, and the bottom panels were acquired on September 1, 2002, during the dry season. Corresponding changes in the abundance of vegetation are apparent. The images on the left are natural color (red, green, blue) images from MISR's vertical-viewing (nadir) camera. The images on the right represent one of MISR's derived surface products.

The radiance (light intensity) in each pixel of the so-called 'top-of-atmosphere' images on the left includes light that is reflected by the Earth's surface in addition to light that is transmitted and reflected by the atmosphere. The amount of radiation reflected by the surface into all upward directions, as opposed to any single direction, is important when studying Earth's energy budget. A quantity called the surface 'directional hemispherical reflectance' (DHR), sometimes called the 'black-sky albedo', captures this information, and is depicted in the images on the right. MISR's multi-angle views lead to more accurate estimates of the amount of radiation reflected into all directions than can be obtained as a result of looking at a single (e.g., vertically downward) view angle. Furthermore, to generate this surface product accurately, it is necessary to compensate for the effects of the intervening atmosphere, and MISR provides the ability to characterize and account for scattering of light by airborne particulates (aerosols).

The DHR is called a hemispherical reflectance because it measures the amount of radiation reflected into all upward directions, and which therefore traverses an imaginary hemisphere situated above each surface point. The 'directional' part of the name describes the illumination geometry, and indicates that in the absence of an intervening atmosphere, light from the Sun illuminates the surface from a single direction (that is, there is no diffuse skylight, hence the 'black-sky' terminology). The DHR is retrieved over land surfaces in each of MISR's four wavelength bands, and the images on the right are red, green, blue spectral composites. Regions where DHR could not be derived, either due to an inability to retrieve the necessary atmospheric characteristics or due to the presence of clouds, are shown in dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 6466 and 14388. The panels cover an area of about 380 kilometers x 760 kilometers, and utilize data from blocks 102 to 107 within World Reference System-2 path 181.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center,Greenbelt, MD. JPL is a division of the California Institute of Technology.

Smoke from Fires in Southern Mexico

NASA Technical Reports Server (NTRS)

2002-01-01

On May 2, 2002, numerous fires in southern Mexico sent smoke drifting northward over the Gulf of Mexico. These views from the Multi-angle Imaging SpectroRadiometer illustrate the smoke extent over parts of the Gulf and the southern Mexican states of Tabasco, Campeche and Chiapas. At the same time, dozens of other fires were also burning in the Yucatan Peninsula and across Central America. A similar situation occurred in May and June of 1998, when Central American fires resulted in air quality warnings for several U.S. States.

The image on the left is a natural color view acquired by MISR's vertical-viewing (nadir) camera. Smoke is visible, but sunglint in some ocean areas makes detection difficult. The middle image, on the other hand, is a natural color view acquired by MISR's 70-degree backward-viewing camera; its oblique view angle simultaneously suppresses sunglint and enhances the smoke. A map of aerosol optical depth, a measurement of the abundance of atmospheric particulates, is provided on the right. This quantity is retrieved using an automated computer algorithm that takes advantage of MISR's multi-angle capability. Areas where no retrieval occurred are shown in black.

The images each represent an area of about 380 kilometers x 1550 kilometers and were captured during Terra orbit 12616.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Determining Aerosol Plume Height from Two GEO Imagers: Lessons from MISR and GOES

NASA Technical Reports Server (NTRS)

Wu, Dong L.

2012-01-01

Aerosol plume height is a key parameter to determine impacts of particulate matters generated from biomass burning, wind-blowing dust, and volcano eruption. Retrieving cloud top height from stereo imageries from two GOES (Geostationary Operational Environmental Satellites) have been demonstrated since 1970's and the principle should work for aerosol plumes if they are optically thick. The stereo technique has also been used by MISR (Multiangle Imaging SpectroRadiometer) since 2000 that has nine look angles along track to provide aerosol height measurements. Knowing the height of volcano aerosol layers is as important as tracking the ash plume flow for aviation safety. Lack of knowledge about ash plume height during the 2010 Eyja'rjallajokull eruption resulted in the largest air-traffic shutdown in Europe since World War II. We will discuss potential applications of Asian GEO satellites to make stereo measurements for dust and volcano plumes.

April Showers Bring May Flowers to the Southern United States

NASA Technical Reports Server (NTRS)

2004-01-01

Vigorous vegetation growth in the Southern United States after heavy rains fell during April and early May, 2004, is quantified in these images and data products from the Multi-angle Imaging SpectroRadiometer (MISR). The images were acquired on April 1 (top set) and May 3 (bottom set), and extend through Kansas and Missouri, Oklahoma and Arkansas, and eastern Texas, with the Texas-Louisiana border at the bottom right-hand corner.

The left-hand images are natural-color views from MISR's nadir camera. In the month between the April and May images, the overall greenness is enhanced, and the Boston and Ouachita Mountains are transformed from brownish hues to vivid green. The city of Dallas, Texas, appears as the pale gray area at lower left and the Red River (which corresponds with the Texas-Oklahoma border) is apparent as the yellowish feature flowing toward the lower left-hand edge. Scattered clouds appear in the upper right-hand corners of both images. Quantitative values for the vegetation changes are provided by the center and right-hand images. The middle panels show Leaf Area Index (LAI), or the area of leaves per unit area of ground below them, as measured from above. The right-hand panels show FPAR, which is the fraction of the photosynthetically active region (PAR) of visible light (400 - 700 nm) absorbed by green vegetation. LAI and FPAR are two important quantities for monitoring the photosynthetic activity and carbon uptake efficiency of live vegetation. MISR's LAI and FPAR products make use of aerosol retrievals to correct for atmospheric scattering and absorption effects, and use plant canopy structural models to determine the partitioning of solar radiation. Both of these aspects are facilitated by the multiangular nature of the MISR measurements.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 22810 and 23276. The panels cover an area of about 380 kilometers x 704 kilometers, and utilize data from blocks 61 to 65 within World Reference System-2 path 26.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Cloud Spirals and Outflow in Tropical Storm Katrina

NASA Technical Reports Server (NTRS)

2005-01-01

On Tuesday, August 30, 2005, NASA's Multi-angle Imaging SpectroRadiometer retrieved cloud-top heights and cloud-tracked wind velocities for Tropical Storm Katrina, as the center of the storm was situated over the Tennessee valley. At this time Katrina was weakening and no longer classified as a hurricane, and would soon become an extratropical depression. Measurements such as these can help atmospheric scientists compare results of computer-generated hurricane simulations with observed conditions, ultimately allowing them to better represent and understand physical processes occurring in hurricanes.

Because air currents are influenced by the Coriolis force (caused by the rotation of the Earth), Northern Hemisphere hurricanes are characterized by an inward counterclockwise (cyclonic) rotation towards the center. It is less widely known that, at high altitudes, outward-spreading bands of cloud rotate in a clockwise (anticyclonic) direction. The image on the left shows the retrieved cloud-tracked winds as red arrows superimposed across the natural color view from MISR's nadir (vertical-viewing) camera. Both the counter-clockwise motion for the lower-level storm clouds and the clockwise motion for the upper clouds are apparent in these images. The speeds for the clockwise upper level winds have typical values between 40 and 45 m/s (144-162 km/hr). The low level counterclockwise winds have typical values between 7 and 24 m/s (25-86 km/hr), weakening with distance from the storm center. The image on the right displays the cloud-top height retrievals. Areas where cloud heights could not be retrieved are shown in dark gray. Both the wind velocity vectors and the cloud-top height field were produced by automated computer recognition of displacements in spatial features within successive MISR images acquired at different view angles and at slightly different times.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82o north and 82o south latitude every nine days. This image covers an area of about 380 kilometers by 1970 kilometers. These data products were generated from a portion of the imagery acquired during Terra orbit 30324 and utilize data from blocks 55-68 within World Reference System-2 path 22.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology.

Multi-layer Clouds Over the South Indian Ocean

NASA Technical Reports Server (NTRS)

2003-01-01

The complex structure and beauty of polar clouds are highlighted by these images acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on April 23, 2003. These clouds occur at multiple altitudes and exhibit a noticeable cyclonic circulation over the Southern Indian Ocean, to the north of Enderbyland, East Antarctica.

The image at left was created by overlying a natural-color view from MISR's downward-pointing (nadir) camera with a color-coded stereo height field. MISR retrieves heights by a pattern recognition algorithm that utilizes multiple view angles to derive cloud height and motion. The opacity of the height field was then reduced until the field appears as a translucent wash over the natural-color image. The resulting purple, cyan and green hues of this aesthetic display indicate low, medium or high altitudes, respectively, with heights ranging from less than 2 kilometers (purple) to about 8 kilometers (green). In the lower right corner, the edge of the Antarctic coastline and some sea ice can be seen through some thin, high cirrus clouds.

The right-hand panel is a natural-color image from MISR's 70-degree backward viewing camera. This camera looks backwards along the path of Terra's flight, and in the southern hemisphere the Sun is in front of this camera. This perspective causes the cloud-tops to be brightly outlined by the sun behind them, and enhances the shadows cast by clouds with significant vertical structure. An oblique observation angle also enhances the reflection of light by atmospheric particles, and accentuates the appearance of polar clouds. The dark ocean and sea ice that were apparent through the cirrus clouds at the bottom right corner of the nadir image are overwhelmed by the brightness of these clouds at the oblique view.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 17794. The panels cover an area of 335 kilometers x 605 kilometers, and utilize data from blocks 142 to 145 within World Reference System-2 path 155.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Icebergs Adrift in the Amundsen Sea

NASA Technical Reports Server (NTRS)

2002-01-01

The Thwaites Ice Tongue is a large sheet of glacial ice extending from the West Antarctic mainland into the southern Amundsen Sea. A large crack in the Thwaites Tongue was discovered in imagery from Terra's Moderate Resolution Imaging Spectroradiometer (MODIS). Subsequent widening of the crack led to the calving of a large iceberg. The development of this berg, designated B-22 by the National Ice Center, can be observed in these images from the Multi-angle Imaging SpectroRadiometer, also aboard Terra. The two views were acquired by MISR's nadir (vertical-viewing) camera on March 10 and 24, 2002. The B-22 iceberg, located below and to the left of image center, measures approximately 82 kilometers long x 62 kilometers wide. Comparison of the two images shows the berg to have drifted away from the ice shelf edge. The breakup of ice near the shelf edge, in the area surrounding B-22, is also visible in the later image. These natural-color images were acquired during Terra orbits 11843 and 12047, respectively. At the right-hand edge is Pine Island Bay, where the calving of another large iceberg (B-21) occurred in November 2001. B-21 subsequently split into two smaller bergs, both of which are visible to the right of B-22. Antarctic researchers have reported an increase in the frequency of iceberg calvings in recent years. Whether this is the result of a regional climate variation, or connected to the global warming trend, has not yet been established. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

Drought and Burn Scars in Southeastern Australia

NASA Technical Reports Server (NTRS)

2003-01-01

More than 2 million acres were consumed by hundreds of fires between December 2002 and February 2003 in southeastern Australia's national parks, forests, foothills and city suburbs. These images were acquired on February 14, 2002 (left) and February 17, 2003 (right) by the Multi-angle Imaging SpectroRadiometer (MISR) instrument onboard NASA's Terra satellite. The year 2002 was one of Australia's hottest and driest on record, and the acreage burnt during the summer 2002-2003 fire season in Victoria, the Australian Capital Territory and southern New South Wales, is the largest since 1938-1939, when more than 3 million acres were scorched.

The extent of the burnt area and the dry conditions as of February 2003 are indicated by these contrasting false-color views. Both image panels display data from the near-infrared, red and blue spectral bands of MISR's downward-viewing (nadir) camera, as red, green and blue, respectively. This display technique causes healthy vegetation to appear red and burnt areas to show as dark brown. The data displayed from the two dates were processed identically to preserve relative brightness variations. Vegetation changes related to the dry conditions (not related to the brown burn scars) are also indicated in the February 2003 panel, where many previously red areas exhibit instead the pale yellow-brown of the underlying soils and geology. Significant reduction in the surface area of several large and important water bodies are also apparent. The diminished extent of Lake Hume (along the left-hand edge) in the later date provides a good example.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 14999 and 16858. The panels cover an area of about 208 kilometers x 286 kilometers, and utilize data from blocks 118 to 121 within World Reference System-2 path 91.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Quantification of Asian Dust Plume Seasonal Dynamics and Regional Features

NASA Technical Reports Server (NTRS)

Goetz, Michael

2011-01-01

Dust is but one of many aerosols that are analyzed at the Jet Propulsion Laboratory in Pasadena. The purpose of this paper is to describe the process in analyzing and digitizing dust within a source region to better explain the work achieved by my internship. This paper will go over how to view collected data by Multi-angle Imaging SpectroRadiometer (MISR) [1] and the procedure of downloading data to be analyzed. With this data, one can digitize dust plumes using two methods called plume lines and plume polygons with the help of the software MISR INteractive eXplorer (MINX)[3]; thus, the theory of MINX's[3] algorithm and these methods are discussed in detail. Research was gathered from these techniques and emphasis is also focused on the obtained data and results.

Icebergs Adrift in the Amundsen Sea

NASA Technical Reports Server (NTRS)

2002-01-01

The Thwaites Ice Tongue is a large sheet of glacial ice extending from the West Antarctic mainland into the southern Amundsen Sea. A large crack in the Thwaites Tongue was discovered in imagery from Terra's Moderate Resolution Imaging SpectroRadiometer (MODIS). Subsequent widening of the crack led to the calving of a large iceberg. The development of this berg, designated B-22 by the National Ice Center, can be observed in these images from the Multi-angle Imaging SpectroRadiometer, also aboard Terra. The two views were acquired by MISR's nadir (vertical-viewing)camera on March 10 and 24, 2002.

The B-22 iceberg, located below and to the left of image center, measures approximately 82 kilometers long x 62 kilometers wide. Comparison of the two images shows the berg to have drifted away from the ice shelf edge. The breakup of ice near the shelf edge, in the area surrounding B-22, is also visible in the later image.

These natural-color images were acquired during Terra orbits 11843 and 12047, respectively. At the right-hand edge is Pine Island Bay, where the calving of another large iceberg (B-21) occurred in November 2001. B-21 subsequently split into two smaller bergs, both of which are visible to the right of B-22.

Antarctic researchers have reported an increase in the frequency of iceberg calvings in recent years. Whether this is the result of a regional climate variation, or connected to the global warming trend, has not yet been established.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Flooding in the Aftermath of Hurricane Katrina

NASA Technical Reports Server (NTRS)

2005-01-01

These views of the Louisiana and Mississippi regions were acquired before and one day after Katrina made landfall along the Gulf of Mexico coast, and highlight many of the changes to the rivers and vegetation that occurred between the two views. The images were acquired by NASA's Multi-angle Imaging SpectroRadiometer (MISR) on August 14 and August 30, 2005. These multiangular, multispectral false-color composites were created using red band data from MISR's 46o backward and forward-viewing cameras, and near-infrared data from MISR's nadir camera. Such a display causes water bodies and inundated soil to appear in blue and purple hues, and highly vegetated areas to appear bright green. The scene differentiation is a result of both spectral effects (living vegetation is highly reflective at near-infrared wavelengths whereas water is absorbing) and of angular effects (wet surfaces preferentially forward scatter sunlight). The two images were processed identically and extend from the regions of Greenville, Mississippi (upper left) to Mobile Bay, Alabama (lower right).

There are numerous rivers along the Mississippi coast that were not apparent in the pre-Katrina image; the most dramatic of these is a new inlet in the Pascagoula River that was not apparent before Katrina. The post-Katrina flooding along the edges of Lake Pontchartrain and the city of New Orleans is also apparent. In addition, the agricultural lands along the Mississippi floodplain in the upper left exhibit stronger near-infrared brightness before Katrina. After Katrina, many of these agricultural areas exhibit a stronger signal to MISR's oblique cameras, indicating the presence of inundated soil throughout the floodplain. Note that clouds appear in a different spot for each view angle due to a parallax effect resulting from their height above the surface.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82o north and 82o south latitude every nine days. Each image covers an area of about 380 kilometers by 410 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbits 30091 and 30324 and utilize data from blocks 64-67 within World Reference System-2 path 22.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology.

Cloud Arcs in the Western Pacific

NASA Technical Reports Server (NTRS)

2002-01-01

Small cumulus clouds in this natural-color view from the Multi-angle Imaging SpectroRadiometer have formed a distinctive series of quasi-circular arcs. Clues regarding the formation of these arcs can be found by noting that larger clouds exist in the interior of each arc.

The interior clouds are thicker and likely to be more convectively active than the other clouds, causing much of the air near the centers of the arcs to rise. This air spreads out horizontally in all directions as it rises and continues to spread out as it begins to sink back to the surface. This pushes any existing small cumulus clouds away from the central region of convection.

As the air sinks, it also warms, preventing other small clouds from forming, so that the regions just inside the arcs are kept clear. At the arcs, the horizontal flow of sinking air is now quite weak and on meeting the undisturbed air it can rise again slightly -- possibly assisting in the formation of new small cumulus clouds. Although examples of the continuity of air, in which every rising air motion must be compensated by a sinking motion elsewhere, are very common, the degree of organization exhibited here is relatively rare, as the wind field at different altitudes usually disrupts such patterns. The degree of self organization of this cloud image, whereby three or four such circular events form a quasi-periodic pattern, probably also requires a relatively uncommon combination of wind, temperature and humidity conditions for it to occur.

The image was acquired by MISR's nadir camera on March 11, 2002, and is centered west of the Marshall Islands. Enewetak Atoll is discernible through thin cloud as the turquoise band near the right-hand edge of the image.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. This image is a portion of the data acquired during Terra orbit 11863, and covers an area of about 380 kilometers x 345 kilometers. It utilizes data from blocks 80 to 82 within World Reference System-2 path 90.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Satellite retrievals of dust aerosol over the Red Sea and the Persian Gulf (2005-2015)

NASA Astrophysics Data System (ADS)

Banks, Jamie R.; Brindley, Helen E.; Stenchikov, Georgiy; Schepanski, Kerstin

2017-03-01

The inter-annual variability of the dust aerosol presence over the Red Sea and the Persian Gulf is analysed over the period 2005-2015. Particular attention is paid to the variation in loading across the Red Sea, which has previously been shown to have a strong, seasonally dependent latitudinal gradient. Over the 11 years considered, the July mean 630 nm aerosol optical depth (AOD) derived from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) varies between 0.48 and 1.45 in the southern half of the Red Sea. In the north, the equivalent variation is between 0.22 and 0.66. The temporal and spatial pattern of variability captured by SEVIRI is also seen in AOD retrievals from the MODerate Imaging Spectroradiometer (MODIS), but there is a systematic offset between the two records. Comparisons of both sets of retrievals with ship- and land-based AERONET measurements show a high degree of correlation with biases of < 0.08. However, these comparisons typically only sample relatively low aerosol loadings. When both records are stratified by AOD retrievals from the Multi-angle Imaging SpectroRadiometer (MISR), opposing behaviour is revealed at high MISR AODs ( > 1), with offsets of +0.19 for MODIS and -0.06 for SEVIRI. Similar behaviour is also seen over the Persian Gulf. Analysis of the scattering angles at which retrievals from the SEVIRI and MODIS measurements are typically performed in these regions suggests that assumptions concerning particle sphericity may be responsible for the differences seen.

Characterizing error distributions for MISR and MODIS optical depth data

NASA Astrophysics Data System (ADS)

Paradise, S.; Braverman, A.; Kahn, R.; Wilson, B.

2008-12-01

The Multi-angle Imaging SpectroRadiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's EOS satellites collect massive, long term data records on aerosol amounts and particle properties. MISR and MODIS have different but complementary sampling characteristics. In order to realize maximum scientific benefit from these data, the nature of their error distributions must be quantified and understood so that discrepancies between them can be rectified and their information combined in the most beneficial way. By 'error' we mean all sources of discrepancies between the true value of the quantity of interest and the measured value, including instrument measurement errors, artifacts of retrieval algorithms, and differential spatial and temporal sampling characteristics. Previously in [Paradise et al., Fall AGU 2007: A12A-05] we presented a unified, global analysis and comparison of MISR and MODIS measurement biases and variances over lives of the missions. We used AErosol RObotic NETwork (AERONET) data as ground truth and evaluated MISR and MODIS optical depth distributions relative to AERONET using simple linear regression. However, AERONET data are themselves instrumental measurements subject to sources of uncertainty. In this talk, we discuss results from an improved analysis of MISR and MODIS error distributions that uses errors-in-variables regression, accounting for uncertainties in both the dependent and independent variables. We demonstrate on optical depth data, but the method is generally applicable to other aerosol properties as well.

A Multi-Year Aerosol Characterization for the Greater Tehran Area Using Satellite, Surface, and Modeling Data

PubMed Central

Crosbie, Ewan; Sorooshian, Armin; Monfared, Negar Abolhassani; Shingler, Taylor; Esmaili, Omid

2014-01-01

This study reports a multi-year (2000–2009) aerosol characterization for metropolitan Tehran and surrounding areas using multiple datasets (Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging Spectroradiometer (MISR), Total Ozone Mapping Spectrometer (TOMS), Goddard Ozone Chemistry Aerosol Radiation and Transport (GOCART), and surface and upper air data from local stations). Monthly trends in aerosol characteristics are examined in the context of the local meteorology, regional and local emission sources, and air mass back-trajectory data. Dust strongly affects the region during the late spring and summer months (May–August) when aerosol optical depth (AOD) is at its peak and precipitation accumulation is at a minimum. In addition, the peak AOD that occurs in July is further enhanced by a substantial number of seasonal wildfires in upwind regions. Conversely, AOD is at a minimum during winter; however, reduced mixing heights and a stagnant lower atmosphere trap local aerosol emissions near the surface and lead to significant reductions in visibility within Tehran. The unique meteorology and topographic setting makes wintertime visibility and surface aerosol concentrations particularly sensitive to local anthropogenic sources and is evident in the noteworthy improvement in visibility observed on weekends. Scavenging of aerosol due to precipitation is evident during the winter when aconsistent increase in surface visibility and concurrent decrease in AOD is observed in the days after rain compared with the days immediately before rain. PMID:25083295

Top-down estimate of dust emissions through integration of MODIS and MISR aerosol retrievals with the GEOS-Chem adjoint model

NASA Astrophysics Data System (ADS)

Wang, Jun; Xu, Xiaoguang; Henze, Daven K.; Zeng, Jing; Ji, Qiang; Tsay, Si-Chee; Huang, Jianping

2012-04-01

Predicting the influences of dust on atmospheric composition, climate, and human health requires accurate knowledge of dust emissions, but large uncertainties persist in quantifying mineral sources. This study presents a new method for combined use of satellite-measured radiances and inverse modeling to spatially constrain the amount and location of dust emissions. The technique is illustrated with a case study in May 2008; the dust emissions in Taklimakan and Gobi deserts are spatially optimized using the GEOS-Chem chemical transport model and its adjoint constrained by aerosol optical depth (AOD) that are derived over the downwind dark-surface region in China from MODIS (Moderate Resolution Imaging Spectroradiometer) reflectance with the aerosol single scattering properties consistent with GEOS-chem. The adjoint inverse modeling yields an overall 51% decrease in prior dust emissions estimated by GEOS-Chem over the Taklimakan-Gobi area, with more significant reductions south of the Gobi Desert. The model simulation with optimized dust emissions shows much better agreement with independent observations from MISR (Multi-angle Imaging SpectroRadiometer) AOD and MODIS Deep Blue AOD over the dust source region and surface PM10 concentrations. The technique of this study can be applied to global multi-sensor remote sensing data for constraining dust emissions at various temporal and spatial scales, and hence improving the quantification of dust effects on climate, air quality, and human health.

Trend analysis of the aerosol optical depth from fusion of MISR and MODIS retrievals over China

NASA Astrophysics Data System (ADS)

Guo, Jing; Gu, Xingfa; Yu, Tao; Cheng, Tianhai; Chen, Hao

2014-03-01

Atmospheric aerosol plays an important role in the climate change though direct and indirect processes. In order to evaluate the effects of aerosols on climate, it is necessary to have a research on their spatial and temporal distributions. Satellite aerosol remote sensing is a developing technology that may provide good temporal sampling and superior spatial coverage to study aerosols. The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) have provided aerosol observations since 2000, with large coverage and high accuracy. However, due to the complex surface, cloud contamination, and aerosol models used in the retrieving process, the uncertainties still exist in current satellite aerosol products. There are several observed differences in comparing the MISR and MODIS AOD data with the AERONET AOD. Combing multiple sensors could reduce uncertainties and improve observational accuracy. The validation results reveal that a better agreement between fusion AOD and AERONET AOD. The results confirm that the fusion AOD values are more accurate than single sensor. We have researched the trend analysis of the aerosol properties over China based on nine-year (2002-2010) fusion data. Compared with trend analysis in Jingjintang and Yangtze River Delta, the accuracy has increased by 5% and 3%, respectively. It is obvious that the increasing trend of the AOD occurred in Yangtze River Delta, where human activities may be the main source of the increasing AOD.

Top-down Estimate of Dust Emissions Through Integration of MODIS and MISR Aerosol Retrievals With the Geos-chem Adjoint Model

NASA Technical Reports Server (NTRS)

Wang, Jun; Xu, Xiaoguang; Henze, Daven K.; Zeng, Jing; Ji, Qiang; Tsay, Si-Chee; Huang, Jianping

2012-01-01

Predicting the influences of dust on atmospheric composition, climate, and human health requires accurate knowledge of dust emissions, but large uncertainties persist in quantifying mineral sources. This study presents a new method for combined use of satellite-measured radiances and inverse modeling to spatially constrain the amount and location of dust emissions. The technique is illustrated with a case study in May 2008; the dust emissions in Taklimakan and Gobi deserts are spatially optimized using the GEOSChem chemical transport model and its adjoint constrained by aerosol optical depth (AOD) that are derived over the downwind dark-surface region in China from MODIS (Moderate Resolution Imaging Spectroradiometer) reflectance with the aerosol single scattering properties consistent with GEOS-chem. The adjoint inverse modeling yields an overall 51% decrease in prior dust emissions estimated by GEOS-Chem over the Taklimakan-Gobi area, with more significant reductions south of the Gobi Desert. The model simulation with optimized dust emissions shows much better agreement with independent observations from MISR (Multi-angle Imaging SpectroRadiometer) AOD and MODIS Deep Blue AOD over the dust source region and surface PM10 concentrations. The technique of this study can be applied to global multi-sensor remote sensing data for constraining dust emissions at various temporal and spatial scales, and hence improving the quantification of dust effects on climate, air quality, and human health.

Sensitivity of Multiangle Imaging to the Optical and Microphysical Properties of Biomass Burning Aerosols

NASA Technical Reports Server (NTRS)

Chen, Wei-Ting; Kahn, Ralph A.; Nelson, David; Yau, Kevin; Seinfeld, John H.

2008-01-01

The treatment of biomass burning (BB) carbonaceous particles in the Multiangle Imaging SpectroRadiometer (MISR) Standard Aerosol Retrieval Algorithm is assessed, and algorithm refinements are suggested, based on a theoretical sensitivity analysis and comparisons with near-coincident AERONET measurements at representative BB sites. Over the natural ranges of BB aerosol microphysical and optical properties observed in past field campaigns, patterns of retrieved Aerosol Optical Depth (AOD), particle size, and single scattering albedo (SSA) are evaluated. On the basis of the theoretical analysis, assuming total column AOD of 0.2, over a dark, uniform surface, MISR can distinguish two to three groups in each of size and SSA, except when the assumed atmospheric particles are significantly absorbing (mid-visible SSA approx.0.84), or of medium sizes (mean radius approx.0.13 pin); sensitivity to absorbing, medium-large size particles increases considerably when the assumed column AOD is raised to 0.5. MISR Research Aerosol Retrievals confirm the theoretical results, based on coincident AERONET inversions under BB-dominated conditions. When BB is externally mixed with dust in the atmosphere, dust optical model and surface reflection uncertainties, along with spatial variability, contribute to differences between the Research Retrievals and AERONET. These results suggest specific refinements to the MISR Standard Aerosol Algorithm complement of component particles and mixtures. They also highlight the importance for satellite aerosol retrievals of surface reflectance characterization, with accuracies that can be difficult to achieve with coupled surface-aerosol algorithms in some higher AOD situations.

Stereoscopic Retrieval of Smoke Plume Heights and Motion from Space-Based Multi-Angle Imaging, Using the MISR INteractive eXplorer(MINX)

NASA Technical Reports Server (NTRS)

Nelson, David L.; Kahn, Ralph A.

2014-01-01

Airborne particles desert dust, wildfire smoke, volcanic effluent, urban pollution affect Earth's climate as well as air quality and health. They are found in the atmosphere all over the planet, but vary immensely in amount and properties with season and location. Most aerosol particles are injected into the near-surface boundary layer, but some, especially wildfire smoke, desert dust and volcanic ash, can be injected higher into the atmosphere, where they can stay aloft longer, travel farther, produce larger climate effects, and possibly affect human and ecosystem health far downwind. So monitoring aerosol injection height globally can make important contributions to climate science and air quality studies. The Multi-angle Imaging Spectro-Radiometer (MISR) is a space borne instrument designed to study Earths clouds, aerosols, and surface. Since late February 2000 it has been retrieving aerosol particle amount and properties, as well as cloud height and wind data, globally, about once per week. The MINX visualization and analysis tool complements the operational MISR data products, enabling users to retrieve heights and winds locally for detailed studies of smoke plumes, at higher spatial resolution and with greater precision than the operational product and other space-based, passive remote sensing techniques. MINX software is being used to provide plume height statistics for climatological studies as well as to investigate the dynamics of individual plumes, and to provide parameterizations for climate modeling.

Self-Organizing-Map Program for Analyzing Multivariate Data

NASA Technical Reports Server (NTRS)

Li, P. Peggy; Jacob, Joseph C.; Block, Gary L.; Braverman, Amy J.

2005-01-01

SOM_VIS is a computer program for analysis and display of multidimensional sets of Earth-image data typified by the data acquired by the Multi-angle Imaging Spectro-Radiometer [MISR (a spaceborne instrument)]. In SOM_VIS, an enhanced self-organizing-map (SOM) algorithm is first used to project a multidimensional set of data into a nonuniform three-dimensional lattice structure. The lattice structure is mapped to a color space to obtain a color map for an image. The Voronoi cell-refinement algorithm is used to map the SOM lattice structure to various levels of color resolution. The final result is a false-color image in which similar colors represent similar characteristics across all its data dimensions. SOM_VIS provides a control panel for selection of a subset of suitably preprocessed MISR radiance data, and a control panel for choosing parameters to run SOM training. SOM_VIS also includes a component for displaying the false-color SOM image, a color map for the trained SOM lattice, a plot showing an original input vector in 36 dimensions of a selected pixel from the SOM image, the SOM vector that represents the input vector, and the Euclidean distance between the two vectors.

Coordinated Airborne, Spaceborne, and Ground-Based Measurements of Massive, Thick Aerosol Layers During the Dry Season in Southern Africa

NASA Technical Reports Server (NTRS)

Schmid, B.; Redemann, J.; Russell, P. B.; Hobbs, P. V.; Hlavka, D. L.; McGill, M. J.; Holben, B. N.; Welton, E. J.; Campbell, J.; Torres, O.;

MISR CMVs and Multiangular Views of Tropical Cyclone Inner-Core Dynamics

NASA Technical Reports Server (NTRS)

Wu, Dong L.; Diner, David J.; Garay, Michael J; Jovanovic, Veljko M.; Lee, Jae N.; Moroney, Catherine M.; Mueller, Kevin J.; Nelson, David L.

2010-01-01

Multi-camera stereo imaging of cloud features from the MISR (Multiangle Imaging SpectroRadiometer) instrument on NASA's Terra satellite provides accurate and precise measurements of cloud top heights (CTH) and cloud motion vector (CMV) winds. MISR observes each cloudy scene from nine viewing angles (Nadir, +/-26(sup o), +/-46(sup o), +/-60(sup o), +/-70(sup o)) with approximatel 275-m pixel resolution. This paper provides an update on MISR CMV and CTH algorithm improvements, and explores a high-resolution retrieval of tangential winds inside the eyewall of tropical cyclones (TC). The MISR CMV and CTH retrievals from the updated algorithm are significantly improved in terms of spatial coverage and systematic errors. A new product, the 1.1-km cross-track wind, provides high accuracy and precision in measuring convective outflows. Preliminary results obtained from the 1.1-km tangential wind retrieval inside the TC eyewall show that the inner-core rotation is often faster near the eyewall, and this faster rotation appears to be related linearly to cyclone intensity.

[The research on bidirectional reflectance computer simulation of forest canopy at pixel scale].

PubMed

Song, Jin-Ling; Wang, Jin-Di; Shuai, Yan-Min; Xiao, Zhi-Qiang

2009-08-01

Computer simulation is based on computer graphics to generate the realistic 3D structure scene of vegetation, and to simulate the canopy regime using radiosity method. In the present paper, the authors expand the computer simulation model to simulate forest canopy bidirectional reflectance at pixel scale. But usually, the trees are complex structures, which are tall and have many branches. So there is almost a need for hundreds of thousands or even millions of facets to built up the realistic structure scene for the forest It is difficult for the radiosity method to compute so many facets. In order to make the radiosity method to simulate the forest scene at pixel scale, in the authors' research, the authors proposed one idea to simplify the structure of forest crowns, and abstract the crowns to ellipsoids. And based on the optical characteristics of the tree component and the characteristics of the internal energy transmission of photon in real crown, the authors valued the optical characteristics of ellipsoid surface facets. In the computer simulation of the forest, with the idea of geometrical optics model, the gap model is considered to get the forest canopy bidirectional reflectance at pixel scale. Comparing the computer simulation results with the GOMS model, and Multi-angle Imaging SpectroRadiometer (MISR) multi-angle remote sensing data, the simulation results are in agreement with the GOMS simulation result and MISR BRF. But there are also some problems to be solved. So the authors can conclude that the study has important value for the application of multi-angle remote sensing and the inversion of vegetation canopy structure parameters.

Southern Quebec in Late Winter

NASA Technical Reports Server (NTRS)

2002-01-01

These images of Canada's Quebec province were acquired by the Multi-angle Imaging SpectroRadiometer on March 4, 2001. The region's forests are a mixture of coniferous and hardwood trees, and 'sugar-shack' festivities are held at this time of year to celebrate the beginning of maple syrup production. The large river visible in the images is the northeast-flowing St. Lawrence. The city of Montreal is located near the lower left corner, and Quebec City, at the upper right, is near the mouth of the partially ice-covered St. Lawrence Seaway.

Both spectral and angular information are retrieved for every scene observed by MISR. The left-hand image was acquired by the instrument's vertical-viewing (nadir) camera, and is a false-color spectral composite from the near-infrared, red, and blue bands. The right-hand image is a false-color angular composite using red band data from the 60-degree backward-viewing, nadir, and 60-degree forward-viewing cameras. In each case, the individual channels of data are displayed as red, green, and blue, respectively.

Much of the ground remains covered or partially covered with snow. Vegetation appears red in the left-hand image because of its high near-infrared brightness. In the multi-angle composite, vegetated areas appear in shades of green because they are brighter at nadir, possibly as a result of an underlying blanket of snow which is more visible from this direction. Enhanced forward scatter from the smooth water surface results in bluer hues, whereas urban areas look somewhat orange, possibly due to the effect of vertical structures which preferentially backscatter sunlight.

The data were acquired during Terra orbit 6441, and cover an area measuring 275 kilometers x 310 kilometers.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Typhoon Sinlaku

NASA Technical Reports Server (NTRS)

2002-01-01

One of the more destructive cyclones to emerge from the northern hemisphere 2002 summer storm season was Typhoon Sinlaku. Several attributes of this storm event are portrayed in these data products from the Multi-angle Imaging SpectroRadiometer. The images were acquired on September 5, when the western portion of the storm was situated over the Okinawan island chain. Over the next few days it moved west-northwest, sweeping over Taiwan before making landfall along China's Zhejian province on the 7th. The typhoon forced hundreds of thousands of people from their homes, caused major power outages, and at least 26 people were reported dead or missing before the storm weakened as it moved inland.

While the nature and formation of individual storm events is relatively well understood, the influence of clouds on climate is difficult to assess due to the variable nature of cloud cover at various altitudes. MISR's data products are designed to help understand these influences. Typhoon Sinlaku is shown at left as a natural-color view observed by MISR's vertical-viewing (nadir)camera. The center panel shows the cloud-top height field derived using automated stereoscopic processing of data from multiple MISR cameras. Relative height variations, such as the clearing within the storm's eye, are well represented. Areas where heights could not be retrieved are shown in dark gray.

Clouds have a significant influence on the global radiation balance of the Earth's atmosphere, and the improvement of climate models requires more accurate information on how different types of clouds influence Earth's energy budget. One measure of this influence is albedo, which is the amount of sunlight reflected back to space divided by amount of incident sunlight. Bright objects have high albedo. Retrieved local albedo values for Typhoon Sinlaku are shown at right. Generation of this product is dependent on observed cloud radiances as a function of viewing angle and the cloud height field. Over the short distances (2.2 kilometers) that MISR's local albedo product is generated, values can be greater than 1.0 due to the contributions from the sides of the clouds. Areas where albedo could not be retrieved are shown in dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. This image is a portion of the data acquired during Terra orbit 14442, and covers an area of about 380 kilometers x 1408 kilometers. It utilizes data from blocks 65 to 74 within World Reference System-2 path 113.

Quantifying the radiative and microphysical impacts of fire aerosols on cloud dynamics in the tropics using temporally offset satellite observations

NASA Astrophysics Data System (ADS)

Tosca, M. G.; Diner, D. J.; Garay, M. J.; Kalashnikova, O.

2013-12-01

Anthropogenic fires in Southeast Asia and Central America emit smoke that affects cloud dynamics, meteorology, and climate. We measured the cloud response to direct and indirect forcing from biomass burning aerosols using aerosol retrievals from the Multi-angle Imaging SpectroRadiometer (MISR) and non-synchronous cloud retrievals from the MODerate resolution Imaging Spectroradiometer (MODIS) from collocated morning and afternoon overpasses. Level 2 data from thirty-one individual scenes acquired between 2006 and 2010 were used to quantify changes in cloud fraction, cloud droplet size, cloud optical depth and cloud top temperature from morning (10:30am local time) to afternoon (1:30pm local time) in the presence of varying aerosol burdens. We accounted for large-scale meteorological differences between scenes by normalizing observed changes to the mean difference per individual scene. Elevated AODs reduced cloud fraction and cloud droplet size and increased cloud optical depths in both Southeast Asia and Central America. In mostly cloudy regions, aerosols significantly reduced cloud fraction and cloud droplet sizes, but in clear skies, cloud fraction, cloud optical thickness and cloud droplet sizes increased. In clouds with vertical development, aerosols reduced cloud fraction via semi-direct effects but spurred cloud growth via indirect effects. These results imply a positive feedback loop between anthropogenic burning and cloudiness in both Central America and Southeast Asia, and are consistent with previous studies linking smoke aerosols to both cloud reduction and convective invigoration.

Determination of Ice Cloud Models Using MODIS and MISR Data

NASA Technical Reports Server (NTRS)

Xie, Yu; Yang, Ping; Kattawar, George W.; Minnis, Patrick; Hu, Yongxiang; Wu, Dong L.

2012-01-01

Representation of ice clouds in radiative transfer simulations is subject to uncertainties associated with the shapes and sizes of ice crystals within cirrus clouds. In this study, we examined several ice cloud models consisting of smooth, roughened, homogeneous and inhomogeneous hexagonal ice crystals with various aspect ratios. The sensitivity of the bulk scattering properties and solar reflectances of cirrus clouds to specific ice cloud models is investigated using the improved geometric optics method (IGOM) and the discrete ordinates radiative transfer (DISORT) model. The ice crystal habit fractions in the ice cloud model may significantly affect the simulations of cloud reflectances. A new algorithm was developed to help determine an appropriate ice cloud model for application to the satellite-based retrieval of ice cloud properties. The ice cloud particle size retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) data, collocated with Multi-angle Imaging Spectroradiometer (MISR) observations, is used to infer the optical thicknesses of ice clouds for nine MISR viewing angles. The relative differences between view-dependent cloud optical thickness and the averaged value over the nine MISR viewing angles can vary from -0.5 to 0.5 and are used to evaluate the ice cloud models. In the case for 2 July 2009, the ice cloud model with mixed ice crystal habits is the best fit to the observations (the root mean square (RMS) error of cloud optical thickness reaches 0.365). This ice cloud model also produces consistent cloud property retrievals for the nine MISR viewing configurations within the measurement uncertainties.

Detecting Thin Cirrus in Multiangle Imaging Spectroradiometer Aerosol Retrievals

NASA Technical Reports Server (NTRS)

Pierce, Jeffrey R.; Kahn, Ralph A.; Davis, Matt R.; Comstock, Jennifer M.

2010-01-01

Thin cirrus clouds (optical depth (OD) < 03) are often undetected by standard cloud masking in satellite aerosol retrieval algorithms. However, the Mu]tiangle Imaging Spectroradiometer (MISR) aerosol retrieval has the potential to discriminate between the scattering phase functions of cirrus and aerosols, thus separating these components. Theoretical tests show that MISR is sensitive to cirrus OD within Max{0.05 1 20%l, similar to MISR's sensitivity to aerosol OD, and MISR can distinguish between small and large crystals, even at low latitudes, where the range of scattering angles observed by MISR is smallest. Including just two cirrus components in the aerosol retrieval algorithm would capture typical MISR sensitivity to the natural range of cinus properties; in situations where cirrus is present but the retrieval comparison space lacks these components, the retrieval tends to underestimate OD. Generally, MISR can also distinguish between cirrus and common aerosol types when the proper cirrus and aerosol optical models are included in the retrieval comparison space and total column OD is >-0.2. However, in some cases, especially at low latitudes, cirrus can be mistaken for some combinations of dust and large nonabsorbing spherical aerosols, raising a caution about retrievals in dusty marine regions when cirrus is present. Comparisons of MISR with lidar and Aerosol Robotic Network show good agreement in a majority of the cases, but situations where cirrus clouds have optical depths >0.15 and are horizontally inhomogeneous on spatial scales shorter than 50 km pose difficulties for cirrus retrieval using the MISR standard aerosol algorithm..

MISR Instrument Data Visualization

NASA Technical Reports Server (NTRS)

Nelson, David; Garay, Michael; Diner, David; Thompson, Charles; Hall, Jeffrey; Rheingans, Brian; Mazzoni, Dominic

2008-01-01

The MISR Interactive eXplorer (MINX) software functions both as a general-purpose tool to visualize Multiangle Imaging SpectroRadiometer (MISR) instrument data, and as a specialized tool to analyze properties of smoke, dust, and volcanic plumes. It includes high-level options to create map views of MISR orbit locations; scrollable, single-camera RGB (red-greenblue) images of MISR level 1B2 (L1B2) radiance data; and animations of the nine MISR camera images that provide a 3D perspective of the scenes that MISR has acquired. NASA Tech Briefs, September 2008 55 The plume height capability provides an accurate estimate of the injection height of plumes that is needed by air quality and climate modelers. MISR provides global high-quality stereo height information, and this program uses that information to perform detailed height retrievals of aerosol plumes. Users can interactively digitize smoke, dust, or volcanic plumes and automatically retrieve heights and winds, and can also archive MISR albedos and aerosol properties, as well as fire power and brightness temperatures associated with smoke plumes derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data. Some of the specialized options in MINX enable the user to do other tasks. Users can display plots of top-of-atmosphere bidirectional reflectance factors (BRFs) versus camera-angle for selected pixels. Images and animations can be saved to disk in various formats. Also, users can apply a geometric registration correction to warp camera images when the standard processing correction is inadequate. It is possible to difference the images of two MISR orbits that share a path (identical ground track), as well as to construct pseudo-color images by assigning different combinations of MISR channels (angle or spectral band) to the RGB display channels. This software is an interactive application written in IDL and compiled into an IDL Virtual Machine (VM) ".sav" file.

Stereoscopic Height and Wind Retrievals for Aerosol Plumes with the MISR INteractive eXplorer (MINX)

NASA Technical Reports Server (NTRS)

Nelson, D.L.; Garay, M.J.; Kahn, Ralph A.; Dunst, Ben A.

2013-01-01

The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the Terra satellite acquires imagery at 275-m resolution at nine angles ranging from 0deg (nadir) to 70deg off-nadir. This multi-angle capability facilitates the stereoscopic retrieval of heights and motion vectors for clouds and aerosol plumes. MISR's operational stereo product uses this capability to retrieve cloud heights and winds for every satellite orbit, yielding global coverage every nine days. The MISR INteractive eXplorer (MINX) visualization and analysis tool complements the operational stereo product by providing users the ability to retrieve heights and winds locally for detailed studies of smoke, dust and volcanic ash plumes, as well as clouds, at higher spatial resolution and with greater precision than is possible with the operational product or with other space-based, passive, remote sensing instruments. This ability to investigate plume geometry and dynamics is becoming increasingly important as climate and air quality studies require greater knowledge about the injection of aerosols and the location of clouds within the atmosphere. MINX incorporates features that allow users to customize their stereo retrievals for optimum results under varying aerosol and underlying surface conditions. This paper discusses the stereo retrieval algorithms and retrieval options in MINX, and provides appropriate examples to explain how the program can be used to achieve the best results.

Sensitivity analysis of observed reflectivity to ice particle surface roughness using MISR satellite observations

NASA Astrophysics Data System (ADS)

Bell, A.; Hioki, S.; Wang, Y.; Yang, P.; Di Girolamo, L.

2016-12-01

Previous studies found that including ice particle surface roughness in forward light scattering calculations significantly reduces the differences between observed and simulated polarimetric and radiometric observations. While it is suggested that some degree of roughness is desirable, the appropriate degree of surface roughness to be assumed in operational cloud property retrievals and the sensitivity of retrieval products to this assumption remains uncertain. In an effort to extricate this ambiguity, we will present a sensitivity analysis of space-borne multi-angle observations of reflectivity, to varying degrees of surface roughness. This process is two fold. First, sampling information and statistics of Multi-angle Imaging SpectroRadiometer (MISR) sensor data aboard the Terra platform, will be used to define the most coming viewing observation geometries. Using these defined geometries, reflectivity will be simulated for multiple degrees of roughness using results from adding-doubling radiative transfer simulations. Sensitivity of simulated reflectivity to surface roughness can then be quantified, thus yielding a more robust retrieval system. Secondly, sensitivity of the inverse problem will be analyzed. Spherical albedo values will be computed by feeding blocks of MISR data comprising cloudy pixels over ocean into the retrieval system, with assumed values of surface roughness. The sensitivity of spherical albedo to the inclusion of surface roughness can then be quantified, and the accuracy of retrieved parameters can be determined.

Altering rainfall patterns through aerosol dispersion

NASA Astrophysics Data System (ADS)

Emetere, M. E.; Bakeko, M.; Onyechekwa, L.; Ayara, W.

2017-05-01

The possibility of recirculation mechanism on rainfall patterns is salient for sustenance of the human race through agricultural produce. The peculiarity of the lower atmosphere of south west region of Nigeria was explored using theoretical and experimental approach. In the theoretical approach, the reconstruction of 1D model as an extraction from the 3D aerosol dispersion model was used to examine the physics of the recirculation theory. The experimental approach which consists of obtaining dataset from ground instruments was used to provide on-site guide for developing the new recirculation theories. The data set was obtained from the Davis weather station, Nigeria Meteorological agency and Multi-angle Imaging Spectro-radiometer (MISR). We looked at the main drivers of recirculation and propounded that recirculation is a complex process which triggers a reordering of the mixing layer- a key factor for initiating the type of rainfall in this region.

A new multi-angle remote sensing framework for scaling vegetation properties from tower-based spectro-radiometers to next generation "CubeSat"-satellites.

NASA Astrophysics Data System (ADS)

Hilker, T.; Hall, F. G.; Dyrud, L. P.; Slagowski, S.

2014-12-01

Frequent earth observations are essential for assessing the risks involved with global climate change, its feedbacks on carbon, energy and water cycling and consequences for live on earth. Often, satellite-remote sensing is the only practical way to provide such observations at comprehensive spatial scales, but relationships between land surface parameters and remotely sensed observations are mostly empirical and cannot easily be scaled across larger areas or over longer time intervals. For instance, optically based methods frequently depend on extraneous effects that are unrelated to the surface property of interest, including the sun-server geometry or background reflectance. As an alternative to traditional, mono-angle techniques, multi-angle remote sensing can help overcome some of these limitations by allowing vegetation properties to be derived from comprehensive reflectance models that describe changes in surface parameters based on physical principles and radiative transfer theory. Recent results have shown in theoretical and experimental research that multi-angle techniques can be used to infer and scale the photosynthetic rate of vegetation, its biochemical and structural composition robustly from remote sensing. Multi-angle remote sensing could therefore revolutionize estimates of the terrestrial carbon uptake as scaling of primary productivity may provide a quantum leap in understanding the spatial and temporal complexity of terrestrial earth science. Here, we introduce a framework of next generation tower-based instruments to a novel and unique constellation of nano-satellites (Figure 1) that will allow us to systematically scale vegetation parameters from stand to global levels. We provide technical insights, scientific rationale and present results. We conclude that future earth observation from multi-angle satellite constellations, supported by tower based remote sensing will open new opportunities for earth system science and earth system modeling.

Western United States beyond the Four Corners

NASA Technical Reports Server (NTRS)

2002-01-01

The breathtaking beauty of the western United States is apparent in this image from the Multi-angle Imaging SpectroRadiometer on NASA's Terra spacecraft. Data from 16 different swaths acquired between April 2000 and September 2001by MISR's vertical-viewing (nadir) camera were used to create this cloud-free natural-color image mosaic. The image is draped over a 100-meter (328-foot)shaded relief Digital Terrain Elevation Model from the United States Geological Survey.

Among the prominent features are the snow-capped Rocky Mountains traversing Montana, Wyoming, Colorado and New Mexico. In the northern portion of the image, the Columbia Plateau stretches across Washington, Oregon and Idaho. Many major rivers originate in this region, including the Missouri to the east of the Continental Divide, the Snake to the west, and the Colorado which wends across Utah and Arizona. The Colorado Plateau and vibrant red-colored rocks of the Painted Desert extend south from Utah into Arizona. In the southwestern portion of the image, California's San Joaquin Valley and the Mojave Desert of California and Nevada give way to the Los Angeles basin and the Pacific Ocean.

The Terra spacecraft is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.

Distinguishing Clouds from Ice over the East Siberian Sea, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

As a consequence of its capability to retrieve cloud-top elevations, stereoscopic observations from the Multi-angle Imaging SpectroRadiometer (MISR) can discriminate clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya Sibir, are portrayed in these views from data acquired on May 28, 2002.

The left-hand image is a natural color view from MISR's nadir camera. On the right is a height field retrieved using automated computer processing of data from multiple MISR cameras. Although both clouds and ice appear white in the natural color view, the stereoscopic retrievals are able to identify elevated clouds based on the geometric parallax which results when they are observed from different angles. Owing to their elevation above sea level, clouds are mapped as green and yellow areas, whereas land, sea ice, and very low clouds appear blue and purple. Purple, in particular, denotes elevations very close to sea level. The island of Novaya Sibir is located in the lower left of the images. It can be identified in the natural color view as the dark area surrounded by an expanse of fast ice. In the stereo map the island appears as a blue region indicating its elevation of less than 100 meters above sea level. Areas where the automated stereo processing failed due to lack of sufficient spatial contrast are shown in dark gray. The northern edge of the Siberian mainland can be found at the very bottom of the panels, and is located a little over 250 kilometers south of Novaya Sibir. Pack ice containing numerous fragmented ice floes surrounds the fast ice, and narrow areas of open ocean are visible.

The East Siberian Sea is part of the Arctic Ocean and is ice-covered most of the year. The New Siberian Islands are almost always covered by snow and ice, and tundra vegetation is very scant. Despite continuous sunlight from the end of April until the middle of August, the ice between the island and the mainland typically remains until August or September.

The Multi-angle Imaging SpectroRadiometer views almost the entire Earth every 9 days. These images were acquired during Terra orbit 12986 and cover an area of about 380 kilometers x 1117 kilometers. They utilize data from blocks 24 to 32 within World Reference System-2 path 117.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

A Hazy Day in Mexico City

NASA Technical Reports Server (NTRS)

2002-01-01

Mexico City has one of the world's most serious air pollution problems. The city is located atop a high plain at an altitude of 2200 meters, and is surrounded on three sides by mountains and snow-capped volcanoes. Since incident solar radiation does not vary significantly with season at tropical latitudes, photochemical smog is produced much of the year. In winter, air quality can worsen significantly when thermal inversions keep polluted air masses close to the surface.

Atmospheric particulates (aerosols) are readily visible at oblique view angles, and differences in aerosol amount on two days are indicated by these images of central Mexico from the Multi-angle Imaging SpectroRadiometer (MISR). The images at left and center are natural color views acquired by MISR's 70-degree forward-viewing camera on April 9 and December 5, 2001, respectively. Mexico City can be identified in the center panel by the large area of haze accumulation above image center. Two small brighter patches within the hazy area indicate low fog. In the left-hand panel, the city basin appears significantly clearer, but some haze remains apparent across the Sierra Madre mountains in the lower portion of the images. On the right is an elevation field corresponding to the December 5 view. Automated MISR stereoscopic retrievals reveal the clouds at lower right to be at very high altitudes, in contrast to the low-lying haze and fog near Mexico City. When the stereo retrieval determines that a location is not covered by clouds, digital terrain elevation data are displayed instead. High clouds appear as the orange and red areas, and mountainous areas appear light blue and green. The position of the clouds within the 70-degree image are slightly southward of their location in the elevation map as a consequence of geometric parallax.

Major sources of air pollutants within the basin enclosing the Mexico City urban area include exhaust from 3.5 million vehicles, thousands of industries, and mineral dust. The ancient lakebed valley in which Mexico City is situated became a major source of dust when it was drained in the 16th century. The city basin stretches approximately 70 kilometers wide; it is reported that the local air quality causes the surrounding mountains to be rarely visible from the urban center.

The Multi-angle Imaging SpectroRadiometer views almost the entire Earth every 9 days. These images were acquired during Terra orbits 6966 and 10461 and cover an area of 330 kilometers x 464 kilometers. They utilize data from blocks 75 to 77 within World Reference System-2 path 26.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Constraining the Global, Cloud-Free Reflected Solar Radiation Flux (RSRF) with Earth Observing System (EOS) Instruments

NASA Technical Reports Server (NTRS)

Kahn, Ralph

1999-01-01

Variations in the top-of-atmosphere reflected solar radiation flux, and in the factors that determine its value, are among the most important diagnostic indicators of changes in Earth's energy balance. Data from the MISR (Multi-angle Imaging SpectroRadiometer), MODIS (Moderate-resolution Imaging Spectroradiometer), SAGE-3 (Stratospheric Aerosol and Gas Experiment), and CERES (Clouds and Earth's Radiant Energy System), all of which are spacecraft instruments scheduled for launch in 1999, will each constrain pieces of the RSRF budget. Prior to launch, we are performing studies to determine the sensitivity of these instruments to key factors that influence the cloud-free RSRF: aerosol optical depth, aerosol scattering properties, and surface visible bidirectional reflectance distribution function (BRDF). We are also assessing the ability of the aggregate of instruments to constrain the overall RSRF budget under natural conditions over the globe. Consider the MISR retrieval of aerosols: according to simulations over cloud-free, calm ocean, for pure particles with natural ranges of optical depth, particle size, and indices of refraction, MISR can retrieve column aerosol optical depth for all but the darkest particles, to an uncertainty of at most 0.05 or 20%, whichever is larger, even if the particle properties are poorly known. For one common particle type, soot, constraints on the optical depth over dark ocean are very poor. The simulated measurements also allow us to distinguish spherical from non-spherical particles, to separate two to four compositional groups based on indices of refraction, and to identify three to four distinct size groups between 0. 1 and 2.0 microns characteristic radius at most latitudes. Based on these results, we expect to distinguish air masses containing different aerosol types, routinely and globally, with multiangle remote sensing data. Such results far exceed current satellite aerosol retrieval capabilities, which provide only total optical depth for assumed particle properties; the new information will complement in situ data, which give details about aerosol size and composition locally. In addition, our team is using climatologies that reflect the constraints each instrument is expected to provide, along with ERBE (Earth Radiation Budget Experiment) data and a radiative transfer code, to study overall sensitivity to RSRF, helping us prepare for similar studies with new data from the EOS-era instruments.

A Geostatistical Data Fusion Technique for Merging Remote Sensing and Ground-Based Observations of Aerosol Optical Thickness

NASA Technical Reports Server (NTRS)

Chatterjee, Abhishek; Michalak, Anna M.; Kahn, Ralph A.; Paradise, Susan R.; Braverman, Amy J.; Miller, Charles E.

2010-01-01

Particles in the atmosphere reflect incoming sunlight, tending to cool the Earth below. Some particles, such as soot, also absorb sunlight, which tens to warm the ambient atmosphere. Aerosol optical depth (AOD) is a measure of the amount of particulate matter in the atmosphere, and is a key input to computer models that simulate and predict Earth's changing climate. The global AOD products from the Multi-angle Imaging SpectroRadiometer (MISR) and the MODerate resolution Imaging Spectroradiometer (MODIS), both of which fly on the NASA Earth Observing System's Terra satellite, provide complementary views of the particles in the atmosphere. Whereas MODIS offers global coverage about four times as frequent as MISR, the multi-angle data makes it possible to separate the surface and atmospheric contributions to the observed top-of-atmosphere radiances, and also to more effectively discriminate particle type. Surface-based AERONET sun photometers retrieve AOD with smaller uncertainties than the satellite instruments, but only at a few fixed locations. So there are clear reasons to combine these data sets in a way that takes advantage of their respective strengths. This paper represents an effort at combining MISR, MODIS and AERONET AOD products over the continental US, using a common spatial statistical technique called kriging. The technique uses the correlation between the satellite data and the "ground-truth" sun photometer observations to assign uncertainty to the satellite data on a region-by-region basis. The larger fraction of the sun photometer variance that is duplicated by the satellite data, the higher the confidence assigned to the satellite data in that region. In the Western and Central US, MISR AOD correlation with AERONET are significantly higher than those with MODIS, likely due to bright surfaces in these regions, which pose greater challenges for the single-view MODIS retrievals. In the east, MODIS correlations are higher, due to more frequent sampling of the varying AOD. These results demonstrate how the MISR and MODIS aerosol products are complementary. The underlying technique also provides one method for combining these products in such a way that takes advantage of the strengths of each, in the places and times when they are maximal, and in addition, yields an estimate of the associated uncertainties in space and time.

MISR Where on Earth…? Mystery Image Quiz #29

Atmospheric Science Data Center

2017-09-07

... ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA’s MISR (Multi-angle Imaging ... ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA’s MISR (Multi-angle Imaging ...

Updated MISR Dark Water Research Aerosol Retrieval Algorithm - Part 1: Coupled 1.1 km Ocean Surface Chlorophyll a Retrievals with Empirical Calibration Corrections

NASA Technical Reports Server (NTRS)

Limbacher, James A.; Kahn, Ralph A.

2017-01-01

As aerosol amount and type are key factors in the 'atmospheric correction' required for remote-sensing chlorophyll alpha concentration (Chl) retrievals, the Multi-angle Imaging SpectroRadiometer (MISR) can contribute to ocean color analysis despite a lack of spectral channels optimized for this application. Conversely, an improved ocean surface constraint should also improve MISR aerosol-type products, especially spectral single-scattering albedo (SSA) retrievals. We introduce a coupled, self-consistent retrieval of Chl together with aerosol over dark water. There are time-varying MISR radiometric calibration errors that significantly affect key spectral reflectance ratios used in the retrievals. Therefore, we also develop and apply new calibration corrections to the MISR top-of-atmosphere (TOA) reflectance data, based on comparisons with coincident MODIS (Moderate Resolution Imaging Spectroradiometer) observations and trend analysis of the MISR TOA bidirectional reflectance factors (BRFs) over three pseudo-invariant desert sites. We run the MISR research retrieval algorithm (RA) with the corrected MISR reflectances to generate MISR-retrieved Chl and compare the MISR Chl values to a set of 49 coincident SeaBASS (SeaWiFS Bio-optical Archive and Storage System) in situ observations. Where Chl(sub in situ) less than 1.5 mg m(exp -3), the results from our Chl model are expected to be of highest quality, due to algorithmic assumption validity. Comparing MISR RA Chl to the 49 coincident SeaBASS observations, we report a correlation coefficient (r) of 0.86, a root-mean-square error (RMSE) of 0.25, and a median absolute error (MAE) of 0.10. Statistically, a two-sample Kolmogorov- Smirnov test indicates that it is not possible to distinguish between MISR Chl and available SeaBASS in situ Chl values (p greater than 0.1). We also compare MODIS-Terra and MISR RA Chl statistically, over much broader regions. With about 1.5 million MISR-MODIS collocations having MODIS Chl less than 1.5 mg m(exp -3), MISR and MODIS show very good agreement: r = 0.96, MAE = 0.09, and RMSE = 0.15. The new dark water aerosol/Chl RA can retrieve Chl in low-Chl, case I waters, independent of other imagers such as MODIS, via a largely physical algorithm, compared to the commonly applied statistical ones. At a minimum, MISR's multi-angle data should help reduce uncertainties in the MODIS-Terra ocean color retrieval where coincident measurements are made, while also allowing for a more robust retrieval of particle properties such as spectral single-scattering albedo.

Updated MISR dark water research aerosol retrieval algorithm - Part 1: Coupled 1.1 km ocean surface chlorophyll a retrievals with empirical calibration corrections

NASA Astrophysics Data System (ADS)

Limbacher, James A.; Kahn, Ralph A.

2017-04-01

As aerosol amount and type are key factors in the atmospheric correction required for remote-sensing chlorophyll a concentration (Chl) retrievals, the Multi-angle Imaging SpectroRadiometer (MISR) can contribute to ocean color analysis despite a lack of spectral channels optimized for this application. Conversely, an improved ocean surface constraint should also improve MISR aerosol-type products, especially spectral single-scattering albedo (SSA) retrievals. We introduce a coupled, self-consistent retrieval of Chl together with aerosol over dark water. There are time-varying MISR radiometric calibration errors that significantly affect key spectral reflectance ratios used in the retrievals. Therefore, we also develop and apply new calibration corrections to the MISR top-of-atmosphere (TOA) reflectance data, based on comparisons with coincident MODIS (Moderate Resolution Imaging Spectroradiometer) observations and trend analysis of the MISR TOA bidirectional reflectance factors (BRFs) over three pseudo-invariant desert sites. We run the MISR research retrieval algorithm (RA) with the corrected MISR reflectances to generate MISR-retrieved Chl and compare the MISR Chl values to a set of 49 coincident SeaBASS (SeaWiFS Bio-optical Archive and Storage System) in situ observations. Where Chlin situ < 1.5 mg m-3, the results from our Chl model are expected to be of highest quality, due to algorithmic assumption validity. Comparing MISR RA Chl to the 49 coincident SeaBASS observations, we report a correlation coefficient (r) of 0.86, a root-mean-square error (RMSE) of 0.25, and a median absolute error (MAE) of 0.10. Statistically, a two-sample Kolmogorov-Smirnov test indicates that it is not possible to distinguish between MISR Chl and available SeaBASS in situ Chl values (p > 0.1). We also compare MODIS-Terra and MISR RA Chl statistically, over much broader regions. With about 1.5 million MISR-MODIS collocations having MODIS Chl < 1.5 mg m-3, MISR and MODIS show very good agreement: r = 0. 96, MAE = 0.09, and RMSE = 0.15. The new dark water aerosol/Chl RA can retrieve Chl in low-Chl, case I waters, independent of other imagers such as MODIS, via a largely physical algorithm, compared to the commonly applied statistical ones. At a minimum, MISR's multi-angle data should help reduce uncertainties in the MODIS-Terra ocean color retrieval where coincident measurements are made, while also allowing for a more robust retrieval of particle properties such as spectral single-scattering albedo.

America National Parks Viewed in 3D by NASA MISR Anaglyph 2

NASA Image and Video Library

2016-08-25

Just in time for the U.S. National Park Service's Centennial celebration on Aug. 25, NASA's Multiangle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite is releasing four new anaglyphs that showcase 33 of our nation's national parks, monuments, historical sites and recreation areas in glorious 3D. Shown in the annotated image are Grand Teton National Park, John D. Rockefeller Memorial Parkway, Yellowstone National Park, and parts of Craters of the Moon National Monument. MISR views Earth with nine cameras pointed at different angles, giving it the unique capability to produce anaglyphs, stereoscopic images that allow the viewer to experience the landscape in three dimensions. The anaglyphs were made by combining data from MISR's vertical-viewing and 46-degree forward-pointing camera. You will need red-blue glasses in order to experience the 3D effect; ensure you place the red lens over your left eye. The images have been rotated so that north is to the left in order to enable 3D viewing because the Terra satellite flies from north to south. All of the images are 235 miles (378 kilometers) from west to east. These data were acquired June 25, 2016, Orbit 87876. http://photojournal.jpl.nasa.gov/catalog/PIA20890

America National Parks Viewed in 3D by NASA MISR Anaglyph 4

NASA Image and Video Library

2016-08-25

Just in time for the U.S. National Park Service's Centennial celebration on Aug. 25, NASA's Multiangle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite is releasing four new anaglyphs that showcase 33 of our nation's national parks, monuments, historical sites and recreation areas in glorious 3D. Shown in the annotated image are Sequoia National Park, Kings Canyon National Park, Manzanar National Historic Site, Devils Postpile National Monument, Yosemite National Park, and parts of Death Valley National Park. MISR views Earth with nine cameras pointed at different angles, giving it the unique capability to produce anaglyphs, stereoscopic images that allow the viewer to experience the landscape in three dimensions. The anaglyphs were made by combining data from MISR's vertical-viewing and 46-degree forward-pointing camera. You will need red-blue glasses in order to experience the 3D effect; ensure you place the red lens over your left eye. The images have been rotated so that north is to the left in order to enable 3D viewing because the Terra satellite flies from north to south. All of the images are 235 miles (378 kilometers) from west to east. These data were acquired July 7, 2016, Orbit 88051. http://photojournal.jpl.nasa.gov/catalog/PIA20892

Mystery #28

Atmospheric Science Data Center

2017-06-14

... ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA’s MISR (Multi-angle Imaging ... ready for a challenge? Become a geographical detective and solve the latest mystery quiz from NASA’s MISR (Multi-angle Imaging ...

Aerosol Optical Depth Over India

NASA Astrophysics Data System (ADS)

David, Liji Mary; Ravishankara, A. R.; Kodros, John K.; Venkataraman, Chandra; Sadavarte, Pankaj; Pierce, Jeffrey R.; Chaliyakunnel, Sreelekha; Millet, Dylan B.

2018-04-01

Tropospheric aerosol optical depth (AOD) over India was simulated by Goddard Earth Observing System (GEOS)-Chem, a global 3-D chemical-transport model, using SMOG (Speciated Multi-pOllutant Generator from Indian Institute of Technology Bombay) and GEOS-Chem (GC) (current inventories used in the GEOS-Chem model) inventories for 2012. The simulated AODs were 80% (SMOG) and 60% (GC) of those measured by the satellites (Moderate Resolution Imaging Spectroradiometer and Multi-angle Imaging SpectroRadiometer). There is no strong seasonal variation in AOD over India. The peak AOD values are observed/simulated during summer. The simulated AOD using SMOG inventory has particulate black and organic carbon AOD higher by a factor 5 and 3, respectively, compared to GC inventory. The model underpredicted coarse-mode AOD but agreed for fine-mode AOD with Aerosol Robotic Network data. It captured dust only over Western India, which is a desert, and not elsewhere, probably due to inaccurate dust transport and/or noninclusion of other dust sources. The calculated AOD, after dust correction, showed the general features in its observed spatial variation. Highest AOD values were observed over the Indo-Gangetic Plain followed by Central and Southern India with lowest values in Northern India. Transport of aerosols from Indo-Gangetic Plain and Central India into Eastern India, where emissions are low, is significant. The major contributors to total AOD over India are inorganic aerosol (41-64%), organic carbon (14-26%), and dust (7-32%). AOD over most regions of India is a factor of 5 or higher than over the United States.

Transpacific Transport of Dust to North American High-Elevation Sites: Integrated Dataset and Model Outputs

NASA Astrophysics Data System (ADS)

Kassianov, E.; Pekour, M. S.; Flynn, C. J.; Berg, L. K.; Beranek, J.; Zelenyuk, A.; Zhao, C.; Leung, L. R.; Ma, P. L.; Riihimaki, L.; Fast, J. D.; Barnard, J.; Hallar, G. G.; McCubbin, I.; Eloranta, E. W.; McComiskey, A. C.; Rasch, P. J.

2017-12-01

Understanding the effects of dust on the regional and global climate requires detailed information on particle size distributions and their changes with distance from the source. Awareness is now growing about the tendency of the dust coarse mode with moderate ( 3.5 µm) volume median diameter (VMD) to be rather insensitive to complex removal processes associated with long-range transport of dust from the main sources. Our study, with a focus on the transpacific transport of dust, demonstrates that the impact of coarse mode aerosol (VMD 3µm) is well defined at the high-elevation mountain-top Storm Peak Laboratory (SPL, about 3.2 km MSL) and nearby Atmospheric Radiation Measurement (ARM) Climate Research Facility Mobile Facility (AMF) during March 2011. Significant amounts of coarse mode aerosol are also found at the nearest Aerosol Robotic Network (AERONET) site. Outputs from the high-resolution Weather Research and Forecasting (WRF) Model coupled with chemistry (WRF-Chem) show that the major dust event is likely associated with transpacific transport of Asian and African plumes. Satellite data, including the Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR) aerosol optical depth (AOD) and plume height from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) lidar data provide the observational support of the WRF-Chem simulations. Our study complements previous findings by indicating that the quasi-static nature of the coarse mode appears to be a reasonable approximation for Asian and African dust despite expected frequent orographic precipitation over mountainous regions in the western United States.

Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Booth, James F.; Del Genio, Anthony D.

2014-01-01

The Southern Ocean cloud cover modeled by the Interim ECMWF Re-Analysis (ERA-Interim) and Modern- Era Retrospective Analysis for Research and Applications (MERRA) reanalyses are compared against Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) observations. ERA-Interim monthly mean cloud amounts match the observations within 5%, while MERRA significantly underestimates the cloud amount. For a compositing analysis of clouds in warm season extratropical cyclones, both reanalyses show a low bias in cloud cover. They display a larger bias to the west of the cyclones in the region of subsidence behind the cold fronts. This low bias is larger for MERRA than for ERA-Interim. Both MODIS and MISR retrievals indicate that the clouds in this sector are at a low altitude, often composed of liquid, and of a broken nature. The combined CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) cloud profiles confirm these passive observations, but they also reveal that low-level clouds in other parts of the cyclones are also not properly represented in the reanalyses. The two reanalyses are in fairly good agreement for the dynamic and thermodynamic characteristics of the cyclones, suggesting that the cloud, convection, or boundary layer schemes are the problem instead. An examination of the lower-tropospheric stability distribution in the cyclones from both reanalyses suggests that the parameterization of shallow cumulus clouds may contribute in a large part to the problem. However, the differences in the cloud schemes and in particular in the precipitation processes, which may also contribute, cannot be excluded.

Multiple Satellite Observations of Cloud Cover in Extratropical Cyclones

NASA Technical Reports Server (NTRS)

Naud, Catherine M.; Booth, James F.; Posselt, Derek J.; van den Heever, Susan C.

2013-01-01

Using cloud observations from NASA Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, and CloudSat-CALIPSO, composites of cloud fraction in southern and northern hemisphere extratropical cyclones are obtained for cold and warm seasons between 2006 and 2010, to assess differences between these three data sets, and between summer and winter cyclones. In both hemispheres and seasons, over the open ocean, the cyclone-centered cloud fraction composites agree within 5% across the three data sets, but behind the cold fronts, or over sea ice and land, the differences are much larger. To supplement the data set comparison and learn more about the cyclones, we also examine the differences in cloud fraction between cold and warm season for each data set. The difference in cloud fraction between cold and warm season southern hemisphere cyclones is small for all three data sets, but of the same order of magnitude as the differences between the data sets. The cold-warm season contrast in northern hemisphere cyclone cloud fractions is similar for all three data sets: in the warm sector, the cold season cloud fractions are lower close to the low, but larger on the equator edge than their warm season counterparts. This seasonal contrast in cloud fraction within the cyclones warm sector seems to be related to the seasonal differences in moisture flux within the cyclones. Our analysis suggests that the three different data sets can all be used confidently when studying the warm sector and warm frontal zone of extratropical cyclones but caution should be exerted when studying clouds in the cold sector.

Karymsky volcano eruptive plume properties based on MISR multi-angle imagery and the volcanological implications

NASA Astrophysics Data System (ADS)

Flower, Verity J. B.; Kahn, Ralph A.

2018-03-01

Space-based operational instruments are in unique positions to monitor volcanic activity globally, especially in remote locations or where suborbital observing conditions are hazardous. The Multi-angle Imaging SpectroRadiometer (MISR) provides hyper-stereo imagery, from which the altitude and microphysical properties of suspended atmospheric aerosols can be derived. These capabilities are applied to plumes emitted at Karymsky volcano from 2000 to 2017. Observed plumes from Karymsky were emitted predominantly to an altitude of 2-4 km, with occasional events exceeding 6 km. MISR plume observations were most common when volcanic surface manifestations, such as lava flows, were identified by satellite-based thermal anomaly detection. The analyzed plumes predominantly contained large (1.28 µm effective radius), strongly absorbing particles indicative of ash-rich eruptions. Differences between the retrievals for Karymsky volcano's ash-rich plumes and the sulfur-rich plumes emitted during the 2014-2015 eruption of Holuhraun (Iceland) highlight the ability of MISR to distinguish particle types from such events. Observed plumes ranged from 30 to 220 km in length and were imaged at a spatial resolution of 1.1 km. Retrieved particle properties display evidence of downwind particle fallout, particle aggregation and chemical evolution. In addition, changes in plume properties retrieved from the remote-sensing observations over time are interpreted in terms of shifts in eruption dynamics within the volcano itself, corroborated to the extent possible with suborbital data. Plumes emitted at Karymsky prior to 2010 display mixed emissions of ash and sulfate particles. After 2010, all plumes contain consistent particle components, indicative of entering an ash-dominated regime. Post-2010 event timing, relative to eruption phase, was found to influence the optical properties of observed plume particles, with light absorption varying in a consistent sequence as each respective eruption phase progressed.

Karymsky volcano eruptive plume properties based on MISR multi-angle imagery, and volcanological implications.

PubMed

Flower, Verity J B; Kahn, Ralph A

2018-01-01

Space-based, operational instruments are in unique positions to monitor volcanic activity globally, especially in remote locations or where suborbital observing conditions are hazardous. The Multi-angle Imaging SpectroRadiometer (MISR) provides hyper-stereo imagery, from which the altitude and microphysical properties of suspended atmospheric aerosols can be derived. These capabilities are applied to plumes emitted at Karymsky volcano from 2000 to 2017. Observed plumes from Karymsky were emitted predominantly to an altitude of 2-4 km, with occasional events exceeding 6 km. MISR plume observations were most common when volcanic surface manifestations, such as lava flows, were identified by satellite-based thermal anomaly detection. The analyzed plumes predominantly contained large (1.28 µm effective radius), strongly absorbing particles indicative of ash-rich eruptions. Differences between the retrievals for Karymsky volcano's ash-rich plumes and the sulfur-rich plumes emitted during the 2014-2015 eruption of Holuhraun (Iceland) highlight the ability of MISR to distinguish particle types from such events. Observed plumes ranged from 30 to 220 km in length, and were imaged at a spatial resolution of 1.1 km. Retrieved particle properties display evidence of downwind particle fallout, particle aggregation and chemical evolution. In addition, changes in plume properties retrieved from the remote-sensing observations over time are interpreted in terms of shifts in eruption dynamics within the volcano itself, corroborated to the extent possible with suborbital data. Plumes emitted at Karymsky prior to 2010 display mixed emissions of ash and sulfate particles. After 2010, all plumes contain consistent particle components, indicative of entering an ash-dominated regime. Post-2010 event timing, relative to eruption phase, was found to influence the optical properties of observed plume particles, with light-absorption varying in a consistent sequence as each respective eruption phase progressed.

Aerosol Airmass Type Mapping Over the Urban Mexico City Region From Space-based Multi-angle Imaging

NASA Technical Reports Server (NTRS)

Patadia, F.; Kahn, R. A.; Limbacher, J. A.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.

2013-01-01

Using Multi-angle Imaging SpectroRadiometer (MISR) and sub-orbital measurements from the 2006 INTEX-B/MILAGRO field campaign, in this study we explore MISR's ability to map different aerosol air mass types over the Mexico City metropolitan area. The aerosol air mass distinctions are based on shape, size and single scattering albedo retrievals from the MISR Research Aerosol Retrieval algorithm. In this region, the research algorithm identifies dust-dominated aerosol mixtures based on non-spherical particle shape, whereas spherical biomass burning and urban pollution particles are distinguished by particle size. Two distinct aerosol air mass types based on retrieved particle microphysical properties, and four spatially distributed aerosol air masses, are identified in the MISR data on 6 March 2006. The aerosol air mass type identification results are supported by coincident, airborne high-spectral-resolution lidar (HSRL) measurements. Aerosol optical depth (AOD) gradients are also consistent between the MISR and sub-orbital measurements, but particles having single-scattering albedo of approx. 0.7 at 558 nm must be included in the retrieval algorithm to produce good absolute AOD comparisons over pollution-dominated aerosol air masses. The MISR standard V22 AOD product, at 17.6 km resolution, captures the observed AOD gradients qualitatively, but retrievals at this coarse spatial scale and with limited spherical absorbing particle options underestimate AOD and do not retrieve particle properties adequately over this complex urban region. However, we demonstrate how AOD and aerosol type mapping can be accomplished with MISR data over complex urban regions, provided the retrieval is performed at sufficiently high spatial resolution, and with a rich enough set of aerosol components and mixtures.

Casting Light and Shadows on a Saharan Dust Storm

NASA Technical Reports Server (NTRS)

2003-01-01

On March 2, 2003, near-surface winds carried a large amount of Saharan dust aloft and transported the material westward over the Atlantic Ocean. These observations from the Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite depict an area near the Cape Verde Islands (situated about 700 kilometers off of Africa's western coast) and provide images of the dust plume along with measurements of its height and motion. Tracking the three-dimensional extent and motion of air masses containing dust or other types of aerosols provides data that can be used to verify and improve computer simulations of particulate transport over large distances, with application to enhancing our understanding of the effects of such particles on meteorology, ocean biological productivity, and human health.

MISR images the Earth by measuring the spatial patterns of reflected sunlight. In the upper panel of the still image pair, the observations are displayed as a natural-color snapshot from MISR's vertical-viewing (nadir) camera. High-altitude cirrus clouds cast shadows on the underlying ocean and dust layer, which are visible in shades of blue and tan, respectively. In the lower panel, heights derived from automated stereoscopic processing of MISR's multi-angle imagery show the cirrus clouds (yellow areas) to be situated about 12 kilometers above sea level. The distinctive spatial patterns of these clouds provide the necessary contrast to enable automated feature matching between images acquired at different view angles. For most of the dust layer, which is spatially much more homogeneous, the stereoscopic approach was unable to retrieve elevation data. However, the edges of shadows cast by the cirrus clouds onto the dust (indicated by blue and cyan pixels) provide sufficient spatial contrast for a retrieval of the dust layer's height, and indicate that the top of layer is only about 2.5 kilometers above sea level.

Motion of the dust and clouds is directly observable with the assistance of the multi-angle 'fly-over' animation (Below). The frames of the animation consist of data acquired by the 70-degree, 60-degree, 46-degree and 26-degree forward-viewing cameras in sequence, followed by the images from the nadir camera and each of the four backward-viewing cameras, ending with 70-degree backward image. Much of the south-to-north shift in the position of the clouds is due to geometric parallax between the nine view angles (rather than true motion), whereas the west-to-east motion is due to actual motion of the clouds over the seven minutes during which all nine cameras observed the scene. MISR's automated data processing retrieved a primarily westerly (eastward) motion of these clouds with speeds of 30-40 meters per second. Note that there is much less geometric parallax for the cloud shadows owing to the relatively low altitude of the dust layer upon which the shadows are cast (the amount of parallax is proportional to elevation and a feature at the surface would have no geometric parallax at all); however, the westerly motion of the shadows matches the actual motion of the clouds. The automated processing was not able to resolve a velocity for the dust plume, but by manually tracking dust features within the plume images that comprise the animation sequence we can derive an easterly (westward) speed of about 16 meters per second. These analyses and visualizations of the MISR data demonstrate that not only are the cirrus clouds and dust separated significantly in elevation, but they exist in completely different wind regimes, with the clouds moving toward the east and the dust moving toward the west.

[figure removed for brevity, see original site]

(Click on image above for high resolution version)

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 17040. The panels cover an area of about 312 kilometers x 242 kilometers, and use data from blocks 74 to 77 within World Reference System-2 path 207.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Remote Sensing of Smoke, Land and Clouds from the NASA ER-2 during SAFARI 2000

NASA Technical Reports Server (NTRS)

King, Michael D.; Platnick, Steven; Moeller, Christopher C.; Revercomb, Henry E.; Chu, D. Allen

2002-01-01

The NASA ER-2 aircraft was deployed to southern Africa between August 17 and September 25, 2000 as part of the Southern Africa Regional Science Initiative (SAFARI) 2000. This aircraft carried a sophisticated array of multispectral scanners, multiangle spectroradiometers, a monostatic lidar, a gas correlation radiometer, upward and downward spectral flux radiometers, and two metric mapping cameras. These observations were obtained over a 3200 x 2800 km region of savanna, woody savanna, open shrubland, and grassland ecosystems throughout southern Africa, and were quite often coordinated with overflights by NASA's Terra and Landsat 7 satellites. The primary purpose of this sophisticated high altitude observing platform was to obtain independent observations of smoke, clouds, and land surfaces that could be used to check the validity of various remote sensing measurements derived by Earth-orbiting satellites. These include such things as the accuracy of the Moderate Resolution Imaging Spectro-radiometer (MODIS) cloud mask for distinguishing clouds and heavy aerosol from land and ocean surfaces, and Terra analyses of cloud optical and micro-physical properties, aerosol properties, leaf area index, vegetation index, fire occurrence, carbon monoxide, and surface radiation budget. In addition to coordination with Terra and Landsat 7 satellites, numerous flights were conducted over surface AERONET sites, flux towers in South Africa, Botswana, and Zambia, and in situ aircraft from the University of Washington, South Africa, and the United Kingdom.

Development and Applications of a New, High-Resolution, Operational MISR Aerosol Product

NASA Astrophysics Data System (ADS)

Garay, M. J.; Diner, D. J.; Kalashnikova, O.

2014-12-01

Since early 2000, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite has been providing aerosol optical depth (AOD) and particle property retrievals at 17.6 km spatial resolution. Capitalizing on the capabilities provided by multi-angle viewing, the operational MISR algorithm performs well, with about 75% of MISR AOD retrievals falling within 0.05 or 20% × AOD of the paired validation data from the ground-based Aerosol Robotic Network (AERONET), and is able to distinguish aerosol particles by size and sphericity, over both land and water. These attributes enable a variety of applications, including aerosol transport model validation and global air quality assessment. Motivated by the adverse impacts of aerosols on human health at the local level, and taking advantage of computational speed advances that have occurred since the launch of Terra, we have implemented an operational MISR aerosol product with 4.4 km spatial resolution that maintains, and sometimes improves upon, the quality of the 17.6 km resolution product. We will describe the performance of this product relative to the heritage 17.6 km product, the global AERONET validation network, and high spatial density AERONET-DRAGON sites. Other changes that simplify product content, and make working with the data much easier for users, will also be discussed. Examples of how the new product demonstrates finer spatial variability of aerosol fields than previously retrieved, and ways this new dataset can be used for studies of local aerosol effects, will be shown.

Near Real Time MISR Wind Observations for Numerical Weather Prediction

NASA Astrophysics Data System (ADS)

Mueller, K. J.; Protack, S.; Rheingans, B. E.; Hansen, E. G.; Jovanovic, V. M.; Baker, N.; Liu, J.; Val, S.

2014-12-01

The Multi-angle Imaging SpectroRadiometer (MISR) project, in association with the NASA Langley Atmospheric Science Data Center (ASDC), has this year adapted its original production software to generate near-real time (NRT) cloud-motion winds as well as radiance imagery from all nine MISR cameras. These products are made publicly available at the ASDC with a latency of less than 3 hours. Launched aboard the sun-synchronous Terra platform in 1999, the MISR instrument continues to acquire near-global, 275 m resolution, multi-angle imagery. During a single 7 minute overpass of any given area, MISR retrieves the stereoscopic height and horizontal motion of clouds from the multi-angle data, yielding meso-scale near-instantaneous wind vectors. The ongoing 15-year record of MISR height-resolved winds at 17.6 km resolution has been validated against independent data sources. Low-level winds dominate the sampling, and agree to within ±3 ms-1 of collocated GOES and other observations. Low-level wind observations are of particular interest to weather forecasting, where there is a dearth of observations suitable for assimilation, in part due to reliability concerns associated with winds whose heights are assigned by the infrared brightness temperature technique. MISR cloud heights, on the other hand, are generated from stereophotogrammetric pattern matching of visible radiances. MISR winds also address data gaps in the latitude bands between geostationary satellite coverage and polar orbiting instruments that obtain winds from multiple overpasses (e.g. MODIS). Observational impact studies conducted by the Naval Research Laboratory (NRL) and by the German Weather Service (Deutscher Wetterdienst) have both demonstrated forecast improvements when assimilating MISR winds. An impact assessment using the GEOS-5 system is currently in progress. To benefit air quality forecasts, the MISR project is currently investigating the feasibility of generating near-real time aerosol products.

Cloud Height Maps for Hurricanes Frances and Ivan

NASA Technical Reports Server (NTRS)

2004-01-01

NASA's Multi-angle Imaging SpectroRadiometer (MISR) captured these images and cloud-top height retrievals of Hurricane Frances on September 4, 2004, when the eye sat just off the coast of eastern Florida, and Hurricane Ivan on September 5th, after this cyclone had devastated Grenada and was heading toward the central and western Caribbean. Hurricane Frances made landfall in the early hours of September 5, and was downgraded to Tropical Storm status as it swept inland through the Florida panhandle and continued northward. On the heels of Frances is Hurricane Ivan, which is on record as the strongest tropical cyclone to form at such a low latitude in the Atlantic, and was the most powerful hurricane to have hit the Caribbean in nearly a decade.

The ability of forecasters to predict the intensity and amount of rainfall associated with hurricanes still requires improvement, especially on the 24 to 48 hour timescale vital for disaster planning. To improve the operational models used to make hurricane forecasts, scientists need to better understand the multi-scale interactions at the cloud, mesoscale and synoptic scales that lead to hurricane intensification and dissipation, and the various physical processes that affect hurricane intensity and rainfall distributions. Because these uncertainties with regard to how to represent cloud processes still exist, it is vital that the model findings be evaluated against hurricane observations whenever possible. Two-dimensional maps of cloud height such as those shown here offer an unprecedented opportunity for comparing simulated cloud fields against actual hurricane observations.

The left-hand panel in each image pair is a natural color view from MISR's nadir camera. The right-hand panels are cloud-top height retrievals produced by automated computer recognition of the distinctive spatial features between images acquired at different view angles. These results indicate that at the time that these images were acquired, clouds within Frances and Ivan had attained altitudes of 15 kilometers and 16 kilometers above sea level, respectively. The height fields pictured here are uncorrected for the effects of cloud motion. Wind-corrected heights (which have higher accuracy but sparser spatial coverage) are within about 1 kilometer of the heights shown here.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 25081 and 25094. The panels cover an area of 380 kilometers x 924 kilometers, and utilize data from within blocks 65 to 87 within World Reference System-2 paths 14 and 222, respectively.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California In

MISR at 15: Multiple Perspectives on Our Changing Earth

NASA Astrophysics Data System (ADS)

Diner, D. J.; Ackerman, T. P.; Braverman, A. J.; Bruegge, C. J.; Chopping, M. J.; Clothiaux, E. E.; Davies, R.; Di Girolamo, L.; Garay, M. J.; Jovanovic, V. M.; Kahn, R. A.; Kalashnikova, O.; Knyazikhin, Y.; Liu, Y.; Marchand, R.; Martonchik, J. V.; Muller, J. P.; Nolin, A. W.; Pinty, B.; Verstraete, M. M.; Wu, D. L.

2014-12-01

Launched aboard NASA's Terra satellite in December 1999, the Multi-angle Imaging SpectroRadiometer (MISR) instrument has opened new vistas in remote sensing of our home planet. Its 9 pushbroom cameras provide as many view angles ranging from 70 degrees forward to 70 degrees backward along Terra's flight track, in four visible and near-infrared spectral bands. MISR's well-calibrated, accurately co-registered, and moderately high spatial resolution radiance images have been coupled with novel data processing algorithms to mine the information content of angular reflectance anisotropy and multi-camera stereophotogrammetry, enabling new perspectives on the 3-D structure and dynamics of Earth's atmosphere and surface in support of climate and environmental research. Beginning with "first light" in February 2000, the nearly 15-year (and counting) MISR observational record provides an unprecedented data set with applications to multiple disciplines, documenting regional, global, short-term, and long-term changes in aerosol optical depths, aerosol type, near-surface particulate pollution, spectral top-of-atmosphere and surface albedos, aerosol plume-top and cloud-top heights, height-resolved cloud fractions, atmospheric motion vectors, and the structure of vegetated and ice-covered terrains. Recent computational advances include aerosol retrievals at finer spatial resolution than previously possible, and production of near-real time tropospheric winds with a latency of less than 3 hours, making possible for the first time the assimilation of MISR data into weather forecast models. In addition, recent algorithmic and technological developments provide the means of using and acquiring multi-angular data in new ways, such as the application of optical tomography to map 3-D atmospheric structure; building smaller multi-angle instruments in the future; and extending the multi-angular imaging methodology to the ultraviolet, shortwave infrared, and polarimetric realms. Such advances promise further enhancements to the observational power of the remote sensing approaches that MISR has pioneered.

Development of the algorithm of measurement data and tomographic section reconstruction results processing for evaluating the respiratory activity of the lungs using the multi-angle electric impedance tomography

NASA Astrophysics Data System (ADS)

Aleksanyan, Grayr; Shcherbakov, Ivan; Kucher, Artem; Sulyz, Andrew

2018-04-01

Continuous monitoring of the patient's breathing by the method of multi-angle electric impedance tomography allows to obtain images of conduction change in the chest cavity during the monitoring. Direct analysis of images is difficult due to the large amount of information and low resolution images obtained by multi-angle electrical impedance tomography. This work presents a method for obtaining a graph of respiratory activity of the lungs based on the results of continuous lung monitoring using the multi-angle electrical impedance tomography method. The method makes it possible to obtain a graph of the respiratory activity of the left and right lungs separately, as well as a summary graph, to which it is possible to apply methods of processing the results of spirography.

Smoke Blankets New South Wales, Australia

NASA Technical Reports Server (NTRS)

2002-01-01

Australia's largest city of Sydney was clouded with smoke when more than 70 wildfires raged across the state of New South Wales. These images were captured on the morning of December 30, 2001, by the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra spacecraft. The left-hand image is from the instrument's 26-degree forward-viewing camera, and the right-hand image is from the 60-degree forward-viewing camera. The vast extent of smoke from numerous fires is visible, particularly in the more oblique view. Sydney is located just above image center.

Dubbed the 'black Christmas' fires, the blazes destroyed more than 150 homes and blackened over 5000 square kilometers (about 1.24 million acres) of farmland and wilderness between December 23, 2001 and January 3, 2002. Many of the fires are believed to have been caused by arsonists, with only one fire linked to natural causes. The fires were aggravated by gusty winds and hot dry weather conditions. Approximately 20,000 people have worked to contain the blazes. No people have lost their lives or been seriously injured. Nevertheless, the fires are considered to be the most prolonged and destructive of any in Australia since the Ash Wednesday conflagration of 1983 that claimed 72 lives.

The images represent an area 322 kilometers x 374 kilometers and were captured during Terra orbit 10829.

Observational evidence of fire-driven changes to tropical cloudiness

NASA Astrophysics Data System (ADS)

Tosca, Michael; Diner, David; Garay, Michael; Kalashnikova, Olga

2014-05-01

Anthropogenic fires in the tropics emit smoke aerosols that affect cloud dynamics, meteorology and climate (Tosca et al., 2013). We developed a new technique to observationally quantify the cloud response to biomass burning aerosols using aerosol retrievals from the Multi-angle Imaging SpectroRadiometer (MISR) and non-coincident cloud retrievals from the MODerate resolution Imaging Spectroradiometer (MODIS) from collocated morning and afternoon overpasses. The Global Fire Emissions Database, version 3 and Level 2 data from scenes acquired between 2006 and 2010 were used to quantify changes in cloud fraction from morning (10:30am local time) to afternoon (1:30pm local time) in the presence of varying fire-aerosol burdens. This temporal offset allowed for analysis of the evolution of clouds in the presence of aerosols, something that previous methods using coincident observations could not produce. We controlled for large-scale meteorological differences between scenes using reanalysis data from the ERA-interim product and matching scenes with fire smoke to those with no smoke and similar initial (morning) meteorological conditions. Elevated aerosol optical depths (AODs) reduced cloud fraction from morning to afternoon in the Southeast Asia, Central America and northern Africa burning regions. In mostly cloudy conditions, aerosols significantly reduced cloud fraction, but in clear skies, cloud fraction increased. These results support the general hypothesis of a positive feedback loop between anthropogenic burning and cloudiness in tropical regions, and are consistent with previous studies linking smoke aerosols to convective cloud reduction. Tosca, M.G., J.T. Randerson and C.S. Zender (2013), Global impact of smoke aerosols from landscape fires on climate and the Hadley circulation, Atmos. Chem. Phys., 13, 5227-5241, doi: 10.5194/acp-13-5227-2013.

Investigation of the "elevated heat pump" hypothesis of the Asian monsoon using satellite observations

NASA Astrophysics Data System (ADS)

Wonsick, M. M.; Pinker, R. T.; Ma, Y.

2014-08-01

The "elevated heat pump" (EHP) hypothesis has been a topic of intensive research and controversy. It postulates that aerosol-induced anomalous mid- and upper-tropospheric warming in the Himalayan foothills and above the Tibetan Plateau leads to an early onset and intensification of Asian monsoon rainfall. This finding is primarily based on results from a NASA finite-volume general circulation model run with and without radiative forcing from different types of aerosols. In particular, black carbon emissions from sources in northern India and dust from Western China, Afghanistan, Pakistan, the Thar Desert, and the Arabian Peninsula drive the modeled anomalous heating. Since the initial discussion of the EHP hypothesis in 2006, the aerosol-monsoon relationship has been investigated using various modeling and observational techniques. The current study takes a novel observational approach to detect signatures of the "elevated heat pump" effect on convection, precipitation, and temperature for contrasting aerosol content years during the period of 2000-2012. The analysis benefits from unique high-resolution convection information inferred from Meteosat-5 observations as available through 2005. Additional data sources include temperature data from the NCEP/NCAR Reanalysis and the European Reanalysis (ERA-Interim) precipitation data from the Global Precipitation Climatology Project (GPCP), aerosol optical depth from the Multi-angle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and aerosol optical properties from the Modern-Era Retrospective Analysis for Research and Applications (MERRA) aerosol reanalysis. Anomalous upper-tropospheric warming and the early onset and intensification of the Indian monsoon were not consistently observed during the years with high loads of absorbing aerosols. Possibly, model assumptions and/or unaccounted semi-direct aerosol effects caused the disagreement between observed and hypothesized behavior.

Long-term variations of aerosol optical depth and aerosol radiative forcing over Iran based on satellite and AERONET data.

PubMed

Arkian, F; Nicholson, S E

2017-12-01

In this study, three different sensors of satellites including the Moderate Resolution Imaging Spectroradiometer (MODIS), Multi-angle Imaging SpectroRadiometer (MISR), and Total Ozone Mapping Spectrometer (TOMS) were used to study spatial and temporal variations of aerosols over ten populated cities in Iran. Also, the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used for analyzing the origins of air masses and their trajectory in the area. An increasing trend in aerosol concentration was observed in the most studied cities in Iran during 1979-2016. The cities in the western part of Iran had the highest annual mean of aerosol concentration. The highest aerosol optical depth (AOD) value (0.76 ± 0.51) was recorded in May 2012 over Ahvaz, and the lowest value (0.035 ± 0.27) was recorded in December 2013 over Tabriz. After Ahvaz, the highest AOD value was found over Tehran (annual mean 0.11 ± 0.20). The results show that AOD increases with increasing industrial activities, but the increased frequency of aerosols due to land degradation and desertification is more powerful in Iran. The trajectory analysis by the HYSPLIT model showed that the air masses come from Egypt, Syria, and Lebanon and passed over the Iraq and then reached to Iran during summer. Aerosol radiative forcing (ARF) has been analyzed for Zanjan (Aerosol Robotic Network site) during 2010-2013. The ARF at surface and top of the atmosphere was found to be ranging from - 79 to - 10W m -2 (average - 33.45 W m -2 ) and from - 25 to 6 W m -2 (average - 12.80 W m -2 ), respectively.

Tropical Atlantic Dust and Smoke Aerosol Variations Related to the Madden-Julian Oscillation in MODIS and MISR Observations

NASA Technical Reports Server (NTRS)

Guo, Yanjuan; Tian, Baijun; Kahn, Ralph A.; Kalashnikova, Olga; Wong, Sun; Waliser, Duane E.

2013-01-01

In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) fine mode fraction and Multi-angle Imaging SpectroRadiometer (MISR) nonspherical fraction data are used to derive dust and smoke aerosol optical thickness (T(sub dust) and T(sub smoke)) over the tropical Atlantic in a complementary way: due to its wider swath, MODIS has 3-4 times greater sampling than MISR, but MISR dust discrimination is based on particle shape retrievals, whereas an empirical scheme is used for MODIS. MODIS and MISR show very similar dust and smoke winter climatologies. T(sub dust) is the dominant aerosol component over the tropical Atlantic, accounting for 40-70 percent of the total aerosol optical thickness (AOT), whereas T(sub smoke) is significantly smaller than T(sub dust). The consistency and high correlation between these climatologies and their daily variations lends confidence to their use for investigating the relative dust and smoke contributions to the total AOT variation associated with the Madden-Julian Oscillation (MJO). The temporal evolution and spatial patterns of the tdus anomalies associated with the MJO are consistent between MODIS and MISR: the magnitude of MJO-realted T(sub dust) anomalies is comparable to or even larger than that of the total T, while the T(sub smoke) anomaly represents about 15 percent compared to the total, which is quite different from their relative magnitudes to the total T on the climatological time scale. This suggests that dust and smoke are not influenced by the MJO in the same way. Based on correlation analysis, dust is strongly influenced by the MJO-modulated trade wind and precipitation anomalies, and can last as long as one MJO phase, whereas smoke is less affected.

Using Airborne High Spectral Resolution Lidar Data to Evaluate Combined Active Plus Passive Retrievals of Aerosol Extinction Profiles

NASA Technical Reports Server (NTRS)

Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.; Kittaka, C.; Vaughn, M. A.; Remer, L. A.

2010-01-01

We derive aerosol extinction profiles from airborne and space-based lidar backscatter signals by constraining the retrieval with column aerosol optical thickness (AOT), with no need to rely on assumptions about aerosol type or lidar ratio. The backscatter data were acquired by the NASA Langley Research Center airborne High Spectral Resolution Lidar (HSRL) and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. The HSRL also simultaneously measures aerosol extinction coefficients independently using the high spectral resolution lidar technique, thereby providing an ideal data set for evaluating the retrieval. We retrieve aerosol extinction profiles from both HSRL and CALIOP attenuated backscatter data constrained with HSRL, Moderate-Resolution Imaging Spectroradiometer (MODIS), and Multiangle Imaging Spectroradiometer column AOT. The resulting profiles are compared with the aerosol extinction measured by HSRL. Retrievals are limited to cases where the column aerosol thickness is greater than 0.2 over land and 0.15 over water. In the case of large AOT, the results using the Aqua MODIS constraint over water are poorer than Aqua MODIS over land or Terra MODIS. The poorer results relate to an apparent bias in Aqua MODIS AOT over water observed in August 2007. This apparent bias is still under investigation. Finally, aerosol extinction coefficients are derived from CALIPSO backscatter data using AOT from Aqua MODIS for 28 profiles over land and 9 over water. They agree with coincident measurements by the airborne HSRL to within +/-0.016/km +/- 20% for at least two-thirds of land points and within +/-0.028/km +/- 20% for at least two-thirds of ocean points.

Sources, Sinks, and Transatlantic Transport of North African Dust Aerosol: A Multimodel Analysis and Comparison With Remote Sensing Data

NASA Technical Reports Server (NTRS)

Kim, Dongchul; Chin, Mian; Yu, Hongbin; Diehl, Thomas; Tan, Qian; Kahn, Ralph A.; Tsigaridis, Kostas; Bauer, Susanne E.; Takemura, Toshihiko; Pozzoli, Luca;

Evaluation of 3-D Air Quality System Remotely-Sensed Aerosol Optical Depth for the Baltimore/Washington Metropolitan Air Shed

NASA Astrophysics Data System (ADS)

Weber, S. A.; Engel-Cox, J. A.; Hoff, R. M.; Prados, A.; Zhang, H.

2008-12-01

Integrating satellite- and ground-based aerosol optical depth (AOD) observations with surface total fine particulate (PM2.5) and sulfate concentrations allows for a more comprehensive understanding of local- and urban-scale air quality. This study evaluates the utility of integrated databases being developed for NOAA and EPA through the 3D-AQS project by examining the relationship between remotely-sensed AOD and PM2.5 concentrations for each platform for the summer of 2004 and the entire year of 2005. We compare results for the Baltimore, MD/Washington, DC metropolitan air shed, incorporating AOD products from the Terra and GOES-12 satellites, AERONET sunphotometer, and ground-based lidar, and PM2.5 concentrations from five surface monitoring sites. The satellite-derived products include AOD from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR), as well as the GOES Aerosol/Smoke Product (GASP). The vertical profile of lidar backscatter is used to retrieve the planetary boundary layer (PBL) height in an attempt to capture only that fraction of the AOD arising from near surface aerosols. Adjusting the AOD data using platform- and season-specific ratios, calculated using the parameters of the regression equations, for two case studies resulted in a more accurate representation of surface PM2.5 concentrations when compared to a constant ratio that is currently being used in the NOAA IDEA product. This work demonstrates that quantitative relationships between remotely-sensed and in-situ aerosol observations in an integrated database can be computed and applied to improve the use of remotely-sensed observations for estimating surface concentrations.

MISR Aerosol Product Attributes and Statistical Comparisons with MODIS

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.; Nelson, David L.; Garay, Michael J.; Levy, Robert C.; Bull, Michael A.; Diner, David J.; Martonchik, John V.; Paradise, Susan R.; Hansen, Earl G.; Remer, Lorraine A.

2009-01-01

In this paper, Multi-angle Imaging SpectroRadiometer (MISR) aerosol product attributes are described, including geometry and algorithm performance flags. Actual retrieval coverage is mapped and explained in detail using representative global monthly data. Statistical comparisons are made with coincident aerosol optical depth (AOD) and Angstrom exponent (ANG) retrieval results from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The relationship between these results and the ones previously obtained for MISR and MODIS individually, based on comparisons with coincident ground-truth observations, is established. For the data examined, MISR and MODIS each obtain successful aerosol retrievals about 15% of the time, and coincident MISR-MODIS aerosol retrievals are obtained for about 6%-7% of the total overlap region. Cloud avoidance, glint and oblique-Sun exclusions, and other algorithm physical limitations account for these results. For both MISR and MODIS, successful retrievals are obtained for over 75% of locations where attempts are made. Where coincident AOD retrievals are obtained over ocean, the MISR-MODIS correlation coefficient is about 0.9; over land, the correlation coefficient is about 0.7. Differences are traced to specific known algorithm issues or conditions. Over-ocean ANG comparisons yield a correlation of 0.67, showing consistency in distinguishing aerosol air masses dominated by coarse-mode versus fine-mode particles. Sampling considerations imply that care must be taken when assessing monthly global aerosol direct radiative forcing and AOD trends with these products, but they can be used directly for many other applications, such as regional AOD gradient and aerosol air mass type mapping and aerosol transport model validation. Users are urged to take seriously the published product data-quality statements.

Online Simulations of Global Aerosol Distributions in the NASA GEOS-4 Model and Comparisons to Satellite and Ground-Based Aerosol Optical Depth

NASA Technical Reports Server (NTRS)

Colarco, Peter; daSilva, Arlindo; Chin, Mian; Diehl, Thomas

2010-01-01

We have implemented a module for tropospheric aerosols (GO CART) online in the NASA Goddard Earth Observing System version 4 model and simulated global aerosol distributions for the period 2000-2006. The new online system offers several advantages over the previous offline version, providing a platform for aerosol data assimilation, aerosol-chemistry-climate interaction studies, and short-range chemical weather forecasting and climate prediction. We introduce as well a methodology for sampling model output consistently with satellite aerosol optical thickness (AOT) retrievals to facilitate model-satellite comparison. Our results are similar to the offline GOCART model and to the models participating in the AeroCom intercomparison. The simulated AOT has similar seasonal and regional variability and magnitude to Aerosol Robotic Network (AERONET), Moderate Resolution Imaging Spectroradiometer, and Multiangle Imaging Spectroradiometer observations. The model AOT and Angstrom parameter are consistently low relative to AERONET in biomass-burning-dominated regions, where emissions appear to be underestimated, consistent with the results of the offline GOCART model. In contrast, the model AOT is biased high in sulfate-dominated regions of North America and Europe. Our model-satellite comparison methodology shows that diurnal variability in aerosol loading is unimportant compared to sampling the model where the satellite has cloud-free observations, particularly in sulfate-dominated regions. Simulated sea salt burden and optical thickness are high by a factor of 2-3 relative to other models, and agreement between model and satellite over-ocean AOT is improved by reducing the model sea salt burden by a factor of 2. The best agreement in both AOT magnitude and variability occurs immediately downwind of the Saharan dust plume.

Weekly Cycle of Lightning and Associated Patterns of Rainfall, Cloud, and Aerosols over Korea and Adjacent Oceans during Boreal Summer

NASA Technical Reports Server (NTRS)

Kim, Ji-In; Kim, Kyu-Myong

2011-01-01

In this study, we analyze the weekly cycle of lightning over Korea and adjacent oceans and associated variations of aerosols, clouds, precipitation, and atmospheric circulations, using aerosol optical depth (AOD) from the NASA Moderate resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging SpectroRadiometer (MISR), cloud properties from MODIS, precipitation and storm height from Tropical Rainfall Measuring Mission (TRMM) satellite, and lightning data from the Korean Lightning Detection Network (KLDN) during 9-year from 2002 to 2010. Lightning data was divided into three approximately equal areas, land area of Korea, and two adjacent oceans, Yellow Sea and South Sea. Preliminary results show that the number of lightning increases during the middle of the week over Yellow Sea. AOD data also shows moderately significant midweek increase at about the same time as lightning peaks. These results are consistent with the recent studies showing the invigoration of storms with more ice hydrometeors by aerosols, and subsequently wash out of aerosols by rainfall. Frequency of lightning strokes tend to peak at weekend in land area and over South Sea, indicating local weekly anomalous circulation between land and adjacent ocean. On the other hand, lightning frequency over Yellow Sea appears to have very strong weekly cycle with midweek peak on around Wednesday. It is speculated that the midweek peak of lightning over Yellow Sea was related with aerosol transport from adjacent land area. AOD data also suggests midweek peak over Yellow Sea, however, the weekly cycle of AOD was not statistically significant. Changes in weekly cycle of lightning from pre-monsoon to monsoon season, as well as associated clouds and circulation patterns are also discussed.

Application of Spectral Analysis Techniques in the Intercomparison of Aerosol Data: Part III. Using Combined PCA to Compare Spatiotemporal Variability of MODIS, MISR and OMI Aerosol Optical Depth

NASA Technical Reports Server (NTRS)

Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

2014-01-01

Satellite measurements of global aerosol properties are very useful in constraining aerosol parameterization in climate models. The reliability of different data sets in representing global and regional aerosol variability becomes an essential question. In this study, we present the results of a comparison using combined principal component analysis (CPCA), applied to monthly mean, mapped (Level 3) aerosol optical depth (AOD) product from Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), and Ozone Monitoring Instrument (OMI). This technique effectively finds the common space-time variability in the multiple data sets by decomposing the combined AOD field. The results suggest that all of the sensors capture the globally important aerosol regimes, including dust, biomass burning, pollution, and mixed aerosol types. Nonetheless, differences are also noted. Specifically, compared with MISR and OMI, MODIS variability is significantly higher over South America, India, and the Sahel. MODIS deep blue AOD has a lower seasonal variability in North Africa, accompanied by a decreasing trend that is not found in either MISR or OMI AOD data. The narrow swath of MISR results in an underestimation of dust variability over the Taklamakan Desert. The MISR AOD data also exhibit overall lower variability in South America and the Sahel. OMI does not capture the Russian wild fire in 2010 nor the phase shift in biomass burning over East South America compared to Central South America, likely due to cloud contamination and the OMI row anomaly. OMI also indicates a much stronger (boreal) winter peak in South Africa compared with MODIS and MISR.

Intercomparison of clumping index estimates from POLDER, MODIS, and MISR satellite data over reference sites

NASA Astrophysics Data System (ADS)

Pisek, Jan; Govind, Ajit; Arndt, Stefan K.; Hocking, Darren; Wardlaw, Timothy J.; Fang, Hongliang; Matteucci, Giorgio; Longdoz, Bernard

2015-03-01

Clumping index is the measure of foliage grouping relative to a random distribution of leaves in space. It is a key structural parameter of plant canopies that influences canopy radiation regimes and controls canopy photosynthesis and other land-atmosphere interactions. The Normalized Difference between Hotspot and Darkspot (NDHD) index has been previously used to retrieve global clumping index maps from POLarization and Directionality of the Earth's Reflectances (POLDER) data at ˜6 km resolution and the Bidirectional Reflectance Distribution Function (BRDF) product from Moderate Resolution Imaging Spectroradiometer (MODIS) at 500 m resolution. Most recently the algorithm was also applied with Multi-angle Imaging SpectroRadiometer (MISR) data at 275 m resolution over selected areas. In this study for the first time we characterized and compared the three products over a set of sites representing diverse biomes and different canopy structures. The products were also directly validated with both in-situ vertical profiles and available seasonal trajectories of clumping index over several sites. We demonstrated that the vertical distribution of foliage and especially the effect of understory need to be taken into account while validating foliage clumping products from remote sensing products with values measured in the field. Satellite measurements responded to the structural effects near the top of canopies, while ground measurements may be biased by the lower vegetation layers. Additionally, caution should be taken regarding the misclassification in land cover maps as their errors can propagate into the foliage clumping maps. Our results indicate that MODIS data and MISR data, with 275 m in particular, can provide good quality clumping index estimates at spatial scales pertinent for modeling local carbon and energy fluxes.

EOS Terra Validation Program

NASA Technical Reports Server (NTRS)

Starr, David

2000-01-01

The EOS Terra mission will be launched in July 1999. This mission has great relevance to the atmospheric radiation community and global change issues. Terra instruments include Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multi-Angle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiometer (MODIS) and Measurements of Pollution in the Troposphere (MOPITT). In addition to the fundamental radiance data sets, numerous global science data products will be generated, including various Earth radiation budget, cloud and aerosol parameters, as well as land surface, terrestrial ecology, ocean color, and atmospheric chemistry parameters. Significant investments have been made in on-board calibration to ensure the quality of the radiance observations. A key component of the Terra mission is the validation of the science data products. This is essential for a mission focused on global change issues and the underlying processes. The Terra algorithms have been subject to extensive pre-launch testing with field data whenever possible. Intensive efforts will be made to validate the Terra data products after launch. These include validation of instrument calibration (vicarious calibration) experiments, instrument and cross-platform comparisons, routine collection of high quality correlative data from ground-based networks, such as AERONET, and intensive sites, such as the SGP ARM site, as well as a variety field experiments, cruises, etc. Airborne simulator instruments have been developed for the field experiment and underflight activities including the MODIS Airborne Simulator (MAS) AirMISR, MASTER (MODIS-ASTER), and MOPITT-A. All are integrated on the NASA ER-2 though low altitude platforms are more typically used for MASTER. MATR is an additional sensor used for MOPITT algorithm development and validation. The intensive validation activities planned for the first year of the Terra mission will be described with emphasis on derived geophysical parameters of most relevance to the atmospheric radiation community.

Global Estimates of Average Ground-Level Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth

NASA Technical Reports Server (NTRS)

Van Donkelaar, A.; Martin, R. V.; Brauer, M.; Kahn, R.; Levy, R.; Verduzco, C.; Villeneuve, P.

2010-01-01

Exposure to airborne particles can cause acute or chronic respiratory disease and can exacerbate heart disease, some cancers, and other conditions in susceptible populations. Ground stations that monitor fine particulate matter in the air (smaller than 2.5 microns, called PM2.5) are positioned primarily to observe severe pollution events in areas of high population density; coverage is very limited, even in developed countries, and is not well designed to capture long-term, lower-level exposure that is increasingly linked to chronic health effects. In many parts of the developing world, air quality observation is absent entirely. Instruments aboard NASA Earth Observing System satellites, such as the MODerate resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging SpectroRadiometer (MISR), monitor aerosols from space, providing once daily and about once-weekly coverage, respectively. However, these data are only rarely used for health applications, in part because the can retrieve the amount of aerosols only summed over the entire atmospheric column, rather than focusing just on the near-surface component, in the airspace humans actually breathe. In addition, air quality monitoring often includes detailed analysis of particle chemical composition, impossible from space. In this paper, near-surface aerosol concentrations are derived globally from the total-column aerosol amounts retrieved by MODIS and MISR. Here a computer aerosol simulation is used to determine how much of the satellite-retrieved total column aerosol amount is near the surface. The five-year average (2001-2006) global near-surface aerosol concentration shows that World Health Organization Air Quality standards are exceeded over parts of central and eastern Asia for nearly half the year.

Impact of the Growing Population and Energy Demand on the Climatic Conditions of the Indo-Gangetic Basin

NASA Astrophysics Data System (ADS)

Singh, R. P.; Prasad, A. K.; Kafatos, M.

2005-12-01

The Indo-Gangetic (IG) basin is one of the largest basins in the world which is densely populated and suffers with dense fog, haze and smog during winter season. About 500 million people live in the IG basin and due to the dense fog, haze and smog day to day life suffers. India is the third largest producer of the coal in the world and a large share is used in power and industrial sector. The coal used in the power plants is of poor quality (mostly E-F grade or lignite) with high ash content (35-50%) and low calorific value. India's energy consumption has increased 208% from 4.16 quadrillion Btu (quads) in 1980 to 12.8 quads in 2001 with a coal share of ~50.9%. Recent studies using satellite (Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR)) and AERONET measurements show high aerosol optical depth (AOD) representing the intense air pollution over the IG basin that persists throughout the year. Such high concentrations of AOD show spatial and temporal variations which are controlled by the meteorological conditions (wind pattern, relative humidity, air temperature etc.) and topography. The high AOD observed over the IG basin is attributed to the emissions of fossil fuel SO2 and black carbon which has increased about 6 fold since 1930. The high AOD over the IG basin is attributed to the huge emission from the dense network of coal based thermal power plants in the IG basin and its surroundings that may be the probable cause for the atmospheric brown clouds (ABC). The impact of aerosol parameters on the climatic conditions will be discussed.

A Seasonal Trend of Single Scattering Albedo in Southern African Biomass-burning Particles: Implications for Satellite Products and Estimates of Emissions for the World's Largest Biomass-burning Source

NASA Technical Reports Server (NTRS)

Eck, T. F.; Holben, B. N.; Reid, J. S.; Mukelabai, M. M.; Piketh, S. J.; Torres, O.; Jethva, H. T.; Hyer, E. J.; Ward, D. E.; Dubovik, O.;

Reducing Multisensor Satellite Monthly Mean Aerosol Optical Depth Uncertainty: 1. Objective Assessment of Current AERONET Locations

NASA Technical Reports Server (NTRS)

Li, Jing; Li, Xichen; Carlson, Barbara E.; Kahn, Ralph A.; Lacis, Andrew A.; Dubovik, Oleg; Nakajima, Teruyuki

2016-01-01

Various space-based sensors have been designed and corresponding algorithms developed to retrieve aerosol optical depth (AOD), the very basic aerosol optical property, yet considerable disagreement still exists across these different satellite data sets. Surface-based observations aim to provide ground truth for validating satellite data; hence, their deployment locations should preferably contain as much spatial information as possible, i.e., high spatial representativeness. Using a novel Ensemble Kalman Filter (EnKF)- based approach, we objectively evaluate the spatial representativeness of current Aerosol Robotic Network (AERONET) sites. Multisensor monthly mean AOD data sets from Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, Sea-viewing Wide Field-of-view Sensor, Ozone Monitoring Instrument, and Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar are combined into a 605-member ensemble, and AERONET data are considered as the observations to be assimilated into this ensemble using the EnKF. The assessment is made by comparing the analysis error variance (that has been constrained by ground-based measurements), with the background error variance (based on satellite data alone). Results show that the total uncertainty is reduced by approximately 27% on average and could reach above 50% over certain places. The uncertainty reduction pattern also has distinct seasonal patterns, corresponding to the spatial distribution of seasonally varying aerosol types, such as dust in the spring for Northern Hemisphere and biomass burning in the fall for Southern Hemisphere. Dust and biomass burning sites have the highest spatial representativeness, rural and oceanic sites can also represent moderate spatial information, whereas the representativeness of urban sites is relatively localized. A spatial score ranging from 1 to 3 is assigned to each AERONET site based on the uncertainty reduction, indicating its representativeness level.

Physical Interpretation of the Correlation Between Multi-Angle Spectral Data and Canopy Height

NASA Technical Reports Server (NTRS)

Schull, M. A.; Ganguly, S.; Samanta, A.; Huang, D.; Shabanov, N. V.; Jenkins, J. P.; Chiu, J. C.; Marshak, A.; Blair, J. B.; Myneni, R. B.;

A target field design of open multi-purpose RF coil for musculoskeletal MR imaging at 3T.

PubMed

Gao, Fei; Zhang, Rui; Zhou, Diange; Wang, Xiaoying; Huang, Kefu; Zhang, Jue

2016-10-01

Musculoskeletal MR imaging under multi-angle situations plays an increasingly important role in assessing joint and muscle tissues system. However, there are still limitations due to the closed structures of most conventional RF coils. In this study, a time-harmonic target-field method was employed to design open multi-purpose coil (OMC) for multi-angle musculoskeletal MR imaging. The phantom imaging results suggested that the proposed OMC could achieve homogeneously distributed magnetic field and high signal-to-noise ratio (SNR) of 239.04±0.83 in the region of interest (ROI). The maximum temperature in the heating hazard test was 16°C lower than the standard regulation, which indicated the security of the designed OMC. Furthermore, to demonstrate the effectiveness of the proposed OMC for musculoskeletal MR imaging, especially for multi-angle imaging, a healthy volunteer was examined for MR imaging of elbow, ankle and knee using OMC. The in vivo imaging results showed that the proposed OMC is effective for MR imaging of musculoskeletal tissues at different body parts, with satisfied B1 field homogeneity and SNR. Moreover, the open structure of the OMC could provide a large joint movement region. The proposed open multi-purpose coil is feasible for musculoskeletal MR imaging, and potentially, it is more suitable for the evaluation of musculoskeletal tissues under multi-angle conditions. Copyright © 2016. Published by Elsevier Inc.

10-year spatial and temporal trends of PM2.5 concentrations in the southeastern US estimated using high-resolution satellite data

PubMed Central

Hu, X.; Waller, L. A.; Lyapustin, A.; Wang, Y.; Liu, Y.

2017-01-01

Long-term PM2.5 exposure has been associated with various adverse health outcomes. However, most ground monitors are located in urban areas, leading to a potentially biased representation of true regional PM2.5 levels. To facilitate epidemiological studies, accurate estimates of the spatiotemporally continuous distribution of PM2.5 concentrations are important. Satellite-retrieved aerosol optical depth (AOD) has been increasingly used for PM2.5 concentration estimation due to its comprehensive spatial coverage. Nevertheless, previous studies indicated that an inherent disadvantage of many AOD products is their coarse spatial resolution. For instance, the available spatial resolutions of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging SpectroRadiometer (MISR) AOD products are 10 and 17.6 km, respectively. In this paper, a new AOD product with 1 km spatial resolution retrieved by the multi-angle implementation of atmospheric correction (MAIAC) algorithm based on MODIS measurements was used. A two-stage model was developed to account for both spatial and temporal variability in the PM2.5–AOD relationship by incorporating the MAIAC AOD, meteorological fields, and land use variables as predictors. Our study area is in the southeastern US centered at the Atlanta metro area, and data from 2001 to 2010 were collected from various sources. The model was fitted annually, and we obtained model fitting R2 ranging from 0.71 to 0.85, mean prediction error (MPE) from 1.73 to 2.50 μg m−3, and root mean squared prediction error (RMSPE) from 2.75 to 4.10 μg m−3. In addition, we found cross-validation R2 ranging from 0.62 to 0.78, MPE from 2.00 to 3.01 μgm−3, and RMSPE from 3.12 to 5.00 μgm−3, indicating a good agreement between the estimated and observed values. Spatial trends showed that high PM2.5 levels occurred in urban areas and along major highways, while low concentrations appeared in rural or mountainous areas. Our time-series analysis showed that, for the 10-year study period, the PM2.5 levels in the southeastern US have decreased by ∼20 %. The annual decrease has been relatively steady from 2001 to 2007 and from 2008 to 2010 while a significant drop occurred between 2007 and 2008. An observed increase in PM2.5 levels in year 2005 is attributed to elevated sulfate concentrations in the study area in warm months of 2005. PMID:28966656

Clouds and Ice of the Lambert-Amery System, East Antarctica

NASA Technical Reports Server (NTRS)

2002-01-01

These views from the Multi-angle Imaging SpectroRadiometer (MISR) illustrate ice surface textures and cloud-top heights over the Amery Ice Shelf/Lambert Glacier system in East Antarctica on October 25, 2002.

The left-hand panel is a natural-color view from MISR's downward-looking (nadir) camera. The center panel is a multi-angular composite from three MISR cameras, in which color acts as a proxy for angular reflectance variations related to texture. Here, data from the red-band of MISR's 60o forward-viewing, nadir and 60o backward-viewing cameras are displayed as red, green and blue, respectively. With this display technique, surfaces which predominantly exhibit backward-scattering (generally rough surfaces) appear red/orange, while surfaces which predominantly exhibit forward-scattering (generally smooth surfaces) appear blue. Textural variation for both the grounded and sea ice are apparent. The red/orange pixels in the lower portion of the image correspond with a rough and crevassed region near the grounding zone, that is, the area where the Lambert and four other smaller glaciers merge and the ice starts to float as it forms the Amery Ice Shelf. In the natural-color view, this rough ice is spectrally blue in color.

Clouds exhibit both forward and backward-scattering properties in the middle panel and thus appear purple, in distinct contrast with the underlying ice and snow. An additional multi-angular technique for differentiating clouds from ice is shown in the right-hand panel, which is a stereoscopically derived height field retrieved using automated pattern recognition involving data from multiple MISR cameras. Areas exhibiting insufficient spatial contrast for stereoscopic retrieval are shown in dark gray. Clouds are apparent as a result of their heights above the surface terrain. Polar clouds are an important factor in weather and climate. Inadequate characterization of cloud properties is currently responsible for large uncertainties in climate prediction models. Identification of polar clouds, mapping of their distributions, and retrieval of their heights provide information that will help to reduce this uncertainty.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire Earth between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 15171. The panels cover an area of 380 kilometers x 984 kilometers, and utilize data from blocks 145 to 151 within World Reference System-2 path 127.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center,Greenbelt, MD. JPL is a division of the California Institute of Technology.

A method for automatic grain segmentation of multi-angle cross-polarized microscopic images of sandstone

NASA Astrophysics Data System (ADS)

Jiang, Feng; Gu, Qing; Hao, Huizhen; Li, Na; Wang, Bingqian; Hu, Xiumian

2018-06-01

Automatic grain segmentation of sandstone is to partition mineral grains into separate regions in the thin section, which is the first step for computer aided mineral identification and sandstone classification. The sandstone microscopic images contain a large number of mixed mineral grains where differences among adjacent grains, i.e., quartz, feldspar and lithic grains, are usually ambiguous, which make grain segmentation difficult. In this paper, we take advantage of multi-angle cross-polarized microscopic images and propose a method for grain segmentation with high accuracy. The method consists of two stages, in the first stage, we enhance the SLIC (Simple Linear Iterative Clustering) algorithm, named MSLIC, to make use of multi-angle images and segment the images as boundary adherent superpixels. In the second stage, we propose the region merging technique which combines the coarse merging and fine merging algorithms. The coarse merging merges the adjacent superpixels with less evident boundaries, and the fine merging merges the ambiguous superpixels using the spatial enhanced fuzzy clustering. Experiments are designed on 9 sets of multi-angle cross-polarized images taken from the three major types of sandstones. The results demonstrate both the effectiveness and potential of the proposed method, comparing to the available segmentation methods.

Remote Sensing of Radiative and Microphysical Properties of Clouds During TC (sup 4): Results from MAS, MASTER, MODIS, and MISR

NASA Technical Reports Server (NTRS)

King, Michael D.; Platnick, Steven; Wind, Galina; Arnold, G. Thomas; Dominguez, Roseanne T.

2010-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator (MAS) and MODIS/Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Airborne Simulator (MASTER) were used to obtain measurements of the bidirectional reflectance and brightness temperature of clouds at 50 discrete wavelengths between 0.47 and 14.2 microns (12.9 microns for MASTER). These observations were obtained from the NASA ER-2 aircraft as part of the Tropical Composition, Cloud and Climate Coupling (TC4) experiment conducted over Central America and surrounding Pacific and Atlantic Oceans between 17 July and 8 August 2007. Multispectral images in eleven distinct bands were used to derive a confidence in clear sky (or alternatively the probability Of cloud) over land and ocean ecosystems. Based on the results of individual tests run as part of the cloud mask, an algorithm was developed to estimate the phase of the clouds (liquid water, ice, or undetermined phase). The cloud optical thickness and effective radius were derived for both liquid water and ice clouds that were detected during each flight, using a nearly identical algorithm to that implemented operationally to process MODIS Cloud data from the Aqua and Terra satellites (Collection 5). This analysis shows that the cloud mask developed for operational use on MODIS, and tested using MAS and MASTER data in TC(sup 4), is quite capable of distinguishing both liquid water and ice clouds during daytime conditions over both land and ocean. The cloud optical thickness and effective radius retrievals use five distinct bands of the MAS (or MASTER), and these results were compared with nearly simultaneous retrievals of marine liquid water clouds from MODIS on the Terra spacecraft. Finally, this MODIS-based algorithm was adapted to Multiangle Imaging SpectroRadiometer (MISR) data to infer the cloud optical thickness Of liquid water clouds from MISR. Results of this analysis are compared and contrasted.

Bathymetric mapping of submarine sand waves using multiangle sun glitter imagery: a case of the Taiwan Banks with ASTER stereo imagery

NASA Astrophysics Data System (ADS)

Zhang, Hua-guo; Yang, Kang; Lou, Xiu-lin; Li, Dong-ling; Shi, Ai-qin; Fu, Bin

2015-01-01

Submarine sand waves are visible in optical sun glitter remote sensing images and multiangle observations can provide valuable information. We present a method for bathymetric mapping of submarine sand waves using multiangle sun glitter information from Advanced Spaceborne Thermal Emission and Reflection Radiometer stereo imagery. Based on a multiangle image geometry model and a sun glitter radiance transfer model, sea surface roughness is derived using multiangle sun glitter images. These results are then used for water depth inversions based on the Alpers-Hennings model, supported by a few true depth data points (sounding data). Case study results show that the inversion and true depths match well, with high-correlation coefficients and root-mean-square errors from 1.45 to 2.46 m, and relative errors from 5.48% to 8.12%. The proposed method has some advantages over previous methods in that it requires fewer true depth data points, it does not require environmental parameters or knowledge of sand-wave morphology, and it is relatively simple to operate. On this basis, we conclude that this method is effective in mapping submarine sand waves and we anticipate that it will also be applicable to other similar topography types.

Deep Ocean Tsunami Waves off the Sri Lankan Coast

NASA Technical Reports Server (NTRS)

2004-01-01

The initial tsunami waves resulting from the undersea earthquake that occurred at 00:58:53 UTC (Coordinated Universal Time) on December 26, 2004, off the island of Sumatra, Indonesia, took a little over 2 hours to reach the teardrop-shaped island of Sri Lanka. Additional waves continued to arrive for many hours afterward. At approximately 05:15 UTC, as NASA's Terra satellite passed overhead, the Multi-angle Imaging SpectroRadiometer (MISR) captured this image of deep ocean tsunami waves about 30-40 kilometers from Sri Lanka's southwestern coast. The waves are made visible due to the effects of changes in sea-surface slope on the reflected sunglint pattern, shown here in MISR's 46-degree-forward-pointing camera. Sunglint occurs when sunlight reflects off a water surface in much the same way light reflects off a mirror, and the position of the Sun, angle of observation, and orientation of the sea surface determines how bright each part of the ocean appears in the image. These large wave features were invisible to MISR's nadir (vertical-viewing) camera. The image covers an area of 208 kilometers by 207 kilometers. The greatest impact of the tsunami was generally in an east-west direction, so the havoc caused by the tsunami along the southwestern shores of Sri Lanka was not as severe as along the eastern coast. However, substantial damage did occur in this region' as evidenced by the brownish debris in the water' because tsunami waves can diffract around land masses. The ripple-like wave pattern evident in this MISR image roughly correlates with the undersea boundary of the continental shelf. The surface wave pattern is likely to have been caused by interaction of deep waves with the ocean floor, rather than by the more usually observed surface waves, which are driven by winds. It is possible that this semi-concentric pattern represents wave reflection from the continental land mass; however, a combination of wave modeling and detailed bathymetric data is required to fully understand the dynamics. Examination of other MISR images of this area, taken under similar illumination conditions, has not uncovered any surface patterns resembling those seen here. This image is an example of how MISR's multi-angular capability provides unique information for understanding how tsunamis propagate. Another application of MISR data enabled scientists to measure the motion of breaking tsunami waves along the eastern shores of Andhra Pradesh, India. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees North and 82 degrees South latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 85 to 86 within World Reference System-2 path 142. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. Text by Clare Averill (Raytheon ITSS/JPL); Michael Garay and David J. Diner (JPL, California Institute of Technology); and Vasily Titov (NOAA/Pacific Marine Environmental Laboratory and University of Washington/Joint Institute for the Study of the Atmosphere and Oceans).

Birth of a Large Iceberg in Pine Island Bay, Antarctica

NASA Image and Video Library

2001-11-14

A large tabular iceberg (42 kilometers x 17 kilometers) broke off Pine Island Glacier, West Antarctica (75ºS latitude, 102ºW longitude) sometime between November 4 and 12, 2001. Images of the glacier were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra spacecraft. This event was preceded by the formation of a large crack across the glacier in mid 2000. Data gathered by other imaging instruments revealed the crack to be propagating through the shelf ice at a rate averaging 15 meters per day, accompanied by a slight rotation of about one percent per year at the seaward margin of the rift. The image set shows three views of Pine Island Glacier acquired by MISR's vertical-viewing (nadir) camera. The first was captured in late 2000, early in the development of the crack. The second and third views were acquired in November 2001, just before and just after the new iceberg broke off. The existence of the crack took the glaciological community by surprise, and the rapid rate at which the crack propagated was also not anticipated. Glaciologists predicted that the rift would reach the other side of the glacier sometime in 2002. However, the iceberg detached much sooner than anticipated, and the last 10-kilometer segment that was still attached to the ice shelf snapped off in a matter of days. http://photojournal.jpl.nasa.gov/catalog/PIA03431

Angular difference feature extraction for urban scene classification using ZY-3 multi-angle high-resolution satellite imagery

NASA Astrophysics Data System (ADS)

Huang, Xin; Chen, Huijun; Gong, Jianya

2018-01-01

Spaceborne multi-angle images with a high-resolution are capable of simultaneously providing spatial details and three-dimensional (3D) information to support detailed and accurate classification of complex urban scenes. In recent years, satellite-derived digital surface models (DSMs) have been increasingly utilized to provide height information to complement spectral properties for urban classification. However, in such a way, the multi-angle information is not effectively exploited, which is mainly due to the errors and difficulties of the multi-view image matching and the inaccuracy of the generated DSM over complex and dense urban scenes. Therefore, it is still a challenging task to effectively exploit the available angular information from high-resolution multi-angle images. In this paper, we investigate the potential for classifying urban scenes based on local angular properties characterized from high-resolution ZY-3 multi-view images. Specifically, three categories of angular difference features (ADFs) are proposed to describe the angular information at three levels (i.e., pixel, feature, and label levels): (1) ADF-pixel: the angular information is directly extrapolated by pixel comparison between the multi-angle images; (2) ADF-feature: the angular differences are described in the feature domains by comparing the differences between the multi-angle spatial features (e.g., morphological attribute profiles (APs)). (3) ADF-label: label-level angular features are proposed based on a group of urban primitives (e.g., buildings and shadows), in order to describe the specific angular information related to the types of primitive classes. In addition, we utilize spatial-contextual information to refine the multi-level ADF features using superpixel segmentation, for the purpose of alleviating the effects of salt-and-pepper noise and representing the main angular characteristics within a local area. The experiments on ZY-3 multi-angle images confirm that the proposed ADF features can effectively improve the accuracy of urban scene classification, with a significant increase in overall accuracy (3.8-11.7%) compared to using the spectral bands alone. Furthermore, the results indicated the superiority of the proposed ADFs in distinguishing between the spectrally similar and complex man-made classes, including roads and various types of buildings (e.g., high buildings, urban villages, and residential apartments).

Vegetation chlorophyll estimates in the Amazon from multi-angle MODIS observations and canopy reflectance model

NASA Astrophysics Data System (ADS)

Hilker, Thomas; Galvão, Lênio Soares; Aragão, Luiz E. O. C.; de Moura, Yhasmin M.; do Amaral, Cibele H.; Lyapustin, Alexei I.; Wu, Jin; Albert, Loren P.; Ferreira, Marciel José; Anderson, Liana O.; dos Santos, Victor A. H. F.; Prohaska, Neill; Tribuzy, Edgard; Barbosa Ceron, João Vitor; Saleska, Scott R.; Wang, Yujie; de Carvalho Gonçalves, José Francisco; de Oliveira Junior, Raimundo Cosme; Cardoso Rodrigues, João Victor Figueiredo; Garcia, Maquelle Neves

2017-06-01

As a preparatory study for future hyperspectral missions that can measure canopy chemistry, we introduce a novel approach to investigate whether multi-angle Moderate Resolution Imaging Spectroradiometer (MODIS) data can be used to generate a preliminary database with long-term estimates of chlorophyll. MODIS monthly chlorophyll estimates between 2000 and 2015, derived from a fully coupled canopy reflectance model (ProSAIL), were inspected for consistency with eddy covariance fluxes, tower-based hyperspectral images and chlorophyll measurements. MODIS chlorophyll estimates from the inverse model showed strong seasonal variations across two flux-tower sites in central and eastern Amazon. Marked increases in chlorophyll concentrations were observed during the early dry season. Remotely sensed chlorophyll concentrations were correlated to field measurements (r2 = 0.73 and r2 = 0.98) but the data deviated from the 1:1 line with root mean square errors (RMSE) ranging from 0.355 μg cm-2 (Tapajós tower) to 0.470 μg cm-2 (Manaus tower). The chlorophyll estimates were consistent with flux tower measurements of photosynthetically active radiation (PAR) and net ecosystem productivity (NEP). We also applied ProSAIL to mono-angle hyperspectral observations from a camera installed on a tower to scale modeled chlorophyll pigments to MODIS observations (r2 = 0.73). Chlorophyll pigment concentrations (ChlA+B) were correlated to changes in the amount of young and mature leaf area per month (0.59 ≤ r2 ≤ 0.64). Increases in MODIS observed ChlA+B were preceded by increased PAR during the dry season (0.61 ≤ r2 ≤ 0.62) and followed by changes in net carbon uptake. We conclude that, at these two sites, changes in LAI, coupled with changes in leaf chlorophyll, are comparable with seasonality of plant productivity. Our results allowed the preliminary development of a 15-year time series of chlorophyll estimates over the Amazon to support canopy chemistry studies using future hyperspectral sensors.

Method of lungs regional ventilation function assessment on the basis of continuous lung monitoring results using multi-angle electrical impedance tomography

NASA Astrophysics Data System (ADS)

Aleksanyan, Grayr; Shcherbakov, Ivan; Kucher, Artem; Sulyz, Andrew

2018-04-01

With continuous monitoring of the lungs using multi-angle electric impedance tomography method, a large array of images of impedance changes in the patient's chest cavity is accumulated. This article proposes a method for evaluating the regional ventilation function of lungs based on the results of continuous monitoring using the multi-angle electric impedance tomography method, which allows one image of the thoracic cavity to be formed on the basis of a large array of images of the impedance change in the patient's chest cavity. In the presence of pathologies in the lungs (neoplasms, fluid, pneumothorax, etc.) in these areas, air filling will be disrupted, which will be displayed on the generated image. When conducting continuous monitoring in several sections, a three-dimensional pattern of air filling of the thoracic cavity is possible.

Drought in the Black Hills

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Annotated Color-Coded Map

Despite good rainfall and record-setting snowstorms in the spring of 2005, most of northeastern Wyoming, the Black Hills, and western South Dakota remain in the midst of a severe drought. This set of images and maps from NASA's Multi-angle Imaging SpectroRadiometer (MISR) contrast the appearance of the Black Hills region of northwestern South Dakota on July 12, 2000 (left column), with views acquired four years later, on July 14, 2004 (right column). The natural-color images along the top are from MISR's nadir (downward-looking) camera. The browning that appears in 2004 compared with 2000 indicates that the vigor of green vegetation was significantly diminished in 2004.

The color-coded maps (along the bottom) provide a quantitative measurement of the sunlight reflected from these surfaces, and the loss of sunlight-absorbing vegetation between the 2000 and 2004 dates. As the vegetation faded with the drought, the albedo at the surface increased. Albedo measures the fraction of incident sunlight that is reflected by a surface, and can vary between zero (if all the incident sunlight is absorbed and none is reflected) and one (if all sunlight is reflected and none is absorbed). Dense forest has a low albedo; bright desert, snow and clouds, have a high albedo. Here, albedo is provided for the wavelengths of sunlight that plants use for photosynthesis (400 - 700 nanometers). This measurement is known as the albedo for Photosynthetically Active Radiation (PAR). Surfaces with greater absorption of PAR appear here in blue hues, whereas surfaces with lower absorption appear as green, yellow, orange or red. Black pixels indicate areas where albedo could not be derived, usually due to the presence of clouds. In July 2004, low albedo areas (blue pixels) are notably reduced in extent, and higher albedo areas (yellow, orange and red pixels) have increased.

Because incoming sunlight is scattered by tiny particles in the atmosphere, satellite measurements of albedo and other surface properties must correct for the effects of the intervening atmosphere. These albedo retrievals make use of MISR's simultaneously derived aerosol properties to make these corrections. The multiangular nature of MISR data is also used to account for the fact that most surfaces reflect sunlight into all upward directions, with intensities that vary with angle of view.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. This image area covers about 243 kilometers by 259 kilometers. These data products were generated from a portion of the imagery acquired during Terra orbits 3020 and 24325 and utilize data from within blocks 54 to 56 within World Reference System-2 paths 33 and 34.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

America National Parks Viewed in 3D by NASA MISR Anaglyph 3

NASA Image and Video Library

2016-08-25

Just in time for the U.S. National Park Service's Centennial celebration on Aug. 25, NASA's Multiangle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite is releasing four new anaglyphs that showcase 33 of our nation's national parks, monuments, historical sites and recreation areas in glorious 3D. Shown in the annotated image are Lewis and Clark National Historic Park, Mt. Rainier National Park, Olympic National Park, Ebey's Landing National Historical Reserve, San Juan Island National Historic Park, North Cascades National Park, Lake Chelan National Recreation Area, and Ross Lake National Recreation Area (also Mt. St. Helens National Volcanic Monument, administered by the U.S. Forest Service) MISR views Earth with nine cameras pointed at different angles, giving it the unique capability to produce anaglyphs, stereoscopic images that allow the viewer to experience the landscape in three dimensions. The anaglyphs were made by combining data from MISR's vertical-viewing and 46-degree forward-pointing camera. You will need red-blue glasses in order to experience the 3D effect; ensure you place the red lens over your left eye. The images have been rotated so that north is to the left in order to enable 3D viewing because the Terra satellite flies from north to south. All of the images are 235 miles (378 kilometers) from west to east. These data were acquired May 12, 2012, Orbit 65960. http://photojournal.jpl.nasa.gov/catalog/PIA20891

America National Parks Viewed in 3D by NASA MISR Anaglyph 1

NASA Image and Video Library

2016-08-25

Just in time for the U.S. National Park Service's Centennial celebration on Aug. 25, NASA's Multiangle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite is releasing four new anaglyphs that showcase 33 of our nation's national parks, monuments, historical sites and recreation areas in glorious 3D. Shown in the annotated image are Walnut Canyon National Monument, Sunset Crater Volcano National Monument, Wupatki National Monument, Grand Canyon National Park, Pipe Spring National Monument, Zion National Park, Cedar Breaks National Monument, Bryce Canyon National Park, Capitol Reef National Park, Navajo National Monument, Glen Canyon National Recreation Area, Natural Bridges National Monument, Canyonlands National Park, and Arches National Park. MISR views Earth with nine cameras pointed at different angles, giving it the unique capability to produce anaglyphs, stereoscopic images that allow the viewer to experience the landscape in three dimensions. The anaglyphs were made by combining data from MISR's vertical-viewing and 46-degree forward-pointing camera. You will need red-blue glasses in order to experience the 3D effect; ensure you place the red lens over your left eye. The images have been rotated so that north is to the left in order to enable 3D viewing because the Terra satellite flies from north to south. All of the images are 235 miles (378 kilometers) from west to east. These data were acquired June 18, 2016, Orbit 87774. http://photojournal.jpl.nasa.gov/catalog/PIA20889

Amery Ice Shelf's 'Loose Tooth' Gets Looser

NASA Technical Reports Server (NTRS)

2002-01-01

The Amery Ice Shelf is an important dynamic system responsible for draining about 16% of the grounded East Antarctic ice sheet through only 2% of its coastline. Most of the mass input to the system occurs from the Lambert and several other glaciers. Mass loss from the system occurs through basal melting and iceberg calving. These images from the Multi-angle Imaging SpectroRadiometer (MISR) portray the ice shelf front on October 6, 2001 (top) and September 29, 2002 (bottom), and illustrate changes that took place over the year elapsed between the two views.

Two longitudinal rifts, oriented roughly parallel to the direction of ice flow and measuring about 25 and 15 kilometers in length, are apparent near the seaward edge of the ice shelf. Between them, a transverse fracture extends eastward from the base of the western rift. This rift system is colloquially named the Amery 'loose tooth.' Over the course of the one-year interval between these two MISR images, the ice front has advanced approximately 1.6 - 1.7 kilometers, and the transverse fracture and a three-way fissure at the juncture of the rifts have widened. When the transverse fracture eventually reaches the eastern rift, a large iceberg (25 kilometers x 25 kilometers) will be released.

These false-color multi-angle composites combine red-band data from MISR's 60o forward, nadir, and 60o aftward viewing cameras, displayed as red, green and blue, respectively. Different colors represent angular reflectance variations. Since generally smooth surfaces predominantly forward-scatter sunlight, these appear in shades of blue. Rough surfaces tend to backward-scatter sunlight, and these appear in shades of red or orange. Low clouds appear bright purple, since they exhibit both forward and backward-scattering. Using this technique, textural variations among ice types are revealed, and clouds can be easily distinguished from ice. Illumination conditions on the two dates are nearly identical.

Understanding the 'normal' frequency of calving events from a particular ice shelf is necessary before it can be determined whether calving rates are changing. As part of an effort to determine the normal rate of ice flow and iceberg calving events, the Amery Ice Shelf front has been monitored by various remote sensing instruments for many years. The Amery Ice Shelf is currently considered to be about two-thirds of the way through a calving cycle. The last major calving event occurred in the early 1960's, when a massive iceberg (measuring about 140 kilometers x 70 kilometers) was released.

The Amery 'loose tooth' is the subject of a joint field experiment during the 2002 austral summer, partially funded by NASA and undertaken by the Scripps Institution of Oceanography and the Australian Antarctic Division. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 9579 and 14807. The panels cover an area of about 204 kilometers x 110 kilometers, and utilize data from blocks 146 to 147 within World Reference System-2 paths 127 and 128, respectively. Data from the two orbital paths have been remapped to identical polar projections, and were cropped to include the same geographic area.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center,Greenbelt, MD. JPL is a division of the California Institute of Technology.

Introducing MISR Version 23: Resolution and Content Improvements to MISR Aerosol and Land Surface Product

NASA Astrophysics Data System (ADS)

Garay, M. J.; Bull, M. A.; Witek, M. L.; Diner, D. J.; Seidel, F.

2017-12-01

Since early 2000, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite has been providing operational Level 2 (swath-based) aerosol optical depth (AOD) and particle property retrievals at 17.6 km spatial resolution and atmospherically corrected land surface products at 1.1 km resolution. A major, multi-year development effort has led to the release of updated operational MISR Level 2 aerosol and land surface retrieval products. The spatial resolution of the aerosol product has been increased to 4.4 km, allowing more detailed characterization of aerosol spatial variability, especially near local sources and in urban areas. The product content has been simplified and updated to include more robust measures of retrieval uncertainty and other fields to benefit users. The land surface product has also been updated to incorporate the Version 23 aerosol product as input and to improve spatial coverage, particularly over mountainous terrain and snow/ice-covered surfaces. We will describe the major upgrades incorporated in Version 23, present validation of the aerosol product, and describe some of the applications enabled by these product updates.

Retrieval of cloud properties from POLDER-3 data using the neural network approach

NASA Astrophysics Data System (ADS)

Di Noia, A.; Hasekamp, O. P.

2017-12-01

Satellite multi-angle spectroplarimetry is a useful technique for observing the microphysical properties of clouds and aerosols. Most of the algorithms for the retrieval of cloud and aerosol properties from satellite measurements require multiple calls to radiative transfer models, which make the retrieval computationally expensive. A traditional alternative to these schemes is represented by lookup-tables (LUTs), where the retrieval is performed by choosing, within a predefined database of combinations of clouds or aerosol properties, the combination that best fits the measurements. LUT retrievals are quicker than full-physics, iterative retrievals, but their accuracy is limited by the number of entries stored in the LUT. Another retrieval method capable of producing very quick retrievals without a big sacrifice in accuracy is the neural network method. Neural network methods are routinely applied to several types of satellite measurements, but their application to multi-angle spectropolarimetric data is still in its early stage, because of the difficulty of accounting for the angular variability of the measurements in the training process. We have recently developed a neural network scheme for the retrieval of cloud properties from POLDER-3 data. The neural network retrieval is trained using synthetic measurements performed for realistic combinations of cloud properties and measurement angles, and is able to process an entire orbit in about 20 seconds. Comparisons of the retrieved cloud properties with Moderate Resolution Imaging Spectroradiometer (MODIS) gridded products during one year show encouraging retrieval performance for cloud optical thickness and effective radius. A discussion of the setup of the neural network and of the validation results will be the main topic of our presentation.

Multi-Angle Implementation of Atmospheric Correction for MODIS (MAIAC). Part 3: Atmospheric Correction

NASA Technical Reports Server (NTRS)

Lyapustin, A.; Wang, Y.; Laszlo, I.; Hilker, T.; Hall, F.; Sellers, P.; Tucker, J.; Korkin, S.

2012-01-01

This paper describes the atmospheric correction (AC) component of the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC) which introduces a new way to compute parameters of the Ross-Thick Li-Sparse (RTLS) Bi-directional reflectance distribution function (BRDF), spectral surface albedo and bidirectional reflectance factors (BRF) from satellite measurements obtained by the Moderate Resolution Imaging Spectroradiometer (MODIS). MAIAC uses a time series and spatial analysis for cloud detection, aerosol retrievals and atmospheric correction. It implements a moving window of up to 16 days of MODIS data gridded to 1 km resolution in a selected projection. The RTLS parameters are computed directly by fitting the cloud-free MODIS top of atmosphere (TOA) reflectance data stored in the processing queue. The RTLS retrieval is applied when the land surface is stable or changes slowly. In case of rapid or large magnitude change (as for instance caused by disturbance), MAIAC follows the MODIS operational BRDF/albedo algorithm and uses a scaling approach where the BRDF shape is assumed stable but its magnitude is adjusted based on the latest single measurement. To assess the stability of the surface, MAIAC features a change detection algorithm which analyzes relative change of reflectance in the Red and NIR bands during the accumulation period. To adjust for the reflectance variability with the sun-observer geometry and allow comparison among different days (view geometries), the BRFs are normalized to the fixed view geometry using the RTLS model. An empirical analysis of MODIS data suggests that the RTLS inversion remains robust when the relative change of geometry-normalized reflectance stays below 15%. This first of two papers introduces the algorithm, a second, companion paper illustrates its potential by analyzing MODIS data over a tropical rainforest and assessing errors and uncertainties of MAIAC compared to conventional MODIS products.

A calibrated iterative reconstruction for quantitative photoacoustic tomography using multi-angle light-sheet illuminations

NASA Astrophysics Data System (ADS)

Wang, Yihan; Lu, Tong; Zhang, Songhe; Song, Shaoze; Wang, Bingyuan; Li, Jiao; Zhao, Huijuan; Gao, Feng

2018-02-01

Quantitative photoacoustic tomography (q-PAT) is a nontrivial technique can be used to reconstruct the absorption image with a high spatial resolution. Several attempts have been investigated by setting point sources or fixed-angle illuminations. However, in practical applications, these schemes normally suffer from low signal-to-noise ratio (SNR) or poor quantification especially for large-size domains, due to the limitation of the ANSI-safety incidence and incompleteness in the data acquisition. We herein present a q-PAT implementation that uses multi-angle light-sheet illuminations and a calibrated iterative multi-angle reconstruction. The approach can acquire more complete information on the intrinsic absorption and SNR-boosted photoacoustic signals at selected planes from the multi-angle wide-field excitations of light-sheet. Therefore, the sliced absorption maps over whole body can be recovered in a measurementflexible, noise-robust and computation-economic way. The proposed approach is validated by the phantom experiment, exhibiting promising performances in image fidelity and quantitative accuracy.

Spacebased Estimation of Moisture Transport in Marine Atmosphere Using Support Vector Regression

NASA Technical Reports Server (NTRS)

Xie, Xiaosu; Liu, W. Timothy; Tang, Benyang

2007-01-01

An improved algorithm is developed based on support vector regression (SVR) to estimate horizonal water vapor transport integrated through the depth of the atmosphere ((Theta)) over the global ocean from observations of surface wind-stress vector by QuikSCAT, cloud drift wind vector derived from the Multi-angle Imaging SpectroRadiometer (MISR) and geostationary satellites, and precipitable water from the Special Sensor Microwave/Imager (SSM/I). The statistical relation is established between the input parameters (the surface wind stress, the 850 mb wind, the precipitable water, time and location) and the target data ((Theta) calculated from rawinsondes and reanalysis of numerical weather prediction model). The results are validated with independent daily rawinsonde observations, monthly mean reanalysis data, and through regional water balance. This study clearly demonstrates the improvement of (Theta) derived from satellite data using SVR over previous data sets based on linear regression and neural network. The SVR methodology reduces both mean bias and standard deviation comparedwith rawinsonde observations. It agrees better with observations from synoptic to seasonal time scales, and compare more favorably with the reanalysis data on seasonal variations. Only the SVR result can achieve the water balance over South America. The rationale of the advantage by SVR method and the impact of adding the upper level wind will also be discussed.

The Clouds of Isidore

NASA Technical Reports Server (NTRS)

2002-01-01

These views of Hurricane Isidore were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on September 20, 2002. After bringing large-scale flooding to western Cuba, Isidore was upgraded (on September 21) from a tropical storm to a category 3hurricane. Sweeping westward to Mexico's Yucatan Peninsula, the hurricane caused major destruction and left hundreds of thousands of people homeless. Although weakened after passing over the Yucatan landmass, Isidore regained strength as it moved northward over the Gulf of Mexico.

At left is a colorful visualization of cloud extent that superimposes MISR's radiometric camera-by-camera cloud mask (RCCM) over natural-color radiance imagery, both derived from data acquired with the instrument's vertical-viewing (nadir) camera. Using brightness and statistical metrics, the RCCM is one of several techniques MISR uses to determine whether an area is clear or cloudy. In this rendition, the RCCM has been color-coded, and purple = cloudy with high confidence, blue = cloudy with low confidence, green = clear with low confidence, and red = clear with high confidence.

In addition to providing information on meteorological events, MISR's data products are designed to help improve our understanding of the influences of clouds on climate. Cloud heights and albedos are among the variables that govern these influences. (Albedo is the amount of sunlight reflected back to space divided by the amount of incident sunlight.) The center panel is the cloud-top height field retrieved using automated stereoscopic processing of data from multiple MISR cameras. Areas where heights could not be retrieved are shown in dark gray. In some areas, such as the southern portion of the image, the stereo retrieval was able to detect thin, high clouds that were not picked up by the RCCM's nadir view. Retrieved local albedo values for Isidore are shown at right. Generation of the albedo product is dependent upon observed cloud radiances as a function of viewing angle as well as the height field. Note that over the short distances (2.2 kilometers) that the local albedo product is generated, values can be greater than 1.0 due to contributions from cloud sides. Areas where albedo could not be retrieved are shown in dark gray.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 14669. The panels cover an area of about 380 kilometers x 704 kilometers, and utilize data from blocks 70 to 79within World Reference System-2 path 17.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

10 Yr Spatial and Temporal Trends of PM2.5 Concentrations in the Southeastern US Estimated Using High-resolution Satellite Data

NASA Technical Reports Server (NTRS)

Hu, X.; Waller, L. A.; Lyapustin, A.; Wang, Y.; Liu, Y.

2013-01-01

Long-term PM2.5 exposure has been reported to be associated with various adverse health outcomes. However, most ground monitors are located in urban areas, leading to a potentially biased representation of the true regional PM2.5 levels. To facilitate epidemiological studies, accurate estimates of spatiotemporally continuous distribution of PM2.5 concentrations are essential. Satellite-retrieved aerosol optical depth (AOD) has been widely used for PM2.5 concentration estimation due to its comprehensive spatial coverage. Nevertheless, an inherent disadvantage of current AOD products is their coarse spatial resolutions. For instance, the spatial resolutions of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging SpectroRadiometer (MISR) are 10 km and 17.6 km, respectively. In this paper, a new AOD product with 1 km spatial resolution retrieved by the multi-angle implementation of atmospheric correction (MAIAC) algorithm was used. A two-stage model was developed to account for both spatial and temporal variability in the PM2.5-AOD relationship by incorporating the MAIAC AOD, meteorological fields, and land use variables as predictors. Our study area is in the southeastern US, centered at the Atlanta Metro area, and data from 2001 to 2010 were collected from various sources. The model was fitted for each year individually, and we obtained model fitting R2 ranging from 0.71 to 0.85, MPE from 1.73 to 2.50 g m3, and RMSPE from 2.75 to 4.10 g m3. In addition, we found cross validation R2 ranging from 0.62 to 0.78, MPE from 2.00 to 3.01 g m3, and RMSPE from 3.12 to 5.00 g m3, indicating a good agreement between the estimated and observed values. Spatial trends show that high PM2.5 levels occurred in urban areas and along major highways, while low concentrations appeared in rural or mountainous areas. A time series analysis was conducted to examine temporal trends of PM2.5 concentrations in the study area from 2001 to 2010. The results showed that the PM2.5 levels in the study area followed a generally declining trend from 2001 to 2010 and decreased about 20 during the period. However, there was an exception of an increase in year 2005, which is attributed to elevated sulfate concentrations in the study area in warm months of 2005. An investigation of the impact of wild and prescribed fires on PM2.5 levels in 2007 suggests a positive relationship between them.

Highlights from Johannesburg, Gauteng Province, South Africa

NASA Technical Reports Server (NTRS)

2002-01-01

Although the extraction of mineral wealth has been the major influence in the history of Johannesburg and the surrounding Witwatersrand regions (with about 45% of all gold ever mined coming from there), the discovery of now-famous hominid fossils at the Sterkfontein Caves, and the convening of the world's largest-ever conference on environment and development, are setting a new stage for the future. The United Nations began the second Development and Environment Conference in Johannesburg on August 26, 2002. This meeting addresses the implementation of international goals to fight poverty and protect the global environment that were established at the first such conference held in Rio de Janeiro in 1992. The Johannesburg summit involves about forty thousand participants, and perhaps 100 world leaders. One of several official opening ceremonies for the conference was held at the Sterkfontein Caves to recognize the outstanding universal value of the paleo-anthropological fossils found there.

These views from the Multi-angle Imaging SpectroRadiometer (MISR) highlight a number of the land use, vegetation, and geological features found within Gauteng Province (including the urban center of Johannesburg and the capital city Pretoria) and parts of the North West and Free State Provinces. The image on the right displays vegetation in red hues and is a false-color view utilizing data from MISR's near-infrared, red and blue bands. Both the natural-color view (left) and the false-color version were acquired by MISR's nadir camera on June 16, 2002. The urban areas appear as gray-colored pixels in the natural-color view, and exhibit colors corresponding with the relative abundance of vegetation found in the urban parts of this arid region.

The mountains trending east-west near the center of the images extend from Pretoria in the east to Rustenberg in the west. These ranges, the Magaliesberg and Witwatersberg, separate the low-lying, hotter bushveld to the north from the cooler highveld to the south. The large round feature near the north-west corner indicates an ancient volcanic crater in the Pilanesberg National Park. Many bright, buff-colored rectangular patches around Johannesburg are associated with mining activities, and at least two of these areas (situated 40 kilometers southeast of the city) hold large amounts of water. The Sterkfontein Caves (now included within the recently created 'Cradle of Humankind' World Heritage Site) are located about 35 kilometers northwest of Johannesburg. In the southern portion of the images, a section of the Vredefort Hills are apparent to the west, and to the east the Vaal River and a large water body contained by the Vaal Dam delineate the border between the Gauteng and Free State provinces.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and views almost the entire globe every 9 days. This image is a portion of the data acquired during Terra orbit 13266, and covers an area of about 190 kilometers x 221 kilometers. It utilizes data from blocks 111 to 112 within World Reference System-2 path 170.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

NASA MISR Studies Smoke Plumes from California Sand Fire

NASA Image and Video Library

2016-08-02

39,000 acres (60 square miles, or 160 square kilometers). Thousands of residents were evacuated, and the fire claimed the life of one person. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed over the region on July 23 around 11:50 a.m. PDT. At left is an image acquired by MISR's 60-degree forward-viewing camera. The oblique view angle makes the smoke more apparent than it would be in a more conventional vertical view. This cropped image is about 185 miles (300 kilometers) wide. Smoke from the Sand Fire is visible on the right-hand side of the image. Stereoscopic analysis of MISR's multiple camera angles is used to compute the height of the smoke plume from the Sand Fire. In the right-hand image, these heights are superimposed on the underlying image. The color scale shows that the plume extends up to about 4 miles (6 kilometers) above its source in Santa Clarita, but rapidly diminishes in height as winds push it to the southwest. The data compare well with a pilot report issued at Los Angeles International Airport on the evening of July 22, which reported smoke at 15,000-18,000 feet altitude (4.5 to 5.5 kilometers). Air quality warnings were issued for the San Fernando Valley and the western portion of Los Angeles due to this low-hanging smoke. However, data from air quality monitoring instruments seem to indicate that the smoke did not actually reach the ground. These data were captured during Terra orbit 88284. http://photojournal.jpl.nasa.gov/catalog/PIA20724

Real-Time On-Board Processing Validation of MSPI Ground Camera Images

NASA Technical Reports Server (NTRS)

Pingree, Paula J.; Werne, Thomas A.; Bekker, Dmitriy L.

2010-01-01

The Earth Sciences Decadal Survey identifies a multiangle, multispectral, high-accuracy polarization imager as one requirement for the Aerosol-Cloud-Ecosystem (ACE) mission. JPL has been developing a Multiangle SpectroPolarimetric Imager (MSPI) as a candidate to fill this need. A key technology development needed for MSPI is on-board signal processing to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASA's Advanced Information Systems Technology (AIST) Program, JPL is solving the real-time data processing requirements to demonstrate, for the first time, how signal data at 95 Mbytes/sec over 16-channels for each of the 9 multiangle cameras in the spaceborne instrument can be reduced on-board to 0.45 Mbytes/sec. This will produce the intensity and polarization data needed to characterize aerosol and cloud microphysical properties. Using the Xilinx Virtex-5 FPGA including PowerPC440 processors we have implemented a least squares fitting algorithm that extracts intensity and polarimetric parameters in real-time, thereby substantially reducing the image data volume for spacecraft downlink without loss of science information.

Theory and Practice in Determining the Long-Term Spatial Productivity of Drylands: A California Blue Oak Case Study

NASA Astrophysics Data System (ADS)

Washington-Allen, R. A.; Therrell, M. D.; Emanuel, R. E.

2007-12-01

Herbivory, fire, and climatic events such as El Niño-Southern Oscillation (ENSO) and La Niña have been shown to have proximal and evolutionary effects on the dynamics of Dryland fauna, flora, and soils. However, spatially-explicit historical impacts of these climatic events on Dryland ecosystems is not known. Consequently, this paper has the purpose of presenting the theory and practical application for estimating the historical spatial impacts of these climatic events. We hypothesize that if remotely-sensed vegetation indices (VI) are correlated to historical tree ring data and also to functional ecosystem processes, specifically gross primary productivity (GPP) and net ecosystem production (NEP) as measured by eddy covariance flux towers, then VIs can be used to spatially and temporally distribute GPP and NEP within the species- or community-specific land cover extent over the length of the tree ring record of selected Dryland ecosystems. Secondly, the Shuttle Radar Topography Mission (SRTM) digital terrain model (DTM) data has been used to estimate tree height and in conjuction with plant allometric equations: biomass and standing carbon in various forest ecosystems. Tree height data in relation to tree ring age data and fire history can be used to reconstruct the spatial distribution of savanna demographic age structure, predict standing carbon and thus provide a complementary and independent dataset for comparison to DTMs from Multiangle Imaging Spectroradiometer (MISR), Interferometric Synthetic Aperture Radar (IFSAR), and Moderate Resolution Imaging Spectroradiometer (MODIS) derived GPP spatial maps. We developed a database consisting of a dendrochronology record, SRTM data, globa fre history data, Long term Data Record Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index (LTDR AVHRR NDVI, 1981 - 2003), contemporary gridded climate data, National Land Cover Data (NLCD), and short term eddy covariance flux tower data for the California Blue Oak woodland ecosystem to estimate both regional aboveground productivity and past disturbance history relative climate, particularly droughts, for the last 500 years.

An advanced initiative for tracking operationally aerosol events over the last decade based on MSG/SEVIRI satellite observations

NASA Astrophysics Data System (ADS)

Carrer, Dominique; Ceamanos, Xavier; Moparthy, Suman; Six, Bruno; Roujean, Jean-Louis; Descloitres, Jacques

2017-04-01

The major difficulty to detect properly the aerosol signal by using remote sensing observations in the visible range relies on a clear separation of the scattering components between the atmospheric layer and the ground surface. This turns to be quite challenging over bright targets like deserts. We propose a method that combines the directional and temporal dimensions of the satellite signal through out the use of a semi-empirical BRDF kernel-driven model of the surface/atmosphere coupled system. As a result, a simultaneous retrieval of surface albedo and aerosol properties (optical thickness) is performed. The method proves to be meaningful to track anthropogenic aerosol emissions in the troposphere, to monitor volcanic ash release and above all to estimate dust events over bright targets. The proposed method is applied to MSG/SEVIRI slots in the three spectral bands (VIS, NIR, SWIR) at the frequency of 15min and for a geographic coverage that encompasses Europe, Africa, and South America regions. The SEVIRI-derived optical aerosol depth (AOD) estimates compare favourably with measurements carried on over well distributed AERONET stations. The comparison with state of art MODIS-derived (Moderate Resolution Imaging Spectro-radiometer), and MISR-derived (Multi-angle Imaging Spectro-Radiometer) AOD products falls within 20% of accuracy while it reveals the capability of AERUS-GEO to depict more aerosol events still quantitatively. Owing to that, more AOD products offers new insights to better estimate the aerosol radiative forcing (ARF) from GEO compared to low-orbit elevation orbit (LEO) satellite data. The AERUS-GEO algorithm was implemented in the ICARE/AERIS Data Center based in Lille (France) (http://www.icare.univ-lille1.fr). It disseminates operationally from 2014 a daily AOD product (AERUS-GEO) at 670 nm over the MSG disk. In addition to the NRT AOD product, a long term reprocessing is also available over the last decade.

Trans-Pacific transport of Asian dust: the CESM model analysis and comparison with satellite observations

NASA Astrophysics Data System (ADS)

Wu, M.; Liu, X.; Luo, T.; Wang, Z.; Yang, K.; Wu, C.; Wang, H.; Zhang, K.

2017-12-01

Mineral dust plays an important role in the Earth's climate system due to its effects on radiation budgets, clouds, chemistry and biosphere. However, modeled dust aerosol is not well constrained and large uncertainties exist in modeled dust lifecycles. We evaluate dust spatial distributions in the Community Earth System Model (CESM) with new dust extinction retrievals (Luo et al., 2015a, b) based on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) and CloudSat measurement, with special focus on the Asian dust transport across the Pacific. It is shown that the default CESM underestimates the dust extinction over the Pacific by 1-2 order of magnitude. Especially, the model fails to capture the observed high values of dust extinction occurring from 850 to 500 hPa across the North Pacific (20°N-50°N). Modeled dust optical depth (DOD) decreases faster across the Pacific compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging SpectroRadiometer (MISR) observations. Sensitivity experiments with altered emission, vertical transport and deposition schemes have been conducted to identify the key process impacting dust transport. For that purpose, two new dust emission schemes by Kok et al. (2014a, b) and Ginoux et al. (2001), a new dry deposition scheme by Petroff and Zhang (2010) are implemented to the CESM. In addition, a new unified scheme for convective transport and wet removal of aerosols (Wang et al., 2013) is implemented to the same version of CESM to examine the influence of convective transport and wet deposition on dust transport. It is found that changes in wet scavenging and convective transport can strongly impact dust transport over the Pacific compared to changes in other processes. One of the new emission schemes further decreases the dust extinction across the Pacific. Dust extinction across the Pacific slightly increases when dry deposition velocity for fine particles is reduced.

Characterization, validation and intercomparison of clumping index maps from POLDER, MODIS, and MISR satellite data over reference sites

NASA Astrophysics Data System (ADS)

Pisek, Jan; He, Liming; Chen, Jing; Govind, Ajit; Sprintsin, Michael; Ryu, Youngryel; Arndt, Stefan; Hocking, Darren; Wardlaw, Timothy; Kuusk, Joel; Oliphant, Andrew; Korhonen, Lauri; Fang, Hongliang; Matteucci, Giorgio; Longdoz, Bernard; Raabe, Kairi

2015-04-01

Vegetation foliage clumping significantly alters its radiation environment and therefore affects vegetation growth as well as water and carbon cycles. The clumping index is useful in ecological and meteorological models because it provides new structural information in addition to the effective leaf area index (LAI) retrieved from mono-angle remote sensing and allows accurate separation of sunlit and shaded leaves in the canopy. Not accounting for the foliage clumping in LAI retrieval algorithms leads to substantial underestimation of actual LAI, especially for needleleaf forests. Normalized Difference between Hotspot and Darkspot (NDHD) index has been previously used to retrieve global clumping index maps from POLarization and Directionality of the Earth's Reflectances (POLDER) data at ~6 km resolution, from Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) product at 500 m resolution. Most recently the algorithm was applied with Multi-angle Imaging SpectroRadiometer (MISR) data at 275 m resolution over selected areas. In this presentation we characterize and intercompare the three products over a set of sites representing diverse biomes and different canopy structures. The products are also directly validated with both in-situ vertical profiles and seasonal trajectories of clumping index. We illustrate that the vertical distribution of foliage and especially the effect of understory needs to be taken into account while validating foliage clumping products from remote sensing products with values measured in the field. Satellite measurements respond to the structural effects near the top of canopies, while ground measurements may be biased by the lower vegetation layers. Additionally, caution should be taken regarding the misclassification in land cover maps as their errors can be propagated into the foliage clumping maps. Our results indicate that MODIS data and MISR data with 275 m in particular can provide good quality clumping index estimates at pertinent scales for modeling local carbon and energy fluxes.

Characterization, Validation and Intercomparison of Clumping Index Maps from POLDER, MODIS, and MISR Satellite Data Over Reference Sites

NASA Astrophysics Data System (ADS)

Pisek, J.; He, L.; Chen, J. M.; Govind, A.; Sprintsin, M.; Ryu, Y.; Arndt, S. K.; Hocking, D.; Wardlaw, T.; Kuusk, J.; Oliphant, A. J.; Korhonen, L.; Fang, H.; Matteucci, G.; Longdoz, B.; Raabe, K.

2015-12-01

Vegetation foliage clumping significantly alters its radiation environment and therefore affects vegetation growth as well as water and carbon cycles. The clumping index is useful in ecological and meteorological models because it provides new structural information in addition to the effective leaf area index (LAI) retrieved from mono-angle remote sensing and allows accurate separation of sunlit and shaded leaves in the canopy. Not accounting for the foliage clumping in LAI retrieval algorithms leads to substantial underestimation of actual LAI, especially for needleleaf forests. Normalized Difference between Hotspot and Darkspot (NDHD) index has been previously used to retrieve global clumping index maps from POLarization and Directionality of the Earth's Reflectances (POLDER) data at ~6 km resolution, from Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) product at 500 m resolution. Most recently the algorithm was applied with Multi-angle Imaging SpectroRadiometer (MISR) data at 275 m resolution over selected areas. In this presentation we characterize and intercompare the three products over a set of sites representing diverse biomes and different canopy structures. The products are also directly validated with both in-situ vertical profiles and seasonal trajectories of clumping index. We illustrate that the vertical distribution of foliage and especially the effect of understory needs to be taken into account while validating foliage clumping products from remote sensing products with values measured in the field. Satellite measurements respond to the structural effects near the top of canopies, while ground measurements may be biased by the lower vegetation layers. Additionally, caution should be taken regarding the misclassification in land cover maps as their errors can be propagated into the foliage clumping maps. Our results indicate that MODIS data and MISR data with 275 m resolution in particular can provide good quality clumping index estimates at pertinent scales for modeling local carbon and energy fluxes.

Variability of Aerosol and its Impact on Cloud Properties Over Different Cities of Pakistan

NASA Astrophysics Data System (ADS)

Alam, Khan

Interaction between aerosols and clouds is the subject of considerable scientific research, due to the importance of clouds in controlling climate. Aerosols vary in time in space and can lead to variations in cloud microphysics. This paper is a pilot study to examine the temporal and spatial variation of aerosol particles and their impact on different cloud optical properties in the territory of Pakistan using the Moderate resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite data and Multi-angle Imaging Spectroradiometer (MISR) data. We also use Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for trajectory analysis to obtain origin of air masses in order to understand the spatial and temporal variability of aerosol concentrations. We validate data of MODIS and MISR by using linear correlation and regression analysis, which shows that there is an excellent agreement between data of these instruments. Seasonal study of Aerosol Optical Depth (AOD) shows that maximum value is found in monsoon season (June-August) over all study areas. We analyze the relationships between aerosol optical depth (AOD) and some cloud parameters like water vapor (WV), cloud fraction (CF), cloud top temperature (CTT) and cloud top pressure (CTP). We construct the regional correlation maps and time series plots for aerosol and cloud parameters mandatory for the better understanding of aerosol-cloud interaction. Our analyses show that there is a strong positive correlation between AOD and water vapor in all cities. The correlation between AOD and CF is positive for the cities where the air masses are moist while the correlation is negative for cities where air masses are relatively dry and with lower aerosol abundance. It shows that these correlations depend on meteorological conditions. Similarly as AOD increases Cloud Top Pressure (CTP) is decreasing while Cloud Top Temperature (CTT) is increasing. Key Words: MODIS, MISR, HYSPLIT, AOD, CF, CTP, CTT

Evolution of aerosol loading in Santiago de Chile between 1997 and 2014

NASA Astrophysics Data System (ADS)

Pistone, Kristina; Gallardo, Laura

2015-04-01

While aerosols produced by major cities are a significant component of anthropogenic climate forcing as well as an important factor in public health, many South American cities have not been a major focus of aerosol studies due in part to relatively few long-term observations in the region. Here we present a synthesis of the available data for the emerging megacity of Santiago, Chile. We report new results from a recent NASA AERONET (AErosol RObotic NETwork) site in the Santiago basin, combining these with previous AERONET observations in Santiago as well as with a new assessment of the 11-station air quality monitoring network currently administered by the Chilean Environment Ministry (MMA, Ministerio del Medio Ambiente) to assess changes in aerosol composition since 1997. While the average surface concentration of pollution components (specifically PM2.5 and PM10) has decreased, no significant change in total aerosol optical depth was observed. However, changes in aerosol size and composition are suggested by the proxy measurements. Previous studies have revealed limitations in purely satellite-based studies over Santiago due to biases from high surface reflection in the region, particularly in summer months (e.g. Escribano et al 2014). To overcome this difficulty and certain limitations in the air quality data, we next incorporate analysis of aerosol products from the Multi-angle Imaging SpectroRadiometer (MISR) instrument along with those from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, both on NASA's Terra satellite, to better quantify the high bias of MODIS. Thus incorporating these complementary datasets, we characterize the aerosol over Santiago over the period 1997 to 2014, including the evolution of aerosol properties over time and seasonal dependencies in the observed trends. References: Escribano et al (2014), "Satellite Retrievals of Aerosol Optical Depth over a Subtropical Urban Area: The Role of Stratification and Surface Reflectance," Aerosol and Air Quality Research, doi:10.4209/aaqr.2013.03.0082.

AOD trends during 2001-2010 from observations and model simulations

NASA Astrophysics Data System (ADS)

Pozzer, Andrea; de Meij, Alexander; Yoon, Jongmin; Astitha, Marina

2016-04-01

The trend of aerosol optical depth (AOD) between 2001 and 2010 is estimated globally and regionally from remote sensed observations by the MODIS (Moderate Resolution Imaging Spectroradiometer), MISR (Multi-angle Imaging SpectroRadiometer) and SeaWIFS (Sea-viewing Wide Field-of-view Sensor) satellite sensor. The resulting trends have been compared to model results from the EMAC (ECHAM5/MESSy Atmospheric Chemistry {[1]}), model. Although interannual variability is applied only to anthropogenic and biomass-burning emissions, the model is able to quantitatively reproduce the AOD trends as observed by MODIS, while some discrepancies are found when compared to MISR and SeaWIFS. An additional numerical simulation with the same model was performed, neglecting any temporal change in the emissions, i.e. with no interannual variability for any emission source. It is shown that decreasing AOD trends over the US and Europe are due to the decrease in the (anthropogenic) emissions. On contrary over the Sahara Desert and the Middle East region, the meteorological/dynamical changes in the last decade play a major role in driving the AOD trends. Further, over Southeast Asia, both meteorology and emissions changes are equally important in defining AOD trends {[2]}. Finally, decomposing the regional AOD trends into individual aerosol components reveals that the soluble components are the most dominant contributors to the total AOD, as their influence on the total AOD is enhanced by the aerosol water content. {[1]}: Jöckel, P., Kerkweg, A., Pozzer, A., Sander, R., Tost, H., Riede, H., Baumgaertner, A., Gromov, S., and Kern, B.: Development cycle 2 of the Modular Earth Submodel System (MESSy2), Geosci. Model Dev., 3, 717-752, doi:10.5194/gmd-3-717-2010, 2010. {[2]}: Pozzer, A., de Meij, A., Yoon, J., Tost, H., Georgoulias, A. K., and Astitha, M.: AOD trends during 2001-2010 from observations and model simulations, Atmos. Chem. Phys., 15, 5521-5535, doi:10.5194/acp-15-5521-2015, 2015.

Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application

PubMed Central

van Donkelaar, Aaron; Martin, Randall V.; Brauer, Michael; Kahn, Ralph; Levy, Robert; Verduzco, Carolyn; Villeneuve, Paul J.

2010-01-01

Background Epidemiologic and health impact studies of fine particulate matter with diameter < 2.5 μm (PM2.5) are limited by the lack of monitoring data, especially in developing countries. Satellite observations offer valuable global information about PM2.5 concentrations. Objective In this study, we developed a technique for estimating surface PM2.5 concentrations from satellite observations. Methods We mapped global ground-level PM2.5 concentrations using total column aerosol optical depth (AOD) from the MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR (Multiangle Imaging Spectroradiometer) satellite instruments and coincident aerosol vertical profiles from the GEOS-Chem global chemical transport model. Results We determined that global estimates of long-term average (1 January 2001 to 31 December 2006) PM2.5 concentrations at approximately 10 km × 10 km resolution indicate a global population-weighted geometric mean PM2.5 concentration of 20 μg/m3. The World Health Organization Air Quality PM2.5 Interim Target-1 (35 μg/m3 annual average) is exceeded over central and eastern Asia for 38% and for 50% of the population, respectively. Annual mean PM2.5 concentrations exceed 80 μg/m3 over eastern China. Our evaluation of the satellite-derived estimate with ground-based in situ measurements indicates significant spatial agreement with North American measurements (r = 0.77; slope = 1.07; n = 1057) and with noncoincident measurements elsewhere (r = 0.83; slope = 0.86; n = 244). The 1 SD of uncertainty in the satellite-derived PM2.5 is 25%, which is inferred from the AOD retrieval and from aerosol vertical profile errors and sampling. The global population-weighted mean uncertainty is 6.7 μg/m3. Conclusions Satellite-derived total-column AOD, when combined with a chemical transport model, provides estimates of global long-term average PM2.5 concentrations. PMID:20519161

Imaging of earthquake faults using small UAVs as a pathfinder for air and space observations

USGS Publications Warehouse

Donnellan, Andrea; Green, Joseph; Ansar, Adnan; Aletky, Joseph; Glasscoe, Margaret; Ben-Zion, Yehuda; Arrowsmith, J. Ramón; DeLong, Stephen B.

2017-01-01

Large earthquakes cause billions of dollars in damage and extensive loss of life and property. Geodetic and topographic imaging provide measurements of transient and long-term crustal deformation needed to monitor fault zones and understand earthquakes. Earthquake-induced strain and rupture characteristics are expressed in topographic features imprinted on the landscapes of fault zones. Small UAVs provide an efficient and flexible means to collect multi-angle imagery to reconstruct fine scale fault zone topography and provide surrogate data to determine requirements for and to simulate future platforms for air- and space-based multi-angle imaging.

The application of support vector machines to analysis of global satellite data sets from MlSR

NASA Technical Reports Server (NTRS)

Garay, Michael J.; Mazzoni, Dominic; Davies, Roger; Diner, David J.

2005-01-01

The Multi-angle Imaging Spectro Radiometer (MISR) is one of a suite of five instruments onboard NASA's Terra EOS satellite, launched in December 1999. Typical satellite imagers view the earth from a single direction, but MISR's cameras image the earth simultaneously from nine different directions in four spectral bands. In this way, MISR provides unique multiangle information about solar radiation scattered from clouds, aerosols and other terrestrial surfaces. One of the primary goals of the MISR mission is to improve our understanding of how clouds and aerosols affect the earth's global energy balance.

Floodwaters Renew Zambia's Kafue Wetland

NASA Technical Reports Server (NTRS)

2004-01-01

Not all floods are unwanted. Heavy rainfall in southern Africa between December 2003 and April 2004 provided central Zambia with floodwaters needed to support the diverse uses of water within the Kafue Flats area. The Kafue Flats are home to about one million people and provide a rich inland fishery, habitat for an array of unique wildlife, and the means for hydroelectricity production. The Flats falls between two dams: Upstream to the west (not visible here) is the Izhi-tezhi, and downstream (middle right of the images) is the Kafue Gorge dam. Since the construction of these dams, the flooded area has been reduced and the timing and intensity of the inundation has changed. During June 2004 an agreement was made with the hydroelectricity company to restore water releases from the dams according to a more natural flooding regime. These images from NASA's Multi-angle Imaging SpectroRadiometer (MISR) illustrate surface changes to the wetlands and other surfaces in central Zambia resulting from an unusually lengthy wet season. The Kafue Flats appear relatively dry on July 19, 2003 (upper images), with the Kafue River visible as a slender dark line that snakes from east to west on its way to join the Zambezi (visible in the lower right-hand corner). On July 21, 2004 (lower images), well into the dry season, much of the 6,500-square kilometer area of the Kafue Flats remains inundated. To the east of the Kafue Flats is Lusaka, the Zambian capital, visible as a pale area in the middle right of the picture, north of the river. In the upper portions of these images is the prominent roundish shape of the Lukanga Swamp, another important wetland.

The images along the left are natural-color views from MISR's nadir camera, and the images along the right are angular composites in which red band data from MISR's 46o forward, nadir, and 46o backward viewing cameras is displayed as red, green and blue, respectively. In order to preserve brightness variations among the various cameras, the data from each camera were processed identically. Here, color changes indicate surface texture, and are influenced by terrain, vegetation structure, soil type and soil moisture content. Wet surfaces or areas with standing water appear blue in this display because sun glitter makes smooth, wet surfaces look brighter at the backward camera's view angle. Mostly the landscape appears somewhat purple, indicating that most of the surfaces scatter sunlight in both backward and forward directions. Areas that appear with a slight greenish hue can indicate sparce vegetation, since the nadir camera is more likely to sight the gaps between the trees or shrubs, and since vegetation is darker (in the red band) than the underlying soil surface. Areas which preferentially exhibit a red or pink hue correspond with wetland vegetation. The plateau of the Kafue National Park, to the west of Lukanga Swamp, appears brighter in 2004 compared with 2003, which indicates weaker absorption at the red band. Overall, the 2004 image exhibits a subtle blue hue (preference for forward-scattering) compared with 2003, which indicates overall surface changes that may be a result of enhanced surface wetness.

The Multiangle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 19072 and 24421. The panels cover an area of 235 kilometers x 239 kilometers, and utilize data from blocks 100 to 103 within World Reference System-2 path 172.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Observing a Severe Dust Storm Event over China using Multiple Satellite Data

NASA Astrophysics Data System (ADS)

Xu, Hui; Xue, Yong; Guang, Jie; Mei, Linlu

2013-04-01

A severe dust storm (SDS) event occurred from 19 to 21 March 2010 in China, originated in western China and Mongolia and propagated into eastern/southern China, affecting human's life in a large area. As reported by National Meteorological Center of CMA (China Meteorological Administration), 16 provinces (cities) of China were hit by the dust storm (Han et al., 2012). Satellites can provide global measurements of desert dust and have particular importance in remote areas where there is a lack of in situ measurements (Carboni et al., 2012). To observe a dust, it is necessary to estimate the spatial and temporal distributions of dust aerosols. An important metric in the characterisation of aerosol distribution is the aerosol optical depth (AOD) (Adhikary et al., 2008). Satellite aerosol retrievals have improved considerably in the last decade, and numerous satellite sensors and algorithms have been generated. Reliable retrievals of dust aerosol over land were made using POLarization and Directionality of the Earth's Reflectance instrument-POLDER (Deuze et al., 2001), Moderate Resolution Imaging Spectroradiometer-MODIS (Kaufman et al., 1997; Hsu et al., 2004), Multiangle Imaging Spectroradiometer-MISR (Martonchik et al., 1998), and Cloud-aerosol Lidar and infrared pathfinder satellite observations (CALIPSO). However, intercomparison exercises (Myhre et al., 2005) have revealed that discrepancies between satellite measurements are particularly large during events of heavy aerosol loading. The reason is that different AOD retrieval algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. For MISR, POLDER and MODIS instrument, the multi-angle approaches, the polarization measurements and single-view approaches were used to retrieval AOD respectively. Combining of multi-sensor AOD data can potentially create a more consistent, reliable and complete picture of the space-time evolution of dust storms (Ehlers, 1991). In order to make use of all useful satellite data to observe one severe dust procedure, multi-sensor and multi-algorithm AOD data were combined. In this paper, the satellite instruments considered are MISR, MODIS, POLDER and CALIPSO. In addition, air pollution index (API) data were used to validate the satellite AOD data. We chose the study region with a longitude range from 76°N to 136°N and a latitude range from 15°E to 60°E. Index Terms—aerosol optical depth, dust, satellite REFERENCES Adhikary, B., Kulkarni, S., Dallura A., Tang, Y., Chai, T., Leung, L. R., Qian, Y., Chung, C. E., Ramanathan,V. and Carmichael, G. R., 2008, A regional scale chemical transport modeling of Asian aerosols with data assimilation of AOD observations using optimal interpolation technique, Atmospheric Environment, 42(37), 8600-8615. Carboni, E., Thomas, G. E., Sayer, A. M., Siddans, R., Poulsen, C. A., Grainger, R. G., Ahn, C., Antoine, D., Bevan, S., Braak, R., Brindley, H., DeSouza-Machado, S., Deuz'e, J. L., Diner, D., Ducos, F., Grey, W., Hsu, C., Kalashnikova, O. V., Kahn, R., North, P. R. J., Salustro, C., Smith, A., Tanr'e, D., Torres, O., and Veihelmann, B., 2012, Intercomparison of desert dust optical depth from satellite measurements, Atmospheric Measurement Techniques, 5, 1973-2002. Deuze', J. L., Bre'on, F. M., Devaux, C., Goloub, Herman, M., Lafrance, B., Maignan, F., Marchand, A.,Nadal, F., Perry, G., and Tanre', D., 2001, Remote sensing of aerosols over land surfaces from POLDER-ADEOS-1 polarized measurements, Journal of Geophysical Research, 106(D5), 4913-4926. Ehlers, M., 1991, Multisensor image fusion techniques in remote sensing, ISPRS Journal of Photogrammetry and Remote Sensing, 46, 19-30. Han, X., Ge. C., Tao, J. H., Zhang, M. G., Zhang, R. J., 2012, Air Quality Modeling for a Strong Dust Event in East Asia in March 2010, Aerosol and Air Quality Research, 12: 615-628. Hsu, N. C., Tsay, S. C., King, M. D. and Herman, J. R., 2004, Aerosol Properties over Bright-Reflecting Source Regions, IEEE Transactions on Geoscience and Remote Sensing, 42(3), 557-569. Martonchik, J. V., Diner, D. J., Kahn, R., Ackerman, T. P., Verstraete, M. M., Pinty, B., and Gordon, H. R., 1998, Techniques for the retrieval of aerosol properties over land and ocean using multiangle imaging, IEEE Transactions on Geoscience and Remote Sensing, 36(4), 1212-1227. Myhre, G., Stordal, F., Johnsrud, M., Diner, D. J., Geogdzhayev, I. V., Haywood, J. M., Holben, B. N., Holzer-Popp, T., Ignatov, A., Kahn, R. A., Kaufman, Y. J., Loeb, N., Martonchik, J. V., Mishchenko, M. I., Nalli, N. R., Remer, L. A., Schroedter-Homscheidt, M., Tanr'e, D., Torres, O., and Wang, M., 2005, Intercomparison of satellite retrieved aerosol optical depth over ocean during the period September 1997 to December 2000, Atmospheric Chemistry and Physics, 5, 1697-1719. Kaufman, Y.J., Tanre', D., Remer, L.A., Vermote, E.F., Chu, A., and Holben, B.N., 1997, Operationalremote sensing of tropospheric aerosol over land from EOS moderate resolution imaging spectroradiometer, Journal of Geophysical Research, 102(D14), 17,051-17,067.

NASA Tech Briefs, November 2004

NASA Technical Reports Server (NTRS)

2004-01-01

Topics include: Multifunction Imaging and Spectroscopic Instrument; Position-Finding Instrument Built Around a Magnetometer; Improved Measurement of Dispersion in an Optical Fiber; Probe for Sampling of Interstitial Fluid From Bone; Neuropsychological Testing of Astronauts; Method of Calibration for a Large Cathetometer System; Four-Channel PC/104 MIL-STD-1553 Circuit Board; Improved Method of Locating Defects in Wiring Insulation; Strobe Traffic Lights Warn of Approaching Emergency Vehicles; Improved Timing Scheme for Spaceborne Precipitation Radar; Concept for Multiple-Access Free-Space Laser Communications; Variable Shadow Screens for Imaging Optical Devices; Verifying Diagnostic Software; Initial Processing of Infrared Spectral Data; Activity-Centric Approach to Distributed Programming; Controlling Distributed Planning; New Material for Surface-Enhanced Raman Spectroscopy; Treated Carbon Nanofibers for Storing Energy in Aqueous KOH; Advanced Infant Car Seat Would Increase Highway Safety; Development of Biomorphic Flyers; Second-Generation Six-Limbed Experimental Robot; Miniature Linear Actuator for Small Spacecraft; Process for Making Single-Domain Magnetite Crystals; A New Process for Fabricating Random Silicon Nanotips; Resin-Transfer-Molding of a Tool Face; Improved Phase-Mask Fabrication of Fiber Bragg Gratings; Tool for Insertion of a Fiber-Optic Terminus in a Connector; Nanofluidic Size-Exclusion Chromatograph; Lightweight, Low-CTE Tubes Made From Biaxially Oriented LCPs; Using Redundancy To Reduce Errors in Magnetometer Readings; Compact Instrument for Measuring Profile of a Light Beam; Multilayer Dielectric Transmissive Optical Phase Modulator; Second-Generation Multi-Angle Imaging Spectroradiometer; Real-Time Adaptive Color Segmentation by Neural Networks; Research and Development in Optical Communications; Tests of Multibeam Scintillation Mitigation on Laser Uplinks; and Spaceborne Infrared Atmospheric Sounder.

Cloud Motion Vectors from MISR using Sub-pixel Enhancements

NASA Technical Reports Server (NTRS)

Davies, Roger; Horvath, Akos; Moroney, Catherine; Zhang, Banglin; Zhu, Yanqiu

2007-01-01

The operational retrieval of height-resolved cloud motion vectors by the Multiangle Imaging SpectroRadiometer on the Terra satellite has been significantly improved by using sub-pixel approaches to co-registration and disparity assessment, and by imposing stronger quality control based on the agreement between independent forward and aft triplet retrievals. Analysis of the fore-aft differences indicates that CMVs pass the basic operational quality control 67% of the time, with rms differences - in speed of 2.4 m/s, in direction of 17 deg, and in height assignment of 290 m. The use of enhanced quality control thresholds reduces these rms values to 1.5 m/s, 17 deg and 165 m, respectively, at the cost of reduced coverage to 45%. Use of the enhanced thresholds also eliminates a tendency for the rms differences to increase with height. Comparison of CMVs from an earlier operational version that had slightly weaker quality control, with 6-hour forecast winds from the Global Modeling and Assimilation Office yielded very low bias values and an rms vector difference that ranged from 5 m/s for low clouds to 10 m/s for high clouds.

Arctic PBL Cloud Height and Motion Retrievals from MISR and MINX

NASA Technical Reports Server (NTRS)

Wu, Dong L.

2012-01-01

How Arctic clouds respond and feedback to sea ice loss is key to understanding of the rapid climate change seen in the polar region. As more open water becomes available in the Arctic Ocean, cold air outbreaks (aka. off-ice flow from polar lows) produce a vast sheet of roll clouds in the planetary boundary layer (PBl). The cold air temperature and wind velocity are the critical parameters to determine and understand the PBl structure formed under these roll clouds. It has been challenging for nadir visible/IR sensors to detect Arctic clouds due to lack of contrast between clouds and snowy/icy surfaces. In addition) PBl temperature inversion creates a further problem for IR sensors to relate cloud top temperature to cloud top height. Here we explore a new method with the Multiangle Imaging Spectro-Radiometer (MISR) instrument to measure cloud height and motion over the Arctic Ocean. Employing a stereoscopic-technique, MISR is able to measure cloud top height accurately and distinguish between clouds and snowy/icy surfaces with the measured height. We will use the MISR INteractive eXplorer (MINX) to quantify roll cloud dynamics during cold-air outbreak events and characterize PBl structures over water and over sea ice.

MISR Decadal Observations of Mineral Dust: Property Characterization and Climate Applications

NASA Technical Reports Server (NTRS)

Kalashnikova, Olga V.; Garay, Michael J.; Sokolik, Irina; Kahn, Ralph A.; Lyapustin, A.; Diner, David J.; Lee, Jae N.; Torres, Omar; Leptoukh, Gregory G.; Sabbah, Ismail

2012-01-01

The Multi-angle Imaging SpectroRadiometer (MISR) provides a unique, independent source of data for studying dust emission and transport. MISR's multiple view angles allow the retrieval of aerosol properties over bright surfaces, and such retrievals have been shown to be sensitive to the non-sphericity of dust aerosols over both land and water. MISR stereographic views of thick aerosol plumes allow height and instantaneous wind derivations at spatial resolutions of better than 1.1 km horizontally and 200m vertically. We will discuss the radiometric and stereo-retrieval capabilities of MISR specifically for dust, and demonstrate the use of MISR data in conjunction with other available satellite observations for dust property characterization and climate studies.First, we will discuss MISR non-spherical (dust) fraction product over the global oceans. We will show that over the Atlantic Ocean, changes in the MISR-derived non-spherical AOD fraction illustrate the evolution of dust during transport. Next, we will present a MISR satellite perspective on dust climatology in major dust source regions with a particular emphasis on the West Africa and Middle East and discuss MISR's unique strengths as well as current product biases. Finally, we will discuss MISR dust plume product and climatological applications.

Ice Types in the Beaufort Sea, Alaska

NASA Technical Reports Server (NTRS)

2003-01-01

Determining the amount and type of sea ice in the polar oceans is crucial to improving our knowledge and understanding of polar weather and long term climate fluctuations. These views from two satellite remote sensing instruments; the synthetic aperture radar (SAR) on board the RADARSAT satellite and the Multi-angle Imaging SpectroRadiometer (MISR), illustrate different methods that may be used to assess sea ice type. Sea ice in the Beaufort Sea off the north coast of Alaska was classified and mapped in these concurrent images acquired March 19, 2001 and mapped to the same geographic area.

To identify sea ice types, the National Oceanic and Atmospheric Administration (NOAA) National Ice Center constructs ice charts using several data sources including RADARSAT SAR images such as the one shown at left. SAR classifies sea ice types primarily by how the surface and subsurface roughness influence radar backscatter. In the SAR image, white lines delineate different sea ice zones as identified by the National Ice Center. Regions of mostly multi-year ice (A) are separated from regions with large amounts of first year and younger ice (B-D), and the dashed white line at bottom marks the coastline. In general, sea ice types that exhibit increased radar backscatter appear bright in SAR and are identified as rougher, older ice types. Younger, smoother ice types appear dark to SAR. Near the top of the SAR image, however, red arrows point to bright areas in which large, crystalline 'frost flowers' have formed on young, thin ice, causing this young ice type to exhibit an increased radar backscatter. Frost flowers are strongly backscattering at radar wavelengths (cm) due to both surface roughness and the high salinity of frost flowers, which causes them to be highly reflective to radar energy.

Surface roughness is also registered by MISR, although the roughness observed is at a different spatial scale. Older, rougher ice areas are predominantly backward scattering to the MISR cameras, whereas younger, smoother ice types are predominantly forward scattering. The MISR map at right was generated using a statistical classification routine (called ISODATA) and analyzed using ice charts from the National Ice Center. Five classes of sea ice were found based upon the classification of MISR angular data. These are described, based on interpretation of the SAR image, by the image key. Very smooth ice areas that are predominantly forward scattering are colored red. Frost flowers are largely smooth to the MISR visible band sensor and are mapped as forward scattering. Areas mapped as blue are predominantly backward scattering, and the other three classes have statistically distinct angular signatures and fall within the middle of the forward/backward scattering continuum. Some areas that may be first year or younger ice between the multi year ice floes are not discernible to SAR, illustrating how MISR potentially can make a unique contribution to sea ice mapping.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This data product was generated from a portion of the imagery acquired during Terra orbit 6663. The MISR image has been cropped to include an area that is 200 kilometers wide, and utilizes data from blocks 30 to 33 within World Reference System-2 path 71.

MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Tracking Hurricane Wilma Across the Caribbean

NASA Technical Reports Server (NTRS)

2005-01-01

Information on cloud top heights at different stages in the life cycle of the rapidly intensifying Hurricane Wilma may prove useful for evaluating the ability of numerical weather models to predict the intensity changes of hurricanes. NASA's Multi-angle Imaging SpectroRadiometer (MISR) acquired this sequence of images and cloud-top height observations for Hurricane Wilma as it progressed across the Caribbean in October 2005. Each pair in the sequence has a photo-like view of the storm on the left and a matching color-coded image of cloud-top height on the right. Cloud-top heights range from 0 (purple) to 18 (red) kilometers altitude. Areas where cloud heights could not be determined are shown in dark gray.

The pair on the left show Wilma on Tuesday, October 18, when Hurricane watches were posted for Cuba and Mexico. The central pair shows the eye of Hurricane Wilma just hours before the storm began to cross the Yucatan Peninsula on Friday, October 21. At that time, Wilma was a powerful Category 4 Hurricane on the Saffir-Simpson scale, and had a minimum recorded central pressure of 930 millibars. Hurricane Wilma surged from tropical storm to Category 5 hurricane status in record time, but the storm slowed and weakened considerably after battering Mexico's Yucatan Peninsula and the Caribbean. The right-hand image pair displays the eastern edges of a weakened Wilma, when Wilma had been reduced to Category 2 status and was just starting to reach southern Florida on the morning of Sunday, October 23. Wilma gathered speed and strengthened on Sunday night, crossing Florida as a Category 3 storm on Monday, October 24.

On the 18th, Wilma looked a bit ragged. Its eye is located at the center of the left edge, and its outer bands of clouds appear to be dominated by a rather loose collection of thunderstorms. In the photo-like images, these look like areas of 'boiling clouds,' and in the cloud-height image, these appear as orange blobs, sometimes topped with pinkish-red. On October 21 (center), when Wilma was a Category 4 storm, cloud-top height on the eastern side of the storm near the eye reached 18 kilometers in altitude, with lower heights on the western side. The image from the 23rd shows the eastern edge of Wilma as it approached Florida (upper right) and Cuba (center right).

MISR has nine different cameras which view the Earth from a variety of angles. Shifts in the clouds' apparent position from one camera's perspective to another's allows MISR to measure the height of the cloud-tops. MISR scientists have programmed computers to compare the different views, identify features that appear to shift from view to view, and use that information to calculate cloud height automatically. The height fields pictured have not been corrected for the effects of cloud motion. Wind-corrected heights (which have higher accuracy but sparser spatial coverage) are within about 1 kilometer of the heights shown here.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82o north and 82o south latitude every nine days. Each image covers an area of about 380 kilometers by 1830 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbits 31037, 31081 and 31110, and utilize data from within blocks 68-83 within World Reference System-2 paths 13, 16 and 18, respectively.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology.

Regional Changes in Earths Color and Texture as Observed From Space Over a 15-Year Period

NASA Technical Reports Server (NTRS)

Zhao, Guangyu; Di Girolamo, Larry; Diner, David J.; Bruegge, Carol J.; Mueller, Kevin J.; Wu, Dong L.

2016-01-01

Earth-observing satellites provide global observations of many geophysical variables. As these variables are derived from measured radiances, the underlying radiance data are the most reliable sources of information for change detection. Here, we identify statistically significant trends in the color and spatial texture of the Earth as viewed from multiple directions from the Multi-angle Imaging SpectroRadiometer (MISR), which has been sampling the angular distribution of scattered sunlight since 2000. Globally, our results show that the Earth has been appearing relatively bluer (up to 1.6 % per decade from both nadir and oblique views) and smoother (up to 1.5 % per decade only from oblique views) over the past 15 years. The magnitude of the global blueing trends is comparable to that of uncertainties in radiometric calibration stability. Regional shifts in color and texture, which are significantly larger than global means, are observed, particularly over polar regions, along the boundaries of the subtropical highs, the tropical western Pacific, Southwestern Asia, and Australia. We demonstrate that the large regional trends cannot be explained either by uncertainties in radiometric calibration or variability in total or spectral solar irradiance; hence, they reflect changes internal to the Earths climate system. The 15-year-mean true color composites and texture images of the Earth at both nadir and oblique views are also presented for the first time.

NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE): Changing patterns in the use of NRT satellite imagery

NASA Astrophysics Data System (ADS)

Davies, D.; Michael, K.; Schmaltz, J. E.; Harrison, S.; Ding, F.; Durbin, P. B.; Boller, R. A.; Cechini, M. F.; Rinsland, P. L.; Ye, G.; Mauoka, E.

2015-12-01

NASA's Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery approximately 3 hours from satellite observation, to monitor natural events globally and to meet the needs of the near real-time (NRT) applications community. This article describes LANCE, and how the use of NRT data and imagery has evolved. Since 2010 there has been a four-fold increase in both the volume of data and the number of files downloaded. Over the last year there has been a marked shift in the way in which users are accessing NRT imagery; users are gravitating towards Worldview and the Global Imagery Browse Services (GIBS) and away from MODIS Rapid Response, in part due to the increased exposure through social media. In turn this is leading to a broader range of users viewing NASA NRT imagery. This article also describes new, and planned, product enhancements to LANCE. Over the last year, LANCE has expanded to support NRT products from the Advanced Microwave Scanning Radiometer 2 (AMSR2), and the Multi-angle Imaging SpectroRadiometer (MISR). LANCE elements are also planning to ingest and process NRT data from the Visible Infrared Imager Radiometer Suite (VIIRS), and the advanced Ozone Mapping and Profiler Suite (OMPS) instruments onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite in the near future.

MISR Global Images See the Light of Day

NASA Technical Reports Server (NTRS)

2002-01-01

As of July 31, 2002, global multi-angle, multi-spectral radiance products are available from the MISR instrument aboard the Terra satellite. Measuring the radiative properties of different types of surfaces, clouds and atmospheric particulates is an important step toward understanding the Earth's climate system. These images are among the first planet-wide summary views to be publicly released from the Multi-angle Imaging SpectroRadiometer experiment. Data for these images were collected during the month of March 2002, and each pixel represents monthly-averaged daylight radiances from an area measuring 1/2 degree in latitude by 1/2 degree in longitude.

The top panel is from MISR's nadir (vertical-viewing) camera and combines data from the red, green and blue spectral bands to create a natural color image. The central view combines near-infrared, red, and green spectral data to create a false-color rendition that enhances highly vegetated terrain. It takes 9 days for MISR to view the entire globe, and only areas within 8 degrees of latitude of the north and south poles are not observed due to the Terra orbit inclination. Because a single pole-to-pole swath of MISR data is just 400 kilometers wide, multiple swaths must be mosaiced to create these global views. Discontinuities appear in some cloud patterns as a consequence of changes in cloud cover from one day to another.

The lower panel is a composite in which red, green, and blue radiances from MISR's 70-degree forward-viewing camera are displayed in the northern hemisphere, and radiances from the 70-degree backward-viewing camera are displayed in the southern hemisphere. At the March equinox (spring in the northern hemisphere, autumn in the southern hemisphere), the Sun is near the equator. Therefore, both oblique angles are observing the Earth in 'forward scattering', particularly at high latitudes. Forward scattering occurs when you (or MISR) observe an object with the Sun at a point in the sky that is in front of you. Relative to the nadir view, this geometry accentuates the appearance of polar clouds, and can even reveal clouds that are invisible in the nadir direction. In relatively clear ocean areas, the oblique-angle composite is generally brighter than its nadir counterpart due to enhanced reflection of light by atmospheric particulates.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

James Bay

Atmospheric Science Data Center

2013-04-17

...     View Larger Image The first images taken by NASA's Multi-angle Imaging ... many of MISR's new and unique capabilities," said Dr. David J. Diner, MISR principal investigator of NASA's Jet Propulsion Laboratory, ...

Arctic Refuge

Atmospheric Science Data Center

2014-05-15

article title:  Summer in the Arctic National Wildlife Refuge     View Larger Image This colorful image of the Arctic National Wildlife Refuge and the Beaufort Sea was acquired by the Multi-angle Imaging ...

Identifying Communities of Vulnerability: Using NASA's Multiangle Imaging Spectroradiometer to Enhance Public Health Tracking of Particle Exposure in Los Angeles - An Empirical Approach to Examining L1 MISR Radiance Measurements and PM2.5 Relationships

NASA Astrophysics Data System (ADS)

Laygo, K.; Kontgis, C.; Hollins, A.

2011-12-01

Los Angeles is consistently ranked as one of the most polluted cities in the United States, exhibiting high levels of both ozone and particulate matter. Particulate matter with an aerodynamic diameter of 2.5 microns or less, or PM2.5, is of special concern for health professionals, since it is fine enough to be inhaled into the lungs. Additionally, studies show that it is associated with respiratory disease risks such as asthma. Remote sensing technologies have the potential to be useful in air pollution health studies, but have so far been sparsely implemented. Satellite-derived measurements would be especially useful in air pollution studies, since the concentrations of interest can change by orders of magnitude over small distances. However, with current remote sensing technologies, it is difficult to predict pollution levels within small areas. This study utilizes remote sensing information in combination with a ground-based network of data to create a more comprehensive approach to tracking public health concerns. According to the 2007 NRC Decadal Survey, there is a continued need for research that establishes the relationship between remotely sensed data and predicting public health risks related to environmental factors. For this study, we conducted linear regression models using Multi-Angle Imaging SpectroRadiometer (MISR) L1 radiance data and ground-based PM2.5 measurements from 13 EPA stations within the Los Angeles Metropolitan Statistical Area. MISR senses in 4 bands (visible blue, green, red and near infrared) and 9 separate angles, producing a total of 36 bands. Using all 36 bands, we generated models for each station individually and for all stations combined. Two time periods were assessed: June, July and August from 2000 - 2009, and all months from 2009. Summer months were looked at specifically, since pollution levels tend to be higher than other parts of the year due to strong inversion layers and low rainfall levels. Generally, the models performed well, suggesting that MISR radiances are able to accurately predict levels of PM2.5. For 2009 data, all models had R-squared values over 0.93. For summer month data, the model R-square values were markedly lower and more varied than for the 2009 data, ranging from 0.33 - 0.92. When looking at the 2009 data, non-summer month models performed better than did summer-month models. A brief analysis of temperature data indicates that temperature and deviation from the norm are not associated with model predictability. All 36 MISR channels were plotted against their weights for each model, but no band combination obviously weighed more than other bands. Further research needs to be conducted to understand why models were able to predict 2009 PM2.5 levels, but were unable to accurately fit summer data from 2000 - 2009.

Celtic Sea

Atmospheric Science Data Center

2013-04-17

article title:  Coccoliths in the Celtic Sea     View Larger Image As ... This image is a natural-color view of the Celtic Sea and English Channel regions, and was acquired by the Multi-angle Imaging ...

Extratropical Cyclone in the Southern Ocean

NASA Technical Reports Server (NTRS)

2002-01-01

These images from the Multi-angle Imaging SpectroRadiometer (MISR) portray an occluded extratropical cyclone situated in the Southern Ocean, about 650 kilometers south of the Eyre Peninsula, South Australia. The left-hand image, a true-color view from MISR's nadir (vertical-viewing) camera, shows clouds just south of the Yorke Peninsula and the Murray-Darling river basin in Australia. Retrieved cloud-tracked wind velocities are indicated by the superimposed arrows. The image on the right displays cloud-top heights. Areas where cloud heights could not be retrieved are shown in black. Both the wind vectors and the cloud heights were derived using data from multiple MISR cameras within automated computer processing algorithms. The stereoscopic algorithms used to generate these results are still being refined, and future versions of these products may show modest changes. Extratropical cyclones are the dominant weather system at midlatitudes, and the term is used generically for regional low-pressure systems in the mid- to high-latitudes. In the southern hemisphere, cyclonic rotation is clockwise. These storms obtain their energy from temperature differences between air masses on either side of warm and cold fronts, and their characteristic pattern is of warm and cold fronts radiating out from a migrating low pressure center which forms, deepens, and dissipates as the fronts fold and collapse on each other. The center of this cyclone has started to decay, with the band of cloud to the south most likely representing the main front that was originally connected with the cyclonic circulation. These views were acquired on October 11, 2001, and the large view represents an area of about 380 kilometers x 1900 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.

Anatahan Island

Atmospheric Science Data Center

2013-04-19

...     View Larger Image This natural-color image of Anatahan Island from the Multi-angle ... (Acro Service Corporation/Jet Propulsion Laboratory), David J. Diner (Jet Propulsion Laboratory). Other formats available at JPL ...

Larsen B Ice Shelf

Atmospheric Science Data Center

2013-04-16

article title:  Unique Views of a Shattered Ice Shelf     View Larger Image ... views of the breakup of the northern section of the Larsen B ice shelf are shown in this image pair from the Multi-angle Imaging ...

New NASA Images of Irma's Towering Clouds (Anaglyph)

NASA Image and Video Library

2017-09-08

On Sept. 7, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite passed over Hurricane Irma at approximately 11:20 am local time. The MISR instrument comprises nine cameras that view the Earth at different angles, and since it takes roughly seven minutes for all nine cameras to capture the same location, the motion of the clouds between images allows scientists to calculate the wind speed at the cloud tops. This stereo anaglyph combines two of the MISR angles to show a three-dimensional view of Irma. You will need red-blue glasses to view the anaglyph; place the red lens over your left eye. At this time, Irma's eye was located approximately 60 miles (100 kilometers) north of the Dominican Republic and 140 miles (230 kilometers) north of its capital, Santo Domingo. Irma was a powerful Category 5 hurricane, with wind speeds at the ocean surface up to 185 miles (300 kilometers) per hour. The MISR data show that at cloud top, winds near the eye wall (the most destructive part of the storm) were approximately 90 miles per hour (145 kilometers per hour), and the maximum cloud-top wind speed throughout the storm calculated by MISR was 135 miles per hour (220 kilometers per hour). While the hurricane's dominant rotation direction is counter-clockwise, winds near the eye wall are consistently pointing outward from it. This is an indication of outflow, the process by which a hurricane draws in warm, moist air at the surface and ejects cool, dry air at its cloud tops. https://photojournal.jpl.nasa.gov/catalog/PIA21945

A study of 15-year aerosol optical thickness and direct shortwave aerosol radiative effect trends using MODIS, MISR, CALIOP and CERES

NASA Astrophysics Data System (ADS)

Alfaro-Contreras, Ricardo; Zhang, Jianglong; Reid, Jeffrey S.; Christopher, Sundar

2017-11-01

By combining Collection 6 Moderate Resolution and Imaging Spectroradiometer (MODIS) and Version 22 Multi-angle Imaging Spectroradiometer (MISR) aerosol products with Cloud and Earth's Radiant Energy System (CERES) flux products, the aerosol optical thickness (AOT, at 0.55 µm) and shortwave (SW) aerosol radiative effect (SWARE) trends are studied over ocean for the near-full Terra (2000-2015) and Aqua (2002-2015) data records. Despite differences in sampling methods, regional SWARE and AOT trends are highly correlated with one another. Over global oceans, weak SWARE (cloud-free SW flux) and AOT trends of 0.5-0.6 W m-2 (-0.5 to -0.6 W m-2) and 0.002 AOT decade-1 are found using Terra data. Near-zero AOT and SWARE trends are also found for using Aqua data, regardless of the angular distribution models (ADMs) used. Regionally, positive AOT and cloud-free SW flux (negative SWARE) trends are found over the Bay of Bengal, the Arabian Sea, the Arabian/Persian Gulf and the Red Sea, while statistically significant negative trends are derived over the Mediterranean Sea and the eastern US coast. In addition, the global mean instantaneous SW aerosol direct forcing efficiencies are found to be ˜ -60 W m-2 AOT-1, with corresponding SWARE values of ˜ -7 W m-2 from both Aqua and Terra data, again regardless of CERES ADMs used. Regionally, SW aerosol direct forcing efficiency values of ˜ -40 W m-2 AOT-1 are found over the southwest coast of Africa where smoke aerosol particles dominate in summer. Larger (in magnitude) SW aerosol direct forcing efficiency values of -50 to -80 W m-2 AOT-1 are found over several other dust- and pollutant-aerosol-dominated regions. Lastly, the AOT and SWARE trends from this study are also intercompared with aerosol trends (such as active-based ones) from several previous studies. Findings suggest that a cohesive understanding of the changing aerosol skies can be achieved through the analysis of observations from both passive- and active-based analyses, as well as from both narrowband and broadband datasets.

Remote Sensing of Aerosol Over the Land from the Earth Observing System MODIS Instrument

NASA Technical Reports Server (NTRS)

Kaufman, Yoram; Tanre, Didier; Remer, Lorraine; Einaudi, Franco (Technical Monitor)

2000-01-01

On Dec 18, 1999, NASA launched the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument on the Earth Observing System (EOS) Terra mission, in a spectacular launch. The mission will provide morning (10:30 AM) global observations of aerosol and other related parameters. It will be followed a year later by a MODIS instrument on EOS Aqua for afternoon observations (1:30 PM). MODIS will measure aerosol over land and ocean with its eight 500 m and 250 m channels in the solar spectrum (0-41 to 2.2 micrometers). Over the land MODIS will measure the total column aerosol loading, and distinguish between submicron pollution particles and large soil particles. Standard daily products of resolution of ten kilometers and global mapped eight day and monthly products on a 1x1 degree global scale will be produced routinely and make available for no or small reproduction charge to the international community. Though the aerosol products will not be available everywhere over the land, it is expected that they will be useful for assessments of the presence, sources and transport of urban pollution, biomass burning aerosol, and desert dust. Other measurements from MODIS will supplement the aerosol information, e.g., land use change, urbanization, presence and magnitude of biomass burning fires, and effect of aerosol on cloud microphysics. Other instruments on Terra, e.g. Multi-angle Imaging SpectroRadiometer (MISR) and the Clouds and the Earth's Radiant Energy System (CERES), will also measure aerosol, its properties and radiative forcing in tandem with the MODIS measurements. During the Aqua period, there are plans to launch in 2003 the Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission for global measurements of the aerosol vertical structure, and the PARASOL mission for aerosol characterization. Aqua-MODIS, PICASSO and PARASOL will fly in formation for detailed simultaneous characterization of the aerosol three-dimensional field, which will feed and evaluate global aerosol transport and climate models. In this talk, some examples of the MODIS measurements will be shown.

Space-based Observational Constraints for 1-D Plume Rise Models

NASA Technical Reports Server (NTRS)

Martin, Maria Val; Kahn, Ralph A.; Logan, Jennifer A.; Paguam, Ronan; Wooster, Martin; Ichoku, Charles

2012-01-01

We use a space-based plume height climatology derived from observations made by the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the NASA Terra satellite to evaluate the ability of a plume-rise model currently embedded in several atmospheric chemical transport models (CTMs) to produce accurate smoke injection heights. We initialize the plume-rise model with assimilated meteorological fields from the NASA Goddard Earth Observing System and estimated fuel moisture content at the location and time of the MISR measurements. Fire properties that drive the plume-rise model are difficult to estimate and we test the model with four estimates for active fire area and four for total heat flux, obtained using empirical data and Moderate Resolution Imaging Spectroradiometer (MODIS) re radiative power (FRP) thermal anomalies available for each MISR plume. We show that the model is not able to reproduce the plume heights observed by MISR over the range of conditions studied (maximum r2 obtained in all configurations is 0.3). The model also fails to determine which plumes are in the free troposphere (according to MISR), key information needed for atmospheric models to simulate properly smoke dispersion. We conclude that embedding a plume-rise model using currently available re constraints in large-scale atmospheric studies remains a difficult proposition. However, we demonstrate the degree to which the fire dynamical heat flux (related to active fire area and sensible heat flux), and atmospheric stability structure influence plume rise, although other factors less well constrained (e.g., entrainment) may also be significant. Using atmospheric stability conditions, MODIS FRP, and MISR plume heights, we offer some constraints on the main physical factors that drive smoke plume rise. We find that smoke plumes reaching high altitudes are characterized by higher FRP and weaker atmospheric stability conditions than those at low altitude, which tend to remain confined below the BL, consistent with earlier results. We propose two simplified parameterizations for computing injection heights for fires in CTMs and discuss current challenges to representing plume injection heights in large scale atmospheric models.

Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to evaluate the NASA MERRA Aerosol Reanalysis

NASA Astrophysics Data System (ADS)

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2014-12-01

A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and Aerosol Absorption Optical Depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the South African and South American biomass burning regions indicates that revising the spectrally-dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons. Finally, during a period where the Asian region was mainly dominated by anthropogenic aerosols, we have performed a qualitative analysis in which the specification of anthropogenic emissions in GEOS-5 is adjusted to provide insight into discrepancies observed in AI comparisons.

Intercomparison of MODIS, MISR, OMI, and CALIPSO aerosol optical depth retrievals for four locations on the Indo-Gangetic plains and validation against AERONET data

NASA Astrophysics Data System (ADS)

Bibi, Humera; Alam, Khan; Chishtie, Farrukh; Bibi, Samina; Shahid, Imran; Blaschke, Thomas

2015-06-01

This study provides an intercomparison of aerosol optical depth (AOD) retrievals from satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), Ozone Monitoring Instrument (OMI), and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) instrumentation over Karachi, Lahore, Jaipur, and Kanpur between 2007 and 2013, with validation against AOD observations from the ground-based Aerosol Robotic Network (AERONET). Both MODIS Deep Blue (MODISDB) and MODIS Standard (MODISSTD) products were compared with the AERONET products. The MODISSTD-AERONET comparisons revealed a high degree of correlation for the four investigated sites at Karachi, Lahore, Jaipur, and Kanpur, the MODISDB-AERONET comparisons revealed even better correlations, and the MISR-AERONET comparisons also indicated strong correlations, as did the OMI-AERONET comparisons, while the CALIPSO-AERONET comparisons revealed only poor correlations due to the limited number of data points available. We also computed figures for root mean square error (RMSE), mean absolute error (MAE) and root mean bias (RMB). Using AERONET data to validate MODISSTD, MODISDB, MISR, OMI, and CALIPSO data revealed that MODISSTD data was more accurate over vegetated locations than over un-vegetated locations, while MISR data was more accurate over areas close to the ocean than over other areas. The MISR instrument performed better than the other instruments over Karachi and Kanpur, while the MODISSTD AOD retrievals were better than those from the other instruments over Lahore and Jaipur. We also computed the expected error bounds (EEBs) for both MODIS retrievals and found that MODISSTD consistently outperformed MODISDB in all of the investigated areas. High AOD values were observed by the MODISSTD, MODISDB, MISR, and OMI instruments during the summer months (April-August); these ranged from 0.32 to 0.78, possibly due to human activity and biomass burning. In contrast, high AOD values were observed by the CALIPSO instrument between September and December, due to high concentrations of smoke and soot aerosols. The variable monthly AOD figures obtained with different sensors indicate overestimation by MODISSTD, MODISDB, OMI, and CALIPSO instruments over Karachi, Lahore, Jaipur and Kanpur, relative to the AERONET data, but underestimation by the MISR instrument.

An 11-year global gridded aerosol optical thickness reanalysis (v1.0) for atmospheric and climate sciences

NASA Astrophysics Data System (ADS)

Lynch, Peng; Reid, Jeffrey S.; Westphal, Douglas L.; Zhang, Jianglong; Hogan, Timothy F.; Hyer, Edward J.; Curtis, Cynthia A.; Hegg, Dean A.; Shi, Yingxi; Campbell, James R.; Rubin, Juli I.; Sessions, Walter R.; Turk, F. Joseph; Walker, Annette L.

2016-04-01

While stand alone satellite and model aerosol products see wide utilization, there is a significant need in numerous atmospheric and climate applications for a fused product on a regular grid. Aerosol data assimilation is an operational reality at numerous centers, and like meteorological reanalyses, aerosol reanalyses will see significant use in the near future. Here we present a standardized 2003-2013 global 1 × 1° and 6-hourly modal aerosol optical thickness (AOT) reanalysis product. This data set can be applied to basic and applied Earth system science studies of significant aerosol events, aerosol impacts on numerical weather prediction, and electro-optical propagation and sensor performance, among other uses. This paper describes the science of how to develop and score an aerosol reanalysis product. This reanalysis utilizes a modified Navy Aerosol Analysis and Prediction System (NAAPS) at its core and assimilates quality controlled retrievals of AOT from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra. The aerosol source functions, including dust and smoke, were regionally tuned to obtain the best match between the model fine- and coarse-mode AOTs and the Aerosol Robotic Network (AERONET) AOTs. Other model processes, including deposition, were tuned to minimize the AOT difference between the model and satellite AOT. Aerosol wet deposition in the tropics is driven with satellite-retrieved precipitation, rather than the model field. The final reanalyzed fine- and coarse-mode AOT at 550 nm is shown to have good agreement with AERONET observations, with global mean root mean square error around 0.1 for both fine- and coarse-mode AOTs. This paper includes a discussion of issues particular to aerosol reanalyses that make them distinct from standard meteorological reanalyses, considerations for extending such a reanalysis outside of the NASA A-Train era, and examples of how the aerosol reanalysis can be applied or fused with other model or remote sensing products. Finally, the reanalysis is evaluated in comparison with other available studies of aerosol trends, and the implications of this comparison are discussed.

Development studies towards an 11-year global gridded aerosol optical thickness reanalysis for climate and applied applications

NASA Astrophysics Data System (ADS)

Lynch, P.; Reid, J. S.; Westphal, D. L.; Zhang, J.; Hogan, T. F.; Hyer, E. J.; Curtis, C. A.; Hegg, D. A.; Shi, Y.; Campbell, J. R.; Rubin, J. I.; Sessions, W. R.; Turk, F. J.; Walker, A. L.

2015-12-01

While standalone satellite and model aerosol products see wide utilization, there is a significant need in numerous climate and applied applications for a fused product on a regular grid. Aerosol data assimilation is an operational reality at numerous centers, and like meteorological reanalyses, aerosol reanalyses will see significant use in the near future. Here we present a standardized 2003-2013 global 1° × 1° and 6 hourly modal aerosol optical thickness (AOT) reanalysis product. This dataset can be applied to basic and applied earth system science studies of significant aerosol events, aerosol impacts on numerical weather prediction, and electro-optical propagation and sensor performance, among other uses. This paper describes the science of how to develop and score an aerosol reanalysis product. This reanalysis utilizes a modified Navy Aerosol Analysis and Prediction System (NAAPS) at its core and assimilates quality controlled retrievals of AOT from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra. The aerosol source functions, including dust and smoke, were regionally tuned to obtain the best match between the model fine and coarse mode AOTs and the Aerosol Robotic Network (AERONET) AOTs. Other model processes, including deposition, were tuned to minimize the AOT difference between the model and satellite AOT. Aerosol wet deposition in the tropics is driven with satellite retrieved precipitation, rather than the model field. The final reanalyzed fine and coarse mode AOT at 550 nm is shown to have good agreement with AERONET observations, with global mean root mean square error around 0.1 for both fine and coarse mode AOTs. This paper includes a discussion of issues particular to aerosol reanalyses that make them distinct from standard meteorological reanalyses, considerations for extending such a reanalysis outside of the NASA A-Train era, and examples of how the aerosol reanalysis can be applied or fused with other model or remote sensing products. Finally, the reanalysis is evaluated in comparison with other available studies of aerosol trends, and the implications of this comparison are discussed.

Assessment of OMI Near-UV Aerosol Optical Depth over Land

NASA Technical Reports Server (NTRS)

Ahn, Changwoo; Torres, Omar; Jethva, Hiren

2014-01-01

This is the first comprehensive assessment of the aerosol optical depth (AOD) product retrieved from the near-UV observations by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite. The OMI-retrieved AOD by the ultraviolet (UV) aerosol algorithm (OMAERUV version 1.4.2) was evaluated using collocated Aerosol Robotic Network (AERONET) level 2.0 direct Sun AOD measurements over 8 years (2005-2012). A time series analysis of collocated satellite and ground-based AOD observations over 8 years shows no discernible drift in OMI's calibration. A rigorous validation analysis over 4 years (2005-2008) was carried out at 44 globally distributed AERONET land sites. The chosen locations are representative of major aerosol types such as smoke from biomass burning or wildfires, desert mineral dust, and urban/industrial pollutants. Correlation coefficient (p) values of 0.75 or better were obtained at 50 percent of the sites with about 33 percent of the sites in the analysis reporting regression line slope values larger than 0.70 but always less than unity. The combined AERONET-OMAERUV analysis of the 44 sites yielded a p of 0.81, slope of 0.79, Y intercept of 0.10, and 65 percent OMAERUV AOD falling within the expected uncertainty range (largest of 30 percent or 0.1) at 440 nanometers. The most accurate OMAERUV retrievals are reported over northern Africa locations where the predominant aerosol type is desert dust and cloud presence is less frequent. Reliable retrievals were documented at many sites characterized by urban-type aerosols with low to moderate AOD values, concentrated in the boundary layer. These results confirm that the near-ultraviolet observations are sensitive to the entire aerosol column. A simultaneous comparison of OMAERUV, Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue, and Multiangle Imaging Spectroradiometer (MISR) AOD retrievals to AERONET measurements was also carried out to evaluate the OMAERUV accuracy in relation to those of the standard aerosol satellite products. The outcome of the comparison indicates that OMAERUV, MODIS Deep Blue, and MISR retrieval accuracies in arid and semiarid environments are statistically comparable.

Using the OMI aerosol index and absorption aerosol optical depth to evaluate the NASA MERRA Aerosol Reanalysis

NASA Astrophysics Data System (ADS)

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2015-05-01

A radiative transfer interface has been developed to simulate the UV aerosol index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and aerosol absorption optical depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the AErosol RObotic NETwork (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model-produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the southern African and South American biomass burning regions indicates that revising the spectrally dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons. Finally, during a period where the Asian region was mainly dominated by anthropogenic aerosols, we have performed a qualitative analysis in which the specification of anthropogenic emissions in GEOS-5 is adjusted to provide insight into discrepancies observed in AI comparisons.

Extratropical Cyclone in the Southern Ocean

NASA Technical Reports Server (NTRS)

2001-01-01

These images from the Multi-angle Imaging SpectroRadiometer portray an occluded extratropical cyclone situated in the Southern Ocean, about 650 kilometers south of the Eyre Peninsula, South Australia.

Parts of the Yorke Peninsula and a portion of the Murray-Darling River basin are visible between the clouds near the top of the left-hand image, a true-color view from MISR's nadir(vertical-viewing) camera. Retrieved cloud-tracked wind velocities are indicated by the superimposed arrows. The image on the right displays cloud-top heights. Areas where cloud heights could not be retrieved are shown in black. Both the wind vectors and the cloud heights were derived using data from multiple MISR cameras within automated computer processing algorithms. The stereoscopic algorithms used to generate these results are still being refined, and future versions of these products may show modest changes.

Extratropical cyclones are the dominant weather system at midlatitudes, and the term is used generically for region allow-pressure systems in the mid- to high-latitudes. In the southern hemisphere, cyclonic rotation is clockwise. These storms obtain their energy from temperature differences between air masses on either side of warm and cold fronts, and their characteristic pattern is of warm and cold fronts radiating out from a migrating low pressure center which forms, deepens, and dissipates as the fronts fold and collapse on each other. The center of this cyclone has started to decay, with the band of cloud to the south most likely representing the main front that was originally connected with the cyclonic circulation.

These views were acquired on October 11, 2001 during Terra orbit 9650, and represent an area of about 380 kilometers x 1900 kilometers.

Tinder Fire in Arizona Viewed by NASA's MISR

NASA Image and Video Library

2018-05-02

On April 27, 2018, the Tinder Fire ignited in eastern Arizona near the Blue Ridge Reservoir, about 50 miles (80 kilometers) southeast of Flagstaff and 20 miles (32 kilometers) northeast of Payson. During the first 24 hours it remained relatively small at 500 acres (202 hectares), but on April 29, during red flag wind conditions, it exploded to 8,600 acres (3,480 hectares). Residents of rural communities in the area were forced to evacuate and an unknown number of structures were burned. As of April 30, the Tinder Fire had burned a total of 11,400 acres (4,613 hectares). On April 30 at 11:15 a.m. local time, the Multi-angle Imaging SpectroRadiometer (MISR) captured imagery of the Tinder Fire as it passed overhead on NASA's Terra satellite. The MISR instrument has nine cameras that view Earth at different angles. This image shows the view from MISR's nadir (downward-pointing) camera. The angular information from MISR's images is used to calculate the height of the smoke plume, results of which are superimposed on the right-hand image. This shows that the plume top near the active fire was at approximately 13,000 feet altitude (4,000 meters). In general, higher-altitude plumes transport smoke greater distances from the source, impacting communities downwind. A stereo anaglyph providing a three-dimensional view of the plume is also shown. Red-blue glasses with the red lens placed over your left eye are required to observe the 3D effect. These data were acquired during Terra orbit 97691. An annotated figure and anaglyph are available at https://photojournal.jpl.nasa.gov/catalog/PIA00698

Andes

Atmospheric Science Data Center

2013-04-18

... Arequipa, provide a striking demonstration of the power of water erosion. This image pair was acquired by the Multi-angle Imaging ... stereo image in 3-D requires red/blue glasses with the red filter placed over your left eye. Two main erosion formations can be seen. ...

Waves on White: Ice or Clouds?

NASA Technical Reports Server (NTRS)

2005-01-01

As it passed over Antarctica on December 16, 2004, the Multi-angle Imaging SpectroRadiometer (MISR) on NASA's Terra satellite captured this image showing a wavy pattern in a field of white. At most other latitudes, such wavy patterns would likely indicate stratus or stratocumulus clouds. MISR, however, saw something different. By using information from several of its multiple cameras (each of which views the Earth's surface from a different angle), MISR was able to tell that what looked like a wavy cloud pattern was actually a wavy pattern on the ice surface. One of MISR's cloud classification products, the Angular Signature Cloud Mask (ASCM), correctly identified the rippled area as being at the surface.

In this image pair, the view from MISR's most oblique backward-viewing camera is on the left, and the color-coded image on the right shows the results of the ASCM. The colors represent the level of certainty in the classification. Areas that were classed as cloudy with high confidence are white, and areas where the confidence was lower are yellow; dark blue shows confidently clear areas, while light blue indicates clear with lower confidence. The ASCM works particularly well at detecting clouds over snow and ice, but also works well over ocean and land. The rippled area on the surface which could have been mistaken for clouds are actually sastrugi -- long wavelike ridges of snow formed by the wind and found on the polar plains. Usually sastrugi are only several centimeters high and several meters apart, but large portions of East Antarctica are covered by mega-sastrugi ice fields, with dune-like features as high as four meters separated by two to five kilometers. The mega-sastrugi fields are a result of unusual snow accumulation and redistribution processes influenced by the prevailing winds and climate conditions. MISR imagery indicates that these mega sastrugi were stationary features between 2002 and 2004.

Being able to distinguish clouds from snow or ice-covered surfaces is important in order to adequately characterize the radiation balance of the polar regions. However, detecting clouds using spaceborne detectors over snow and ice surfaces is notoriously difficult, because the surface may often be as bright and as cold as the overlying clouds, and because polar atmospheric temperature inversions sometimes mean that clouds are warmer than the underlying snow or ice surface. The Angular Signature Cloud Mask (ASCM) was developed based on the Band-Differenced Angular Signature (BDAS) approach, introduced by Di Girolamo and Davies (1994) and updated for MISR application by Di Girolamo and Wilson (2003). BDAS uses both spectral and angular changes in reflectivity to distinguish clouds from the background, and the ASCM calculates the difference between the 446 and 866 nanometer reflectances at MISR's two most oblique cameras that view forward-scattered light. New land thresholds for the ASCM are planned for delivery later this year.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82o north and 82o south latitude. This image area covers about 277 kilometers by 421 kilometers in the interior of the East Antarctic ice sheet. These data products were generated from a portion of the imagery acquired during Terra orbit 26584 and utilize data from within blocks 159 to 161 within World Reference System-2 path 63.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

A Cloud Hydrology and Albedo Synthesis Mission (CHASM)

NASA Technical Reports Server (NTRS)

Davies, Roger

2004-01-01

This slide presentation reviews the Cloud Hydrology and Albedo Synthesis Mission (CHASM). The interaction of clouds with radiation and the hydrological cycle represents a huge uncertainty in our understanding of climate science and the modeling of climate system feedbacks. Despite the recognized need for a unified treatment of cloud processes, the present global average values of remotely sensed cloud liquid water and theoretically accepted values used for cloud physics and precipitation modeling differ by an order of magnitude. This is due in part to sampling and saturation effects, as well as to threedimensional cloud structure effects. In recent work with the Multiangle Imaging SpectroRadiometer (MISR) on Terra, we have gained new insights as to how the remote sensing approach could be significantly improved using a new instrument that combines passive optical (visible and near infrared) and microwave measurements, both as pushbroom scanners with multiple viewing angles, to the degree that measurements of liquid water path over deep convective clouds over land also become possible. This instrument would also have the ability of measuring height-resolved cloud-tracked winds using a hyper stereo retrieval technique. Deployment into a precessing low earth orbit would be optimal for measuring diurnal cloud activity. We have explored an instrument design concept for this that looks promising if we can establish partnerships that provide launch and bus capabilities.

Constraints on Global Aerosol Types: Past, Present, and Near-Future

NASA Astrophysics Data System (ADS)

Kahn, Ralph

2014-05-01

Although the recent IPCC fifth assessment report (AR5) suggests that confidence in estimated direct aerosol radiative forcing (DARF) is high, indications are that there is little agreement among current climate models about the global distribution of aerosol single-scattering albedo (SSA). SSA must be associated with specific surface albedo and aerosol optical depth (AOD) values to calculate DARF with confidence, and global-scale constraints on aerosol type, including SSA, are poor at present. Yet, some constraints on aerosol type have been demonstrated for several satellite instruments, including the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR). The time-series of approximately once-weekly, global MISR observations has grown to about 14 years. The MISR capability amounts to three-to-five bins in particle size, two-to-four bins in SSA, and spherical vs. non-spherical particle distinctions, under good retrieval conditions. As the record of coincident, suborbital validation data has increased steadily, it has become progressively more feasible to assess and to improve the operational algorithm constraints on aerosol type. This presentation will discuss planned refinements to the MISR operational algorithm, and will highlight recent efforts at using MISR results to help better represent wildfire smoke, volcanic ash, and urban pollution in climate models.

New Mexico: Los Alamos

Atmospheric Science Data Center

2014-05-15

article title:  Los Alamos, New Mexico     View Larger JPEG image ... kb) Multi-angle views of the Fire in Los Alamos, New Mexico, May 9, 2000. These true-color images covering north-central New Mexico ...

Axial superresolution via multiangle TIRF microscopy with sequential imaging and photobleaching

PubMed Central

Fu, Yan; Winter, Peter W.; Rojas, Raul; Wang, Victor; McAuliffe, Matthew; Patterson, George H.

2016-01-01

We report superresolution optical sectioning using a multiangle total internal reflection fluorescence (TIRF) microscope. TIRF images were constructed from several layers within a normal TIRF excitation zone by sequentially imaging and photobleaching the fluorescent molecules. The depth of the evanescent wave at different layers was altered by tuning the excitation light incident angle. The angle was tuned from the highest (the smallest TIRF depth) toward the critical angle (the largest TIRF depth) to preferentially photobleach fluorescence from the lower layers and allow straightforward observation of deeper structures without masking by the brighter signals closer to the coverglass. Reconstruction of the TIRF images enabled 3D imaging of biological samples with 20-nm axial resolution. Two-color imaging of epidermal growth factor (EGF) ligand and clathrin revealed the dynamics of EGF-activated clathrin-mediated endocytosis during internalization. Furthermore, Bayesian analysis of images collected during the photobleaching step of each plane enabled lateral superresolution (<100 nm) within each of the sections. PMID:27044072

New NASA Images of Irma's Towering Clouds

NASA Image and Video Library

2017-09-08

On Sept. 7, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite passed over Hurricane Irma at approximately 11:20 a.m. local time. The MISR instrument comprises nine cameras that view the Earth at different angles, and since it takes roughly seven minutes for all nine cameras to capture the same location, the motion of the clouds between images allows scientists to calculate the wind speed at the cloud tops. The animated GIF shows Irma's motion over the seven minutes of the MISR imagery. North is toward the top of the image. This composite image shows Hurricane Irma as viewed by the central, downward-looking camera (left), as well as the wind speeds (right) superimposed on the image. The length of the arrows is proportional to the wind speed, while their color shows the altitude at which the winds were calculated. At the time the image was acquired, Irma's eye was located approximately 60 miles (100 kilometers) north of the Dominican Republic and 140 miles (230 kilometers) north of its capital, Santo Domingo. Irma was a powerful Category 5 hurricane, with wind speeds at the ocean surface up to 185 miles (300 kilometers) per hour, according to the National Oceanic and Atmospheric Administration. The MISR data show that at cloud top, winds near the eye wall (the most destructive part of the storm) were approximately 90 miles per hour (145 kilometers per hour), and the maximum cloud-top wind speed throughout the storm calculated by MISR was 135 miles per hour (220 kilometers per hour). While the hurricane's dominant rotation direction is counter-clockwise, winds near the eye wall are consistently pointing outward from it. This is an indication of outflow, the process by which a hurricane draws in warm, moist air at the surface and ejects cool, dry air at its cloud tops. These data were captured during Terra orbit 94267. An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA21946

Utah: Salt Lake City

Atmospheric Science Data Center

2014-05-15

... title:  Snow-Covered Peaks of the Wasatch and Uinta Mountains     View Larger ... edge of the Rocky Mountains and eastern rim of the Great Basin. This early-winter image pair was acquired by the Multi-angle Imaging ...

Remote sensing of smoke, land, and clouds from the NASA ER-2 during SAFARI 2000

NASA Astrophysics Data System (ADS)

King, Michael D.; Platnick, Steven; Moeller, Christopher C.; Revercomb, Henry E.; Chu, D. Allen

2003-07-01

The NASA ER-2 aircraft was deployed to southern Africa between 13 August and 25 September 2000 as part of the Southern African Regional Science Initiative (SAFARI) 2000. This aircraft carried a sophisticated array of multispectral scanners, multiangle spectroradiometers, a monostatic lidar, a gas correlation radiometer, upward and downward spectral flux radiometers, and two metric mapping cameras. These observations were obtained over a 3200 × 2800 km region of savanna, woody savanna, open shrubland, and grassland ecosystems throughout southern Africa and were quite often coordinated with overflights by NASA's Terra and Landsat 7 satellites. The primary purpose of this high-altitude observing platform was to obtain independent observations of smoke, clouds, and land surfaces that could be used to check the validity of various remote sensing measurements derived by Earth-orbiting satellites. These include such things as the accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask for distinguishing clouds and heavy aerosol from land and ocean surfaces and Terra analyses of cloud optical and microphysical properties, aerosol properties, leaf area index, vegetation index, fire occurrence, carbon monoxide, and surface radiation budget. In addition to coordination with Terra and Landsat 7 satellites, numerous flights were conducted over surface AERONET sites, flux towers in South Africa, Botswana, and Zambia, and in situ aircraft from the University of Washington, South Africa, and the United Kingdom. As a result of this experiment, the MODIS cloud mask was shown to distinguish clouds, cloud shadows, and fires over land ecosystems of southern Africa with a high degree of accuracy. In addition, data acquired from the ER-2 show the vertical distribution and stratification of aerosol layers over the subcontinent and make the first observations of a "blue spike" spectral emission signature associated with air heated by fire advecting over a cooler land surface.

What We are Learning about Airborne Particles from MISR Multi-angle Imaging

NASA Astrophysics Data System (ADS)

Kahn, Ralph

The NASA Earth Observing System’s Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global observations in 36 angular-spectral channels about once per week for over 14 years. Regarding airborne particles, MISR is contributing in three broad areas: (1) aerosol optical depth (AOD), especially over land surface, including bright desert, (2) wildfire smoke, desert dust, and volcanic ash injection and near-source plume height, and (3) aerosol type, the aggregate of qualitative constraints on particle size, shape, and single-scattering albedo (SSA). Early advances in the retrieval of these quantities focused on AOD, for which surface-based sun photometers provided a global network of ground truth, and plume height, for which ground-based and airborne lidar offered near-coincident validation data. MSIR monthly, global AOD products contributed directly to the advances in modeling aerosol impacts on climate made between the Inter-governmental Panel on Climate Change (IPCC) third and fourth assessment reports. MISR stereo-derived plume heights are now being used to constrain source inventories for the AeroCom aerosol-climate modeling effort. The remaining challenge for the MISR aerosol effort is to refine and validate our global aerosol type product. Unlike AOD and plume height, aerosol type as retrieved by MISR is a qualitative classification derived from multi-dimensional constraints, so evaluation must be done on a categorical basis. Coincident aerosol type validation data are far less common than for AOD, and, except for rare Golden Days during aircraft field campaigns, amount to remote sensing retrievals from suborbital instruments having uncertainties comparable to those from the MISR product itself. And satellite remote sensing retrievals of aerosol type are much more sensitive to scene conditions such as surface variability and AOD than either AOD or plume height. MISR aerosol type retrieval capability and information content have been demonstrated in case studies using the MISR Operational as especially the MISR Research aerosol retrieval algorithms. Refinements to the Operational algorithm, as indicated by these studies, are required to generate a high-quality next-generation aerosol type product from the MISR data. This presentation will briefly review the MISR AOD and plume height product attributes, and will then focus on the MISR aerosol type product: validation, data quality, and refinements.

Ocean-atmosphere science from the NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission

NASA Astrophysics Data System (ADS)

Werdell, J.

2016-12-01

The new NASA Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission is a strategic climate continuity activity that will not only extend key heritage ocean color, cloud, and aerosol data records, but also enable new insight into oceanographic and atmospheric responses to Earth's changing climate. The primary PACE instrument will be a spectroradiometer that spans the ultraviolet to shortwave infrared region at 5 nm resolution with a ground sample distance of 1 km at nadir. This payload will likely be complemented by a multi-angle polarimeter with a similar spectral range. Scheduled for launch in 2022, this PACE instrument pair will revolutionize studies of global biogeochemistry and carbon cycles in the ocean-atmosphere system. Here, I present a PACE mission overview, with focus on instrument characteristics, core and advanced data products, and overarching science objectives.

Multi-angle lensless digital holography for depth resolved imaging on a chip.

PubMed

Su, Ting-Wei; Isikman, Serhan O; Bishara, Waheb; Tseng, Derek; Erlinger, Anthony; Ozcan, Aydogan

2010-04-26

A multi-angle lensfree holographic imaging platform that can accurately characterize both the axial and lateral positions of cells located within multi-layered micro-channels is introduced. In this platform, lensfree digital holograms of the micro-objects on the chip are recorded at different illumination angles using partially coherent illumination. These digital holograms start to shift laterally on the sensor plane as the illumination angle of the source is tilted. Since the exact amount of this lateral shift of each object hologram can be calculated with an accuracy that beats the diffraction limit of light, the height of each cell from the substrate can be determined over a large field of view without the use of any lenses. We demonstrate the proof of concept of this multi-angle lensless imaging platform by using light emitting diodes to characterize various sized microparticles located on a chip with sub-micron axial and lateral localization over approximately 60 mm(2) field of view. Furthermore, we successfully apply this lensless imaging approach to simultaneously characterize blood samples located at multi-layered micro-channels in terms of the counts, individual thicknesses and the volumes of the cells at each layer. Because this platform does not require any lenses, lasers or other bulky optical/mechanical components, it provides a compact and high-throughput alternative to conventional approaches for cytometry and diagnostics applications involving lab on a chip systems.

Hurricane Lilli

Atmospheric Science Data Center

2014-05-15

article title:  Hurricane Lili Heads for Louisiana Landfall     ... Image Characteristics of a strengthening Category 3 Hurricane Lili are apparent in these images from the Multi-angle Imaging ... (MISR), including a well-developed clearing at the hurricane eye. When these views were acquired on October 2, 2002, Lili was ...

Three-dimensional super-resolved live cell imaging through polarized multi-angle TIRF.

PubMed

Zheng, Cheng; Zhao, Guangyuan; Liu, Wenjie; Chen, Youhua; Zhang, Zhimin; Jin, Luhong; Xu, Yingke; Kuang, Cuifang; Liu, Xu

2018-04-01

Measuring three-dimensional nanoscale cellular structures is challenging, especially when the structure is dynamic. Owing to the informative total internal reflection fluorescence (TIRF) imaging under varied illumination angles, multi-angle (MA) TIRF has been examined to offer a nanoscale axial and a subsecond temporal resolution. However, conventional MA-TIRF still performs badly in lateral resolution and fails to characterize the depth image in densely distributed regions. Here, we emphasize the lateral super-resolution in the MA-TIRF, exampled by simply introducing polarization modulation into the illumination procedure. Equipped with a sparsity and accelerated proximal algorithm, we examine a more precise 3D sample structure compared with previous methods, enabling live cell imaging with a temporal resolution of 2 s and recovering high-resolution mitochondria fission and fusion processes. We also shared the recovery program, which is the first open-source recovery code for MA-TIRF, to the best of our knowledge.

The Size of Dust and Smoke

NASA Technical Reports Server (NTRS)

2005-01-01

Desert dust particles tend to be larger in size than aerosols that originate from the processes of combustion. How precisely do the size of the aerosol particles comprising the dust that obscured the Red Sea on July 26, 2005, contrast with the size of the haze particles that obscured the United States eastern seaboard on the same day? NASA's Multi-angle Imaging SpectroRadiometer (MISR), which views Earth at nine different angles in four wavelengths, provides information about the amount, size, and shape of airborne particles. Here, MISR aerosol amount and size is presented for these two events. These MISR results distinguish desert dust, the most common non-spherical aerosol type, from pollution and forest fire particles. Determining aerosol characteristics is a key to understanding how aerosol particles influence the size, abundance, and rate of production of cloud droplets, and to a better understanding of how aerosols influence clouds and climate.

The left panel of each of these two image sets (Red Sea, left; U.S. coastline, right) is a natural-color view from MISR's 70-degree forward viewing camera. The color-coded maps in the central panels show aerosol optical depth; the right panels provide a measure of aerosol size, expressed as the 'Angstrom exponent.' For the optical depth maps, yellow pixels indicate the most optically-thick aerosols, whereas the red, green and blue pixels represent progressively decreasing aerosol amounts. For this dramatic dust storm over the Red Sea, the aerosol is quite thick, and in some places, the dust over water is too optically thick for MISR to retrieve the aerosol amount. For the eastern seaboard haze, the thickest aerosols have accumulated over the Atlantic Ocean off the coasts of South Carolina and Georgia. Cases where no successful retrieval occurred, either due to extremely high aerosol optical thickness or to clouds, appear as dark gray pixels.

For the Angstrom exponent maps, the blue and green pixels (smaller values) correspond with more large particles, whilst the yellow and red pixels, representing higher Angstrom exponents, correspond with more small particles. Angstrom exponent is related to the way the aerosol optical depth (AOD) changes with wavelength -- a more steeply decreasing AOD with wavelength indicates smaller particles. The greater the magnitude of the Angstrom exponent, the greater the contribution of smaller particles to the overall particle distribution. For optically thick desert dust storms, as in this case, the Angstrom exponent is expected to be relatively low -- likely below 1. For the eastern seaboard haze, the Angstrom exponent is significantly higher, indicating the relative abundance of small pollution particles, especially over the Atlantic where the aerosol optical depth is also very high.

With a nearly simultaneous data acquisition time, the MODIS instrument also collected data for these events, and image features for both the dust storm and the haze are available.

The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 north and 82 south latitude every nine days. This image covers an area of about 1,265 kilometers by 400 kilometers. These data products were generated from a portion of the imagery acquired during Terra orbits 29809 and 29814 and utilize data from blocks 60 to 67 and 71 to 78 within World Reference System-2 paths 17 and 170, respectively.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology.

Evaluation of applicability of high-resolution multiangle imaging photo-polarimetric observations for aerosol atmospheric correction

NASA Astrophysics Data System (ADS)

Kalashnikova, Olga; Garay, Michael; Xu, Feng; Diner, David; Seidel, Felix

2016-07-01

Multiangle spectro-polarimetric measurements have been advocated as an additional tool for better understanding and quantifying the aerosol properties needed for atmospheric correction for ocean color retrievals. The central concern of this work is the assessment of the effects of absorbing aerosol properties on remote sensing reflectance measurement uncertainty caused by neglecting UV-enhanced absorption of carbonaceous particles and by not accounting for dust nonsphericity. In addition, we evaluate the polarimetric sensitivity of absorbing aerosol properties in light of measurement uncertainties achievable for the next generation of multi-angle polarimetric imaging instruments, and demonstrate advantages and disadvantages of wavelength selection in the UV/VNIR range. In this work a vector Markov Chain radiative transfer code including bio-optical models was used to quantitatively evaluate in water leaving radiances between atmospheres containing realistic UV-enhanced and non-spherical aerosols and the SEADAS carbonaceous and dust-like aerosol models. The phase matrices for the spherical smoke particles were calculated using a standard Mie code, while those for non-spherical dust particles were calculated using the numerical approach developed for modeling dust for the AERONET network of ground-based sunphotometers. As a next step, we have developed a retrieval code that employs a coupled Markov Chain (MC) and adding/doubling radiative transfer method for joint retrieval of aerosol properties and water leaving radiance from Airborne Multiangle SpectroPolarimetric Imager-1 (AirMSPI-1) polarimetric observations. The AirMSPI-1 instrument has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI typically acquires observations of a target area at 9 view angles between ±67° at 10 m resolution. AirMSPI spectral channels are centered at 355, 380, 445, 470, 555, 660, and 865 nm, with 470, 660, and 865 reporting linear polarization. We tested prototype retrievals by comparing the retrieved aerosol concentration, size distribution, water-leaving radiance, and chlorophyll concentrations from Airborne Multiangle SpectroPolarimetric Imager-1 (AirMSPI-1) observations to values reported by the USC SeaPRISM AERONET-OC site off the coast of California. The retrieval was then applied to a variety of costal regions in California to evaluate variability in the water-leaving radiance under different atmospheric conditions. We will present results, and will discuss algorithm sensitivity and potential applications for future space-borne coastal monitoring.

Uniting Satellite Data With Health Records to Address the Societal Impacts of Particulate Air Pollution: NASA's Multi-Angle Imager for Aerosols

NASA Astrophysics Data System (ADS)

Nastan, A.; Diner, D. J.

2017-12-01

Epidemiological studies have demonstrated convincingly that airborne particulate matter has a major impact on human health, particularly in urban areas. However, providing an accurate picture of the health effects of various particle mixtures — distinguished by size, shape, and composition — is difficult due to the constraints of currently available measurement tools and the heterogeneity of atmospheric chemistry and human activities over space and time. The Multi-Angle Imager for Aerosols (MAIA) investigation, currently in development as part of NASA's Earth Venture Instrument Program, will address this issue through a powerful combination of technologies and informatics. Atmospheric measurements collected by the MAIA satellite instrument featuring multiangle and innovative polarimetric imaging capabilities will be combined with available ground monitor data and a chemical transport model to produce maps of speciated particulate matter at 1 km spatial resolution for a selected set of globally distributed cities. The MAIA investigation is also original in integrating data providers (atmospheric scientists), data users (epidemiologists), and stakeholders (public health experts) into a multidisciplinary science team that will tailor the observation and analysis strategy within each target area to improve our understanding of the linkages between different particle types and adverse human health outcomes.

Multi-Angle Imager for Aerosols (MAIA) Investigation of Airborne Particle Health Impacts

NASA Astrophysics Data System (ADS)

Diner, D. J.

2016-12-01

Airborne particulate matter (PM) is a well-known cause of heart disease, cardiovascular and respiratory illness, low birth weight, and lung cancer. The Global Burden of Disease (GBD) Study ranks PM as a major environmental risk factor worldwide. Global maps of PM2.5concentrations derived from satellite instruments, including MISR and MODIS, have provided key contributions to the GBD and many other health-related investigations. Although it is well established that PM exposure increases the risks of mortality and morbidity, our understanding of the relative toxicity of specific PM types is relatively poor. To address this, the Multi-Angle Imager for Aerosols (MAIA) investigation was proposed to NASA's third Earth Venture Instrument (EVI-3) solicitation. The satellite instrument that is part of the investigation is a multiangle, multispectral, and polarimetric camera system based on the first and second generation Airborne Multiangle SpectroPolarimetric Imagers, AirMSPI and AirMSPI-2. MAIA was selected for funding in March 2016. Estimates of the abundances of different aerosol types from the WRF-Chem model will be combined with MAIA instrument data. Geostatistical models derived from collocated surface and MAIA retrievals will then be used to relate retrieved fractional column aerosol optical depths to near-surface concentrations of major PM constituents, including sulfate, nitrate, organic carbon, black carbon, and dust. Epidemiological analyses of geocoded birth, death, and hospital records will be used to associate exposure to PM types with adverse health outcomes. MAIA launch is planned for early in the next decade. The MAIA instrument incorporates a pair of cameras on a two-axis gimbal to provide regional multiangle observations of selected, globally distributed target areas. Primary Target Areas (PTAs) on five continents are chosen to include major population centers covering a range of PM concentrations and particle types, surface-based aerosol sunphotometers, PM size discrimination and chemical speciation monitors, and access to geocoded health datasets. The MAIA investigation brings together an international team of researchers and policy specialists with expertise in remote sensing, aerosol science, air quality, epidemiology, and public health.

Validation of high-resolution MAIAC aerosol product over South America

NASA Astrophysics Data System (ADS)

Martins, V. S.; Lyapustin, A.; de Carvalho, L. A. S.; Barbosa, C. C. F.; Novo, E. M. L. M.

2017-07-01

Multiangle Implementation of Atmospheric Correction (MAIAC) is a new Moderate Resolution Imaging Spectroradiometer (MODIS) algorithm that combines time series approach and image processing to derive surface reflectance and atmosphere products, such as aerosol optical depth (AOD) and columnar water vapor (CWV). The quality assessment of MAIAC AOD at 1 km resolution is still lacking across South America. In the present study, critical assessment of MAIAC AOD550 was performed using ground-truth data from 19 Aerosol Robotic Network (AERONET) sites over South America. Additionally, we validated the MAIAC CWV retrievals using the same AERONET sites. In general, MAIAC AOD Terra/Aqua retrievals show high agreement with ground-based measurements, with a correlation coefficient (R) close to unity (RTerra:0.956 and RAqua: 0.949). MAIAC accuracy depends on the surface properties and comparisons revealed high confidence retrievals over cropland, forest, savanna, and grassland covers, where more than 2/3 ( 66%) of retrievals are within the expected error (EE = ±(0.05 + 0.05 × AOD)) and R exceeding 0.86. However, AOD retrievals over bright surfaces show lower correlation than those over vegetated areas. Both MAIAC Terra and Aqua retrievals are similarly comparable to AERONET AOD over the MODIS lifetime (small bias offset 0.006). Additionally, MAIAC CWV presents quantitative information with R 0.97 and more than 70% of retrievals within error (±15%). Nonetheless, the time series validation shows an upward bias trend in CWV Terra retrievals and systematic negative bias for CWV Aqua. These results contribute to a comprehensive evaluation of MAIAC AOD retrievals as a new atmospheric product for future aerosol studies over South America.

Forest Canopy Cover and Height from MISR in Topographically Complex Southwestern US Landscape Assessed with High Quality Reference Data

NASA Technical Reports Server (NTRS)

Chopping, Mark; North, Malcolm; Chen, Jiquan; Schaaf, Crystal B.; Blair, J. Bryan; Martonchik, John V.; Bull, Michael A.

2012-01-01

This study addresses the retrieval of spatially contiguous canopy cover and height estimates in southwestern USforests via inversion of a geometric-optical (GO) model against surface bidirectional reflectance factor (BRF) estimates from the Multi-angle Imaging SpectroRadiometer (MISR). Model inversion can provide such maps if good estimates of the background bidirectional reflectance distribution function (BRDF) are available. The study area is in the Sierra National Forest in the Sierra Nevada of California. Tree number density, mean crown radius, and fractional cover reference estimates were obtained via analysis of QuickBird 0.6 m spatial resolution panchromatic imagery usingthe CANopy Analysis with Panchromatic Imagery (CANAPI) algorithm, while RH50, RH75 and RH100 (50, 75, and 100 energy return) height data were obtained from the NASA Laser Vegetation Imaging Sensor (LVIS), a full waveform light detection and ranging (lidar) instrument. These canopy parameters were used to drive a modified version of the simple GO model (SGM), accurately reproducing patterns ofMISR 672 nm band surface reflectance (mean RMSE 0.011, mean R2 0.82, N 1048). Cover and height maps were obtained through model inversion against MISR 672 nm reflectance estimates on a 250 m grid.The free parameters were tree number density and mean crown radius. RMSE values with respect to reference data for the cover and height retrievals were 0.05 and 6.65 m, respectively, with of 0.54 and 0.49. MISR can thus provide maps of forest cover and height in areas of topographic variation although refinements are required to improve retrieval precision.

Global and Regional Evaluation of Over-Land Spectral Aerosol Optical Depth Retrievals from SeaWiFS

NASA Technical Reports Server (NTRS)

Sayer, A. M.; Hsu, N. C.; Bettenhausen, C.; Jeong, M. J.; Holben, B. N.; Zhang, J.

2012-01-01

This study evaluates a new spectral aerosol optical depth (AOD) dataset derived from Sea-viewing Wide Field-of-view Sensor (Sea WiFS) measurements over land. First, the data are validated against Aerosol Robotic Network (AERONET) direct-sun AOD measurements, and found to compare well on a global basis. If only data with the highest quality flag are used, the correlation is 0.86 and 72% of matchups fall within an expected absolute uncertainty of 0.05 + 20% (for the wavelength of 550 nm). The quality is similar at other wavelengths and stable over the 13-year (1997-2010) mission length. Performance tends to be better over vegetated, low-lying terrain with typical AOD of 0.3 or less, such as found over much of North America and Eurasia. Performance tends to be poorer for low-AOD conditions near backscattering geometries, where Sea WiFS overestimates AOD, or optically-thick cases of absorbing aerosol, where SeaWiFS tends to underestimate AOD. Second, the SeaWiFS data are compared with midvisible AOD derived from the Moderate Resolution Imaging Spectrometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR). All instruments show similar spatial and seasonal distributions of AOD, although there are regional and seasonal offsets between them. At locations where AERONET data are available, these offsets are largely consistent with the known validation characteristics of each dataset. With the results of this study in mind, the SeaWiFS over-land AOD record should be suitable for quantitative scientific use.

The Retrieval of Aerosol Optical Thickness Using the MERIS Instrument

NASA Astrophysics Data System (ADS)

Mei, L.; Rozanov, V. V.; Vountas, M.; Burrows, J. P.; Levy, R. C.; Lotz, W.

2015-12-01

Retrieval of aerosol properties for satellite instruments without shortwave-IR spectral information, multi-viewing, polarization and/or high-temporal observation ability is a challenging problem for spaceborne aerosol remote sensing. However, space based instruments like the MEdium Resolution Imaging Spectrometer (MERIS) and the successor, Ocean and Land Colour Instrument (OLCI) with high calibration accuracy and high spatial resolution provide unique abilities for obtaining valuable aerosol information for a better understanding of the impact of aerosols on climate, which is still one of the largest uncertainties of global climate change evaluation. In this study, a new Aerosol Optical Thickness (AOT) retrieval algorithm (XBAER: eXtensible Bremen AErosol Retrieval) is presented. XBAER utilizes the global surface spectral library database for the determination of surface properties while the MODIS collection 6 aerosol type treatment is adapted for the aerosol type selection. In order to take the surface Bidirectional Reflectance Distribution Function (BRDF) effect into account for the MERIS reduce resolution (1km) retrieval, a modified Ross-Li mode is used. The AOT is determined in the algorithm using lookup tables including polarization created using Radiative Transfer Model SCIATRAN3.4, by minimizing the difference between atmospheric corrected surface reflectance with given AOT and the surface reflectance calculated from the spectral library. The global comparison with operational MODIS C6 product, Multi-angle Imaging SpectroRadiometer (MISR) product, Advanced Along-Track Scanning Radiometer (AATSR) aerosol product and the validation using AErosol RObotic NETwork (AERONET) show promising results. The current XBAER algorithm is only valid for aerosol remote sensing over land and a similar method will be extended to ocean later.

Southern California Wildfires Observed by NASA MISR

NASA Image and Video Library

2016-06-24

The Los Angeles area is currently suffering the effects of three major wildfires that are blanketing the area with smoke. Over the past few days, Southern California has experienced record-breaking temperatures, topping 110 degrees Fahrenheit in some cities. The heat, in combination with offshore winds, helped to stoke the Sherpa Fire west of Santa Barbara, which has been burning since June 15, 2016. Over the weekend of June 18-19, this fire rapidly expanded in size, forcing freeway closures and evacuations of campgrounds and state beaches. On Monday, June 20, two new fires ignited in the San Gabriel Mountains north of Azusa and Duarte, together dubbed the San Gabriel Complex Fire. They have burned more than 4,900 acres since June 20, sending up plumes of smoke visible to many in the Los Angeles basin and triggering air quality warnings. More than 1,400 personnel have been battling the blazes in the scorching heat, and evacuations were ordered for neighborhoods in the foothills. On June 21, the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite captured this view of the San Gabriel Mountains and Los Angeles Basin from its 46-degree forward-viewing camera, which enhances the visibility of the smoke compared to the more conventional nadir (vertical) view. The width of this image is about 75 miles (120 kilometers) across. Smoke from the San Gabriel Complex Fire is visible at the very right of the image. Stereoscopic analysis of MISR's multiple camera angles is used to compute the height of the smoke plume from the San Gabriel Complex Fire. In the right-hand image, these heights are superimposed on the underlying image. The color scale shows that the plume is not much higher than the surrounding mountains. As a result, much of the smoke is confined to the local area. http://photojournal.jpl.nasa.gov/catalog/PIA20718

Variability in Surface BRDF at Different Spatial Scales (30m-500m) Over a Mixed Agricultural Landscape as Retrieved from Airborne and Satellite Spectral Measurements

NASA Technical Reports Server (NTRS)

Roman, Miguel O.; Gatebe, Charles K.; Schaaf, Crystal B.; Poudyal, Rajesh; Wang, Zhuosen; King, Michael D.

2012-01-01

Over the past decade, the role of multiangle 1 remote sensing has been central to the development of algorithms for the retrieval of global land surface properties including models of the bidirectional reflectance distribution function (BRDF), albedo, land cover/dynamics, burned area extent, as well as other key surface biophysical quantities represented by the anisotropic reflectance characteristics of vegetation. In this study, a new retrieval strategy for fine-to-moderate resolution multiangle observations was developed, based on the operational sequence used to retrieve the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5 reflectance and BRDF/albedo products. The algorithm makes use of a semiempirical kernel-driven bidirectional reflectance model to provide estimates of intrinsic albedo (i.e., directional-hemispherical reflectance and bihemispherical reflectance), model parameters describing the BRDF, and extensive quality assurance information. The new retrieval strategy was applied to NASA's Cloud Absorption Radiometer (CAR) data acquired during the 2007 Cloud and Land Surface Interaction Campaign (CLASIC) over the well-instrumented Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site in Oklahoma, USA. For the case analyzed, we obtained approx.1.6 million individual surface bidirectional reflectance factor (BRF) retrievals, from nadir to 75deg off-nadir, and at spatial resolutions ranging from 3 m - 500 m. This unique dataset was used to examine the interaction of the spatial and angular 18 characteristics of a mixed agricultural landscape; and provided the basis for detailed assessments of: (1) the use of a priori knowledge in kernel-driven BRDF model inversions; (2) the interaction between surface reflectance anisotropy and instrument spatial resolution; and (3) the uncertainties that arise when sub-pixel differences in the BRDF are aggregated to a moderate resolution satellite pixel. Results offer empirical evidence concerning the influence of scale and spatial heterogeneity in kernel-driven BRDF models; providing potential new insights into the behavior and characteristics of different surface radiative properties related to land/use cover change and vegetation structure.

Variability in Surface BRDF at Different Spatial Scales (30 m-500 m) Over a Mixed Agricultural Landscape as Retrieved from Airborne and Satellite Spectral Measurements

NASA Technical Reports Server (NTRS)

Roman, Miguel O.; Gatebe, Charles K.; Schaaf, Crystal B.; Poudyal, Rajesh; Wang, Zhousen; King, Michael D.

2011-01-01

Over the past decade, the role of multiangle remote sensing has been central to the development of algorithms for the retrieval of global land surface properties including models of the bidirectional reflectance distribution function (BRDF), albedo, land cover/dynamics, burned area extent, as well as other key surface biophysical quantities represented by the anisotropic reflectance characteristics of vegetation. In this study, a new retrieval strategy for fine-to-moderate resolution multiangle observations was developed, based on the operational sequence used to retrieve the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 5 reflectance and BRDF/albedo products. The algorithm makes use of a semiempirical kernel-driven bidirectional reflectance model to provide estimates of intrinsic albedo (i.e., directional-hemispherical reflectance and bihemispherical reflectance), model parameters describing the BRDF, and extensive quality assurance information. The new retrieval strategy was applied to NASA's Cloud Absorption Radiometer (CAR) data acquired during the 2007 Cloud and Land Surface Interaction Campaign (CLASIC) over the well-instrumented Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site in Oklahoma, USA. For the case analyzed, we obtained approx.1.6 million individual surface bidirectional reflectance factor (BRF) retrievals, from nadir to 75 off-nadir, and at spatial resolutions ranging from 3 m - 500 m. This unique dataset was used to examine the interaction of the spatial and angular characteristics of a mixed agricultural landscape; and provided the basis for detailed assessments of: (1) the use of a priori knowledge in kernel-driven BRDF model inversions; (2) the interaction between surface reflectance anisotropy and instrument spatial resolution; and (3) the uncertain ties that arise when sub-pixel differences in the BRDF are aggregated to a moderate resolution satellite pixel. Results offer empirical evidence concerning the influence of scale and spatial heterogeneity in kernel-driven BRDF models; providing potential new insights into the behavior and characteristics of different surface radiative properties related to land/use cover change and vegetation structure.

Technology Readiness Level (TRL) Advancement of the MSPI On-Board Processing Platform for the ACE Decadal Survey Mission

NASA Technical Reports Server (NTRS)

Pingree, Paula J.; Werne, Thomas A.; Bekker, Dmitriy L.; Wilson, Thor O.

2011-01-01

The Xilinx Virtex-5QV is a new Single-event Immune Reconfigurable FPGA (SIRF) device that is targeted as the spaceborne processor for the NASA Decadal Survey Aerosol-Cloud-Ecosystem (ACE) mission's Multiangle SpectroPolarimetric Imager (MSPI) instrument, currently under development at JPL. A key technology needed for MSPI is on-board processing (OBP) to calculate polarimetry data as imaged by each of the 9 cameras forming the instrument. With funding from NASA's ESTO1 AIST2 Program, JPL is demonstrating how signal data at 95 Mbytes/sec over 16 channels for each of the 9 multi-angle cameras can be reduced to 0.45 Mbytes/sec, thereby substantially reducing the image data volume for spacecraft downlink without loss of science information. This is done via a least-squares fitting algorithm implemented on the Virtex-5 FPGA operating in real-time on the raw video data stream.

Combined Infrared Stereo and Laser Ranging Cloud Measurements from Shuttle Mission STS-85

NASA Technical Reports Server (NTRS)

Lancaster, R. S.; Spinhirne, J. D.; Manizade, K. F.

2004-01-01

Multiangle remote sensing provides a wealth of information for earth and climate monitoring, such as the ability to measure the height of cloud tops through stereoscopic imaging. As technology advances so do the options for developing spacecraft instrumentation versatile enough to meet the demands associated with multiangle measurements. One such instrument is the infrared spectral imaging radiometer, which flew as part of mission STS-85 of the space shuttle in 1997 and was the first earth- observing radiometer to incorporate an uncooled microbolometer array detector as its image sensor. Specifically, a method for computing cloud-top height with a precision of +/- 620 m from the multispectral stereo measurements acquired during this flight has been developed, and the results are compared with coincident direct laser ranging measurements from the shuttle laser altimeter. Mission STS-85 was the first space flight to combine laser ranging and thermal IR camera systems for cloud remote sensing.

A single camera photogrammetry system for multi-angle fast localization of EEG electrodes.

PubMed

Qian, Shuo; Sheng, Yang

2011-11-01

Photogrammetry has become an effective method for the determination of electroencephalography (EEG) electrode positions in three dimensions (3D). Capturing multi-angle images of the electrodes on the head is a fundamental objective in the design of photogrammetry system for EEG localization. Methods in previous studies are all based on the use of either a rotating camera or multiple cameras, which are time-consuming or not cost-effective. This study aims to present a novel photogrammetry system that can realize simultaneous acquisition of multi-angle head images in a single camera position. Aligning two planar mirrors with the angle of 51.4°, seven views of the head with 25 electrodes are captured simultaneously by the digital camera placed in front of them. A complete set of algorithms for electrode recognition, matching, and 3D reconstruction is developed. It is found that the elapsed time of the whole localization procedure is about 3 min, and camera calibration computation takes about 1 min, after the measurement of calibration points. The positioning accuracy with the maximum error of 1.19 mm is acceptable. Experimental results demonstrate that the proposed system provides a fast and cost-effective method for the EEG positioning.

Study of satellite retrieved aerosol optical depth spatial resolution effect on particulate matter concentration prediction

NASA Astrophysics Data System (ADS)

Strandgren, J.; Mei, L.; Vountas, M.; Burrows, J. P.; Lyapustin, A.; Wang, Y.

2014-10-01

The Aerosol Optical Depth (AOD) spatial resolution effect is investigated for the linear correlation between satellite retrieved AOD and ground level particulate matter concentrations (PM2.5). The Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm was developed for the Moderate Resolution Imaging Spectroradiometer (MODIS) for obtaining AOD with a high spatial resolution of 1 km and provides a good dataset for the study of the AOD spatial resolution effect on the particulate matter concentration prediction. 946 Environmental Protection Agency (EPA) ground monitoring stations across the contiguous US have been used to investigate the linear correlation between AOD and PM2.5 using AOD at different spatial resolutions (1, 3 and 10 km) and for different spatial scales (urban scale, meso-scale and continental scale). The main conclusions are: (1) for both urban, meso- and continental scale the correlation between PM2.5 and AOD increased significantly with increasing spatial resolution of the AOD, (2) the correlation between AOD and PM2.5 decreased significantly as the scale of study region increased for the eastern part of the US while vice versa for the western part of the US, (3) the correlation between PM2.5 and AOD is much more stable and better over the eastern part of the US compared to western part due to the surface characteristics and atmospheric conditions like the fine mode fraction.

Amazon Forests Response to Droughts: A Perspective from the MAIAC Product

NASA Technical Reports Server (NTRS)

Bi, Jian; Myneni, Ranga; Lyapustin, Alexei; Wang, Yujie; Park, Taejin; Chi, Chen; Yan, Kai; Knyazikhin, Yuri

2016-01-01

Amazon forests experienced two severe droughts at the beginning of the 21st century: one in 2005 and the other in 2010. How Amazon forests responded to these droughts is critical for the future of the Earth's climate system. It is only possible to assess Amazon forests' response to the droughts in large areal extent through satellite remote sensing. Here, we used the Multi-Angle Implementation of Atmospheric Correction (MAIAC) Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index (VI) data to assess Amazon forests' response to droughts, and compared the results with those from the standard (Collection 5 and Collection 6) MODIS VI data. Overall, the MAIAC data reveal more realistic Amazon forests inter-annual greenness dynamics than the standard MODIS data. Our results from the MAIAC data suggest that: (1) the droughts decreased the greenness (i.e., photosynthetic activity) of Amazon forests; (2) the Amazon wet season precipitation reduction induced by El Niño events could also lead to reduced photosynthetic activity of Amazon forests; and (3) in the subsequent year after the water stresses, the greenness of Amazon forests recovered from the preceding decreases. However, as previous research shows droughts cause Amazon forests to reduce investment in tissue maintenance and defense, it is not clear whether the photosynthesis of Amazon forests will continue to recover after future water stresses, because of the accumulated damages caused by the droughts.

Scaling estimates of vegetation structure in Amazonian tropical forests using multi-angle MODIS observations

PubMed Central

de Moura, Yhasmin Mendes; Hilker, Thomas; Goncalves, Fabio Guimarães; Galvão, Lênio Soares; dos Santos, João Roberto; Lyapustin, Alexei; Maeda, Eduardo Eiji; de Jesus Silva, Camila Valéria

2018-01-01

Detailed knowledge of vegetation structure is required for accurate modelling of terrestrial ecosystems, but direct measurements of the three dimensional distribution of canopy elements, for instance from LiDAR, are not widely available. We investigate the potential for modelling vegetation roughness, a key parameter for climatological models, from directional scattering of visible and near-infrared (NIR) reflectance acquired from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). We compare our estimates across different tropical forest types to independent measures obtained from: (1) airborne laser scanning (ALS), (2) spaceborne Geoscience Laser Altimeter System (GLAS)/ICESat, and (3) the spaceborne SeaWinds/QSCAT. Our results showed linear correlation between MODIS-derived anisotropy to ALS-derived entropy (r2= 0.54, RMSE=0.11), even in high biomass regions. Significant relationships were also obtained between MODIS-derived anisotropy and GLAS-derived entropy (0.52≤ r2≤ 0.61; p<0.05), with similar slopes and offsets found throughout the season, and RMSE between 0.26 and 0.30 (units of entropy). The relationships between the MODIS-derived anisotropy and backscattering measurements (σ0) from SeaWinds/QuikSCAT presented an r2 of 0.59 and a RMSE of 0.11. We conclude that multi-angular MODIS observations are suitable to extrapolate measures of canopy entropy across different forest types, providing additional estimates of vegetation structure in the Amazon. PMID:29618964

The Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment

NASA Technical Reports Server (NTRS)

Smith, William L., Jr.; Charlock, Thomas; Wielicki, Bruce; Kahn, Ralph; Martins, J. Vanderlei; Gatebe, Charles; Hobbs, Peter V.; Purgold, G. Carl; Redemann, Jens; Remer, Lorraine

2004-01-01

NASA has developed an Earth Observing System (EOS) consisting of a series of satellites designed to study global change from space. The EOS flagship is the EOS TERRA satellite, launched in December 1999, equipped with five unique sensors to monitor and study the Earth s heat budget and many of the key controlling variables governing the Earth's climate system. CLAMS, the Chesapeake Lighthouse and Aircraft Measurements for Satellites field campaign was conducted from NASA Wallops Flight Facility and successfully executed over the middle Atlantic eastern seaboard from July 10 August 2, 2001. CLAMS is primarily a shortwave closure experiment designed to validate and improve EOS TERRA satellite data products being derived from three sensors: CERES (Clouds and Earth's Radiant Energy System), MISR (Multi-angle Imaging Spectro-Radiometer) and MODIS (MODerate Resolution Imaging Spectroradiometer). CLAMS is jointly sponsored by the CERES, MISR and MODIS instrument teams and the NASA GEWEX Global Aerosol Climatology Project (GACP). CLAMS primary objectives are to validate satellite-based retrievals of aerosol properties and vertical profiles of radiative flux, temperature and water vapor. Central to CLAMS measurement strategy is the Chesapeake Lighthouse, a stable sea platform located in the Atlantic Ocean, 13 miles east of Virginia Beach near the mouth of the Chesapeake Bay and the site of an ongoing CERES Ocean Validation Experiment (COVE). Six research aircraft were deployed to make detailed measurements of the atmosphere and ocean surface in the vicinity of COVE, over the surrounding ocean, over nearby NOAA buoys and over a few land sites. The measurements are used to validate and provide ground truth for simultaneous products being derived from TERRA data, a key step toward an improved understanding and ability to predict changes in the Earth's climate. One of the two CERES instruments on-board TERRA was programmed for Rotating Azimuth Plane Scans (RAPS) during CLAMS, increasing the CERES coverage over COVE by a factor of 10. Nine coordinated aircraft missions and numerous additional sorties were flown under a variety of atmospheric conditions and aerosol loadings. On one golden day, July 17, all six aircraft flew coordinated patterns, vertically stacked between 100 ft and 65,000 ft over the COVE site as the TERRA satellite orbited overhead. A summary of CLAMS measurement campaign and a description of the platforms and measurements is given.

Decadal-scale trends in regional aerosol particle properties and their linkage to emission changes

NASA Astrophysics Data System (ADS)

Zhao, Bin; Jiang, Jonathan H.; Gu, Yu; Diner, David; Worden, John; Liou, Kuo-Nan; Su, Hui; Xing, Jia; Garay, Michael; Huang, Lei

2017-05-01

Understanding long-term trends in aerosol loading and properties is essential for evaluating the health and climatic effects of these airborne particulates as well as the effectiveness of pollution control policies. While many studies have used satellite data to examine the trends in aerosol optical depth (AOD), very few have investigated the trends in aerosol properties associated with particle size, morphology, and light absorption. In this study, we investigate decadal-scale (13-15 year) trends in aerosol loading and properties during 2001-2015 over three populous regions: the Eastern United States (EUS), Western Europe (WEU), and Eastern and Central China (ECC). We use observations from MISR (Multi-angle Imaging SpectroRadiometer) and MODIS (Moderate resolution Imaging Spectroradiometer). Relationships between aerosol property trends and air pollutant emission changes are examined. We find that annual mean AOD shows pronounced decreasing trends over EUS and WEU regions, as a result of considerable emission reductions in all major pollutants except for mineral dust and ammonia (NH3). Over the ECC region, AOD increases before 2006 due to emission increases induced by rapid economic development, fluctuates between 2006 and 2011, and subsequently decreases after 2011 in conjunction with effective emission reduction in anthropogenic primary aerosols, sulfur dioxide (SO2), and nitrogen oxides (NOx). The fraction of small-size AOD (<0.7 μm diameter), Ångstrom exponent and single-scattering albedo have generally decreased, while the fractions of large-size (>1.4 μm diameter), nonspherical and absorbing AOD have generally shown increasing trends over EUS and WEU regions, indicating that fine and light-scattering aerosol constituents have been more effectively reduced than coarse and light-absorbing constituents. These trends are consistent with the larger reduction ratios in SO2 and NOx emissions than in primary aerosols, including mineral dust and black carbon (BC). Over the ECC region, no significant trends are observed with respect to size distribution, morphology, or light absorption, which we attribute to a simultaneous increase in emissions of SO2, NOx, and primary aerosols including BC before 2006, and a simultaneous decrease after 2011. This study demonstrates the importance and usefulness of satellite-borne sensors, particularly MISR, in association with evaluating the effectiveness of air pollution control policies.

A multi-model evaluation of aerosols over South Asia: common problems and possible causes

NASA Astrophysics Data System (ADS)

Pan, X.; Chin, M.; Gautam, R.; Bian, H.; Kim, D.; Colarco, P. R.; Diehl, T. L.; Takemura, T.; Pozzoli, L.; Tsigaridis, K.; Bauer, S.; Bellouin, N.

2015-05-01

Atmospheric pollution over South Asia attracts special attention due to its effects on regional climate, water cycle and human health. These effects are potentially growing owing to rising trends of anthropogenic aerosol emissions. In this study, the spatio-temporal aerosol distributions over South Asia from seven global aerosol models are evaluated against aerosol retrievals from NASA satellite sensors and ground-based measurements for the period of 2000-2007. Overall, substantial underestimations of aerosol loading over South Asia are found systematically in most model simulations. Averaged over the entire South Asia, the annual mean aerosol optical depth (AOD) is underestimated by a range 15 to 44% across models compared to MISR (Multi-angle Imaging SpectroRadiometer), which is the lowest bound among various satellite AOD retrievals (from MISR, SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), MODIS (Moderate Resolution Imaging Spectroradiometer) Aqua and Terra). In particular during the post-monsoon and wintertime periods (i.e., October-January), when agricultural waste burning and anthropogenic emissions dominate, models fail to capture AOD and aerosol absorption optical depth (AAOD) over the Indo-Gangetic Plain (IGP) compared to ground-based Aerosol Robotic Network (AERONET) sunphotometer measurements. The underestimations of aerosol loading in models generally occur in the lower troposphere (below 2 km) based on the comparisons of aerosol extinction profiles calculated by the models with those from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data. Furthermore, surface concentrations of all aerosol components (sulfate, nitrate, organic aerosol (OA) and black carbon (BC)) from the models are found much lower than in situ measurements in winter. Several possible causes for these common problems of underestimating aerosols in models during the post-monsoon and wintertime periods are identified: the aerosol hygroscopic growth and formation of secondary inorganic aerosol are suppressed in the models because relative humidity (RH) is biased far too low in the boundary layer and thus foggy conditions are poorly represented in current models, the nitrate aerosol is either missing or inadequately accounted for, and emissions from agricultural waste burning and biofuel usage are too low in the emission inventories. These common problems and possible causes found in multiple models point out directions for future model improvements in this important region.

Evaluation of Detector-to-Detector and Mirror Side Differences for Terra MODIS Reflective Solar Bands Using Simultaneous MISR Observations

NASA Technical Reports Server (NTRS)

Wu, Aisheng; Xiong, Xiaoxiong; Angal, A.; Barnes, W.

2011-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the five Earth-observing instruments on-board the National Aeronautics and Space Administration (NASA) Earth-Observing System(EOS) Terra spacecraft, launched in December 1999. It has 36 spectral bands with wavelengths ranging from 0.41 to 14.4 mm and collects data at three nadir spatial resolutions: 0.25 km for 2 bands with 40 detectors each, 0.5 km for 5 bands with 20 detectors each and 1 km for the remaining 29 bands with 10 detectors each. MODIS bands are located on four separate focal plane assemblies (FPAs) according to their spectral wavelengths and aligned in the cross-track direction. Detectors of each spectral band are aligned in the along-track direction. MODIS makes observations using a two-sided paddle-wheel scan mirror. Its on-board calibrators (OBCs) for the reflective solar bands (RSBs) include a solar diffuser (SD), a solar diffuser stability monitor (SDSM) and a spectral-radiometric calibration assembly (SRCA). Calibration is performed for each band, detector, sub-sample (for sub-kilometer resolution bands) and mirror side. In this study, a ratio approach is applied to MODIS observed Earth scene reflectances to track the detector-to-detector and mirror side differences. Simultaneous observed reflectances from the Multi-angle Imaging Spectroradiometer (MISR), also onboard the Terra spacecraft, are used with MODIS observed reflectances in this ratio approach for four closely matched spectral bands. Results show that the detector-to-detector difference between two adjacent detectors within each spectral band is typically less than 0.2% and, depending on the wavelengths, the maximum difference among all detectors varies from 0.5% to 0.8%. The mirror side differences are found to be very small for all bands except for band 3 at 0.44 mm. This is the band with the shortest wavelength among the selected matching bands, showing a time-dependent increase for the mirror side difference. This study is part of the effort by the MODIS Characterization Support Team (MCST) in order to track the RSB on-orbit performance for MODIS collection 5 data products. To support MCST efforts for future data re-processing, this analysis will be extended to include more spectral bands and temporal coverage.

Deforestation near Rio Branco, Brazil

NASA Technical Reports Server (NTRS)

2001-01-01

Settlement and deforestation surrounding the Brazilian town of Rio Branco are seen here in the striking 'herring bone' deforestation patterns that cut through the rainforest. Rio Brancois the capital of the Brazilian state of Acre and is situated near the border with northeastern Bolivia. The town is a center for the distribution of goods, including rubber, metals, medicinal plants, Brazil nuts and timber. Colonization projects in the region are supported by farming, logging activities, and extensive cattle ranching. Much of the surrounding terrain is of a poorly-draining clay hardpan soil, and heavy rainfall periodically converts parts of the forested region to swamp.

The large overview image was acquired by the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera on July 28, 2000, and covers an area of 336 kilometers x 333 kilometers. A plume of smoke is visible north of the Rio Branco road, which roughly parallels the slender, twisting Rio Abuna. Most of the major rivers in the image provide reference points for state or international (Bolivia-Brazil) boundaries, and flow northeast to the Rio Madeira (east of the smoke plume). The border between Acre and the Bolivian department of Pando is marked by the Rio Abuna. Pando's southern boundary with the department of Beni is marked by the Rio Madre de Dios, the large river in the lower half of the image.

The two higher-resolution inset images highlight a settled area north of the town of Rio Branco. These nadir views cover an area of 60 kilometers x 67 kilometers, and were acquired eleven months apart during Terra orbits 3251 and 8144. In the later image, more haze is present, possibly due to smoke from fires on that day. Comparing the two images provides a method of measuring the changes and expansion in the area of cleared land. One newly cleared patch is apparent near the middle of the later image, slightly off to the right. This polygon represents an area of about 16 square kilometers, or 4000 acres. Other recent clearings can be observed directly beneath this area, as well as toward the lower right-hand corner.

Southern Florida's River of Grass

NASA Technical Reports Server (NTRS)

2002-01-01

Florida's Everglades is a region of broad, slow-moving sheets of water flowing southward over low-lying areas from Lake Okeechobeeto the Gulf of Mexico. In places this remarkable 'river of grass' is 80 kilometers wide. These images from the Multi-angle Imaging SpectroRadiometer show the Everglades region on January 16, 2002. Each image covers an area measuring 191 kilometers x 205 kilometers. The data were captured during Terra orbit 11072.

On the left is a natural color view acquired by MISR's nadir camera. A portion of Lake Okeechobee is visible at the top, to the right of image center. South of the lake, whose name derives from the Seminole word for 'big water,' an extensive region of farmland known as the Everglades Agricultural Area is recognizable by its many clustered squares. Over half of the sugar produced in United States is grown here. Urban areas along the east coast and in the northern part of the image extend to the boundaries of Big Cypress Swamp, situated north of Everglades National Park.

The image on the right combines red-band data from the 46-degree backward, nadir and 46-degree forward-viewing camera angles to create a red, green, blue false-color composite. One of the interesting uses of the composite image is for detecting surface water. Wet surfaces appear blue in this rendition because sun glitter produces a greater signal at the forward camera's view angle. Wetlands visible in these images include a series of shallow impoundments called Water Conservation Areas which were built to speed water flow through the Everglades in times of drought. In parts of the Everglades, these levees and extensive systems such as the Miami and Tamiami Canals have altered the natural cycles of water flow. For example, the water volume of the Shark River Slough, a natural wetland which feeds Everglades National Park, is influenced by the Tamiami Canal. The unique and intrinsic value of the Everglades is now widely recognized, and efforts to restore the natural water cycles are underway.

Volga Delta and the Caspian Sea

NASA Technical Reports Server (NTRS)

2002-01-01

Russia's Volga River is the largest river system in Europe, draining over 1.3 million square kilometers of catchment area into the Caspian Sea. The brackish Caspian is Earth's largest landlocked water body, and its isolation from the world's oceans has enabled the preservation of several unique animal and plant species. The Volga provides most of the Caspian's fresh water and nutrients, and also discharges large amounts of sediment and industrial waste into the relatively shallow northern part of the sea. These images of the region were captured by the Multi-angle Imaging SpectroRadiometer on October 5, 2001, during Terra orbit 9567. Each image represents an area of approximately 275 kilometers x 376 kilometers.

The left-hand image is from MISR's nadir (vertical-viewing) camera, and shows how light is reflected at red, green, and blue wavelengths. The right-hand image is a false color composite of red-band imagery from MISR's 60-degree backward, nadir, and 60-degree forward-viewing cameras, displayed as red, green, and blue, respectively. Here, color variations indicate how light is reflected at different angles of view. Water appears blue in the right-hand image, for example, because sun glitter makes smooth, wet surfaces look brighter at the forward camera's view angle. The rougher-textured vegetated wetlands near the coast exhibit preferential backscattering, and consequently appear reddish. A small cloud near the center of the delta separates into red, green, and blue components due to geometric parallax associated with its elevation above the surface.

Other notable features within the images include several linear features located near the Volga Delta shoreline. These long, thin lines are artificially maintained shipping channels, dredged to depths of at least 2 meters. The crescent-shaped Kulaly Island, also known as Seal Island, is visible near the right-hand edge of the images.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Appalachian Mountains

Atmospheric Science Data Center

2014-05-15

...     View Larger Image Multi-angle views of the Appalachian Mountains, March 6, 2000 . ... Center Atmospheric Science Data Center in Hampton, VA. Photo credit: NASA/GSFC/LaRC/JPL, MISR Science Team Other formats ...

The Multi-Angle Imager for Aerosols (MAIA) Instrument, the Satellite-Based Element of an Investigation to Benefit Public Health

NASA Astrophysics Data System (ADS)

Diner, D. J.

2016-12-01

Maps of airborne particulate matter (PM) derived from satellite instruments, including MISR and MODIS, have provided key contributions to many health-related investigations. Although it is well established that PM exposure increases the risks of cardiovascular and respiratory disease, adverse birth outcomes, and premature deaths, our understanding of the relative toxicity of specific PM types—mixtures having different size distributions and compositions—is relatively poor. To address this, the Multi-Angle Imager for Aerosols (MAIA) investigation was proposed to NASA's third Earth Venture Instrument (EVI-3) solicitation. MAIA was selected for funding in March 2016. The satellite-based MAIA instrument is one element of the scientific investigation, which will combine WRF-Chem transport model estimates of the abundances of different aerosol types with the data acquired from Earth orbit. Geostatistical models derived from collocated surface and MAIA retrievals will be used to relate retrieved fractional column aerosol optical depths to near-surface concentrations of major PM constituents. Epidemiological analyses of geocoded birth, death, and hospital records will be used to associate exposure to PM types with adverse health outcomes. The MAIA instrument obtains its sensitivity to particle type by building upon the legacies of many satellite sensors; observing in the UV, visible, near-IR, and shortwave-IR regions of the electromagnetic spectrum; acquiring images at multiple angles of view; determining the degree to which the scattered light is polarized; and integrating these capabilities at moderately high spatial resolution. The instrument concept is based on the first and second generation Airborne Multiangle SpectroPolarimetric Imagers, AirMSPI and AirMSPI-2. MAIA incorporates a pair of pushbroom cameras on a two-axis gimbal to provide regional multiangle observations of selected, globally distributed target areas. A set of Primary Target Areas (PTAs) on five continents includes major population centers covering a range of PM concentrations and particle types. MAIA will also collect aerosol and cloud observations over regions of interest to the radiation science, climate, and environmental science communities. Launch of the MAIA instrument is planned for early in the next decade.

Atmospheric Motion Vectors from INSAT-3D: Initial quality assessment and its impact on track forecast of cyclonic storm NANAUK

NASA Astrophysics Data System (ADS)

Deb, S. K.; Kishtawal, C. M.; Kumar, Prashant; Kiran Kumar, A. S.; Pal, P. K.; Kaushik, Nitesh; Sangar, Ghansham

2016-03-01

The advanced Indian meteorological geostationary satellite INSAT-3D was launched on 26 July 2013 with an improved imager and an infrared sounder and is placed at 82°E over the Indian Ocean region. With the advancement in retrieval techniques of different atmospheric parameters and with improved imager data have enhanced the scope for better understanding of the different tropical atmospheric processes over this region. The retrieval techniques and accuracy of one such parameter, Atmospheric Motion Vectors (AMV) has improved significantly with the availability of improved spatial resolution data along with more options of spectral channels in the INSAT-3D imager. The present work is mainly focused on providing brief descriptions of INSAT-3D data and AMV derivation processes using these data. It also discussed the initial quality assessment of INSAT-3D AMVs for a period of six months starting from 01 February 2014 to 31 July 2014 with other independent observations: i) Meteosat-7 AMVs available over this region, ii) in-situ radiosonde wind measurements, iii) cloud tracked winds from Multi-angle Imaging Spectro-Radiometer (MISR) and iv) numerical model analysis. It is observed from this study that the qualities of newly derived INSAT-3D AMVs are comparable with existing two versions of Meteosat-7 AMVs over this region. To demonstrate its initial application, INSAT-3D AMVs are assimilated in the Weather Research and Forecasting (WRF) model and it is found that the assimilation of newly derived AMVs has helped in reduction of track forecast errors of the recent cyclonic storm NANAUK over the Arabian Sea. Though, the present study is limited to its application to one case study, however, it will provide some guidance to the operational agencies for implementation of this new AMV dataset for future applications in the Numerical Weather Prediction (NWP) over the south Asia region.

Keyhole imaging method for dynamic objects behind the occlusion area

NASA Astrophysics Data System (ADS)

Hao, Conghui; Chen, Xi; Dong, Liquan; Zhao, Yuejin; Liu, Ming; Kong, Lingqin; Hui, Mei; Liu, Xiaohua; Wu, Hong

2018-01-01

A method of keyhole imaging based on camera array is realized to obtain the video image behind a keyhole in shielded space at a relatively long distance. We get the multi-angle video images by using a 2×2 CCD camera array to take the images behind the keyhole in four directions. The multi-angle video images are saved in the form of frame sequences. This paper presents a method of video frame alignment. In order to remove the non-target area outside the aperture, we use the canny operator and morphological method to realize the edge detection of images and fill the images. The image stitching of four images is accomplished on the basis of the image stitching algorithm of two images. In the image stitching algorithm of two images, the SIFT method is adopted to accomplish the initial matching of images, and then the RANSAC algorithm is applied to eliminate the wrong matching points and to obtain a homography matrix. A method of optimizing transformation matrix is proposed in this paper. Finally, the video image with larger field of view behind the keyhole can be synthesized with image frame sequence in which every single frame is stitched. The results show that the screen of the video is clear and natural, the brightness transition is smooth. There is no obvious artificial stitching marks in the video, and it can be applied in different engineering environment .

Amery Ice Shelf

Atmospheric Science Data Center

2013-04-16

... funded by NASA and undertaken by the Scripps Institution of Oceanography and the Australian Antarctic Division. The Multi-angle Imaging ... Laboratory), and Helen A. Fricker (Scripps Institution of Oceanography). Other formats available at JPL Oct 6, ...

Johannesburg

Atmospheric Science Data Center

2013-04-15

... coming from there), the discovery of now-famous hominid fossils at the Sterkfontein Caves, and the convening of the world's ... the outstanding universal value of the paleo-anthropological fossils found there. These views from the Multi-angle Imaging ...

Validation and understanding of Moderate Resolution Imaging Spectroradiometer aerosol products (C5) using ground-based measurements from the handheld Sun photometer network in China

Treesearch

Zhanqing Li; Feng Niu; Kwon-Ho Lee; Jinyuan Xin; Wei Min Hao; Bryce L. Nordgren; Yuesi Wang; Pucai Wang

2007-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) currently provides the most extensive aerosol retrievals on a global basis, but validation is limited to a small number of ground stations. This study presents a comprehensive evaluation of Collection 4 and 5 MODIS aerosol products using ground measurements from the Chinese Sun Hazemeter Network (CSHNET). The...

Application of Spectral Analysis Techniques in the Intercomparison of Aerosol Data. Part II: Using Maximum Covariance Analysis to Effectively Compare Spatiotemporal Variability of Satellite and AERONET Measured Aerosol Optical Depth

NASA Technical Reports Server (NTRS)

Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

2014-01-01

Moderate Resolution Imaging SpectroRadiometer (MODIS) and Multi-angle Imaging Spectroradiomater (MISR) provide regular aerosol observations with global coverage. It is essential to examine the coherency between space- and ground-measured aerosol parameters in representing aerosol spatial and temporal variability, especially in the climate forcing and model validation context. In this paper, we introduce Maximum Covariance Analysis (MCA), also known as Singular Value Decomposition analysis as an effective way to compare correlated aerosol spatial and temporal patterns between satellite measurements and AERONET data. This technique not only successfully extracts the variability of major aerosol regimes but also allows the simultaneous examination of the aerosol variability both spatially and temporally. More importantly, it well accommodates the sparsely distributed AERONET data, for which other spectral decomposition methods, such as Principal Component Analysis, do not yield satisfactory results. The comparison shows overall good agreement between MODIS/MISR and AERONET AOD variability. The correlations between the first three modes of MCA results for both MODIS/AERONET and MISR/ AERONET are above 0.8 for the full data set and above 0.75 for the AOD anomaly data. The correlations between MODIS and MISR modes are also quite high (greater than 0.9). We also examine the extent of spatial agreement between satellite and AERONET AOD data at the selected stations. Some sites with disagreements in the MCA results, such as Kanpur, also have low spatial coherency. This should be associated partly with high AOD spatial variability and partly with uncertainties in satellite retrievals due to the seasonally varying aerosol types and surface properties.

Validation of High-Resolution MAIAC Aerosol Product over South America

NASA Technical Reports Server (NTRS)

Martins, V. S.; Lyapustin, A.; de Carvalho, L. A. S.; Barbosa, C. C. F.; Novo, E. M. L. M.

2017-01-01

Multiangle Implementation of Atmospheric Correction (MAIAC) is a new Moderate Resolution Imaging Spectroradiometer (MODIS) algorithm that combines time series approach and image processing to derive surface reflectance and atmosphere products, such as aerosol optical depth (AOD) and columnar water vapor (CWV). The quality assessment of MAIAC AOD at 1 km resolution is still lacking across South America. In the present study, critical assessment of MAIAC AOD(sub 550) was performed using ground-truth data from 19 Aerosol Robotic Network (AERONET) sites over South America. Additionally, we validated the MAIAC CWV retrievals using the same AERONET sites. In general, MAIAC AOD Terra/Aqua retrievals show high agreement with ground-based measurements, with a correlation coefficient (R) close to unity (R(sub Terra):0.956 and R(sub Aqua):0.949). MAIAC accuracy depends on the surface properties and comparisons revealed high confidence retrievals over cropland, forest, savanna, and grassland covers, where more than 2/3 (approximately 66%) of retrievals are within the expected error (EE = +/-(0.05 + 0.05 × AOD)) and R exceeding 0.86. However, AOD retrievals over bright surfaces show lower correlation than those over vegetated areas. Both MAIAC Terra and Aqua retrievals are similarly comparable to AERONET AOD over the MODIS lifetime (small bias offset approximately 0.006). Additionally, MAIAC CWV presents quantitative information with R approximatley 0.97 and more than 70% of retrievals within error (+/-15%). Nonetheless, the time series validation shows an upward bias trend in CWV Terra retrievals and systematic negative bias for CWV Aqua. These results contribute to a comprehensive evaluation of MAIAC AOD retrievals as a new atmospheric product for future aerosol studies over South America.

India: Gujarat

Atmospheric Science Data Center

2013-04-16

... Gujarat), and in areas close to the earthquake epicenter.  Research uses the unique capabilities of the Multi-angle Imaging ... Indo-Pakistani border, which were not easily accessible to survey teams on the ground. Changes in reflection at different view angles ...

Hurricane Matthew over Haiti seen by NASA MISR

NASA Image and Video Library

2016-10-04

On the morning of October 4, 2016, Hurricane Matthew passed over the island nation of Haiti. A Category 4 storm, it made landfall around 7 a.m. local time (5 a.m. PDT/8 a.m. EDT) with sustained winds over 145 mph. This is the strongest hurricane to hit Haiti in over 50 years. On October 4, at 10:30 a.m. local time (8:30 a.m. PDT/11:30 a.m. EDT), the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed over Hurricane Matthew. This animation was made from images taken by MISR's downward-pointing (nadir) camera is 235 miles (378 kilometers) across, which is much narrower than the massive diameter of Matthew, so only the hurricane's eye and a portion of the storm's right side are visible. Haiti is completely obscured by Matthew's clouds, but part of the Bahamas is visible to the north. Several hot towers are visible within the central part of the storm, and another at the top right of the image. Hot towers are enormous thunderheads that punch through the tropopause (the boundary between the lowest layer of the atmosphere, the troposphere, and the next level, the stratosphere). The rugged topography of Haiti causes uplift within the storm, generating these hot towers and fueling even more rain than Matthew would otherwise dump on the country. MISR has nine cameras fixed at different angles, which capture images of the same point on the ground within about seven minutes. This animation was created by blending images from these nine cameras. The change in angle between the images causes a much larger motion from south to north than actually exists, but the rotation of the storm is real motion. From this animation, you can get an idea of the incredible height of the hot towers, especially the one to the upper right. The counter-clockwise rotation of Matthew around its closed (cloudy) eye is also visible. These data were acquired during Terra orbit 89345. An animation is available at http://photojournal.jpl.nasa.gov/catalog/PIA21070

Smoke from California Sand and Soberanes Fires Observed by NASA MISR

NASA Image and Video Library

2016-07-26

The Sand Fire in the Santa Clarita Valley area of Southern California erupted on Friday, July 22, 2016, and rapidly grew to more than 37,000 acres (58 square miles, or 150 square kilometers) over the weekend. As of Tuesday, July 26, hundreds of residents still remain under evacuation orders, and the fire claimed the life of a local resident. The fire is currently 25 percent contained. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed over the region on July 23 around 11:50 a.m. PDT. At left is an image acquired by MISR's 60-degree forward-viewing camera. The oblique view angle makes the smoke more apparent than it would be in a more conventional vertical view. Smoke from the Sand Fire is visible on the right-hand side of the image, and a long streamer of smoke from the Soberanes Fire near Big Sur in Central California is visible over the ocean near the left-hand side of the image. Like the Sand Fire, the Soberanes Fire also broke out on July 22, and quickly grew to more than 19,000 acres (30 square miles, or 77 square kilometers), causing the evacuation of hundreds of people and closure of several state parks. The Soberanes Fire is currently only 10 percent contained. The swath width of the MISR image is 257 miles (414 kilometers). At right is a map of aerosol optical depth, a quantitative measure of the smoke abundance in the atmosphere, derived from the images acquired by MISR's nine differently angled cameras. The thick smoke from both fires is apparent. Individual squares making up this map measure 2.7 miles (4.4 kilometers) on a side. The product shown here is a prototype of a new version of the MISR aerosol product to be publicly released in the near future, and increases the spatial resolution of the aerosol information by a factor of 16 compared to the currently available product, making it possible to discern finer details in the distribution of the smoke. These data were captured during Terra orbit 88284. http://photojournal.jpl.nasa.gov/catalog/PIA20720

Multi-Angle Snowflake Camera Value-Added Product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shkurko, Konstantin; Garrett, T.; Gaustad, K

The Multi-Angle Snowflake Camera (MASC) addresses a need for high-resolution multi-angle imaging of hydrometeors in freefall with simultaneous measurement of fallspeed. As illustrated in Figure 1, the MASC consists of three cameras, separated by 36°, each pointing at an identical focal point approximately 10 cm away. Located immediately above each camera, a light aims directly at the center of depth of field for its corresponding camera. The focal point at which the cameras are aimed lies within a ring through which hydrometeors fall. The ring houses a system of near-infrared emitter-detector pairs, arranged in two arrays separated vertically by 32more » mm. When hydrometeors pass through the lower array, they simultaneously trigger all cameras and lights. Fallspeed is calculated from the time it takes to traverse the distance between the upper and lower triggering arrays. The trigger electronics filter out ambient light fluctuations associated with varying sunlight and shadows. The microprocessor onboard the MASC controls the camera system and communicates with the personal computer (PC). The image data is sent via FireWire 800 line, and fallspeed (and camera control) is sent via a Universal Serial Bus (USB) line that relies on RS232-over-USB serial conversion. See Table 1 for specific details on the MASC located at the Oliktok Point Mobile Facility on the North Slope of Alaska. The value-added product (VAP) detailed in this documentation analyzes the raw data (Section 2.0) using Python: images rely on OpenCV image processing library and derived aggregated statistics rely on some clever averaging. See Sections 4.1 and 4.2 for more details on what variables are computed.« less

Aerosol Optical Depth Retrievals from High-Resolution Commercial Satellite Imagery Over Areas of High Surface Reflectance

DTIC Science & Technology

2006-06-01

angle Imaging SpectroRadiometer MODIS Moderate Resolution Imaging Spectroradiometer NGA National Geospatial Intelligence Agency POI Principles of...and µ , the cosine of the viewing zenith angle and the effect of the variation of each of these variables on total optical depth. Extraterrestrial ...Eq. (34). Additionally, solar zenith angle also plays a role in the third term on the RHS of Eq. (34) by modifying extraterrestrial spectral solar

Where on Earth...? MISR Mystery Image Quiz #6

NASA Technical Reports Server (NTRS)

2002-01-01

Here's another chance to play geographical detective! This Multi-angle Imaging SpectroRadiometer (MISR) image covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. Use any reference materials you like and answer the following five questions: The large lagoon in the image is named for a particular type of bird. Name the bird. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. What did they call the river? A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. Which ONE of the following is most responsible for the formation of these cusps? Violent storm impacts on erosion and accretion Wind and tide-driven sediment transport and circulation Tectonic folding associated with nearby mountain ridges Bathymetric effects of dredging operations True or false: Changes in regional precipitation associated with large scale atmospheric circulation patterns have no effect on the salinity of the lagoon's water. Which one of these is NOT distributed within the area covered by this image? Ruppia maritima Chelonia mydas Tapirus bairdii Microcystis aeruginosa E-mail your answers, name (initials are acceptable if you prefer), and your hometown by Tuesday, February 19, 2002 to suggestions@mail-misr.jpl.nasa.gov. Answers will be published on the MISR web site in conjunction with the next weekly image release. The names and home towns of respondents who answer all questions correctly by the deadline will also be published in the order responses were received. The first 3 people on this list who are not affiliated with NASA, JPL, or MISR and who did not win a prize in the last quiz will be sent a print of the image. A new 'Where on Earth...?' mystery appears as the MISR 'image of the week' approximately once per month. A new image of the week is released every Wednesday at noon Pacific time on the MISR home page http://www-misr.jpl.nasa.gov. The image also appears on the Atmospheric Sciences Data Center home page, http://eosweb.larc.nasa.gov, though usually with a several-hour delay. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.

Mixing Waters and Moving Ships off the North Carolina Coast

NASA Technical Reports Server (NTRS)

2000-01-01

The estuarine and marine environments of the United States' eastern seaboard provide the setting for a variety of natural and human activities associated with the flow of water. This set of Multi-angle Imaging SpectroRadiometer images from October 11, 2000 (Terra orbit 4344) captures the intricate system of barrier islands, wetlands, and estuaries comprising the coastal environments of North Carolina and southern Virginia. On the right-hand side of the images, a thin line of land provides a tenuous separation between the Albemarle and Pamlico Sounds and the Atlantic Ocean. The wetland communities of this area are vital to productive fisheries and water quality.

The top image covers an area of about 350 kilometers x 260 kilometers and is a true-color view from MISR's 46-degree backward-looking camera. Looking away from the Sun suppresses glint from the reflective water surface and enables mapping the color of suspended sediments and plant life near the coast. Out in the open sea, the dark blue waters indicate the Gulf Stream. As it flows toward the northeast, this ocean current presses close to Cape Hatteras (the pointed cape in the lower portion of the images), and brings warm, nutrient-poor waters northward from equatorial latitudes. North Carolina's Outer Banks are often subjected to powerful currents and storms which cause erosion along the east-facing shorelines. In an effort to save the historic Cape Hatteras lighthouse from the encroaching sea, it was jacked out of the ground and moved about 350 meters in 1999.

The bottom image was created with red band data from the 46-degree backward, 70-degree forward, and 26-degree forward cameras displayed as red, green, and blue, respectively. The color variations in this multi-angle composite indicate different angular (rather than spectral) signatures. Here, the increased reflection of land vegetation at the angle viewing away from the Sun causes a reddish tint. Water, on the other hand, appears predominantly in shades of blue and green due to the bright sunglint captured by the forward-viewing cameras. Contrasting angular signatures, most likely associated with variations in the orientation and slope of wind-driven surface waves, are apparent in the sunglint patterns.

Details of human activities are visible in these images. Near the top center, the Chesapeake Bay Bridge-Tunnel complex, which links Norfolk with Virginia's eastern shore, can be seen. The locations of two tunnels which route automobiles below the water appear as gaps in the visible roadway. In the top image, the small white specks in the open waters of the Atlantic Ocean are ship wakes. The movements of the ships have been visualized by displaying the views from MISR's four backward-viewing cameras in an animated sequence (below). These cameras successively observe the same surface locations over a time interval of about 160 seconds. The large version of the animation covers an area of 135 kilometers x 130 kilometers. The land area on the left-hand side includes the birthplace of aviation, Kitty Hawk, where the Wright Brothers made their first sustained, powered flight in 1903.

[figure removed for brevity, see original site]

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Aerosol Optical Depths over Oceans: a View from MISR Retrievals and Collocated MAN and AERONET in Situ Observations

NASA Technical Reports Server (NTRS)

Witek, Marcin L.; Garay, Michael J.; Diner, David J.; Smirnov, Alexander

2013-01-01

In this study, aerosol optical depths over oceans are analyzed from satellite and surface perspectives. Multiangle Imaging SpectroRadiometer (MISR) aerosol retrievals are investigated and validated primarily against Maritime Aerosol Network (MAN) observations. Furthermore, AErosol RObotic NETwork (AERONET) data from 19 island and coastal sites is incorporated in this study. The 270 MISRMAN comparison points scattered across all oceans were identified. MISR on average overestimates aerosol optical depths (AODs) by 0.04 as compared to MAN; the correlation coefficient and root-mean-square error are 0.95 and 0.06, respectively. A new screening procedure based on retrieval region characterization is proposed, which is capable of substantially reducing MISR retrieval biases. Over 1000 additional MISRAERONET comparison points are added to the analysis to confirm the validity of the method. The bias reduction is effective within all AOD ranges. Setting a clear flag fraction threshold to 0.6 reduces the bias to below 0.02, which is close to a typical ground-based measurement uncertainty. Twelve years of MISR data are analyzed with the new screening procedure. The average over ocean AOD is reduced by 0.03, from 0.15 to 0.12. The largest AOD decrease is observed in high latitudes of both hemispheres, regions with climatologically high cloud cover. It is postulated that the screening procedure eliminates spurious retrieval errors associated with cloud contamination and cloud adjacency effects. The proposed filtering method can be used for validating aerosol and chemical transport models.

MISR 17.6 KM Gridded Cloud Motion Vectors: Overview and Assessment

NASA Technical Reports Server (NTRS)

Mueller, Kevin; Garay, Michael; Moroney, Catherine; Jovanovic, Veljko

2012-01-01

The MISR (Multi-angle Imaging SpectroRadiometer) instrument on the Terra satellite has been retrieving cloud motion vectors (CMVs) globally and almost continuously since early in 2000. In February 2012 the new MISR Level 2 Cloud product was publicly released, providing cloud motion vectors at 17.6 km resolution with improved accuracy and roughly threefold increased coverage relative to the 70.4 km resolution vectors of the current MISR Level 2 Stereo product (which remains available). MISR retrieves both horizontal cloud motion and height from the apparent displacement due to parallax and movement of cloud features across three visible channel (670nm) camera views over a span of 200 seconds. The retrieval has comparable accuracy to operational atmospheric motion vectors from other current sensors, but holds the additional advantage of global coverage and finer precision height retrieval that is insensitive to radiometric calibration. The MISR mission is expected to continue operation for many more years, possibly until 2019, and Level 2 Cloud has the possibility of being produced with a sensing-to-availability lag of 5 hours. This report compares MISR CMV with collocated motion vectors from arctic rawinsonde sites, and from the GOES and MODISTerra instruments. CMV at heights below 3 km exhibit the smallest differences, as small as 3.3 m/s for MISR and GOES. Clouds above 3 km exhibit larger differences, as large as 8.9 m/s for MISR and MODIS. Typical differences are on the order of 6 m/s.

17 Years of Cloud Heights from Terra, and Beyond

NASA Astrophysics Data System (ADS)

Davies, R.

2017-12-01

The effective cloud height, H, is the integral of observed cloud-top heights, weighted by their frequency of occurrence. Here we look at changes in the effective cloud height, H', as measured by the Multiangle Imaging Spectroradiometer (MISR) on the first Earth Observing System platform, Terra. Terra was launched in December 1999, and now has over 17 years of consistently measured climate records. Globally, HG' has an important influence on Earth's climate, whereas regionally, HR' is a useful measure of low frequency changes in circulation patterns. MISR has a sampling error in the annual mean HG' of ≈11 m, allowing fairly small interannual variations to be detected. This paper extends the previous 15-year summary that showed significant differences in the long term mean hemispheric cloud height changes. Also of interest are the correlations in tropical cloud height changes and related teleconnections. The largest ephemeral values in the annual HR' [over 1.5 km] are noted over the Central Pacific and the Maritime Continent. These changes are strongly anticorrelated with each other, being directly related to changes in ENSO. They are also correlated with the largest ephemeral changes in HG'. Around the equator, we find at least four distinct centres of similar fluctuations in cloud height. This paper examines the relative time dependence of these regional height changes, separately for La Niña and El Niño events, and stresses the value of extending the time series of uniformly measured cloud heights from space beyond EOS-Terra.

A High-Resolution Aerosol Retrieval Method for Urban Areas Using MISR Data

NASA Astrophysics Data System (ADS)

Moon, T.; Wang, Y.; Liu, Y.; Yu, B.

2012-12-01

Satellite-retrieved Aerosol Optical Depth (AOD) can provide a cost-effective way to monitor particulate air pollution without using expensive ground measurement sensors. One of the current state-of-the-art AOD retrieval method is NASA's Multi-angle Imaging SpectroRadiometer (MISR) operational algorithm, which has the spatial resolution of 17.6 km x 17.6 km. While the MISR baseline scheme already leads to exciting research opportunities to study particle compositions at regional scale, its spatial resolution is too coarse for analyzing urban areas where the AOD level has stronger spatial variations. We develop a novel high-resolution AOD retrieval algorithm that still uses MISR's radiance observations but has the resolution of 4.4km x 4.4km. We achieve the high resolution AOD retrieval by implementing a hierarchical Bayesian model and Monte-Carlo Markov Chain (MCMC) inference method. Our algorithm not only improves the spatial resolution, but also extends the coverage of AOD retrieval and provides with additional composition information of aerosol components that contribute to the AOD. We validate our method using the recent NASA's DISCOVER-AQ mission data, which contains the ground measured AOD values for Washington DC and Baltimore area. The validation result shows that, compared to the operational MISR retrievals, our scheme has 41.1% more AOD retrieval coverage for the DISCOVER-AQ data points and 24.2% improvement in mean-squared error (MSE) with respect to the AERONET ground measurements.

Assessing the accuracy of MISR and MISR-simulated cloud top heights using CloudSat- and CALIPSO-retrieved hydrometeor profiles

NASA Astrophysics Data System (ADS)

Hillman, Benjamin R.; Marchand, Roger T.; Ackerman, Thomas P.; Mace, Gerald G.; Benson, Sally

2017-03-01

Satellite retrievals of cloud properties are often used in the evaluation of global climate models, and in recent years satellite instrument simulators have been used to account for known retrieval biases in order to make more consistent comparisons between models and retrievals. Many of these simulators have seen little critical evaluation. Here we evaluate the Multiangle Imaging Spectroradiometer (MISR) simulator by using visible extinction profiles retrieved from a combination of CloudSat, CALIPSO, MODIS, and AMSR-E observations as inputs to the MISR simulator and comparing cloud top height statistics from the MISR simulator with those retrieved by MISR. Overall, we find that the occurrence of middle- and high-altitude topped clouds agrees well between MISR retrievals and the MISR-simulated output, with distributions of middle- and high-topped cloud cover typically agreeing to better than 5% in both zonal and regional averages. However, there are significant differences in the occurrence of low-topped clouds between MISR retrievals and MISR-simulated output that are due to differences in the detection of low-level clouds between MISR and the combined retrievals used to drive the MISR simulator, rather than due to errors in the MISR simulator cloud top height adjustment. This difference highlights the importance of sensor resolution and boundary layer cloud spatial structure in determining low-altitude cloud cover. The MISR-simulated and MISR-retrieved cloud optical depth also show systematic differences, which are also likely due in part to cloud spatial structure.

Use of MISR measurements to study the radiative transfer of an isolated convective cloud: Implications for cloud optical thickness retrieval

NASA Astrophysics Data System (ADS)

Cornet, C.; Davies, R.

2008-02-01

Radiative transfer simulations of an isolated deep convective cloud reconstructed with stereo-techniques from the Multiangle Imaging Spectroradiometer (MISR) are compared with the reflectances measured at the nine MISR viewing angles. The simulations were done using a three dimensional Monte Carlo model, in which ocean reflectance, aerosol and Rayleigh scattering were prescribed to match the surrounding clear-sky MISR measurements. Making reasonable assumptions regarding the vertical and horizontal distribution of the volume extinction coefficient, we were able to reproduce the MISR measurements with the 3D radiative calculations. While the uniqueness of the these distributions cannot be proven, they all lead to retrievals of much larger cloud optical thickness and cloud water content than for a 1D retrieval. Averaged over the cloud, the difference was a factor of about 3, rising to 9 locally. This is a consequence of horizontal photon transport that serves to highlight the inadequacy of 1D retrievals for the case of deep convective cloud. Concerning the internal cloud properties, we noticed the angular distribution of modeled radiances did not match the measured radiances when an ice crystal phase function was applied. Better estimates of the optical depths and water contents of deep convective clouds appear to be obtainable by integrating an estimate of the extinction coefficient over the vertical cloud extent (when this can assessed) than by attempting to invert the radiance measured from a single-angle view using 1D theory.

Scaling Estimates of Vegetation Structure in Amazonian Tropical Forests Using Multi-Angle MODIS Observations

NASA Technical Reports Server (NTRS)

Mendes De Moura, Yhasmin; Hilker, Thomas; Goncalves, Fabio Guimaraes; Galvao, Lenio Soares; Roberto dos Santos, Joao; Lyapustin, Alexei; Maeda, Eduardo Eiji; de Jesus Silva, Camila Valeria

2016-01-01

Detailed knowledge of vegetation structure is required for accurate modelling of terrestrial ecosystems, but direct measurements of the three dimensional distribution of canopy elements, for instance from LiDAR, are not widely available. We investigate the potential for modelling vegetation roughness, a key parameter for climatological models, from directional scattering of visible and near-infrared (NIR) reflectance acquired from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). We compare our estimates across different tropical forest types to independent measures obtained from: (1) airborne laser scanning (ALS), (2) spaceborne Geoscience Laser Altimeter System (GLAS)/ICESat, and (3) the spaceborne SeaWinds/QSCAT. Our results showed linear correlation between MODIS-derived anisotropy to ALS-derived entropy (r(exp 2)= 0.54, RMSE= 0.11), even in high biomass regions. Significant relationships were also obtained between MODIS-derived anisotropy and GLAS-derived entropy(0.52 less than or equal to r(exp 2) less than or equal to 0.61; p less than 0.05), with similar slopes and offsets found throughout the season, and RMSE between 0.26 and 0.30 (units of entropy). The relationships between the MODIS-derived anisotropy and backscattering measurements (sigma(sup 0)) from SeaWinds/QuikSCAT presented an r(exp 2) of 0.59 and a RMSE of 0.11. We conclude that multi-angular MODIS observations are suitable to extrapolate measures of canopy entropy across different forest types, providing additional estimates of vegetation structure in the Amazon.

South Africa

Atmospheric Science Data Center

2013-04-16

... blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they ... known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide. The Multi-angle Imaging ...

The Hemisphere-scale Stratospheric Impact of the Chisholm (Alberta) PyroCumulonimbus Eruption

NASA Astrophysics Data System (ADS)

Fromm, M.; Barnes, J.; Blum, U.; Diner, D.; Fricke, K. H.; Gerding, M.; Giehl, H.; Kahn, R.; Lablanc, T.; Massie, S.; Stuart, M.; O'Neill, M.; Ritter, C.; Servranckx, R.; Shettle, E.; Torres, O.; Trickl, T.

2006-12-01

Extreme pyrocumulonimbus (pyroCb) blowups that polluted the lower stratosphere with smoke and other biomass burning emissions have been documented in the literature to have occurred on at least five separate occasions. However our understanding of the frequency and scale of these events is still far from complete. One pyroCb case study in the literature, the Chisholm Fire in Alberta in May 2001, was restricted to the convective phase and its immediate aftermath (Fromm and Servranckx, Geophys. Res. Lett., 2003). Here we describe the stratospheric impact of the Chisholm pyroCb. We present nadir and imaging satellite views of the post-pyroCb plume by the Multi-angle Imaging Spectroradiometer (MISR), Moderate Resolution Imaging Spectroradiomenter (MODIS), Total Ozone Mapping Spectrometer (TOMS), and a broad array of profile measurements, space- and ground-based. These include the Polar Ozone and Aerosol Measurement (POAM) III, Stratospheric Aerosol and Gas Experiment (SAGE) II, Halogen Occultation Experiment (HALOE), and seven ground-based lidars. We report that the Chisholm pyroCb was the singular cause of a hemispheric stratospheric aerosol increase in northern spring/summer of 2001. The smoke plume on the day after the pyro-eruption reached heights of 15 km, 4 km above the tropopause, was optically opaque at the tropopause, and caused unprecedented, large values of TOMS aerosol index. This plume eventually resulted in a doubling of zonal-average aerosol optical depth in the stratospheric middleworld and overworld. The meridional spread of the plume is confirmed from the tropics (20°N) to the high Arctic (79°N) within the first month. The stratospheric Chisholm smoke became a hemispheric phenomenon in midlatitudes and persisted for at least three months there and in the northern tropics. This work contains the first reported stratospheric smoke layers measured by lidar at Ny Älesund, Kühlungsborn, Garmisch Partenkirchen, Boulder, and Mauna Loa, and the second such reports from the Esrange lidar.

A Spaceborne Perspective on the Red, White, and Blue

NASA Technical Reports Server (NTRS)

2001-01-01

Philadelphia, where the Declaration of Independence was signed 225 years ago on July 4, 1776, lies in the center of this image from NASA's Multi-angle Imaging SpectroRadiometer (MISR). This true-color view of the northeastern United States, taken from the instrument's nadir, or downward-looking, camera includes a fitting display of the reddish colors of soils, grayish-whites of urban areas and clouds, and blue hues of water.

Larger cities, including New York, Newark, Philadelphia, Wilmington, Baltimore and Washington D.C., are visible from upper right to lower left. The bright sands of the New Jersey shoreline and a pattern of highly reflective roads and bridges extend northward along the coast from Delaware Bay. A popular tourist destination for those wanting to avoid the crowds and main roads is the Coastal Heritage Trail, a 440-kilometer collection of historic and other points of interest developed by the National Park Service and the state of New Jersey.

A portion of Pennsylvania's Appalachian Mountains are captured in the upper left corner. The effects of folding and erosion on these ancient, mostly sedimentary deposits are visible, and the reddish colors indicate ironstone and iron-rich sandstone. The southeast-flowing Susquehanna River cuts transversely across these folded formations toward the Chesapeake Bay in Havre de Grace, Maryland, where it provides 50 percent of all the freshwater entering the great estuary. The waters of the Susquehanna originate at Otsego Lake in New York and meander along 700 kilometers until reaching Chesapeake Bay and the sea.

This image was acquired on October 11, 2000, during Terra orbit 4344. It covers an area 334 kilometers x 328 kilometers. North is at the top.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Pine Island Glacier, Antarctica, MISR Multi-angle Composite

Atmospheric Science Data Center

2013-12-17

...     View Larger Image (JPEG) A large iceberg has finally separated from the calving front ... next due to stereo parallax. This parallax is used in MISR processing to retrieve cloud heights over snow and ice. Additionally, a plume ...

Chesapeake Bay

Atmospheric Science Data Center

2016-06-13

... including NASA's high-altitude ER-2 rocket plane and the University of Washington's Convair-580. At the same time, the Multi-angle ... of Cape Henry at the southern end of Chesapeake Bay, though it is not visible at the MISR resolution. The lower right image is a ...

Mystery #6 Answer

Atmospheric Science Data Center

2013-04-22

... title:  MISR Mystery Image Quiz #6: Brazil's Duck Lagoon     View Larger Image ... Imaging SpectroRadiometer (MISR) image of Brazil's Duck Lagoon covers an area of about 298 kilometers x 358 kilometers, and was ...

Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) Level 1B2 V006 Announcement

Atmospheric Science Data Center

2018-05-22

The NASA Langley Atmospheric Science Data Center (ASDC) and Jet Propulsion Laboratory (JPL) announce the public ... SpectroPolarimetric Imager (AirMSPI) Level 1B2 V006 data for all targets acquired for flight campaigns: Radar Definition ... Experiment (RADEX) flight campaign was based out of Joint Base Lewis-McChord, Washington. The campaign focused on characterizing new ...

Extension and statistical analysis of the GACP aerosol optical thickness record

NASA Astrophysics Data System (ADS)

Geogdzhayev, Igor V.; Mishchenko, Michael I.; Li, Jing; Rossow, William B.; Liu, Li; Cairns, Brian

2015-10-01

The primary product of the Global Aerosol Climatology Project (GACP) is a continuous record of the aerosol optical thickness (AOT) over the oceans. It is based on channel-1 and -2 radiance data from the Advanced Very High Resolution Radiometer (AVHRR) instruments flown on successive National Oceanic and Atmospheric Administration (NOAA) platforms. We extend the previous GACP dataset by four years through the end of 2009 using NOAA-17 and -18 AVHRR radiances recalibrated against MODerate resolution Imaging Spectroradiometer (MODIS) radiance data, thereby making the GACP record almost three decades long. The temporal overlap of over three years of the new NOAA-17 and the previous NOAA-16 record reveals an excellent agreement of the corresponding global monthly mean AOT values, thereby confirming the robustness of the vicarious radiance calibration used in the original GACP product. The temporal overlap of the NOAA-17 and -18 instruments is used to introduce a small additive adjustment to the channel-2 calibration of the latter resulting in a consistent record with increased data density. The Principal Component Analysis (PCA) of the newly extended GACP record shows that most of the volcanic AOT variability can be isolated into one mode responsible for ~ 12% of the total variance. This conclusion is confirmed by a combined PCA analysis of the GACP, MODIS, and Multi-angle Imaging SpectroRadiometer (MISR) AOTs during the volcano-free period from February 2000 to December 2009. We show that the modes responsible for the tropospheric AOT variability in the three datasets agree well in terms of correlation and spatial patterns. A previously identified negative AOT trend which started in the late 1980s and continued into the early 2000s is confirmed. Its magnitude and duration indicate that it was caused by changes in tropospheric aerosols. The latest multi-satellite segment of the GACP record shows that this trend tapered off, with no noticeable AOT change after 2002. This result is consistent with the MODIS and MISR AOT records as well as with the recent gradual reversal from brightening to dimming revealed by surface flux measurements in many aerosol producing regions. Thus the robustness of the GACP record is confirmed, increasing our confidence in the validity of the negative trend. Although the nominal negative GACP AOT trend could partially be an artifact of increasing aerosol absorption, we argue that the time dependence of the GACP record, including the latest flat period, is more consistent with the actual decrease in the tropospheric AOT.

The BlueSky Smoke Modeling Framework: Recent Developments

NASA Astrophysics Data System (ADS)

Sullivan, D. C.; Larkin, N.; Raffuse, S. M.; Strand, T.; ONeill, S. M.; Leung, F. T.; Qu, J. J.; Hao, X.

2012-12-01

BlueSky systems—a set of decision support tools including SmartFire and the BlueSky Framework—aid public policy decision makers and scientific researchers in evaluating the air quality impacts of fires. Smoke and fire managers use BlueSky systems in decisions about prescribed burns and wildland firefighting. Air quality agencies use BlueSky systems to support decisions related to air quality regulations. We will discuss a range of recent improvements to the BlueSky systems, as well as examples of applications and future plans. BlueSky systems have the flexibility to accept basic fire information from virtually any source and can reconcile multiple information sources so that duplication of fire records is eliminated. BlueSky systems currently apply information from (1) the National Oceanic and Atmospheric Administration's (NOAA) Hazard Mapping System (HMS), which represents remotely sensed data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR), and Geostationary Operational Environmental Satellites (GOES); (2) the Monitoring Trends in Burn Severity (MTBS) interagency project, which derives fire perimeters from Landsat 30-meter burn scars; (3) the Geospatial Multi-Agency Coordination Group (GeoMAC), which produces helicopter-flown burn perimeters; and (4) ground-based fire reports, such as the ICS-209 reports managed by the National Wildfire Coordinating Group. Efforts are currently underway to streamline the use of additional ground-based systems, such as states' prescribed burn databases. BlueSky systems were recently modified to address known uncertainties in smoke modeling associated with (1) estimates of biomass consumption derived from sparse fuel moisture data, and (2) models of plume injection heights. Additional sources of remotely sensed data are being applied to address these issues as follows: - The National Aeronautics and Space Administration's (NASA) Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis Real-Time (TMPA-RT) data set is being used to improve dead fuel moisture estimates. - EastFire live fuel moisture estimates, which are derived from NASA's MODIS direct broadcast, are being used to improve live fuel moisture estimates. - NASA's Multi-angle Imaging Spectroradiometer (MISR) stereo heights are being used to improve estimates of plume injection heights. Further, the Fire Location and Modeling of Burning Emissions (FLAMBÉ) model was incorporated into the BlueSky Framework as an alternative means of calculating fire emissions. FLAMBÉ directly estimates emissions on the basis of fire detections and radiance measures from NASA's MODIS and NOAA's GOES satellites. (The authors gratefully acknowledge NASA's Applied Sciences Program [Grant Nos. NN506AB52A and NNX09AV76G)], the USDA Forest Service, and the Joint Fire Science Program for their support.)

A multi-sensor lidar, multi-spectral and multi-angular approach for mapping canopy height in boreal forest regions

USGS Publications Warehouse

Selkowitz, David J.; Green, Gordon; Peterson, Birgit E.; Wylie, Bruce

2012-01-01

Spatially explicit representations of vegetation canopy height over large regions are necessary for a wide variety of inventory, monitoring, and modeling activities. Although airborne lidar data has been successfully used to develop vegetation canopy height maps in many regions, for vast, sparsely populated regions such as the boreal forest biome, airborne lidar is not widely available. An alternative approach to canopy height mapping in areas where airborne lidar data is limited is to use spaceborne lidar measurements in combination with multi-angular and multi-spectral remote sensing data to produce comprehensive canopy height maps for the entire region. This study uses spaceborne lidar data from the Geosciences Laser Altimeter System (GLAS) as training data for regression tree models that incorporate multi-angular and multi-spectral data from the Multi-Angle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging SpectroRadiometer (MODIS) to map vegetation canopy height across a 1,300,000 km2 swath of boreal forest in Interior Alaska. Results are compared to in situ height measurements as well as airborne lidar data. Although many of the GLAS-derived canopy height estimates are inaccurate, applying a series of filters incorporating both data associated with the GLAS shots as well as ancillary data such as land cover can identify the majority of height estimates with significant errors, resulting in a filtered dataset with much higher accuracy. Results from the regression tree models indicate that late winter MISR imagery acquired under snow-covered conditions is effective for mapping canopy heights ranging from 5 to 15 m, which includes the vast majority of forests in the region. It appears that neither MISR nor MODIS imagery acquired during the growing season is effective for canopy height mapping, although including summer multi-spectral MODIS data along with winter MISR imagery does appear to provide a slight increase in the accuracy of resulting height maps. The finding that winter, snow-covered MISR imagery can be used to map canopy height is important because clear sky days are nearly three times as common during the late winter period as during the growing season. The increased odds of acquiring cloud-free imagery during the target acquisition period make regularly updated forest height inventories for Interior Alaska much more feasible. A major advantage of the GLAS–MISR–MODIS canopy height mapping methodology described here is that this approach uses only data that is freely available worldwide, making the approach potentially applicable across the entire circumpolar boreal forest region.

James Bay

Atmospheric Science Data Center

2013-04-17

article title:  Hudson Bay and James Bay, Canada   ... which scatters more light in the backward direction. This example illustrates how multi-angle viewing can distinguish physical structures ... MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image ...

Multi-angle polarimeter inter-comparison: the PODEX and ACEPOL field campaigns

NASA Astrophysics Data System (ADS)

Knobelspiesse, K. D.; Tan, Q.; Redemann, J.; Cairns, B.; Diner, D. J.; Ferrare, R. A.; van Harten, G.; Hasekamp, O. P.; Kalashnikova, O. V.; Martins, J. V.; Yorks, J. E.; Seidel, F. C.

2017-12-01

A multi-angle polarimeter has been proposed for the NASA Aerosol-Cloud-Ecosystem (ACE) mission, recommended by the National Research Council's Decadal Survey. Such instruments are uncommon in orbit, and there is a great diversity of prototype instrument characteristics. For that reason, NASA funded two field campaigns where airborne polarimeter prototypes were deployed on the high altitude ER-2 aircraft. The first field campaign, POlarimeter DEfinition EXperiment (PODEX), was carried out in southern California in early 2013. Three polarimeters participated: the Airborne Multi-angle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). PACS, on its first deployment, suffered detector problems, while AirMSPI and RSP performed within expectations. Initial comparisons of AirMSPI and RSP observations found Degree of Linear Polarization (DoLP) biases. Following corrections to both instrument's calibration and/or geolocation techniques, these issues have improved. We will present the details of this comparison. The recent ACEPOL mission returned to southern California in October-November with a larger compliment of multi-angle polarimeters. This included AirMSPI and RSP, like in PODEX. Additional polarimetric instruments included AirHARP (Airborne HyperAngular Rainbow Polarimeter, a successor to PACS) and SPEX Airborne (SPectropolarimeter for Planetary Exploration). Two Lidars were also deployed: The High Spectral Resolution Lidar -2 (HSRL-2) and the Cloud Physics Lidar (CPL). While data processing is still underway, we will describe the objectives of this campaign and give a preview of what to expect in subsequent analysis.

Combined Infrared Stereo and Laser Ranging Cloud Measurements from Shuttle Mission STS-85

NASA Technical Reports Server (NTRS)

Lancaster, Redgie S.; Spinhirne, James D.; OCStarr, David (Technical Monitor)

2001-01-01

Multi-angle remote sensing provides a wealth of information for earth and climate monitoring. And, as technology advances so do the options for developing instrumentation versatile enough to meet the demands associated with these types of measurements. In the current work, the multiangle measurement capability of the Infrared Spectral Imaging Radiometer is demonstrated. This instrument flew as part of mission STS-85 of the space shuttle Columbia in 1997 and was the first earth-observing radiometer to incorporate an uncooled microbolometer array detector as its image sensor. Specifically, a method for computing cloud-top height from the multi-spectral stereo measurements acquired during this flight has been developed and the results demonstrate that a vertical precision of 10.6 km was achieved. Further, the accuracy of these measurements is confirmed by comparison with coincident direct laser ranging measurements from the Shuttle Laser Altimeter. Mission STS-85 was the first space flight to combine laser ranging and thermal IR camera systems for cloud remote sensing.

Pre-Launch Algorithm and Data Format for the Level 1 Calibration Products for the EOS AM-1 Moderate Resolution Imaging Spectroradiometer (MODIS)

NASA Technical Reports Server (NTRS)

Guenther, Bruce W.; Godden, Gerald D.; Xiong, Xiao-Xiong; Knight, Edward J.; Qiu, Shi-Yue; Montgomery, Harry; Hopkins, M. M.; Khayat, Mohammad G.; Hao, Zhi-Dong; Smith, David E. (Technical Monitor)

2000-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) radiometric calibration product is described for the thermal emissive and the reflective solar bands. Specific sensor design characteristics are identified to assist in understanding how the calibration algorithm software product is designed. The reflected solar band software products of radiance and reflectance factor both are described. The product file format is summarized and the MODIS Characterization Support Team (MCST) Homepage location for the current file format is provided.

Site of the 2016 Summer Olympic Games viewed by NASA MISR

NASA Image and Video Library

2016-08-10

The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed directly over Rio de Janeiro, Brazil, on Aug. 2, 2016, just prior to the opening of the Summer Olympic Games. On the left is an image from MISR's nadir (downward-looking) camera; the width of the image is 235 miles (378 kilometers), and Rio de Janeiro is visible as the large gray area on the coast in the center. The black asterisk marks the location of the Maracanã Stadium in downtown, where the opening ceremonies were held. In the weeks leading up to the Aug. 5 opening ceremonies in Rio de Janeiro, there have been reports of elevated levels of particulate matter in the region. Particulate matter refers to tiny airborne droplets or pieces of soot and dust that can end up in the lungs, comprising an all-too-common problem for many cities around the world. MISR data are routinely used to estimate the amount of air pollution via measurements of aerosol optical depth, which is a measure of how much incoming light from the sun is blocked by particles in the atmosphere. On the right, a map of aerosol optical depth is superimposed on the image. Individual squares making up this map measure 2.7 miles (4.4 kilometers) on a side, and holes in the map occur where an aerosol amount could not be determined, such as where clouds are present. Optical depth over Rio is slightly elevated compared to its surroundings, most likely due to the presence of air pollution, with values from 0.15-0.25. For reference, an optical depth of 0.2 corresponds to light haze. The product shown here is a prototype of a new version of the MISR aerosol product to be publicly released in the near future, and increases the spatial resolution of the aerosol information by a factor of 16 compared to the currently available product, making it possible to observe the fine details of optical depth over urban areas. These data were captured during Terra orbit 88426. http://photojournal.jpl.nasa.gov/catalog/PIA20885

NASA MISR Spots Hurricane Hermine Approaching Florida

NASA Image and Video Library

2016-09-01

On the afternoon of Sept. 1, 2016, Tropical Storm Hermine strengthened into a Category 1 hurricane as it approached the coast of Florida. Hermine began life as Tropical Depression Nine, originating off the coast of Cuba on Aug. 28. After heading northwest into the Gulf of Mexico, it took a right turn toward Florida and on Wednesday, Aug. 31, was upgraded to a tropical storm before strengthening to a hurricane a day later. Winds are currently sustained near 75 miles (121 kilometers) per hour, and the storm is expected to make landfall tonight or early tomorrow. Florida Governor Rick Scott has declared a state of emergency in 51 counties, while Georgia Governor Nathan Deal has done the same for 56 counties in his state. Localized flooding is already occurring in some areas of Florida, which has not had a direct landfall by a hurricane in 11 years. After moving across Florida and Georgia, the storm is currently forecast to continue northward along the coast of the Eastern seaboard. On Sept. 1, at 12:30 p.m. EDT, the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra spacecraft passed over the area. This natural-color image from MISR's vertical-pointing camera shows the large, loosely organized hurricane. At the time, the center of the storm was located about 200 miles (325 kilometers) to the west of Sarasota on the Florida coast. The image is 235 miles (378 kilometers) in width. Also included is a 3D stereo anaglyph, made by combining data from MISR's vertical-pointing and 46-degree forward-pointing camera. The image has been rotated so that north is to the left in order to enable stereo viewing. With the aid of red-blue glasses (with the red lens over the left eye), it is possible to observe the storm in three dimensions. Note the towering central thunderstorms around the eye in comparison to the low clouds visible within it. These data were acquired during Terra orbit 88865. http://photojournal.jpl.nasa.gov/catalog/PIA20898

Quantifying the microphysical impacts of fire aerosols on clouds in Indonesia using remote sensing observations

NASA Astrophysics Data System (ADS)

Tosca, M. G.; Diner, D. J.; Garay, M. J.; Kalashnikova, O. V.

2012-12-01

Fire-emitted aerosols modify cloud and precipitation dynamics by acting as cloud condensation nuclei in what is known as the first and second aerosol indirect effect. The cloud response to the indirect effect varies regionally and is not well understood in the highly convective tropics. We analyzed nine years (2003-2011) of aerosol data from the Multi-angle Imaging SpectroRadiometer (MISR), and fire emissions data from the Global Fire Emissions Database, version 3 (GFED3) over southeastern tropical Asia (Indonesia), and identified scenes that contained both a high atmospheric aerosol burden and large surface fire emissions. We then collected scenes from the Cloud Profiling Radar (CPR) on board the CLOUDSAT satellite that corresponded both spatially and temporally to the high-burning scenes from MISR, and identified differences in convective cloud dynamics over areas with varying aerosol optical depths. Differences in overpass times (MISR in the morning, CLOUDSAT in the afternoon) improved our ability to infer that changes in cloud dynamics were a response to increased or decreased aerosol emissions. Our results extended conclusions from initial studies over the Amazon that used remote sensing techniques to identify cloud fraction reductions in high burning areas (Koren et al., 2004; Rosenfeld, 1999) References Koren, I., Y.J. Kaufman, L.A. Remer and J.V. Martins (2004), Measurement of the effect of Amazon smoke on inhibition of cloud formation, Science, 303, 1342-1345 Rosenfeld, D. (1999), TRMM observed first direct evidence of smoke from forest fires inhibiting rainfall, Gephys. Res. Lett., 26, 3105.

Hurricane Alex

Atmospheric Science Data Center

2013-04-19

article title:  Hurricane Alex Disrupts Gulf Cleanup     View Larger Image This view of Hurricane Alex in the western Gulf of Mexico was acquired by the Multi-angle ... Time on June 30, 2010. Around this time NOAA's National Hurricane Center reported Alex to be a strengthening Category 1 hurricane with ...

Model-Derived Global Aerosol Climatology for MISR Analysis ("Clim-Likely" Data Set)

Atmospheric Science Data Center

2018-04-19

Model-Derived Global Aerosol Climatology for MISR Analysis Multi-angle Imaging ... (MISR) monthly, global 1° x 1° "Clim-Likely" aerosol climatology, derived from 'typical-year' aerosol transport model results are available for individual 1° x 1° boxes or ...

Enabling Technologies for High-accuracy Multiangle Spectropolarimetric Imaging from Space

NASA Technical Reports Server (NTRS)

Diner, David J.; Macenka, Steven A.; Seshndri, Suresh; Bruce, Carl E; Jau, Bruno; Chipman, Russell A.; Cairns, Brian; Christoph, Keller; Foo, Leslie D.

2004-01-01

Satellite remote sensing plays a major role in measuring the optical and radiative properties, environmental impact, and spatial and temporal distribution of tropospheric aerosols. In this paper, we envision a new generation of spaceborne imager that integrates the unique strengths of multispectral, multiangle, and polarimetric approaches, thereby achieving better accuracies in aerosol optical depth and particle properties than can be achieved using any one method by itself. Design goals include spectral coverage from the near-UV to the shortwave infrared; global coverage within a few days; intensity and polarimetric imaging simultaneously at multiple view angles; kilometer to sub-kilometer spatial resolution; and measurement of the degree of linear polarization for a subset of the spectral complement with an uncertainty of 0.5% or less. The latter requirement is technically the most challenging. In particular, an approach for dealing with inter-detector gain variations is essential to avoid false polarization signals. We propose using rapid modulation of the input polarization state to overcome this problem, using a high-speed variable retarder in the camera design. Technologies for rapid retardance modulation include mechanically rotating retarders, liquid crystals, and photoelastic modulators (PEMs). We conclude that the latter are the most suitable.

Tropical Storm Harvey Spotted by NASA's MISR

NASA Image and Video Library

2017-08-29

On Aug. 27, 2017, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite passed over then-Tropical Storm Harvey about noon local time, the day after the storm first made landfall in Texas as a Category 4 hurricane. The MISR instrument is equipped with nine cameras that observe Earth at different angles over a time period of seven minutes. Geometric information from the multiple camera views is used to compute the cloud top heights, and motion of the clouds during the image sequence is used to calculate wind speed. This composite image shows the storm as viewed by the central, downward-looking camera (left), as well as the cloud top heights in kilometers (center) and the wind speeds (right) superimposed on the image. The length of the arrows is proportional to the wind speed, while their color shows the altitude at which the winds were calculated. Also included is an animation made by combining all nine images from the MISR cameras, showing the motion of the storm during the seven-minute period. At this time, the center of the tropical storm was located just northwest of the city of Victoria and maximum wind speeds on the ground were around 40 miles per hour (65 kilometers per hour) according to the National Oceanic and Atmospheric Administration (NOAA), which matches well with the near-surface winds calculated by MISR to the west of Corpus Christi. In the 36 hours or so since it had made landfall, Harvey had weakened considerably -- these images show that the eye had disappeared and much of the circular motion of storm had dissipated, as shown by the calculated wind directions. However, the area of very high clouds and strong winds near Houston shows that the storm was continuing to produce powerful rain bands. At this point, hydrographs managed by NOAA in downtown Houston were already recording flood stage at both the Buffalo Bayou (28 feet or 8.5 meters as of 12:15 p.m. CDT August 27) and the White Oak Bayou (40 feet or 12 meters at last record that morning). The MISR data show the storm clouds reaching an altitude of about 10 miles (16 kilometers). These data were captured during Terra orbit 94108. An animation is available at https://photojournal.jpl.nasa.gov/catalog/PIA21927

The application analysis of the multi-angle polarization technique for ocean color remote sensing

NASA Astrophysics Data System (ADS)

Zhang, Yongchao; Zhu, Jun; Yin, Huan; Zhang, Keli

2017-02-01

The multi-angle polarization technique, which uses the intensity of polarized radiation as the observed quantity, is a new remote sensing means for earth observation. With this method, not only can the multi-angle light intensity data be provided, but also the multi-angle information of polarized radiation can be obtained. So, the technique may solve the problems, those could not be solved with the traditional remote sensing methods. Nowadays, the multi-angle polarization technique has become one of the hot topics in the field of the international quantitative research on remote sensing. In this paper, we firstly introduce the principles of the multi-angle polarization technique, then the situations of basic research and engineering applications are particularly summarized and analysed in 1) the peeled-off method of sun glitter based on polarization, 2) the ocean color remote sensing based on polarization, 3) oil spill detection using polarization technique, 4) the ocean aerosol monitoring based on polarization. Finally, based on the previous work, we briefly present the problems and prospects of the multi-angle polarization technique used in China's ocean color remote sensing.

El Nino-Southern Oscillation Correlated Aerosol Angstrom Exponent Anomaly Over the Tropical Pacific Discovered in Satellite Measurements

NASA Technical Reports Server (NTRS)

Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

2011-01-01

El Nino.Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical atmosphere. ENSO could potentially impact local and global aerosol properties through atmospheric circulation anomalies and teleconnections. By analyzing aerosol properties, including aerosol optical depth (AOD) and Angstrom exponent (AE; often used as a qualitative indicator of aerosol particle size) from the Moderate Resolution Imaging Spectrometer, the Multiangle Imaging Spectroradiometer and the Sea ]viewing Wide Field ]of ]view Sensor for the period 2000.2011, we find a strong correlation between the AE data and the multivariate ENSO index (MEI) over the tropical Pacific. Over the western tropical Pacific (WTP), AE increases during El Nino events and decreases during La Nina events, while the opposite is true over the eastern tropical Pacific (ETP). The difference between AE anomalies in the WTP and ETP has a higher correlation coefficient (>0.7) with the MEI than the individual time series and could be considered another type of ENSO index. As no significant ENSO correlation is found in AOD over the same region, the change in AE (and hence aerosol size) is likely to be associated with aerosol composition changes due to anomalous meteorological conditions induced by the ENSO. Several physical parameters or mechanisms that might be responsible for the correlation are discussed. Preliminary analysis indicates surface wind anomaly might be the major contributor, as it reduces sea ]salt production and aerosol transport during El Nino events. Precipitation and cloud fraction are also found to be correlated with tropical Pacific AE. Possible mechanisms, including wet removal and cloud shielding effects, are considered. Variations in relative humidity, tropospheric ozone concentration, and ocean color during El Nino have been ruled out. Further investigation is needed to fully understand this AE ]ENSO covariability and the underlying physical processes responsible for it.

El Niño-Southern Oscillation correlated aerosol Ångström exponent anomaly over the tropical Pacific discovered in satellite measurements

NASA Astrophysics Data System (ADS)

Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

2011-10-01

El Niño-Southern Oscillation (ENSO) is the dominant mode of interannual variability in the tropical atmosphere. ENSO could potentially impact local and global aerosol properties through atmospheric circulation anomalies and teleconnections. By analyzing aerosol properties, including aerosol optical depth (AOD) and Ångström exponent (AE; often used as a qualitative indicator of aerosol particle size) from the Moderate Resolution Imaging Spectrometer, the Multiangle Imaging Spectroradiometer and the Sea-viewing Wide Field-of-view Sensor for the period 2000-2011, we find a strong correlation between the AE data and the multivariate ENSO index (MEI) over the tropical Pacific. Over the western tropical Pacific (WTP), AE increases during El Niño events and decreases during La Niña events, while the opposite is true over the eastern tropical Pacific (ETP). The difference between AE anomalies in the WTP and ETP has a higher correlation coefficient (>0.7) with the MEI than the individual time series and could be considered another type of ENSO index. As no significant ENSO correlation is found in AOD over the same region, the change in AE (and hence aerosol size) is likely to be associated with aerosol composition changes due to anomalous meteorological conditions induced by the ENSO. Several physical parameters or mechanisms that might be responsible for the correlation are discussed. Preliminary analysis indicates surface wind anomaly might be the major contributor, as it reduces sea-salt production and aerosol transport during El Niño events. Precipitation and cloud fraction are also found to be correlated with tropical Pacific AE. Possible mechanisms, including wet removal and cloud shielding effects, are considered. Variations in relative humidity, tropospheric ozone concentration, and ocean color during El Niño have been ruled out. Further investigation is needed to fully understand this AE-ENSO covariability and the underlying physical processes responsible for it.

Mystery #12 Answer

Atmospheric Science Data Center

2013-04-22

... Imaging SpectroRadiometer (MISR) natural-color image of Russia's St. Petersburg was captured by the instrument's nadir camera on May ... The city in the south eastern portion of the image is Russia's St. Petersburg, which is the most northerly large city in the world at ...

A comparison of multi-spectral, multi-angular, and multi-temporal remote sensing datasets for fractional shrub canopy mapping in Arctic Alaska

USGS Publications Warehouse

Selkowitz, D.J.

2010-01-01

Shrub cover appears to be increasing across many areas of the Arctic tundra biome, and increasing shrub cover in the Arctic has the potential to significantly impact global carbon budgets and the global climate system. For most of the Arctic, however, there is no existing baseline inventory of shrub canopy cover, as existing maps of Arctic vegetation provide little information about the density of shrub cover at a moderate spatial resolution across the region. Remotely-sensed fractional shrub canopy maps can provide this necessary baseline inventory of shrub cover. In this study, we compare the accuracy of fractional shrub canopy (> 0.5 m tall) maps derived from multi-spectral, multi-angular, and multi-temporal datasets from Landsat imagery at 30 m spatial resolution, Moderate Resolution Imaging SpectroRadiometer (MODIS) imagery at 250 m and 500 m spatial resolution, and MultiAngle Imaging Spectroradiometer (MISR) imagery at 275 m spatial resolution for a 1067 km2 study area in Arctic Alaska. The study area is centered at 69 ??N, ranges in elevation from 130 to 770 m, is composed primarily of rolling topography with gentle slopes less than 10??, and is free of glaciers and perennial snow cover. Shrubs > 0.5 m in height cover 2.9% of the study area and are primarily confined to patches associated with specific landscape features. Reference fractional shrub canopy is determined from in situ shrub canopy measurements and a high spatial resolution IKONOS image swath. Regression tree models are constructed to estimate fractional canopy cover at 250 m using different combinations of input data from Landsat, MODIS, and MISR. Results indicate that multi-spectral data provide substantially more accurate estimates of fractional shrub canopy cover than multi-angular or multi-temporal data. Higher spatial resolution datasets also provide more accurate estimates of fractional shrub canopy cover (aggregated to moderate spatial resolutions) than lower spatial resolution datasets, an expected result for a study area where most shrub cover is concentrated in narrow patches associated with rivers, drainages, and slopes. Including the middle infrared bands available from Landsat and MODIS in the regression tree models (in addition to the four standard visible and near-infrared spectral bands) typically results in a slight boost in accuracy. Including the multi-angular red band data available from MISR in the regression tree models, however, typically boosts accuracy more substantially, resulting in moderate resolution fractional shrub canopy estimates approaching the accuracy of estimates derived from the much higher spatial resolution Landsat sensor. Given the poor availability of snow and cloud-free Landsat scenes in many areas of the Arctic and the promising results demonstrated here by the MISR sensor, MISR may be the best choice for large area fractional shrub canopy mapping in the Alaskan Arctic for the period 2000-2009.

Wavelength scanning achieves pixel super-resolution in holographic on-chip microscopy

NASA Astrophysics Data System (ADS)

Luo, Wei; Göröcs, Zoltan; Zhang, Yibo; Feizi, Alborz; Greenbaum, Alon; Ozcan, Aydogan

2016-03-01

Lensfree holographic on-chip imaging is a potent solution for high-resolution and field-portable bright-field imaging over a wide field-of-view. Previous lensfree imaging approaches utilize a pixel super-resolution technique, which relies on sub-pixel lateral displacements between the lensfree diffraction patterns and the image sensor's pixel-array, to achieve sub-micron resolution under unit magnification using state-of-the-art CMOS imager chips, commonly used in e.g., mobile-phones. Here we report, for the first time, a wavelength scanning based pixel super-resolution technique in lensfree holographic imaging. We developed an iterative super-resolution algorithm, which generates high-resolution reconstructions of the specimen from low-resolution (i.e., under-sampled) diffraction patterns recorded at multiple wavelengths within a narrow spectral range (e.g., 10-30 nm). Compared with lateral shift-based pixel super-resolution, this wavelength scanning approach does not require any physical shifts in the imaging setup, and the resolution improvement is uniform in all directions across the sensor-array. Our wavelength scanning super-resolution approach can also be integrated with multi-height and/or multi-angle on-chip imaging techniques to obtain even higher resolution reconstructions. For example, using wavelength scanning together with multi-angle illumination, we achieved a halfpitch resolution of 250 nm, corresponding to a numerical aperture of 1. In addition to pixel super-resolution, the small scanning steps in wavelength also enable us to robustly unwrap phase, revealing the specimen's optical path length in our reconstructed images. We believe that this new wavelength scanning based pixel super-resolution approach can provide competitive microscopy solutions for high-resolution and field-portable imaging needs, potentially impacting tele-pathology applications in resource-limited-settings.

Standoff aircraft IR characterization with ABB dual-band hyper spectral imager

NASA Astrophysics Data System (ADS)

Prel, Florent; Moreau, Louis; Lantagne, Stéphane; Bullis, Ritchie D.; Roy, Claude; Vallières, Christian; Levesque, Luc

2012-09-01

Remote sensing infrared characterization of rapidly evolving events generally involves the combination of a spectro-radiometer and infrared camera(s) as separated instruments. Time synchronization, spatial coregistration, consistent radiometric calibration and managing several systems are important challenges to overcome; they complicate the target infrared characterization data processing and increase the sources of errors affecting the final radiometric accuracy. MR-i is a dual-band Hyperspectal imaging spectro-radiometer, that combines two 256 x 256 pixels infrared cameras and an infrared spectro-radiometer into one single instrument. This field instrument generates spectral datacubes in the MWIR and LWIR. It is designed to acquire the spectral signatures of rapidly evolving events. The design is modular. The spectrometer has two output ports configured with two simultaneously operated cameras to either widen the spectral coverage or to increase the dynamic range of the measured amplitudes. Various telescope options are available for the input port. Recent platform developments and field trial measurements performances will be presented for a system configuration dedicated to the characterization of airborne targets.

Super-resolution mapping using multi-viewing CHRIS/PROBA data

NASA Astrophysics Data System (ADS)

Dwivedi, Manish; Kumar, Vinay

2016-04-01

High-spatial resolution Remote Sensing (RS) data provides detailed information which ensures high-definition visual image analysis of earth surface features. These data sets also support improved information extraction capabilities at a fine scale. In order to improve the spatial resolution of coarser resolution RS data, the Super Resolution Reconstruction (SRR) technique has become widely acknowledged which focused on multi-angular image sequences. In this study multi-angle CHRIS/PROBA data of Kutch area is used for SR image reconstruction to enhance the spatial resolution from 18 m to 6m in the hope to obtain a better land cover classification. Various SR approaches like Projection onto Convex Sets (POCS), Robust, Iterative Back Projection (IBP), Non-Uniform Interpolation and Structure-Adaptive Normalized Convolution (SANC) chosen for this study. Subjective assessment through visual interpretation shows substantial improvement in land cover details. Quantitative measures including peak signal to noise ratio and structural similarity are used for the evaluation of the image quality. It was observed that SANC SR technique using Vandewalle algorithm for the low resolution image registration outperformed the other techniques. After that SVM based classifier is used for the classification of SRR and data resampled to 6m spatial resolution using bi-cubic interpolation. A comparative analysis is carried out between classified data of bicubic interpolated and SR derived images of CHRIS/PROBA and SR derived classified data have shown a significant improvement of 10-12% in the overall accuracy. The results demonstrated that SR methods is able to improve spatial detail of multi-angle images as well as the classification accuracy.

Evaluating Nighttime CALIOP 0.532 micron Aerosol Optical Depth and Extinction Coefficient Retrievals

NASA Technical Reports Server (NTRS)

Campbell, J. R.; Tackett, J. L.; Reid, J. S.; Zhang, J.; Curtis, C. A.; Hyer, E. J.; Sessions, W. R.; Westphal, D. L.; Prospero, J. M.; Welton, E. J.;

Influence of Humidity On the Aerosol Scattering Coefficient and Its Effect on the Upwelling Radiance During ACE-2

NASA Technical Reports Server (NTRS)

Gasso, S.; Hegg, D. A.; Covert, D. S.; Collins, D.; Noone, K. J.; Oestroem, E.; Schmid, B.; Russell, P. B.; Livingston, J. M.; Durkee, P. A.

2000-01-01

Aerosol scattering coefficients (sigma(sub sp)) have been measured over the ocean at different relative humidities (RH) as a function of altitude in the region surrounding the Canary Islands during the Second Aerosol Characterization Experiment (ACE-2) in June and July 1997. The data were collected by the University of Washington passive humidigraph (UWPH) mounted on the Pelican research aircraft. Concurrently, particle size distributions, absorption coefficients and aerosol optical depth were measured throughout 17 flights. A parameterization of sigma(sub sp) as a function of RH was utilized to assess the impact of aerosol hydration on the upwelling radiance (normalized to the solar constant and cosine of zenith angle). The top of the atmosphere radiance signal was simulated at wavelengths corresponding to visible and near-infrared bands of the EOS (Earth Observing System) AM-1 (Terra) detectors, MODIS (Moderate Resolution Imaging Spectroradiometer) and MISR (Multi-angle Imaging Spectroradiometer). The UWPH measured sigma(sub sp) at two RHs, one below and the other above ambient conditions. Ambient sigma(sub sp) was obtained by interpolation of these two measurements. The data were stratified in terms of three types of aerosols: Saharan dust, clean marine (marine boundary layer background) and polluted marine aerosols (i.e., two- or one-day old polluted aerosols advected from Europe). An empirical relation for the dependence of sigma(sub sp) on RH, defined by sigma(sub sp)(RH) = k.(1 - RH/100)(sup gamma), was used with the hygroscopic exponent gamma derived from the data. The following gamma values were obtained for the 3 aerosol types: gamma(dust) = 0.23 +/- 0.05, gamma(clean marine) = 0.69 +/- 0.06 and gamma(polluted marine) = 0.57 +/- 0.06. Based on the measured gammas, the above equation was utilized to derive aerosol models with different hygroscopicities. The satellite simulation signal code 6S was used to compute the upwelling radiance corresponding to each of those aerosol models at several ambient humidities. For the prelaunch estimated precision of the sensors and the assumed viewing geometry of the instrument, the simulations suggest that the spectral and angular dependence of the reflectance measured by MISR is not sufficient to distinguish aerosol models with various different combinations of values for dry composition, gamma and ambient RH. A similar behavior is observed for MODIS at visible wavelengths. However, the 2100 nm band of MODIS appears to be able to differentiate between at least same aerosol models with different aerosol hygroscopicity given the MODIS calibration error requirements. This result suggests the possibility of retrieval of aerosol hygroscopicity by MODIS.

Red Tide Strands South African Rock Lobsters

NASA Technical Reports Server (NTRS)

2002-01-01

Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide. The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine. The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

Coccoliths in the Celtic Sea

NASA Technical Reports Server (NTRS)

2002-01-01

As the basis of the marine food chain, phytoplankton are important indicators of change in the oceans. These marine flora also extract carbon dioxide from the atmosphere for use in photosynthesis, and play an important role in global climate. Phytoplankton blooms that occur near the surface are readily visible from space, enabling a global estimation of the presence of chlorophyll and other pigments. There are more than 5,000 different species of phytoplankton however, and it is not always possible to identify the type of phytoplankton present using space-based remote sensing.

Coccolithophores, however, are a group of phytoplankton that are identifiable from space. These microscopic plants armor themselves with external plates of calcium carbonate. The plates, or coccoliths, give the ocean a milky white or turquoise appearance during intense blooms. The long-term flux of coccoliths to the ocean floor is the main process responsible for the formation of chalk and limestone.

This image is a natural-color view of the Celtic Sea and English Channel regions, and was acquired by the Multi-angle Imaging SpectroRadiometer's nadir (vertical-viewing) camera on June 4, 2001 during Terra orbit 7778. It represents an area of 380 kilometers x 445 kilometers, and includes portions of southwestern England and northwestern France. The coccolithophore bloom in the lower left-hand corner usually occurs in the Celtic Sea for several weeks in summer. The coccoliths backscatter light from the water column to create a bright optical effect. Other algal and/or phytoplankton blooms can also be discerned along the coasts near Portsmouth, England and Granville, France.

At full resolution, evidence of human activity is also apparent in this image. White specks associated with ship wakes are present in the open water, and aircraft contrails are visible within the high cirrus clouds over the English Channel.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Sensitivity of multiangle photo-polarimetry to absorbing aerosol vertical layering and properties: Quantifying measurement uncertainties for ACE requirements

NASA Astrophysics Data System (ADS)

Kalashnikova, O. V.; Garay, M. J.; Davis, A. B.; Natraj, V.; Diner, D. J.; Tanelli, S.; Martonchik, J. V.; JPl Team

2011-12-01

The impact of tropospheric aerosols on climate can vary greatly based upon relatively small variations in aerosol properties, such as composition, shape and size distributions, as well as vertical layering. Multi-angle polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol radiative forcing on climate. The central concern of this work is the assessment of the effects of absorbing aerosol properties under measurement uncertainties achievable for future generation multi-angle, polarimetric imaging instruments under ACE mission requirements. As guidelines, the on-orbit performance of MISR for multi-angle intensity measurements and the reported polarization sensitivities of a MSPI prototype were adopted. In particular, we will focus on sensitivities to absorbing aerosol layering and observation-constrained refractive indices (resulting in various single scattering albedos (SSA)) of both spherical and non-spherical absorbing aerosol types. We conducted modeling experiments to determine how the measured Stokes vector elements are affected in UV-NIR range by the vertical distribution, mixing and layering of smoke and dust aerosols, and aerosol SSA under the assumption of a black and polarizing ocean surfaces. We use a vector successive-orders-of-scattering (SOS) and VLIDORT transfer codes that show excellent agreement. Based on our sensitivity studies we will demonstrate advantages and disadvantages of wavelength selection in UV-NIR range to access absorbing aerosol properties. Polarized UV channels do not show particular advantage for absorbing aerosol property characterization due to dominating molecular signal. Polarimetric SSA sensitivity is small, however needed to be considered in the future polarimetric retrievals under ACE-defined uncertainty.

Treatment response assessment of radiofrequency ablation for hepatocellular carcinoma: usefulness of virtual CT sonography with magnetic navigation.

PubMed

Minami, Yasunori; Kitai, Satoshi; Kudo, Masatoshi

2012-03-01

Virtual CT sonography using magnetic navigation provides cross sectional images of CT volume data corresponding to the angle of the transducer in the magnetic field in real-time. The purpose of this study was to clarify the value of this virtual CT sonography for treatment response of radiofrequency ablation for hepatocellular carcinoma. Sixty-one patients with 88 HCCs measuring 0.5-1.3 cm (mean±SD, 1.0±0.3 cm) were treated by radiofrequency ablation. For early treatment response, dynamic CT was performed 1-5 days (median, 2 days). We compared early treatment response between axial CT images and multi-angle CT images using virtual CT sonography. Residual tumor stains on axial CT images and multi-angle CT images were detected in 11.4% (10/88) and 13.6% (12/88) after the first session of RFA, respectively (P=0.65). Two patients were diagnosed as showing hyperemia enhancement after the initial radiofrequency ablation on axial CT images and showed local tumor progression shortly because of unnoticed residual tumors. Only virtual CT sonography with magnetic navigation retrospectively showed the residual tumor as circular enhancement. In safety margin analysis, 10 patients were excluded because of residual tumors. The safety margin more than 5 mm by virtual CT sonographic images and transverse CT images were determined in 71.8% (56/78) and 82.1% (64/78), respectively (P=0.13). The safety margin should be overestimated on axial CT images in 8 nodules. Virtual CT sonography with magnetic navigation was useful in evaluating the treatment response of radiofrequency ablation therapy for hepatocellular carcinoma. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Forest height Mapping using the fusion of Lidar and MULTI-ANGLE spectral data

NASA Astrophysics Data System (ADS)

Pang, Y.; Li, Z.

2016-12-01

Characterizing the complexity of forest ecosystem over large area is highly complex. Light detection and Ranging (LIDAR) approaches have demonstrated a high capacity to accurately estimate forest structural parameters. A number of satellite mission concepts have been proposed to fuse LiDAR with other optical imagery allowing Multi-angle spectral observations to be captured using the Bidirectional Reflectance Distribution Function (BRDF) characteristics of forests. China is developing the concept of Chinese Terrestrial Carbon Mapping Satellite. A multi-beam waveform Lidar is the main sensor. A multi-angle imagery system is considered as the spatial mapping sensor. In this study, we explore the fusion potential of Lidar and multi-angle spectral data to estimate forest height across different scales. We flew intensive airborne Lidar and Multi-angle hyperspectral data in Genhe Forest Ecological Research Station, Northeast China. Then extended the spatial scale with some long transect flights to cover more forest structures. Forest height data derived from airborne lidar data was used as reference data and the multi-angle hyperspectral data was used as model inputs. Our results demonstrate that the multi-angle spectral data can be used to estimate forest height with the RMSE of 1.1 m with an R2 approximately 0.8.

Inter-Comparison of WRF Model Simulated Winds and MISR Stereoscopic Winds Embedded within Mesoscale von Kármán Wake Vortices

NASA Astrophysics Data System (ADS)

Horvath, A.; Nunalee, C. G.; Mueller, K. J.

2014-12-01

Several distinct wake regimes are possible when considering atmospheric flow past a steep mountainous island. Of these regimes, coherent vortex shedding in low-Froude number flow is particularly interesting because it can produce laterally focused paths of counter rotating eddies capable of extending downstream for hundreds of kilometers (i.e., a von Kármán vortex street). Given the spatial scales of atmospheric von Kármán vortices, which typically lies on the interface of the meso-scale and the micro-scale, they are uniquely challenging to model using conventional numerical weather prediction platforms. In this presentation, we present high resolution (1-km horizontally) numerical modeling results using the Weather Research and Forecasting (WRF) model, of multiple real-world von Kármán vortex shedding events associated with steep islands (e.g., Madeira island, Gran Canaria island, etc.). In parallel, we also present corresponding cloud-motion wind and cloud-top height measurements from the satellite-based Multiangle Imaging SpectroRadiometer (MISR) instrument. The MISR stereo algorithm enables experimental retrieval of the horizontal wind vector (both along-track and cross-track components) at 4.4-km resolution, in addition to the operational 1.1-km resolution cross-track wind and cloud-top height products. These products offer the fidelity appropriate for inter-comparison with the numerically simulated vortex streets. In general, we find an agreement between the instantaneous simulated cloud level winds and the MISR stereoscopic winds; however, discrepancies in the vortex street length and localized horizontal wind shear were documented. In addition, the simulated fields demonstrate sensitivity to turbulence closure and input terrain height data.

New approach to the retrieval of AOD and its uncertainty from MISR observations over dark water

NASA Astrophysics Data System (ADS)

Witek, Marcin L.; Garay, Michael J.; Diner, David J.; Bull, Michael A.; Seidel, Felix C.

2018-01-01

A new method for retrieving aerosol optical depth (AOD) and its uncertainty from Multi-angle Imaging SpectroRadiometer (MISR) observations over dark water is outlined. MISR's aerosol retrieval algorithm calculates cost functions between observed and pre-simulated radiances for a range of AODs (from 0.0 to 3.0) and a prescribed set of aerosol mixtures. The previous version 22 (V22) operational algorithm considered only the AOD that minimized the cost function for each aerosol mixture and then used a combination of these values to compute the final, best estimate AOD and associated uncertainty. The new approach considers the entire range of cost functions associated with each aerosol mixture. The uncertainty of the reported AOD depends on a combination of (a) the absolute values of the cost functions for each aerosol mixture, (b) the widths of the cost function distributions as a function of AOD, and (c) the spread of the cost function distributions among the ensemble of mixtures. A key benefit of the new approach is that, unlike the V22 algorithm, it does not rely on empirical thresholds imposed on the cost function to determine the success or failure of a particular mixture. Furthermore, a new aerosol retrieval confidence index (ARCI) is established that can be used to screen high-AOD retrieval blunders caused by cloud contamination or other factors. Requiring ARCI ≥ 0.15 as a condition for retrieval success is supported through statistical analysis and outperforms the thresholds used in the V22 algorithm. The described changes to the MISR dark water algorithm will become operational in the new MISR aerosol product (V23), planned for release in 2017.

New Approach to the Retrieval of AOD and its Uncertainty from MISR Observations Over Dark Water

NASA Astrophysics Data System (ADS)

Witek, M. L.; Garay, M. J.; Diner, D. J.; Bull, M. A.; Seidel, F.

2017-12-01

A new method for retrieving aerosol optical depth (AOD) and its uncertainty from Multi-angle Imaging SpectroRadiometer (MISR) observations over dark water is outlined. MISR's aerosol retrieval algorithm calculates cost functions between observed and pre-simulated radiances for a range of AODs (from 0.0 to 3.0) and a prescribed set of aerosol mixtures. The previous Version 22 (V22) operational algorithm considered only the AOD that minimized the cost function for each aerosol mixture, then used a combination of these values to compute the final, "best estimate" AOD and associated uncertainty. The new approach considers the entire range of cost functions associated with each aerosol mixture. The uncertainty of the reported AOD depends on a combination of a) the absolute values of the cost functions for each aerosol mixture, b) the widths of the cost function distributions as a function of AOD, and c) the spread of the cost function distributions among the ensemble of mixtures. A key benefit of the new approach is that, unlike the V22 algorithm, it does not rely on arbitrary thresholds imposed on the cost function to determine the success or failure of a particular mixture. Furthermore, a new Aerosol Retrieval Confidence Index (ARCI) is established that can be used to screen high-AOD retrieval blunders caused by cloud contamination or other factors. Requiring ARCI≥0.15 as a condition for retrieval success is supported through statistical analysis and outperforms the thresholds used in the V22 algorithm. The described changes to the MISR dark water algorithm will become operational in the new MISR aerosol product (V23), planned for release in 2017.

Satellite aerosol retrieval using dark target algorithm by coupling BRDF effect over AERONET site

NASA Astrophysics Data System (ADS)

Yang, Leiku; Xue, Yong; Guang, Jie; Li, Chi

2012-11-01

For most satellite aerosol retrieval algorithms even for multi-angle instrument, the simple forward model (FM) based on Lambertian surface assumption is employed to simulate top of the atmosphere (TOA) spectral reflectance, which does not fully consider the surface bi-directional reflectance functions (BRDF) effect. The approximating forward model largely simplifies the radiative transfer model, reduces the size of the look-up tables, and creates faster algorithm. At the same time, it creates systematic biases in the aerosol optical depth (AOD) retrieval. AOD product from the Moderate Resolution Imaging Spectro-radiometer (MODIS) data based on the dark target algorithm is considered as one of accurate satellite aerosol products at present. Though it performs well at a global scale, uncertainties are still found on regional in a lot of studies. The Lambertian surface assumpiton employed in the retrieving algorithm may be one of the uncertain factors. In this study, we first use radiative transfer simulations over dark target to assess the uncertainty to what extent is introduced from the Lambertian surface assumption. The result shows that the uncertainties of AOD retrieval could reach up to ±0.3. Then the Lambertian FM (L_FM) and the BRDF FM (BRDF_FM) are respectively employed in AOD retrieval using dark target algorithm from MODARNSS (MODIS/Terra and MODIS/Aqua Atmosphere Aeronet Subsetting Product) data over Beijing AERONET site. The validation shows that accuracy in AOD retrieval has been improved by employing the BRDF_FM accounting for the surface BRDF effect, the regression slope of scatter plots with retrieved AOD against AEROENET AOD increases from 0.7163 (for L_FM) to 0.7776 (for BRDF_FM) and the intercept decreases from 0.0778 (for L_FM) to 0.0627 (for BRDF_FM).

ACE-Asia Aerosol Optical Depth and Water Vapor Measured by Airborne Sunphotometers and Related to Other Measurements and Calculations

NASA Technical Reports Server (NTRS)

Livingston, John M.; Russell, P. B.; Schmid, B.; Redemann, J.; Eilers, J. A.; Ramirez, S. A.; Kahn, R.; Hegg, D.; Pilewskie, P.; Anderson, T.;

MISR Observations of Etna Volcanic Plumes

NASA Technical Reports Server (NTRS)

Scollo, S.; Kahn, R. A.; Nelson, D. L.; Coltelli, M.; Diner, D. J.; Garay, M. J.; Realmuto, V. J.

2012-01-01

In the last twelve years, Mt. Etna, located in eastern Sicily, has produced a great number of explosive eruptions. Volcanic plumes have risen to several km above sea level and created problems for aviation and the communities living near the volcano. A reduction of hazards may be accomplished using remote sensing techniques to evaluate important features of volcanic plumes. Since 2000, the Multiangle Imaging SpectroRadiometer (MISR) on board NASA s Terra spacecraft has been extensively used to study aerosol dispersal and to extract the three-dimensional structure of plumes coming from anthropogenic or natural sources, including volcanoes. In the present work, MISR data from several explosive events occurring at Etna are analyzed using a program named MINX (MISR INteractive eXplorer). MINX uses stereo matching techniques to evaluate the height of the volcanic aerosol with a precision of a few hundred meters, and extracts aerosol properties from the MISR Standard products. We analyzed twenty volcanic plumes produced during the 2000, 2001, 2002-03, 2006 and 2008 Etna eruptions, finding that volcanic aerosol dispersal and column height obtained by this analysis is in good agreement with ground-based observations. MISR aerosol type retrievals: (1) clearly distinguish volcanic plumes that are sulphate and/or water vapor dominated from ash-dominated ones; (2) detect even low concentrations of volcanic ash in the atmosphere; (3) demonstrate that sulphate and/or water vapor dominated plumes consist of smaller-sized particles compared to ash plumes. This work highlights the potential of MISR to detect important volcanic plume characteristics that can be used to constrain the eruption source parameters in volcanic ash dispersion models. Further, the possibility of discriminating sulphate and/or water vapor dominated plumes from ash-dominated ones is important to better understand the atmospheric impact of these plumes.

Effects of Large-Scale Solar Installations on Dust Mobilization and Air Quality

NASA Astrophysics Data System (ADS)

Pratt, J. T.; Singh, D.; Diffenbaugh, N. S.

2012-12-01

Large-scale solar projects are increasingly being developed worldwide and many of these installations are located in arid, desert regions. To examine the effects of these projects on regional dust mobilization and air quality, we analyze aerosol product data from NASA's Multi-angle Imaging Spectroradiometer (MISR) at annual and seasonal time intervals near fifteen photovoltaic and solar thermal stations ranging from 5-200 MW (12-4,942 acres) in size. The stations are distributed over eight different countries and were chosen based on size, location and installation date; most of the installations are large-scale, took place in desert climates and were installed between 2006 and 2010. We also consider air quality measurements of particulate matter between 2.5 and 10 micrometers (PM10) from the Environmental Protection Agency (EPA) monitoring sites near and downwind from the project installations in the U.S. We use monthly wind data from the NOAA's National Center for Atmospheric Prediction (NCEP) Global Reanalysis to select the stations downwind from the installations, and then perform statistical analysis on the data to identify any significant changes in these quantities. We find that fourteen of the fifteen regions have lower aerosol product after the start of the installations as well as all six PM10 monitoring stations showing lower particulate matter measurements after construction commenced. Results fail to show any statistically significant differences in aerosol optical index or PM10 measurements before and after the large-scale solar installations. However, many of the large installations are very recent, and there is insufficient data to fully understand the long-term effects on air quality. More data and higher resolution analysis is necessary to better understand the relationship between large-scale solar, dust and air quality.

Identification of dust source regions and dust emission trends across North Africa and the Middle East using MISR satellite observations

NASA Astrophysics Data System (ADS)

Yu, Y.; Kalashnikova, O. V.; Garay, M. J.; Notaro, M.

2017-12-01

Global arid and semi-arid regions supply 1100 to 5000 Tg of Aeolian dust to the atmosphere each year, primarily from North Africa and secondarily from the Middle East. Previous dust source identification methods, based on either remotely-sensed aerosol optical depth (AOD) or dust activity, yield distinct dust source maps, largely due to the limitations in each method and remote-sensing product. Here we apply a novel motion-based method for dust source identification. Dust plume thickness and motion vectors from Multi-angle Imaging SpectroRadiometer (MISR) Cloud Motion Vector Product (CMVP) are examined to identify the regions with high frequency of fast moving-dust plumes, by season. According to MISR CMVP, Bodele depression is the most important dust source across North Africa, consistent with previous studies. Seasonal variability of dust emission across the North Africa is largely driven by climatology of wind and precipitation, featuring the influence of Sharav Cyclone and western African monsoon. In the Middle East, Iraq, Kuwait, and eastern Saudi Arabia are identified as dust source regions, especially during summer months, when the Middle Eastern Shamal wind is active. Furthermore, dust emission trend at each dust source are diagnosed from the motion-based dust source dataset. Increase in dust emission from the Fertile Crescent, Sahel, and eastern African dust sources are identified from MISR CMVP, implying potential contribution from these dust sources to the upward trend in AOD and dust AOD over the Middle East in the 21st century. By comparing with various dust source identification studies, we conclude that the motion-based identification of dust sources is an encouraging alternative and compliment to the AOD-only source identification method.

Meridional Distribution of Aerosol Optical Thickness over the Tropical Atlantic Ocean

NASA Technical Reports Server (NTRS)

Kishcha, P.; Silva, Arlindo M.; Starobinets, B.; Long, C. N.; Kalashnikova, O.; Alpert, P.

2015-01-01

Previous studies showed that, over the global ocean, there is hemispheric asymmetry in aerosols and no noticeable asymmetry in cloud fraction (CF). In the current study, we focus on the tropical Atlantic (30 Deg N 30 Deg S) which is characterized by significant amounts of Saharan dust dominating other aerosol species over the North Atlantic. We found that, by contrast to the global ocean, over a limited area such as the tropical Atlantic, strong meridional asymmetry in dust aerosols was accompanied by meridional CF asymmetry. During the 10-year study period (July 2002 June 2012), NASA Aerosol Reanalysis (aka MERRAero) showed that, when the meridional asymmetry in dust aerosol optical thickness (AOT) was the most pronounced (particularly in July), dust AOT averaged separately over the tropical North Atlantic was one order of magnitude higher than dust AOT averaged over the tropical South Atlantic. In the presence of such strong meridional asymmetry in dust AOT in July, CF averaged separately over the tropical North Atlantic exceeded CF averaged over the tropical South Atlantic by 20%. Our study showed significant cloud cover, up to 0.8 - 0.9, in July along the Saharan Air Layer which contributed to above-mentioned meridional CF asymmetry. Both Multi-Angle Imaging SpectroRadiometer (MISR) measurements and MERRAero data were in agreement on seasonal variations in meridional aerosol asymmetry. Meridional asymmetry in total AOT over the Atlantic was the most pronounced between March and July, when dust presence over the North Atlantic was maximal. In September and October, there was no noticeable meridional asymmetry in total AOT and meridional CF distribution over the tropical Atlantic was almost symmetrical.

Assessment and application of AirMSPI high-resolution multiangle imaging photo-polarimetric observations for atmospheric correction

NASA Astrophysics Data System (ADS)

Kalashnikova, O. V.; Xu, F.; Garay, M. J.; Seidel, F. C.; Diner, D. J.

2016-02-01

Water-leaving radiance comprises less than 10% of the signal measured from space, making correction for absorption and scattering by the intervening atmosphere imperative. Modern improvements have been developed in ocean color retrieval algorithms to handle absorbing aerosols such as urban particulates in coastal areas and transported desert dust over the open ocean. In addition, imperfect knowledge of the absorbing aerosol optical properties or their height distribution results in well-documented sources of error in the retrieved water leaving radiance. Multi-angle spectro-polarimetric measurements have been advocated as an additional tool to better understand and retrieve the aerosol properties needed for atmospheric correction for ocean color retrievals. The Airborne Multiangle SpectroPolarimetric Imager-1 (AirMSPI-1) has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. AirMSPI typically acquires observations of a target area at 9 view angles between ±67° at 10 m resolution. AirMSPI spectral channels are centered at 355, 380, 445, 470, 555, 660, and 865 nm, with 470, 660, and 865 reporting linear polarization. We have developed a retrieval code that employs a coupled Markov Chain (MC) and adding/doubling radiative transfer method for joint retrieval of aerosol properties and water leaving radiance from AirMSPI polarimetric observations. We tested prototype retrievals by comparing the retrieved aerosol concentration, size distribution, water-leaving radiance, and chlorophyll concentrations to values reported by the USC SeaPRISM AERONET-OC site off the coast of California. The retrieval then was applied to a variety of costal regions in California to evaluate variability in the water-leaving radiance under different atmospheric conditions. We will present results, and will discuss algorithm sensitivity and potential applications for future space-borne coastal monitoring.

Direct multiangle solution for poorly stratified atmospheres

Treesearch

Vladimir Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

2012-01-01

The direct multiangle solution is considered, which allows improving the scanning lidar-data-inversion accuracy when the requirement of the horizontally stratified atmosphere is poorly met. The signal measured at zenith or close to zenith is used as a core source for extracting optical characteristics of the atmospheric aerosol loading. The multiangle signals are used...

Announcement of the Public Release of Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) Level 1B2 V006

Atmospheric Science Data Center

2018-05-21

... Radar Definition Experiment (RADEX) SPEX engineering flights + Porter Ranch gas leak overflights (SPEX-PR) ... The SPEX engineering flights + Porter Ranch gas leak overflights (SPEX-PR) flight ... Armstrong Flight Research Center in Palmdale, CA. The SPEX engineering flights conducted on February 2 through February 5, 2016 focused on ...

Using Multi-Angle WorldView-2 Imagery to Determine Ocean Depth Near Oahu, Hawaii

DTIC Science & Technology

2012-09-01

Reflection geometry used in the definition of BRDF (From McConnon [2010...Visible/InfraRed Imaging Spectrometer BRDF : Bidirectional Reflectance Distribution Function DHMs: Digital Height Maps DNs: Digital Numbers EM...navigation and fisheries management, and are also helpful for improving models of ocean circulation, air-sea interaction, weather forecasting, and

Red Sea

Atmospheric Science Data Center

2013-04-16

article title:  The Red Sea     View Larger Image ... Imaging SpectroRadiometer (MISR) image of the Red Sea was acquired on August 13, 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of algae,  Trichodesmium ...

Hurricane Isabel

Atmospheric Science Data Center

2013-04-19

article title:  Aspects of Hurricane Isabel     View Larger Image Cloud-top radiance and height characteristics of Hurricane Isabel are depicted in these data products and animations from the ... Imaging SpectroRadiometer (MISR). Isabel was upgraded to hurricane status a few hours after the top image panels in this set were ...

Solid laboratory calibration of a nonimaging spectroradiometer.

PubMed

Schaepman, M E; Dangel, S

2000-07-20

Field-based nonimaging spectroradiometers are often used in vicarious calibration experiments for airborne or spaceborne imaging spectrometers. The calibration uncertainties associated with these ground measurements contribute substantially to the overall modeling error in radiance- or reflectance-based vicarious calibration experiments. Because of limitations in the radiometric stability of compact field spectroradiometers, vicarious calibration experiments are based primarily on reflectance measurements rather than on radiance measurements. To characterize the overall uncertainty of radiance-based approaches and assess the sources of uncertainty, we carried out a full laboratory calibration. This laboratory calibration of a nonimaging spectroradiometer is based on a measurement plan targeted at achieving a

Ash from Kilauea Eruption Viewed by NASA's MISR

NASA Image and Video Library

2018-05-09

On May 3, 2018, a new eruption began at a fissure of the Kilauea volcano on the Island of Hawaii. Kilauea is the most active volcano in the world, having erupted almost continuously since 1983. Advancing lava and dangerous sulfur dioxide gas have forced thousands of residents in the neighborhood of Leilani Estates to evacuate. A number of homes have been destroyed, and no one can say how soon the eruption will abate and evacuees can return home. On May 6, 2018, at approximately 11 a.m. local time, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite captured this view of the island as it passed overhead. Much of the island was shrouded by clouds, including the fissure on its eastern point. However, an eruption plume is visible streaming southwest over the ocean. The MISR instrument is unique in that it has nine cameras that view Earth at different angles: one pointing downward, four at various angles in the forward direction, and four in the backward direction. This image shows the view from one of MISR's forward-pointing cameras (60 degrees), which shows the plume more distinctly than the near-vertical views. The information from the images acquired at different view angles is used to calculate the height of the plume, results of which are superimposed on the right-hand image. The top of the plume near the fissure is at approximately 6,500 feet (2,000 meters) altitude, and the height of the plume decreases as it travels south and west. These relatively low altitudes mean that the ash and sulfur dioxide remained near the ground, which can cause health issues for people on the island downwind of the eruption. The "Ocean View" air quality monitor operated by the Clean Air Branch of the State of Hawaii Department of Health recorded a concentration of 18 μg/m3 of airborne particles less than 2.5 micrometers in diameter at 11 a.m. local time. This amount corresponds to an air quality rating of "moderate" and supports the MISR results indicating that ash was most likely present at ground level on this side of the island. These data were acquired during Terra orbit 97780. An annotated version is available at https://photojournal.jpl.nasa.gov/catalog/PIA22451

Deadly Fires Engulfing Madeira seen by NASA MISR

NASA Image and Video Library

2016-08-12

A wildfire spread to the capital city of Funchal on the island of Madeira, an autonomous region of Portugal, over the nighttime hours of Tuesday, Aug. 9, 2016, with three deaths reported and hundreds of others hospitalized. Several homes and a luxury hotel have burned, and a thousand people have been evacuated. The three fatalities are reported to be elderly people who were unable to escape when their homes caught fire. The fire ignited Monday, Aug. 8, after several weeks of scorching temperatures topping 95 degrees Fahrenheit and very dry weather. The entire island is only 30 miles (48 kilometers) from end to end, which naturally makes protecting the island's 270,000 residents and many tourists more difficult. The MISR (Multi-angle Imaging SpectroRadiometer) instrument aboard NASA's Terra satellite passed directly over the island of Madeira on Wednesday, Aug. 10, 2016. The left image is a true-color image taken by MISR's 60-degree forward-pointing camera. This oblique view gives a better view of the smoke than a downward-pointing view. The island of Madeira is the only land within the field of view, and the smoke from the wildfire is being blown to the southwest. The city of Funchal is located on the southeastern coast of the island. MISR's nine cameras, each viewing Earth at a different angle, can be used to determine the height of clouds and smoke above the surface in much the same way that our two eyes, pointing in slightly different directions, give us depth perception. The right-hand image shows MISR's publically available standard cloud top height product. These data show that the main body of clouds is indeed very low, less than 0.6 miles (1 kilometer) above sea level, while the smoke plume is about 1.9 miles (3 kilometers) high at the source, dropping lower as it is blown to the southwest. A stereo "anaglyph" of this scene is also available at PIA20886. As can be seen from both the MISR height product and the 3D anaglyph, the isolated clouds to the south are much higher than either the low clouds or the plume. Interestingly, the low clouds drop to almost sea level and then die out near where the smoke is present. These data were acquired during Terra orbit 88524. http://photojournal.jpl.nasa.gov/catalog/PIA20887

Classification and Accuracy Assessment for Coarse Resolution Mapping within the Great Lakes Basin, USA

EPA Science Inventory

This study applied a phenology-based land-cover classification approach across the Laurentian Great Lakes Basin (GLB) using time-series data consisting of 23 Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) composite images (250 ...

Hyperspectral imaging spectro radiometer improves radiometric accuracy

NASA Astrophysics Data System (ADS)

Prel, Florent; Moreau, Louis; Bouchard, Robert; Bullis, Ritchie D.; Roy, Claude; Vallières, Christian; Levesque, Luc

2013-06-01

Reliable and accurate infrared characterization is necessary to measure the specific spectral signatures of aircrafts and associated infrared counter-measures protections (i.e. flares). Infrared characterization is essential to improve counter measures efficiency, improve friend-foe identification and reduce the risk of friendly fire. Typical infrared characterization measurement setups include a variety of panchromatic cameras and spectroradiometers. Each instrument brings essential information; cameras measure the spatial distribution of targets and spectroradiometers provide the spectral distribution of the emitted energy. However, the combination of separate instruments brings out possible radiometric errors and uncertainties that can be reduced with Hyperspectral imagers. These instruments combine both spectral and spatial information into the same data. These instruments measure both the spectral and spatial distribution of the energy at the same time ensuring the temporal and spatial cohesion of collected information. This paper presents a quantitative analysis of the main contributors of radiometric uncertainties and shows how a hyperspectral imager can reduce these uncertainties.

Techniques for the Retrieval of Aerosol Properties Over Land and Ocean Using Multi-angle Imaging

NASA Technical Reports Server (NTRS)

Martonchik, John V.; Diner, David J.; Kahn, Ralph; Ackerman, Thomas P.; Verstraete, Michel M.; Pinty, Bernard; Gordon, Howard R.

1997-01-01

Aerosols are believed to play a direct role in the radiation budget of Earth but their net radiative effect is not well established, particularly on regional scales. Whether aerosols heat or cool a given location depends on their composition and column amount and also on the surface albedo, information that is not routinely available, especially over land.

A Cut in the Clouds

NASA Image and Video Library

2017-12-08

Like a ship carving its way through the sea, the South Georgia and South Sandwich Islands parted the clouds. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image on February 2, 2017. The ripples in the clouds are known as gravity waves. NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response #nasagoddard

Cyclone Hudah As Seen By MODIS

NASA Technical Reports Server (NTRS)

2002-01-01

Tropical Cyclone Hudah was one of most powerful storms ever seen in the Indian Ocean. This image from the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard Terra was taken on March 29, 2000. The structure of the eye of the storm is brought out by MODIS' 250-meter resolution. Image by Liam Gumley, Space Science and Engineering Center, University of Wisconsin-Madison

Rotational imaging optical coherence tomography for full-body mouse embryonic imaging

PubMed Central

Wu, Chen; Sudheendran, Narendran; Singh, Manmohan; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2016-01-01

Abstract. Optical coherence tomography (OCT) has been widely used to study mammalian embryonic development with the advantages of high spatial and temporal resolutions and without the need for any contrast enhancement probes. However, the limited imaging depth of traditional OCT might prohibit visualization of the full embryonic body. To overcome this limitation, we have developed a new methodology to enhance the imaging range of OCT in embryonic day (E) 9.5 and 10.5 mouse embryos using rotational imaging. Rotational imaging OCT (RI-OCT) enables full-body imaging of mouse embryos by performing multiangle imaging. A series of postprocessing procedures was performed on each cross-section image, resulting in the final composited image. The results demonstrate that RI-OCT is able to improve the visualization of internal mouse embryo structures as compared to conventional OCT. PMID:26848543

Cloud vortices

NASA Image and Video Library

2015-11-02

Cloud vortices off Heard Island, south Indian Ocean. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of sea ice off Heard Island on Nov 2, 2015 at 5:02 AM EST (09:20 UTC). Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

Gulf Coast Wetlands

Atmospheric Science Data Center

2014-05-15

article title:  Wetlands of the Gulf Coast     View Larger Image ... SpectroRadiometer (MISR) highlights coastal areas of four states along the Gulf of Mexico: Louisiana, Mississippi, Alabama and part of ...

An Unusual View: MISR sees the Moon

NASA Image and Video Library

2017-08-17

The job of the Multiangle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite is to view Earth. For more than 17 years, its nine cameras have stared downward 24 hours a day, faithfully collecting images used to study Earth's surface and atmosphere. On August 5, however, MISR captured some very unusual data as the Terra satellite performed a backflip in space. This maneuver was performed to allow MISR and the other instruments on Terra to catch a glimpse of the Moon, something that has been done only once before, in 2003. Why task an elderly satellite with such a radical maneuver? Since we can be confident that the Moon's brightness has remained very constant over the mission, MISR's images of the Moon can be used as a check of the instrument's calibration, allowing an independent verification of the procedures used to correct the images for any changes the cameras have experienced over their many years in space. If changes in the cameras' responses to light aren't properly accounted for, the images captured by MISR would make it appear as if Earth were growing darker or lighter, which would throw off scientists' efforts to characterize air pollution, cloud cover and Earth's climate. Because of this, the MISR team uses several methods to calibrate the data, all of which involve imaging something with a known (or independently measured) brightness and correcting the images to match that brightness. Every month, MISR views two panels of a special material called Spectralon, which reflects sunlight in a very particular way, onboard the instrument. Periodically, this calibration is checked by a field team who measures the brightness of a flat, uniformly colored surface on Earth, usually a dry desert lakebed, as MISR flies overhead. The lunar maneuver offers a third opportunity to check the brightness calibration of MISR's images. While viewing Earth, MISR's cameras are fixed at nine different angles, with one (called An) pointed straight down, four canted forwards (Af, Bf, Cf, and Df) and four angled backwards (Aa, Ba, Ca, and Da). The A, B, C, and D cameras have different focal lengths, with the most oblique (D) cameras having the longest focal lengths in order to preserve spatial resolution on the ground. During the lunar maneuver, however, the spacecraft rotated so that each camera saw the almost-full Moon straight on. This means that the different focal lengths produce images with different resolutions. The D cameras produce the sharpest images. These grayscale images were made with raw data from the red spectral band of each camera. Because the spacecraft is constantly rotating while these images were taken, the images are "smeared" in the vertical direction, producing an oval-shaped Moon. These have been corrected to restore the Moon to its true circular shape. https://photojournal.jpl.nasa.gov/catalog/PIA21876

Smoke from Colorado Wildfires

NASA Technical Reports Server (NTRS)

2002-01-01

The Hayman fire, situated about 65 kilometers southwest of Denver, Colorado, is the largest fire ever recorded in that state. The amount and distribution of smoke from the Hayman fire and from the Ponil Complex fires south of the New Mexico-Colorado border are portrayed in these views from the Multi-angle Imaging SpectroRadiometer (MISR). The images were captured on June 9, 2002, on the second day of the Hayman fire, when only about 13 percent of the total 137,000 acres eventually consumed had been scorched.

The image at top-left was acquired by MISR's most oblique (70-degree) forward-viewing camera, and the view at bottom-left was captured by MISR's 26-degree forward-viewing camera. Both left-hand panels are 'false color' views, utilizing near-infrared, red, and blue spectral bands displayed as red, green and blue respectively. With this spectral combination, highly vegetated areas appear red. At top right is a map of aerosol optical depth. This map utilizes the capability of the oblique view angles to measure the abundance of particles in the atmosphere. Haze distributed across the eastern part of the state is indicated by a large number of green pixels, and areas where no retrieval occurred are shown in dark grey. The more oblique perspective utilized within the top panels enhances the appearance of smoke and reveals the haze. In the lower left-hand panel the view is closer to nadir (downward-looking). Here the smoke plumes appear more compact and the haze across eastern Colorado is not detected. The lower right-hand panel is a stereoscopically derived height field that echoes the compact shape of the smoke plumes in the near-nadir image. Results indicate that the smoke plumes reached altitudes of a few kilometers above the surface terrain, or about the same height as the small clouds that appear orange along the bottom edge to the left of center.

Data used in these visualizations were generated as part of operational processing at the Atmospheric Sciences Data Center at NASA Langley Research Center. The images were acquired during Terra orbit 13170 and cover an area of about 400 kilometers x 565 kilometers. They utilize data from blocks 58 to 61 within World Reference System-2 path 32.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Operational data fusion framework for building frequent Landsat-like imagery in a cloudy region

USDA-ARS?s Scientific Manuscript database

An operational data fusion framework is built to generate dense time-series Landsat-like images for a cloudy region by fusing Moderate Resolution Imaging Spectroradiometer (MODIS) data products and Landsat imagery. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) is integrated in ...

A new instrument for high resolution stereoscopic photography of falling hydrometeors with simultaneous measurement of fallspeed

NASA Astrophysics Data System (ADS)

Yuter, S. E.; Garrett, T. J.; Fallgatter, C.; Shkurko, K.; Howlett, D.; Dean, J.; Hardin, N.

2012-12-01

We introduce a new instrument, the Fallgatter Technologies Multi-Angle Snowflake Camera (MASC), that provides <30 micron resolution stereoscopic photographic images of individual large falling hydrometeors with accurate measurements of their fallspeed. Previously, identification of hydrometeor form has required initial collection on a flat surface, a process that is somewhat subjective and remarkably finicky due to the fragile nature of the particles. Other hydrometeor instruments such as the 2DVD, are automated and leave the particle untouched and provide fallspeed data. However, they provide only 200 micron resolution silhouettes, which can be insufficient for habit and riming identification and the requirements of microwave scattering calculations. The MASC is like the 2DVD but uses a sensitive IR motion sensor for a trigger and actually photographs the particle surface from multiple angles. Field measurements from Alta Ski Area near Salt Lake City are providing beautiful images and fallspeed data, suggesting that MASC measurements may help development of improved parameterizations for hydrometeor microwave scattering. Hundreds of thousands of images have been collected enabling comparisons of hydrometeor development, morphology and fallspeed with a co-located vertically pointing 24 GHz MicroRainRadar radar. Here we show multi-angle images from the MASC, size fallspeed relationships, and discrete dipole approximation scattering calculations for a range of hydrometeor forms at the frequencies of 24 GHz, 94 GHz and 183 GHz. The scattering calculations indicate that complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than graupel particles of similar size.

Airborne Polarimeter Intercomparison for the NASA Aerosols-Clouds-Ecosystems (ACE) Mission

NASA Technical Reports Server (NTRS)

Knobelspiesse, Kirk; Redemann, Jens

2014-01-01

The Aerosols-Clouds-Ecosystems (ACE) mission, recommended by the National Research Council's Decadal Survey, calls for a multi-angle, multi-spectral polarimeter devoted to observations of atmospheric aerosols and clouds. In preparation for ACE, NASA funds the deployment of airborne polarimeters, including the Airborne Multi-angle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). These instruments have been operated together on NASA's ER-2 high altitude aircraft as part of field campaigns such as the POlarimeter DEfinition EXperiment (PODEX) (California, early 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, California and Texas, summer 2013). Our role in these efforts has been to serve as an assessment team performing level 1 (calibrated radiance, polarization) and level 2 (retrieved geophysical parameter) instrument intercomparisons, and to promote unified and generalized calibration, uncertainty assessment and retrieval techniques. We will present our progress in this endeavor thus far and describe upcoming research in 2015.

Progress in Airborne Polarimeter Inter Comparison for the NASA Aerosols-Clouds-Ecosystems (ACE) Mission

NASA Technical Reports Server (NTRS)

Knobelspiesse, Kirk; Redemann, Jens

2014-01-01

The Aerosols-Clouds-Ecosystems (ACE) mission, recommended by the National Research Council's Decadal Survey, calls for a multi-angle, multi-spectral polarimeter devoted to observations of atmospheric aerosols and clouds. In preparation for ACE, NASA funds the deployment of airborne polarimeters, including the Airborne Multiangle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). These instruments have been operated together on NASA's ER-2 high altitude aircraft as part of field campaigns such as the POlarimeter DEfinition EXperiment (PODEX) (California, early 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, California and Texas, summer 2013). Our role in these efforts has been to serve as an assessment team performing level 1 (calibrated radiance, polarization) and level 2 (retrieved geophysical parameter) instrument intercomparisons, and to promote unified and generalized calibration, uncertainty assessment and retrieval techniques. We will present our progress in this endeavor thus far and describe upcoming research in 2015.

Red Tide Strands South African Rock Lobsters

NASA Technical Reports Server (NTRS)

2002-01-01

Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide.

The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine.

The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Mapping Snow Grain Size over Greenland from MODIS

NASA Technical Reports Server (NTRS)

Lyapustin, Alexei; Tedesco, Marco; Wang, Yujie; Kokhanovsky, Alexander

2008-01-01

This paper presents a new automatic algorithm to derive optical snow grain size (SGS) at 1 km resolution using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. Differently from previous approaches, snow grains are not assumed to be spherical but a fractal approach is used to account for their irregular shape. The retrieval is conceptually based on an analytical asymptotic radiative transfer model which predicts spectral bidirectional snow reflectance as a function of the grain size and ice absorption. The analytical form of solution leads to an explicit and fast retrieval algorithm. The time series analysis of derived SGS shows a good sensitivity to snow metamorphism, including melting and snow precipitation events. Preprocessing is performed by a Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm, which includes gridding MODIS data to 1 km resolution, water vapor retrieval, cloud masking and an atmospheric correction. MAIAC cloud mask (CM) is a new algorithm based on a time series of gridded MODIS measurements and an image-based rather than pixel-based processing. Extensive processing of MODIS TERRA data over Greenland shows a robust performance of CM algorithm in discrimination of clouds over bright snow and ice. As part of the validation analysis, SGS derived from MODIS over selected sites in 2004 was compared to the microwave brightness temperature measurements of SSM\\I radiometer, which is sensitive to the amount of liquid water in the snowpack. The comparison showed a good qualitative agreement, with both datasets detecting two main periods of snowmelt. Additionally, MODIS SGS was compared with predictions of the snow model CROCUS driven by measurements of the automatic whether stations of the Greenland Climate Network. We found that CROCUS grain size is on average a factor of two larger than MODIS-derived SGS. Overall, the agreement between CROCUS and MODIS results was satisfactory, in particular before and during the first melting period in mid-June. Following detailed time series analysis of SGS for four permanent sites, the paper presents SGS maps over the Greenland ice sheet for the March-September period of 2004.

Smoke over Sumatra, Indonesia

NASA Technical Reports Server (NTRS)

2002-01-01

At least once a year for a period lasting from a week to several months, northern Sumatra is obscured by smoke and haze produced by agricultural burning and forest fires. These data products from the Multi-angle Imaging SpectroRadiometer document the presence of airborne particulates on March 13, 2002, during Terra orbit 11880. On the left is an image acquired by MISR's 70-degree backward-viewing camera. On the right is a map of aerosol optical depth, a measure of the abundance of atmospheric particulates. This product utilized a test version of the MISR retrieval that incorporates an experimental set of aerosol mixtures. The haze has completely obscured northeastern Sumatra and part of the Strait of Malacca, which separates Sumatra and the Malaysian Peninsula. A northward gradient is apparent as the haze dissipates in the direction of the Malaysian landmass. Each panel covers an area of about 760 kilometers x 400 kilometers.

Haze conditions had posed a health concern during late February (when schools in some parts of North Sumatra were closed), and worsened considerably in the first two weeks of March. By mid-March, local meteorology officials asked residents of North Sumatra's provincial capital, Medan, to minimize their outdoor activities and wear protective masks. Poor visibility at Medan airport forced a passenger plane to divert to Malaysia on March 14, and visibility reportedly ranged between 100 and 600 meters in some coastal towns southeast of Medan.

The number and severity of this year's fires was exacerbated by dry weather conditions associated with the onset of a weak to moderate El Nino. The governments of Indonesia, Malaysia, and Brunei have agreed to ban open burning in plantation and forest areas. The enforcement of such fire bans, however, has proven to be an extremely challenging task.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

iCATSI: multi-pixel imaging differential spectroradiometer for standoff detection and quantification of chemical threats

NASA Astrophysics Data System (ADS)

Prel, Florent; Moreau, Louis; Lavoie, Hugo; Bouffard, François; Thériault, Jean-Marc; Vallieres, Christian; Roy, Claude; Dubé, Denis

2011-11-01

Homeland security and first responders are often faced with safety situations involving the identification of unknown volatile chemicals. Examples include industrial fires, chemical warfare, industrial leak, etc. The Improved Compact ATmospheric Sounding Interferometer (iCATSI) sensor has been developed to investigate the standoff detection and identification of toxic industrial chemicals (TICs), chemical warfare agents (CWA) and other chemicals. iCATSI is a combination of the CATSI instrument, a standoff differential FTIR optimised for the characterization of chemicals and the MR-i, the hyperspectral imaging spectroradiometer of ABB Bomem based on the proven MR spectroradiometers. The instrument is equipped with a dual-input telescope to perform optical background subtraction. The resulting signal is the difference between the spectral radiance entering each input port. With that method, the signal from the background is automatically removed from the signal of the target of interest. The iCATSI sensor is able to detect, spectrally resolve and identify 5 meters plumes up to 5 km range. The instrument is capable of sensing in the VLWIR (cut-off near 14 μm) to support research related to standoff chemical detection. In one of its configurations, iCATSI produces three 24 × 16 spectral images per second from 5.5 to 14 μm at a spectral resolution of 16 cm-1. In another configuration, iCATSI produces from two to four spectral images per second of 256 × 256 pixels from 8 to 13 μm with the same spectral resolution. Overview of the capabilities of the instrument and results from tests and field trials will be presented.

VSF Measurements and Inversion for RaDyO

DTIC Science & Technology

2012-09-30

near-surface waters, including the surf zone. APPROACH MASCOT (Multi-Angle SCattering Optical Tool) has a 30 mW 658 nm laser diode source...in Santa Barbara Channel are provided in Fig. 1. Despite the widespread use of polarized laser sources across a diversity of Navy applications, this...operations that rely on divers, cameras, laser imaging systems, and active and passive remote sensing systems. These include mine countermeasures, harbor

Using ALS and MODIS data to evaluate degradation in different forests types over the Xingu basin - Brazilian Amazon

NASA Astrophysics Data System (ADS)

Moura, Y.; Aragão, L. E.; Galvão, L. S.; Dalagnol, R.; Lyapustin, A.; Santos, E. G.; Espirito-Santo, F.

2017-12-01

Degradation of Amazon rainforests represents a vital threat to carbon storage, climate regulation and biodiversity; however its effect on tropical ecosystems is largely unknown. In this study we evaluate the effects of forest degradation on forest structure and functioning over the Xingu Basin in the Brazilian Amazon. The vegetation types in the area is dominated by Open Ombrophilous Forest (Asc), Semi-decidiuous Forest (Fse) and Dense Ombrophilous Forest (Dse). We used Airborne Laser Scanning (ALS) data together with time series of optical remote sensing images from the Moderate Resolution Imaging Spectroradiometer (MODIS) bi-directional corrected using the Multi-Angle Implementation for Atmospheric Correction (MAIAC). We derive time-series (2008 to 2016) of the Enhanced Vegetation Index (EVI) and Green-Red Normalized Difference (GRND) to analyze the dynamics of degraded areas with related changes in canopy structure and greenness values, respectively. Airborne ALS measurements showed the largest tree heights in the Dse class with values up to 40m tall. Asc and Fse vegetation types reached up to 30m and 25m in height, respectively. Differences in canopy structure were also evident from the analysis of canopy volume models (CVMs). Asc showed higher proportion of sunlit, as expected for open forest types. Fse showed gaps predominantly in lower height levels, and a higher overall proportion of shaded crown. Full canopy closure was reached at about15 m height for both Asc and Dse, and at about 20 m height for Fse. We also used a base map of degraded areas (available from Imazon - Instituto do Homen e Meio Ambiente da Amazônia) to follow these regions throughout time using EVI and GRND from MODIS. All three forest types displayed seasonal cycles. Notable differences in amplitude were detected during the periods when degradation occurred and both indexes showed a decrease in their response. However, there were marked differences in timing and amplitude depending on forest type. These responses were influenced by the spatial resolution of 1km of the MODIS images, limited the ability to observe small degraded regions. In conclusion, ASL together with optical remote sensing used in a straight multi-scale approach may contribute to understand the impacts of degradation in the structure and functioning of tropical forest.

White Sea - Russia

NASA Technical Reports Server (NTRS)

2002-01-01

At bottom center of this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 13, 2001, the White Sea in western Russia is becoming free of ice in its southern extent. Meanwhile, the blue-green waters along the coast of the peninsula jutting out into the Barents Sea to the northeast could be due to a phytoplankton bloom.

Standoff chemical D and Id with extended LWIR hyperspectral imaging spectroradiometer

NASA Astrophysics Data System (ADS)

Prel, Florent; Moreau, Louis; Lavoie, Hugo; Bouffard, François; Thériault, Jean-Marc; Vallieres, Christian; Roy, Claude; Dubé, Denis

2013-05-01

Standoff detection and identification (D and Id) of unknown volatile chemicals such as chemical pollutants and consequences of industrial incidents has been increasingly desired for first responders and for environmental monitoring. On site gas detection sensors are commercially available and several of them can even detect more than one chemical species, however only few of them have the capabilities of detecting a wide variety of gases at long and safe distances. The ABB Hyperspectral Imaging Spectroradiometer (MR-i), configured for gas detection detects and identifies a wide variety of chemical species including toxic industrial chemicals (TICs) and surrogates several kilometers away from the sensor. This configuration is called iCATSI for improved Compact Atmospheric Sounding Interferometer. iCATSI is a standoff passive system. The modularity of the MR-i platform allows optimization of the detection configuration with a 256 x 256 Focal Plane Array imager or a line scanning imager both covering the long wave IR atmospheric window up to 14 μm. The uniqueness of its extended LWIR cut off enables to detect more chemicals as well as provide higher probability of detection than usual LWIR sensors.

Alaska: Beaufort Sea

Atmospheric Science Data Center

2014-05-15

... Imaging SpectroRadiometer (MISR), illustrate different methods that may be used to assess sea ice type. Sea ice in the Beaufort Sea ... March 19, 2001 - Illustration of different methods to assess sea ice type. project:  MISR ...

Space-Based Remote Sensing of Atmospheric Aerosols: The Multi-Angle Spectro-Polarimetric Frontier

NASA Technical Reports Server (NTRS)

Kokhanovsky, A. A.; Davis, A. B.; Cairns, B.; Dubovik, O.; Hasekamp, O. P.; Sano, I.; Mukai, S.; Rozanov, V. V.; Litvinov, P.; Lapyonok, T.;

The High Resolution Stereo Camera (HRSC): 10 Years of Imaging Mars

NASA Astrophysics Data System (ADS)

Jaumann, R.; Neukum, G.; Tirsch, D.; Hoffmann, H.

2014-04-01

The HRSC Experiment: Imagery is the major source for our current understanding of the geologic evolution of Mars in qualitative and quantitative terms.Imaging is required to enhance our knowledge of Mars with respect to geological processes occurring on local, regional and global scales and is an essential prerequisite for detailed surface exploration. The High Resolution Stereo Camera (HRSC) of ESA's Mars Express Mission (MEx) is designed to simultaneously map the morphology, topography, structure and geologic context of the surface of Mars as well as atmospheric phenomena [1]. The HRSC directly addresses two of the main scientific goals of the Mars Express mission: (1) High-resolution three-dimensional photogeologic surface exploration and (2) the investigation of surface-atmosphere interactions over time; and significantly supports: (3) the study of atmospheric phenomena by multi-angle coverage and limb sounding as well as (4) multispectral mapping by providing high-resolution threedimensional color context information. In addition, the stereoscopic imagery will especially characterize landing sites and their geologic context [1]. The HRSC surface resolution and the digital terrain models bridge the gap in scales between highest ground resolution images (e.g., HiRISE) and global coverage observations (e.g., Viking). This is also the case with respect to DTMs (e.g., MOLA and local high-resolution DTMs). HRSC is also used as cartographic basis to correlate between panchromatic and multispectral stereo data. The unique multi-angle imaging technique of the HRSC supports its stereo capability by providing not only a stereo triplet but also a stereo quintuplet, making the photogrammetric processing very robust [1, 3]. The capabilities for three dimensional orbital reconnaissance of the Martian surface are ideally met by HRSC making this camera unique in the international Mars exploration effort.

Brazil The Duck Lagoon

NASA Technical Reports Server (NTRS)

2002-01-01

This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass (Ruppia maritima) which reaches peak production during summer. Sea turtles (Chelonia mydas) can be found in the lagoon during spring and summer. Although the lowland tapir (Tapirus terrestris) is found in some parts of Rio Grande do Sul, the Baird's tapir (Tapirus bairdii), is not distributed within the image area (it is restricted to Central America). MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

Surface Reflectance of Mars Observed by CRISM-MRO: 1. Multi-angle Approach for Retrieval of Surface Reflectance from CRISM Observations (mars-reco)

NASA Technical Reports Server (NTRS)

Ceamanos, Xavier; Doute, S.; Fernando, J.; Pinet, P.; Lyapustin, A.

2013-01-01

This article addresses the correction for aerosol effects in near-simultaneous multiangle observations acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter. In the targeted mode, CRISM senses the surface of Mars using 11 viewing angles, which allow it to provide unique information on the scattering properties of surface materials. In order to retrieve these data, however, appropriate strategies must be used to compensate the signal sensed by CRISM for aerosol contribution. This correction is particularly challenging as the photometric curve of these suspended particles is often correlated with the also anisotropic photometric curve of materials at the surface. This article puts forward an innovative radiative transfer based method named Multi-angle Approach for Retrieval of Surface Reflectance from CRISM Observations (MARS-ReCO). The proposed method retrieves photometric curves of surface materials in reflectance units after removing aerosol contribution. MARS-ReCO represents a substantial improvement regarding previous techniques as it takes into consideration the anisotropy of the surface, thus providing more realistic surface products. Furthermore, MARS-ReCO is fast and provides error bars on the retrieved surface reflectance. The validity and accuracy of MARS-ReCO is explored in a sensitivity analysis based on realistic synthetic data. According to experiments, MARS-ReCO provides accurate results (up to 10 reflectance error) under favorable acquisition conditions. In the companion article, photometric properties of Martian materials are retrieved using MARS-ReCO and validated using in situ measurements acquired during the Mars Exploration Rovers mission.

Implementation of a near real-time burned area detection algorithm calibrated for VIIRS imagery

Treesearch

Brenna Schwert; Carl Albury; Jess Clark; Abigail Schaaf; Shawn Urbanski; Bryce Nordgren

2016-01-01

There is a need to implement methods for rapid burned area detection using a suitable replacement for Moderate Resolution Imaging Spectroradiometer (MODIS) imagery to meet future mapping and monitoring needs (Roy and Boschetti 2009, Tucker and Yager 2011). The Visible Infrared Imaging Radiometer Suite (VIIRS) sensor onboard the Suomi-National Polar-orbiting Partnership...

Tunable Fabry-Perot etalon-based long-wavelength infrared imaging spectroradiometer.

PubMed

Marinelli, W J; Gittins, C M; Gelb, A H; Green, B D

1999-04-20

Imaging spectrometry enables passive, stand-off detection and analysis of the chemical composition of gas plumes and surfaces over wide geographic areas. We describe the use of a long-wavelength infrared imaging spectroradiometer, comprised of a low-order tunable Fabry-Perot etalon coupled to a HgCdTe detector array, to perform multispectral detection of chemical vapor plumes. The tunable Fabry-Perot etalon used in this research provides coverage of the 9.5-14-microm spectral region with a resolution of 7-9 cm(-1). The etalon-based imaging system provides the opportunity to image a scene at only those wavelengths needed for chemical species identification and quantification and thereby minimize the data volume necessary for selective species detection. We present initial results using a brassboard imaging system for stand-off detection and quantification of chemical vapor plumes against near-ambient-temperature backgrounds. These data show detection limits of 22 parts per million by volume times meter (ppmv x m) and 0.6 ppmv x m for dimethyl methyphosphonate and SF6, respectively, for a gas/background DeltaT of 6 K. The system noise-equivalent spectral radiance is approximately 2 microW cm(-2) sr(-1) microm(-1). Model calculations are presented comparing the measured sensitivity of the sensor to the anticipated signal levels for two chemical release scenarios.

Does Management Matter?: Using MISR to Assess the Effects of Charcoal Production and Management on Woodland Regeneration

NASA Astrophysics Data System (ADS)

Wurster, K.

2008-12-01

In much of Sub-Saharan Africa, more than 75 percent of a rapidly growing urban population depends on charcoal as their primary source of energy for cooking. The high demand for charcoal has led many to believe that charcoal harvesting catalyzes widespread deforestation. The Senegalese government and international donors have initiated projects within protected areas to combat deforestation and created land management plans to sustainably harvest charcoal. To date, the effects of forest management techniques on forest sustainability are still in question. This research uses a multiphase approach integrating satellite analysis with field surveys to assess the effect of varying forest management strategies on forest regeneration and sustainability after charcoal harvesting. Phase I involved testing the Multiangle Imaging SpectroRadiometer (MISR) satellites capability in detecting structural changes in vegetative cover caused by charcoal harvesting and production. Analysis of the MISR derived k(red) parameter showed MISR can consistently differentiate between forest cover types and successfully differentiates between sites at pre- and post-charcoal harvest stages. Phase II conducted forestry and social surveys comparing and contrasting local effects of land management, land use, and charcoal production on forest regeneration. Phase III uses the local surveys to validate and train the regional remote sensing data to assess the effectiveness of land management in promoting forest regeneration and sustainability after charcoal harvesting. Combining detailed local knowledge with the regional capabilities of MISR provide valuable insight into the factors that control woodland regeneration and sustainability. Preliminary results from phases II and III indicate that both field and remotely sensed variations in forest cover, tree regeneration, and land use change does not vary when compared against land management type. Final results will provide managers with additional information to create more effective land management strategies that can be implemented across sub- Saharan Africa, ensuring the long-term sustainability of woodland ecosystems and local livelihoods.

Analysis of Accuracy of Modis BRDF Product (MCD43 C6) Based on Misr Land Surface Brf Product - a Case Study of the Central Part of Northeast Asia

NASA Astrophysics Data System (ADS)

Li, J.; Chen, S.; Qin, W.; Murefu, M.; Wang, Y.; Yu, Y.; Zhen, Z.

2018-04-01

EOS/MODIS land surface Bi-directional Reflectance Distribution Function (BRDF) product (MCD43), with the latest version C6, is one of the most important operational BRDF products with global coverage. The core sub-product MCD43A1 stores 3 parameters of the RossThick-LiSparseR semi-empirical kernel-driven BRDF model. It is important for confident use of the product to evaluate the accuracy of bi-directional reflectance factor (BRF) predicted by MCD43A1 BRDF model (mBRF). A typical region in the central part of Northeast Asia is selected as the study area. The performance of MCD43A1 BRDF model is analyzed in various observation geometries and phenological phases, using Multi-angle Imaging SpectroRadiometer (MISR) land-surface reflectance factor product (MILS_BRF) as the reference data. In addition, MODIS products MCD12Q1 and MOD/MYD10A1 are used to evaluate the impacts of land cover types and snow covers on the model accuracy, respectively. The results show an overall excellent performance of MCD43A1 in representing the anisotropic reflectance of land surface, with root mean square error (RMSE) of 0.0262 and correlation coefficient (R) of 0.9537, for all available comparable samples of MILS_BRF and mBRF pairs. The model accuracy varies in different months, which is related to the phenological phases of the study area. The accuracy for pixels labelled as `snow' by MCD43 is obviously low, with RMSE/R of 0.0903/0.8401. Ephemeral snowfall events further decrease the accuracy, with RMSE/R of 0.1001/0.7715. These results provide meaningful information to MCD43 users, especially those, whose study regions are subject to phenological cycles as well as snow cover and change.

The Impact of Biogenic and Anthropogenic Atmospheric Aerosol on Climate in Egypt

NASA Astrophysics Data System (ADS)

Ibrahim, A. I.; Zakey, A.; Steiner, A. L.; Shokr, M. E.; El-Raey, M.; Ahmed, Y.; Al-Hadidi, A.; Zakey, A.

2014-12-01

Aerosols are indicators of air quality as they reduce visibility and adversely affect public health. Aerosol optical depth (AOD) is a measure of the radiation extinction due to interaction of radiation with aerosol particles in the atmosphere. Using this optical measure of atmospheric aerosols we explore the seasonal and annual patterns of aerosols from both anthropogenic and biogenic sources over Egypt. Here, we use an integrated environment-climate-aerosol model in conjunction with inversion technique to identify the aerosol particle size distribution over different locations in Egypt. The online-integrated Environment-Climate-Aerosol model (EnvClimA), which is based on the International Center for Theoretical Physics Regional Climate Model (ICTP-RegCM), is used to study the emission of different aerosols and their impact on climate parameters for a long-term base line simulation run over Egypt and North Africa. The global emission inventory is downscaled and remapping them over Egypt using local factors such as population, traffic and industrial activities to identify the sources of anthropogenic and biogenic emission from local emission over Egypt. The results indicated that the dominant natural aerosols over Egypt are dust emissions that frequently occur during the transitional seasons (Spring and Autumn). From the local observation we identify the number of dust and sand storm occurrences over Egypt. The Multiangle Imaging SpectroRadiometer (MISR) is used to identify the optical characterizations of different types of aerosols over Egypt. Modeled aerosol optical depth and MISR observed (at 555 nm) are compared from March 2000 through November 2013. The results identify that the MISR AOD captures the maximum peaks of AOD in March/April that coincide with the Khamasin dust storms. However, peaks in May are either due to photochemical reactions or anthropogenic activities. Note: This presentation is for a Partnerships for Enhanced Engagement in Research (PEER) project sponsored by USAID/NSF/NAS. Project Link (at National Academies website): http://sites.nationalacademies.org/PGA/dsc/peerscience/PGA_084046.htmwebsite: http://CleanAirEgypt.org

Inter-comparison of model-simulated and satellite-retrieved componential aerosol optical depths in China

NASA Astrophysics Data System (ADS)

Li, Shenshen; Yu, Chao; Chen, Liangfu; Tao, Jinhua; Letu, Husi; Ge, Wei; Si, Yidan; Liu, Yang

2016-09-01

China's large aerosol emissions have major impacts on global climate change as well as regional air pollution and its associated disease burdens. A detailed understanding of the spatiotemporal patterns of aerosol components is necessary for the calculation of aerosol radiative forcing and the development of effective emission control policy. Model-simulated and satellite-retrieved aerosol components can support climate change research, PM2.5 source appointment and epidemiological studies. This study evaluated the total and componential aerosol optical depth (AOD) from the GEOS-Chem model (GC) and the Global Ozone Chemistry Aerosol Radiation and Transport model (GOCART), and the Multiangle Imaging Spectroradiometer (MISR) from 2006 to 2009 in China. Linear regression analysis between the GC and AErosol RObotic NETwork (AERONET) in China yielded similar correlation coefficients (0.6 daily, 0.71 monthly) but lower slopes (0.41 daily, 0.58 monthly) compared with those in the U.S. This difference was attributed to GC's underestimation of water-soluble AOD (WAOD) west of the Heihe-Tengchong Line, the dust AOD (DAOD) in the fall and winter, and the soot AOD (SAOD) throughout the year and throughout the country. GOCART exhibits the strongest dust estimation capability among all datasets. However, the GOCART soot distribution in the Northeast and Southeast has significant errors, and its WAOD in the polluted North China Plain (NCP) and the South is underestimated. MISR significantly overestimates the water-soluble aerosol levels in the West, and does not capture the high dust loadings in all seasons and regions, and the SAOD in the NCP. These discrepancies can mainly be attributed to the uncertainties in the emission inventories of both models, the poor performance of GC under China's high aerosol loading conditions, the omission of certain aerosol tracers in GOCART, and the tendency of MISR to misidentify dust and non-dust mixtures.

Seasonal variability of ice nuclei over Central Europe

NASA Astrophysics Data System (ADS)

Klein, Holger; Nickovic, Slobodan; Schuetz, Lothar; Weinbruch, Stephan; Levin, Zev; Andreae, Meinrat; Barrie, Leonard; Ebert, Martin; Bundke, Ulrich; Bingemer, Heinz

2010-05-01

The abundance of ice nuclei (IN) has been measured every day since April 2008 at the Taunus Observatory on Mt. Kleiner Feldberg (50.22°N, 8.45°E, 825 m. above sea level) at 20 km north of Frankfurt / M., Germany. Aerosol samples were collected on silicon wafers by an electrical aerosol precipitator and analyzed for IN number concentration (condensation and deposition freezing modes) using the static vapor diffusion chamber FRIDGE (Klein et al., Atmos. Res, doi:10.1016/j.atmosres.2009.08.002, 2009). Around 800 samples were analyzed so far. The IN number concentration shows a pronounced seasonal signal with about a factor of 10 higher ice nuclei in summer than in winter. Desert dust transported over long distances appears to be the dominant contributor to IN at the site. Episodes of Sahara dust transport are well represented by individual peaks in the IN record and identified by airmass trajectories, transport modelling and mineralogical analysis. The contribution of mineral dust to IN is further corroborated by the covariance of the individual IN concentrations with the aerosol optical depth (AOD) due to extinction by large particles, which was measured simultaneously at the AERONET site (Max-Planck-Institute for Chemistry) at Mainz, 20 km southwest of our site. The relation between IN and AOD not only holds for our individual daily measurements, but is also valid for the monthly means of our IN record, which are highly correlated to the multi-year monthly means of coarse and middle-sized dust AOD which is derived from the Multi-angle Imaging SpectroRadiometer (MISR) satellite instrument (http://eosweb.larc.nasa.gov/cgi-bin/misr_tools/clim_likely.cgi ) for the grid point closest to our site. Acknowledgements: We gratefully acknowledge funding of this work by the Deutsche Forschungsgemeinschaft (DFG) as part of the collaborative research centre Die troposphärische Eisphase (SFB641) and by the German-Israeli Foundation (GIF).

Airborne Sunphotometry of Aerosol Optical Depth and Columnar Water Vapor During ACE-Asia

NASA Technical Reports Server (NTRS)

Redemann, Jens; Schmid, B.; Russell, P. B.; Livingston, J. M.; Eilers, J. A.; Ramirez, S. A.; Kahn, R.; Hipskind, R. Stephen (Technical Monitor)

2001-01-01

During the Intensive Field Campaign (IFC) of the Aerosol Characterization Experiment - Asia (ACE-Asia), March-May 2001, the 6-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) operated during 15 of the 19 research flights aboard the NCAR C- 130, while its 14-channel counterpart (AATS- 14) was flown successfully on all 18 research flights of a Twin Otter aircraft operated by the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS), Monterey, CA. ACE-Asia was the fourth in a series of aerosol characterization experiments and focused on aerosol outflow from the Asian continent to the Pacific basin. Each ACE was designed to integrate suborbital and satellite measurements and models so as to reduce the uncertainty in calculations of the climate forcing due to aerosols. The Ames Airborne Tracking Sunphotometers measured solar beam transmission at 6 (380-1021 nm, AATS-6) and 14 wavelengths (353-1558 nm, AATS-14) respectively, yielding aerosol optical depth (AOD) spectra and column water vapor (CWV). Vertical differentiation in profiles yielded aerosol extinction and water vapor concentration. The wavelength dependence of AOD and extinction indicates that supermicron dust was often a major component of the aerosol. Frequently this dust-containing aerosol extended to high altitudes. For example, in data flights analyzed to date 34 +/- 13% of full-column AOD(525 nm) was above 3 km. In contrast, only 10 +/- 4% of CWV was above 3 km. In this paper, we will show first sunphotometer-derived results regarding the spatial variation of AOD and CWV, as well as the vertical distribution of aerosol extinction and water vapor concentration. Preliminary comparison studies between our AOD/aerosol extinction data and results from: (1) extinction products derived using in situ measurements and (2) AOD retrievals using the Multi-angle Imaging Spectro-Radiometer (MISR) aboard the TERRA satellite will also be presented.

Background aerosol over the Himalayas and Tibetan Plateau: observed characteristics of aerosol mass loading

NASA Astrophysics Data System (ADS)

Liu, B.; Cong, Z.; Wang, Y.; Xin, J.; Wan, X.; Pan, Y.; Liu, Z.; Wang, Y.; Zhang, G.; Kang, S.

2016-12-01

To investigate the atmospheric aerosols of the Himalayas and Tibetan Plateau (HTP), an observation network was established within the region's various ecosystems, including at Ngari, Qomolangma (QOMS), Nam Co, and SouthEastern Tibetan (SET) stations. In this paper we illustrate aerosol mass loadings by integrating in situ measurements with satellite and ground-based remote sensing datasets for the 2011-2013 period, on both local and large scales. Mass concentrations of these surface atmospheric aerosols were relatively low and varied with land cover, showing a general tendency of Ngari and QOMS (barren sites) > Nam Co (grassland site) > SET (forest site). Bimodal mass distributions of size-segregated particles were found at all sites, with a relatively small peak in accumulation mode and a more notable peak in coarse mode. Diurnal variations in fine aerosol masses generally displayed a bi-peak pattern at the QOMS, Nam Co and SET stations and a single-peak pattern at the Ngari station, controlled by the effects of local geomorphology, mountain-valley breeze circulation and aerosol emissions. Combining surface aerosols data and atmospheric-column aerosol optical properties, the TSP mass and aerosol optical depth (AOD) of the Multi-angle Imaging Spectroradiometer (MISR) generally decreased as land cover changed from barren to forest, in inverse relation to the PM2.5 ratios. The seasonality of aerosol mass parameters was land-cover dependent. Over forest and grassland areas, TSP mass, PM2.5 mass, MISR-AOD and fine-mode AOD were higher in spring and summer, followed by relatively lower values in autumn and winter. At the barren site (the QOMS station), there were inconsistent seasonal variations between surface TSP mass (PM2.5 mass) and atmospheric column AOD (fine-mode AOD). Our findings implicate that, HTP aerosol masses (especially their reginal characteristics and fine particle emissions) need to be treated sensitively in relation to assessments of their climatic effect

Measuring Three-Dimensional Strain and Structural Defects in a Single InGaAs Nanowire Using Coherent X-ray Multiangle Bragg Projection Ptychography

DOE PAGES

Hill, Megan O.; Calvo-Almazan, Irene; Allain, Marc; ...

2018-01-08

III - As nanowires are candidates for near-infrared light emitters and detectors that can be directly integrated onto silicon. However, nanoscale to microscale variations in structure, composition, and strain within a given nanowire, as well as variations between nanowires, pose challenges to correlating microstructure with device performance. In this work, we utilize coherent nanofocused X-rays to characterize stacking defects and strain in a single InGaAs nanowire supported on Si. By reconstructing diffraction patterns from the 2110 Bragg peak, we show that the lattice orientation varies along the length of the wire, while the strain field along the cross-section is largelymore » unaffected, leaving the band structure unperturbed. Diffraction patterns from the 0110 Bragg peak are reproducibly reconstructed to create three-dimensional images of stacking defects and associated lattice strains, revealing sharp planar boundaries between different crystal phases of wurtzite (WZ) structure that contribute to charge carrier scattering. Phase retrieval is made possible by developing multiangle Bragg projection ptychography (maBPP) to accommodate coherent nanodiffraction patterns measured at arbitrary overlapping positions at multiple angles about a Bragg peak, eliminating the need for scan registration at different angles. The penetrating nature of X-ray radiation, together with the relaxed constraints of maBPP, will enable the in operando imaging of nanowire devices.« less

Spectral invariance hypothesis study of polarized reflectance with Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI)

NASA Astrophysics Data System (ADS)

Bradley, Christine L.; Kupinski, Meredith; Diner, David J.; Xu, Feng; Chipman, Russell A.

2015-09-01

Many models used to represent the boundary condition for the separation of atmospheric scattering from the surface reflectance in polarized remote sensing measurements assume that the polarized surface reflectance is spectrally neutral. The Spectral Invariance Hypothesis asserts that the magnitude and shape of the polarized bidirectional reflectance factor (pBRF) is equal for all wavelengths. In order to test this hypothesis, JPL's Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) is used to measure polarization information of different outdoor surface types. GroundMSPI measures the linear polarization Stokes parameters (I, Q, U), at three wavelengths, 470 nm, 660 nm, and 865 nm. The camera is mounted on a two-axis gimbal to accurately select the view azimuth and elevation directions. On clear sky days we acquired day-long scans of scenes that contain various surface types such as grass, dirt, cement, brick, and asphalt and placed a Spectralon panel in the camera field of view to provide a reflectance reference. Over the course of each day, changing solar position in the sky provides a large range of scattering angles for this study. The polarized bidirectional reflectance factor (pBRF) is measured for the three wavelengths and the best fit slope of the spectral correlation is reported. This work reports the range of best fit slopes measured for five region types.

Measuring Three-Dimensional Strain and Structural Defects in a Single InGaAs Nanowire Using Coherent X-ray Multiangle Bragg Projection Ptychography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Megan O.; Calvo-Almazan, Irene; Allain, Marc

III - As nanowires are candidates for near-infrared light emitters and detectors that can be directly integrated onto silicon. However, nanoscale to microscale variations in structure, composition, and strain within a given nanowire, as well as variations between nanowires, pose challenges to correlating microstructure with device performance. In this work, we utilize coherent nanofocused X-rays to characterize stacking defects and strain in a single InGaAs nanowire supported on Si. By reconstructing diffraction patterns from the 2110 Bragg peak, we show that the lattice orientation varies along the length of the wire, while the strain field along the cross-section is largelymore » unaffected, leaving the band structure unperturbed. Diffraction patterns from the 0110 Bragg peak are reproducibly reconstructed to create three-dimensional images of stacking defects and associated lattice strains, revealing sharp planar boundaries between different crystal phases of wurtzite (WZ) structure that contribute to charge carrier scattering. Phase retrieval is made possible by developing multiangle Bragg projection ptychography (maBPP) to accommodate coherent nanodiffraction patterns measured at arbitrary overlapping positions at multiple angles about a Bragg peak, eliminating the need for scan registration at different angles. The penetrating nature of X-ray radiation, together with the relaxed constraints of maBPP, will enable the in operando imaging of nanowire devices.« less

Lensless transport-of-intensity phase microscopy and tomography with a color LED matrix

NASA Astrophysics Data System (ADS)

Zuo, Chao; Sun, Jiasong; Zhang, Jialin; Hu, Yan; Chen, Qian

2015-07-01

We demonstrate lens-less quantitative phase microscopy and diffraction tomography based on a compact on-chip platform, using only a CMOS image sensor and a programmable color LED array. Based on multi-wavelength transport-of- intensity phase retrieval and multi-angle illumination diffraction tomography, this platform offers high quality, depth resolved images with a lateral resolution of ˜3.7μm and an axial resolution of ˜5μm, over wide large imaging FOV of 24mm2. The resolution and FOV can be further improved by using a larger image sensors with small pixels straightforwardly. This compact, low-cost, robust, portable platform with a decent imaging performance may offer a cost-effective tool for telemedicine needs, or for reducing health care costs for point-of-care diagnostics in resource-limited environments.

Laboratory Measurement of Bidirectional Reflectance of Radiometric Tarps

NASA Technical Reports Server (NTRS)

Knowlton, Kelly

2006-01-01

Objectives: a) To determine the magnitude of radiometric tarp BRDF; b) To determine whether an ASD FieldSpec Pro spectroradiometer can be used to perform the experiment. Radiometric tarps with nominal reflectance values of 52%, 35%, and 3.5%, deployed for IKONOS. QuickBird, and OrbView-3 overpasses Ground-based spectroradiometric measurements of tarp and Spectralon@ panel taken during overpass using ASD FieldSpec Pro spectroradiometer, and tarp reflectance calculated. Reflectance data used in atmospheric radiative transfer model (MODTRAN) to predict satellite at-sensor radiance for radiometric calibration. Reflectance data also used to validate atmospheric correction of high-spatial-resolution multispectral image products

First Moderate Resolution Imaging Spectroradiometer (MODIS) Snow and Ice Workshop

NASA Technical Reports Server (NTRS)

Hall, Dorothy K. (Editor)

1995-01-01

This document is a compilation of summaries of talks presented at a 2-day workshop on Moderate Resolution maging Spectroradiometer (MODIS) snow and ice products. The objectives of the workshop were to: inform the snow and ce community of potential MODIS products, seek advice from the participants regarding the utility of the products, and letermine the needs for future post-launch MODIS snow and ice products. Four working groups were formed to discuss at-launch snow products, at-launch ice products, post-launch snow and ice products and utility of MODIS snow and ice products, respectively. Each working group presented recommendations at the conclusion of the workshop.

Hyperspectral radiometer for automated measurement of global and diffuse sky irradiance

NASA Astrophysics Data System (ADS)

Kuusk, Joel; Kuusk, Andres

2018-01-01

An automated hyperspectral radiometer for the measurement of global and diffuse sky irradiance, SkySpec, has been designed for providing the SMEAR-Estonia research station with spectrally-resolved solar radiation data. The spectroradiometer has been carefully studied in the optical radiometry laboratory of Tartu Observatory, Estonia. Recorded signals are corrected for spectral stray light as well as for changes in dark signal and spectroradiometer spectral responsivity due to temperature effects. Comparisons with measurements of shortwave radiation fluxes made at the Baseline Surface Radiation Network (BSRN) station at Tõravere, Estonia, and with fluxes simulated using the atmospheric radiative transfer model 6S and Aerosol Robotic Network (AERONET) data showed that the spectroradiometer is a reliable instrument that provides accurate estimates of integrated fluxes and of their spectral distribution. The recorded spectra can be used to estimate the amount of atmospheric constituents such as aerosol and column water vapor, which are needed for the atmospheric correction of spectral satellite images.

4-mm-diameter three-dimensional imaging endoscope with steerable camera for minimally invasive surgery (3-D-MARVEL).

PubMed

Bae, Sam Y; Korniski, Ronald J; Shearn, Michael; Manohara, Harish M; Shahinian, Hrayr

2017-01-01

High-resolution three-dimensional (3-D) imaging (stereo imaging) by endoscopes in minimally invasive surgery, especially in space-constrained applications such as brain surgery, is one of the most desired capabilities. Such capability exists at larger than 4-mm overall diameters. We report the development of a stereo imaging endoscope of 4-mm maximum diameter, called Multiangle, Rear-Viewing Endoscopic Tool (MARVEL) that uses a single-lens system with complementary multibandpass filter (CMBF) technology to achieve 3-D imaging. In addition, the system is endowed with the capability to pan from side-to-side over an angle of [Formula: see text], which is another unique aspect of MARVEL for such a class of endoscopes. The design and construction of a single-lens, CMBF aperture camera with integrated illumination to generate 3-D images, and the actuation mechanism built into it is summarized.

MODIS Atmospheric Data Handler

NASA Technical Reports Server (NTRS)

Anantharaj, Valentine; Fitzpatrick, Patrick

2008-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) Atmosphere Data Handler software converts the HDF data to ASCII format, and outputs: (1) atmospheric profiles of temperature and dew point and (2) total precipitable water. Quality-control data are also considered in the export procedure.

China Dust

Atmospheric Science Data Center

2013-04-16

... SpectroRadiometer (MISR) nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a ... arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the ...

Comparison of Sub-pixel Classification Approaches for Crop-specific Mapping

EPA Science Inventory

The Moderate Resolution Imaging Spectroradiometer (MODIS) data has been increasingly used for crop mapping and other agricultural applications. Phenology-based classification approaches using the NDVI (Normalized Difference Vegetation Index) 16-day composite (250 m) data product...

Phytoplankton off the Coast of Portugal

NASA Technical Reports Server (NTRS)

2002-01-01

A large phytoplankton bloom off of the coast of Portugal can be seen in this true-color image taken on April 23, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra satellite. The bloom is roughly half the size of Portugal and forms a bluish-green cloud in the water. The red spots in northwest Spain denote what are likely small agricultural fires. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

Fires and Heavy Smoke in Alaska

NASA Technical Reports Server (NTRS)

2002-01-01

On May 28, 2002, the Moderate Resolution Imaging Spectroradiometer (MODIS) captured this image of fires that continue to burn in central Alaska. Alaska is very dry and warm for this time of year, and has experienced over 230 wildfires so far this season. Please note that the high-resolution scene provided here is 500 meters per pixel. For a copy of the scene at the sensor's fullest resolution, visit the MODIS Rapid Response Image Gallery.

Fires and Smoke in Central Africa

NASA Technical Reports Server (NTRS)

2002-01-01

This year's fire season in central Africa may have been the most severe ever. This true-color image also shows the location of fires (red dots) in the Democratic Republic of the Congo, Angola, and Zambia. The image was taken by the Moderate-Resolution Imaging Spectroradiometer (MODIS) aboard NASA 's Terra spacecraft on August 23, 2000, and was produced using the MODIS Active Fire Detection product. NASA scientists studied these fires during the SAFARI 2000 field campaign. Image By Jacques Descloitres, MODIS Land Team

Coast of the East Siberian Sea, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

Sea ice is pulling away from the coastline of northeastern Siberia in the east Siberia Sea. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 26, 2002, also the thinning of ice in bays and coves, and the blue reflection of the water from beneath causes the ice to appear bright blue. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Fires in Philippines

NASA Technical Reports Server (NTRS)

2002-01-01

Roughly a dozen fires (red pixels) dotted the landscape on the main Philippine island of Luzon on April 1, 2002. This true-color image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. Please note that the high-resolution scene provided here is 500 meters per pixel. For a copy of this scene at the sensor's fullest resolution, visit the MODIS Rapidfire site.

Detecting leaf phenology of seasonally moist tropical forests in South America with multi-temporal MODIS images.

Treesearch

Xiangming Xiao; Stephen Hagen; Qingyuan Zhang; Michael Keller; Berrien Moore III

2006-01-01

Leaf phenology of tropical evergreen forests affects carbon and water fluxes. In an earlier study of a seasonally moist evergreen tropical forest site in the Amazon basin, time series data of Enhanced Vegetation Index (EVI) from the VEGETATION and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors showed an unexpected seasonal pattern, with higher EVI in the...

Passive remote sensing of aerosol layer height using near-UV multiangle polarization measurements

NASA Astrophysics Data System (ADS)

Wu, Lianghai; Hasekamp, Otto; van Diedenhoven, Bastiaan; Cairns, Brian; Yorks, John E.; Chowdhary, Jacek

2016-08-01

We demonstrate that multiangle polarization measurements in the near-UV and blue part of the spectrum are very well suited for passive remote sensing of aerosol layer height. For this purpose we use simulated measurements with different setups (different wavelength ranges, with and without polarization, different polarimetric accuracies) as well as airborne measurements from the Research Scanning Polarimeter (RSP) obtained over the continental USA. We find good agreement of the retrieved aerosol layer height from RSP with measurements from the Cloud Physics Lidar showing a mean absolute difference of less than 1 km. Furthermore, we found that the information on aerosol layer height is provided for large part by the multiangle polarization measurements with high accuracy rather than the multiangle intensity measurements. The information on aerosol layer height is significantly decreased when the shortest RSP wavelength (410 nm) is excluded from the retrieval and is virtually absent when 550 nm is used as shortest wavelength.

Assessment of capabilities of multiangle imaging photo-polarimetry for atmospheric correction in presence of absorbing aerosols

NASA Astrophysics Data System (ADS)

Kalashnikova, O. V.; Garay, M. J.; Xu, F.; Seidel, F. C.; Diner, D. J.

2015-12-01

Satellite remote sensing of ocean color is a critical tool for assessing the productivity of marine ecosystems and monitoring changes resulting from climatic or environmental influences. Yet water-leaving radiance comprises less than 10% of the signal measured from space, making correction for absorption and scattering by the intervening atmosphere imperative. Traditional ocean color retrieval algorithms utilize a standard set of aerosol models and the assumption of negligible water-leaving radiance in the near-infrared. Modern improvements have been developed to handle absorbing aerosols such as urban particulates in coastal areas and transported desert dust over the open ocean, where ocean fertilization can impact biological productivity at the base of the marine food chain. Even so, imperfect knowledge of the absorbing aerosol optical properties or their height distribution results in well-documented sources of error. In the UV, the problem of UV-enhanced absorption and nonsphericity of certain aerosol types are amplified due to the increased Rayleigh and aerosol optical depth, especially at off-nadir view angles. Multi-angle spectro-polarimetric measurements have been advocated as an additional tool to better understand and retrieve the aerosol properties needed for atmospheric correction for ocean color retrievals. The central concern of the work to be described is the assessment of the effects of absorbing aerosol properties on water leaving radiance measurement uncertainty by neglecting UV-enhanced absorption of carbonaceous particles and by not accounting for dust nonsphericity. In addition, we evaluate the polarimetric sensitivity of absorbing aerosol properties in light of measurement uncertainties achievable for the next generation of multi-angle polarimetric imaging instruments, and demonstrate advantages and disadvantages of wavelength selection in the UV/VNIR range. The phase matrices for the spherical smoke particles were calculated using a standard Mie code, while those for non-spherical dust particles were calculated using the numerical approach described by Dubovik et al., 2006. A vector Markov Chain radiative transfer code including bio-optical models was used to evaluate TOA and water leaving radiances.

Coupled Retrieval of Liquid Water Cloud and Above-Cloud Aerosol Properties Using the Airborne Multiangle SpectroPolarimetric Imager (AirMSPI)

NASA Astrophysics Data System (ADS)

Xu, Feng; van Harten, Gerard; Diner, David J.; Davis, Anthony B.; Seidel, Felix C.; Rheingans, Brian; Tosca, Mika; Alexandrov, Mikhail D.; Cairns, Brian; Ferrare, Richard A.; Burton, Sharon P.; Fenn, Marta A.; Hostetler, Chris A.; Wood, Robert; Redemann, Jens

2018-03-01

An optimization algorithm is developed to retrieve liquid water cloud properties including cloud optical depth (COD), droplet size distribution and cloud top height (CTH), and above-cloud aerosol properties including aerosol optical depth (AOD), single-scattering albedo, and microphysical properties from sweep-mode observations by Jet Propulsion Laboratory's Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) instrument. The retrieval is composed of three major steps: (1) initial estimate of the mean droplet size distribution across the entire image of 80-100 km along track by 10-25 km across track from polarimetric cloudbow observations, (2) coupled retrieval of image-scale cloud and above-cloud aerosol properties by fitting the polarimetric data at all observation angles, and (3) iterative retrieval of 1-D radiative transfer-based COD and droplet size distribution at pixel scale (25 m) by establishing relationships between COD and droplet size and fitting the total radiance measurements. Our retrieval is tested using 134 AirMSPI data sets acquired during the National Aeronautics and Space Administration (NASA) field campaign ObseRvations of Aerosols above CLouds and their intEractionS. The retrieved above-cloud AOD and CTH are compared to coincident HSRL-2 (HSRL-2, NASA Langley Research Center) data, and COD and droplet size distribution parameters (effective radius reff and effective variance veff) are compared to coincident Research Scanning Polarimeter (RSP) (NASA Goddard Institute for Space Studies) data. Mean absolute differences between AirMSPI and HSRL-2 retrievals of above-cloud AOD at 532 nm and CTH are 0.03 and <0.5 km, respectively. At RSP's footprint scale ( 323 m), mean absolute differences between RSP and AirMSPI retrievals of COD, reff, and veff in the cloudbow area are 2.33, 0.69 μm, and 0.020, respectively. Neglect of smoke aerosols above cloud leads to an underestimate of image-averaged COD by 15%.

Development of Fire Emissions Inventory Using Satellite Data

EPA Science Inventory

There are multiple satellites observing and reporting fire imagery at various spatial and temporal resolutions and each system has inherent merits and deficiencies. In our study, data are acquired from the Moderate Resolution Imaging Spectro-radiometer (MODIS) aboard the Nationa...

A COMPARISON OF CMAQ-BASED AEROSOL PROPERTIES WITH IMPROVE, MODIS, AND AERONET DATA

EPA Science Inventory

We compare select aerosol Properties derived from the Community Multiscale Air Quality (CMAQ) model-simulated aerosol mass concentrations with routine data from the National Aeronautics and Space Administration (NASA) satellite-borne Moderate Resolution Imaging Spectro-radiometer...

Multi-angle Imaging SpectroRadiometer

NASA Technical Reports Server (NTRS)

Diner, David J. (Principal Investigator)

MISR views the sunlit Earth simultaneously at nine widely spaced angles and provides ongoing global coverage with high spatial detail. Its imagery is carefully calibrated to provide accurate measures of the brightness, contrast, and color of reflected sunlight. MISR provides new types of information for scientists studying Earth's climate, such as the regional and global distribution of different types of atmospheric particles and aerosols. The change in reflection at different view angles provides the means to distinguish aerosol types, cloud forms, and land surface cover. Combined with stereoscopic techniques, this enables construction of 3-D cloud models and estimation of the total amount of sunlight reflected by Earth's diverse environments. MISR was built for NASA by the Jet Propulsion Laboratory (JPL) in Pasadena, California. It is part of NASA's first Earth Observing System (EOS) spacecraft, the Terra spacecraft, which was launched into polar orbit from Vandenberg Air Force Base on December 18, 1999. MISR has been continuously providing data since February 24, 2000. [Mission Objectives] The MISR instrument acquires systematic multi-angle measurements for global monitoring of top-of-atmosphere and surface albedos and for measuring the shortwave radiative properties of aerosols, clouds, and surface scenes in order to characterize their impact on the Earth's climate. The Earth's climate is constantly changing -- as a consequence of both natural processes and human activities. Scientists care a great deal about even small changes in Earth's climate, since they can affect our comfort and well-being, and possibly our survival. A few years of below-average rainfall, an unusually cold winter, or a change in emissions from a coal-burning power plant, can influence the quality of life of people, plants, and animals in the region involved. The goal of NASA's Earth Observing System (EOS) is to increase our understanding of the climate changes that are occurring on our planet, and the reasons for these changes, so we are better equipped to anticipate and prepare for the future. The MISR instrument is a part of EOS. Its role is to measure the amount of sunlight scattered in different directions under natural conditions. These measurements will help quantify the amount of solar energy that heats the Earth's surface and atmosphere, and the changes that occur in them over the lifetime of the MISR instrument. From the MISR observations, we are also learning more about those components of the Earth's environment that scatter sunlight: particles in the atmosphere, the planet's surface, and clouds. MISR monitors changes in surface reflection properties, in atmospheric aerosol content and composition, and in cloudiness. Scientists use these data to study land use changes, air pollution, volcanic eruptions, as well as processes such as desertification, deforestation, and soil erosion. As part of the EOS program, computer models that predict future climate will be improved by the results of these studies. [Temporal_Coverage: Start_Date=2000-02-24; Stop_Date=] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

Long Smoke Plumes from California Destructive Bluecut Fire Spotted by NASA MISR

NASA Image and Video Library

2016-08-17

On Aug. 16, 2016, at around 10:30 a.m., a brush fire ignited in the Cajon Pass east of Los Angeles, just to the west of Interstate 15. Within a matter of hours, extreme temperatures, high winds and low humidity allowed the fire to spread rapidly, burning through brush left tinder-dry by years of drought. Firefighters quickly responded, ordering the evacuation of about 83,000 people in and around the Cajon Pass, Wrightwood, Lytle Creek, Oak Hills and surrounding areas. An as-yet uncounted number of homes and structures have burned, and Interstate 15 remains closed to downed power lines and barrier damage. By Aug. 17, the fire had expanded to more than 30,000 acres and remains zero percent contained as some 1,300 firefighters continue to battle to save homes and evacuate residents. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed over the region on Aug. 17 around 11:50 a.m. PDT and captured this natural-color image from MISR's 70-degree forward-viewing camera, which covers an areas about 257 miles (414 kilometers) wide. The oblique view angle makes the smoke more apparent than it would be in a more conventional vertical view. The Los Angeles metropolitan area is the large gray area on the coast in the center of the image. Three plumes from the Blue Cut Fire are clearly visible in the mountains to the north. This oblique view also shows an enormous cloud of smoke spreading northeastward over a significant portion of eastern California and Nevada. This smoke probably originated from the fire as it consumed almost 20,000 acres on the evening of the 16th and traveled north overnight. Also visible from this oblique view is considerable haziness filling California's Central Valley, to the northwest of the Blue Cut Fire. This haziness is most likely due to smoke from several other fires burning in California, including the Soberanes Fire near Monterey, the Clayton Fire that has destroyed 175 structures north of San Francisco, the Chimney Fire and the Cedar Fire, which is visible in the image in the southern Sierra Nevada. The total number of acres burned in California this year has tripled in just the past week. The 3D stereo anaglyph is made by combining data from MISR's 60-degree and 70-degree forward-viewing cameras. You will need red-blue glasses to view the 3D effect (ensure the red lens is over your left eye). In order to enable stereo viewing, the image has been rotated so north is to the left. These data were acquired during Terra orbit 88648. http://photojournal.jpl.nasa.gov/catalog/PIA20888

Automatic lumbar vertebrae detection based on feature fusion deep learning for partial occluded C-arm X-ray images.

PubMed

Yang Li; Wei Liang; Yinlong Zhang; Haibo An; Jindong Tan

2016-08-01

Automatic and accurate lumbar vertebrae detection is an essential step of image-guided minimally invasive spine surgery (IG-MISS). However, traditional methods still require human intervention due to the similarity of vertebrae, abnormal pathological conditions and uncertain imaging angle. In this paper, we present a novel convolutional neural network (CNN) model to automatically detect lumbar vertebrae for C-arm X-ray images. Training data is augmented by DRR and automatic segmentation of ROI is able to reduce the computational complexity. Furthermore, a feature fusion deep learning (FFDL) model is introduced to combine two types of features of lumbar vertebrae X-ray images, which uses sobel kernel and Gabor kernel to obtain the contour and texture of lumbar vertebrae, respectively. Comprehensive qualitative and quantitative experiments demonstrate that our proposed model performs more accurate in abnormal cases with pathologies and surgical implants in multi-angle views.

Spatial and temporal remote sensing data fusion for vegetation monitoring

USDA-ARS?s Scientific Manuscript database

The suite of available remote sensing instruments varies widely in terms of sensor characteristics, spatial resolution and acquisition frequency. For example, the Moderate-resolution Imaging Spectroradiometer (MODIS) provides daily global observations at 250m to 1km spatial resolution. While imagery...

The Use of MODIS NDVI Data for Characterizing Cropland Across the Great Lakes Basin

EPA Science Inventory

The Moderate Resolution Imaging Spectroradiometer (MODIS) provides new opportunities for characterizing land-cover (LC) to support monitoring and assessment studies at watershed, regional and global scales. This research evaluated the potential for using the MODIS Normalized Diff...

Monitoring Rangeland Health by Remote Sensing

USDA-ARS?s Scientific Manuscript database

Based on a land-cover classification from NASA’s MODerate resolution Imaging Spectroradiometer (MODIS), rangelands cover 48% of the Earth’s land surface, not including Antarctica. Nearly all analyses imply the most economical means of monitoring large areas of rangelands worldwide is with remote s...

Improved meteorology from an updated WRF/CMAQ modeling system with MODIS vegetation and albedo

EPA Science Inventory

Realistic vegetation characteristics and phenology from the Moderate Resolution Imaging Spectroradiometer (MODIS) products improve the simulation for the meteorology and air quality modeling system WRF/CMAQ (Weather Research and Forecasting model and Community Multiscale Air Qual...

Northern Gulf of Mexico estuarine coloured dissolved organic matter derived from MODIS data

EPA Science Inventory

Coloured dissolved organic matter (CDOM) is relevant for water quality management and may become an important measure to complement future water quality assessment programmes. An approach to derive CDOM using the Moderate Resolution Imaging Spectroradiometer (MODIS) was developed...

Monitoring Agricultural Cropping Patterns in the Great Lakes Basin Using MODIS-NDVI Time Series Data

EPA Science Inventory

This research examined changes in agricultural cropping patterns across the Great Lakes Basin (GLB) using the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data. Specific research objectives were to characterize the distribut...

Wetlands of the Gulf Coast

NASA Technical Reports Server (NTRS)

2001-01-01

This set of images from the Multi-angle Imaging SpectroRadiometer highlights coastal areas of four states along the Gulf of Mexico: Louisiana, Mississippi, Alabama and part of the Florida panhandle. The images were acquired on October 15, 2001 (Terra orbit 9718)and represent an area of 345 kilometers x 315 kilometers.

The two smaller images on the right are (top) a natural color view comprised of red, green, and blue band data from MISR's nadir(vertical-viewing) camera, and (bottom) a false-color view comprised of near-infrared, red, and blue band data from the same camera. The predominantly red color of the false-color image is due to the presence of vegetation, which is bright at near-infrared wavelengths. Cities appear as grey patches, with New Orleans visible at the southern edge of Lake Pontchartrain, along the left-hand side of the images. The Lake Pontchartrain Bridge runs approximately north-south across the middle of the lake. The distinctive shape of the Mississippi River Delta can be seen to the southeast of New Orleans. Other coastal cities are visible east of the Mississippi, including Biloxi, Mobile and Pensacola.

The large image is similar to the true-color nadir view, except that red band data from the 60-degree backward-looking camera has been substituted into the red channel; the blue and green data from the nadir camera have been preserved. In this visualization, green hues appear somewhat subdued, and a number of areas with a reddish color are present, particularly near the mouths of the Mississippi, Pascagoula, Mobile-Tensaw, and Escambia Rivers. Here, the red color is highlighting differences in surface texture. This combination of angular and spectral information differentiates areas with aquatic vegetation associated with poorly drained bottom lands, marshes, and/or estuaries from the surrounding surface vegetation. These wetland regions are not as well differentiated in the conventional nadir views.

Variations in ocean color are apparent in all three views, and represent the outflow of suspended sediment from the seabed shelf to the open waters of the Gulf of Mexico. Major features include the Mississippi Delta, where large amounts of land-derived sediments have been deposited in shallow coastal waters. These deltaic environments form a complex, interconnected web of estuarine channels and extensive coastal wetlands that provide important habitat for fisheries. The city of New Orleans is prone to flooding, with about 45% of the metropolitan core situated at or below sea level. The city is protected by levees, but the wetlands which also function as a buffer from storm surges have been disappearing.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

A precise laboratory goniometer system to collect spectral BRDF data of materials

NASA Astrophysics Data System (ADS)

Jiao, Guangping; Jiao, Ziti; Wang, Jie; Zhang, Hu; Dong, Yadong

2014-11-01

This paper presents a precise laboratory goniometer system to quickly collect bidirectional reflectance distribution factor(BRDF)of typical materials such soil, canopy and artificial materials in the laboratory. The system consists of the goniometer, SVC HR1024 spectroradiometer, and xenon long-arc lamp as light source. the innovation of cantilever slab can reduce the shadow of the goniometer in the principle plane. The geometric precision of the footprint centre is better than +/-4cm in most azimuth directions, and the angle-controlling accuracy is better than 0.5°. The light source keeps good stability, with 0.8% irradiance decrease in 3 hours. But the large areal heterogeneity of the light source increase the data processing difficulty to capture the accurate BRDF. First measurements are taken from soil in a resolution of 15° and 30° in zenith and azimuth direction respectively, with the +/-50° biggest view angle. More observations are taken in the hot-spot direction. The system takes about 40 minutes to complete all measurements. A spectralon panel is measured at the beginning and end of the whole period. A simple interactive interface on the computer can automatically control all operations of the goniometer and data-processing. The laboratory experiment of soil layer and grass lawn shows that the goniometer can capture the the multi-angle variation of BRDF.

Saskatchewan and Manitoba

NASA Technical Reports Server (NTRS)

2001-01-01

Surface brightness contrasts accentuated by a thin layer of snow enable a network of rivers, roads, and farmland boundaries to stand out clearly in these MISR images of southeastern Saskatchewan and southwestern Manitoba. The lefthand image is a multi-spectral false-color view made from the near-infrared, red, and green bands of MISR's vertical-viewing (nadir) camera. The righthand image is a multi-angle false-color view made from the red band data of the 60-degree aftward camera, the nadir camera, and the 60-degree forward camera. In each image, the selected channels are displayed as red, green, and blue, respectively. The data were acquired April 17, 2001 during Terra orbit 7083, and cover an area measuring about 285 kilometers x 400 kilometers. North is at the top.

The junction of the Assiniboine and Qu'Apelle Rivers in the bottom part of the images is just east of the Saskatchewan-Manitoba border. During the growing season, the rich, fertile soils in this area support numerous fields of wheat, canola, barley, flaxseed, and rye. Beef cattle are raised in fenced pastures. To the north, the terrain becomes more rocky and forested. Many frozen lakes are visible as white patches in the top right. The narrow linear, north-south trending patterns about a third of the way down from the upper right corner are snow-filled depressions alternating with vegetated ridges, most probably carved by glacial flow.

In the lefthand image, vegetation appears in shades of red, owing to its high near-infrared reflectivity. In the righthand image, several forested regions are clearly visible in green hues. Since this is a multi-angle composite, the green arises not from the color of the leaves but from the architecture of the surface cover. Progressing southeastward along the Manitoba Escarpment, the forested areas include the Pasquia Hills, the Porcupine Hills, Duck Mountain Provincial Park, and Riding Mountain National Park. The forests are brighter in the nadir than at the oblique angles, probably because more of the snow-covered surface is visible in the gaps between the trees. In contrast, the valley between the Pasquia and Porcupine Hills near the top of the images appears bright red in the lefthand image (indicating high vegetation abundance) but shows a mauve color in the multi-angle view. This means that it is darker in the nadir than at the oblique angles. Examination of imagery acquired after the snow has melted should establish whether this difference is related to the amount of snow on the surface or is indicative of a different type of vegetation structure.

Saskatchewan and Manitoba are believed to derive their names from the Cree words for the winding and swift-flowing waters of the Saskatchewan River and for a narrows on Lake Manitoba where the roaring sound of wind and water evoked the voice of the Great Spirit. They are two of Canada's Prairie Provinces; Alberta is the third.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Application of the Kano-Hamilton multiangle inversion method in clear atmospheres

Treesearch

Mariana Adam; Vladimir A. Kovalev; Cyle Wold; Jenny Newton; Markus Pahlow; Wei M. Hao; Marc B. Parlange

2007-01-01

An improved measurement methodology and a data-processing technique for multiangle data obtained with an elastic scanning lidar in clear atmospheres are introduced. Azimuthal and slope scans are combined to reduce the atmospheric heterogeneity. Vertical profiles of optical depth and intercept (proportional to the logarithm of the backscatter coefficient) are determined...

Coupled retrieval of aerosol properties and land surface reflection using the Airborne Multiangle SpectroPolarimetric Imager

NASA Astrophysics Data System (ADS)

Xu, Feng; van Harten, Gerard; Diner, David J.; Kalashnikova, Olga V.; Seidel, Felix C.; Bruegge, Carol J.; Dubovik, Oleg

2017-07-01

The Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) has been flying aboard the NASA ER-2 high-altitude aircraft since October 2010. In step-and-stare operation mode, AirMSPI acquires radiance and polarization data in bands centered at 355, 380, 445, 470*, 555, 660*, 865*, and 935 nm (* denotes polarimetric bands). The imaged area covers about 10 km by 11 km and is typically observed from nine viewing angles between ±66° off nadir. For a simultaneous retrieval of aerosol properties and surface reflection using AirMSPI, an efficient and flexible retrieval algorithm has been developed. It imposes multiple types of physical constraints on spectral and spatial variations of aerosol properties as well as spectral and temporal variations of surface reflection. Retrieval uncertainty is formulated by accounting for both instrumental errors and physical constraints. A hybrid Markov-chain/adding-doubling radiative transfer (RT) model is developed to combine the computational strengths of these two methods in modeling polarized RT in vertically inhomogeneous and homogeneous media, respectively. Our retrieval approach is tested using 27 AirMSPI data sets with low to moderately high aerosol loadings, acquired during four NASA field campaigns plus one AirMSPI preengineering test flight. The retrieval results including aerosol optical depth, single-scattering albedo, aerosol size and refractive index are compared with Aerosol Robotic Network reference data. We identify the best angular combinations for 2, 3, 5, and 7 angle observations from the retrieval quality assessment of various angular combinations. We also explore the benefits of polarimetric and multiangular measurements and target revisits in constraining aerosol property and surface reflection retrieval.

Winter precipitation particle size distribution measurement by Multi-Angle Snowflake Camera

NASA Astrophysics Data System (ADS)

Huang, Gwo-Jong; Kleinkort, Cameron; Bringi, V. N.; Notaroš, Branislav M.

2017-12-01

From the radar meteorology viewpoint, the most important properties for quantitative precipitation estimation of winter events are 3D shape, size, and mass of precipitation particles, as well as the particle size distribution (PSD). In order to measure these properties precisely, optical instruments may be the best choice. The Multi-Angle Snowflake Camera (MASC) is a relatively new instrument equipped with three high-resolution cameras to capture the winter precipitation particle images from three non-parallel angles, in addition to measuring the particle fall speed using two pairs of infrared motion sensors. However, the results from the MASC so far are usually presented as monthly or seasonally, and particle sizes are given as histograms, no previous studies have used the MASC for a single storm study, and no researchers use MASC to measure the PSD. We propose the methodology for obtaining the winter precipitation PSD measured by the MASC, and present and discuss the development, implementation, and application of the new technique for PSD computation based on MASC images. Overall, this is the first study of the MASC-based PSD. We present PSD MASC experiments and results for segments of two snow events to demonstrate the performance of our PSD algorithm. The results show that the self-consistency of the MASC measured single-camera PSDs is good. To cross-validate PSD measurements, we compare MASC mean PSD (averaged over three cameras) with the collocated 2D Video Disdrometer, and observe good agreements of the two sets of results.

Multiple Scale Remote Sensing for Monitoring Rangelands

USDA-ARS?s Scientific Manuscript database

Based on a land-cover classification from NASA’s MODerate resolution Imaging Spectroradiometer (MODIS), rangelands cover 48% of the Earth’s land surface, not including Antarctica. Nearly all analyses imply the most economical means of monitoring large areas of rangelands worldwide is with remote se...

A Review of Selected MODIS Algorithms, Data Products, and Applications

EPA Science Inventory

The Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the key instruments designed as part of NASA’s Earth Observing System (EOS) to provide long-term global observation of the Earth’s land, ocean, and atmospheric properties (Asrar and Dokken, 1993). The developmen...

Recent weather extremes and impact agricultural production and vector-borne disease patterns

USDA-ARS?s Scientific Manuscript database

We document significant worldwide weather anomalies that affected agriculture and vector-borne disease outbreaks during the 2010-2012 period. We utilized 2000-2012 vegetation index and land surface temperature data from NASA’s satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) to ...

Producing Global Science Products for the Moderate Resolution Imaging Spectroradiometer (MODIS) in MODAPS

NASA Technical Reports Server (NTRS)

Masuoka, Edward J.; Tilmes, Curt A.; Ye, Gang; Devine, Neal; Smith, David E. (Technical Monitor)

2000-01-01

The MODerate resolution Imaging Spectroradiometer (MODIS) was launched on NASA's EOS-Terra spacecraft December 1999. With 36 spectral bands covering the visible, near wave and short wave infrared. MODIS produces over 40 global science data products, including sea surface temperature, ocean color, cloud properties, vegetation indices land surface temperature and land cover change. The MODIS Data Processing System (MODAPS) produces 400 GB/day of global MODIS science products from calibrated radiances generated in the Earth Observing System Data and Information System (EOSDIS). The science products are shipped to the EOSDIS for archiving and distribution to the public. An additional 200 GB of products are shipped each day to MODIS team members for quality assurance and validation of their products. In the sections that follow, we will describe the architecture of the MODAPS, identify processing bottlenecks encountered in scaling MODAPS from 50 GB/day backup system to a 400 GB/day production system and discuss how these were handled.

Recent Results From The Nasa Earth Science Terra Mission and Future Possibilities

NASA Technical Reports Server (NTRS)

Salomonson, Vincent V.

2000-01-01

The NASA Earth Sciences Enterprise has made some remarkable strides in recent times in using developing, implementing, and utilizing spaceborne observations to better understand how the Earth works as a coupled, interactive system of the land, ocean, and atmosphere. Notable examples include the Upper Atmosphere Research (UARS) Satellite, the Topology Ocean Experiment (TOPEX) mission, Landsat-7, SeaWiFS, the Tropical Rainfall Monitoring Mission (TRMM), Quickscatt, the Shuttle Radar Topography Mission (SRTM), and, quite recently, the Terra'/Earth Observing System-1 mission. The Terra mission, for example, represents a major step forward in providing sensors that offer considerable advantages and progress over heritage instruments. The Moderate Resolution Imaging Spectrometer (MODIS), the Multi-angle Imaging SpectroRadiometer (MISR), the Measurements of Pollution in the Troposphere (MOPITT), the Advanced Spaceborne Thermal Emissions and Reflections (ASTER) radiometer, and the Clouds and Earth's Radiant Energy System (CERES) radiometer are the instruments involved. Early indications in March indicate that each of these instruments are working well and will be augmenting data bases from heritage instruments as well as producing new, unprecedented observations of land, ocean, and atmosphere features. Several missions will follow the Terra mission as the Earth Observing mission systems complete development and go into operation. These missions include EOS PM-1/'Aqua', Icesat, Vegetation Canopy Lidar (VCL), Jason/TOPEX Follow-on, the Chemistry mission, etc. As the Earth Observing systems completes its first phase in about 2004 a wealth of data enabling better understanding of the Earth and the management of its resources will have been provided. Considerable thought is beginning to be placed on what advances in technology can be implemented that will enable further advances in the early part of the 21st century; e.g., in the time from of 2020. Concepts such as 'constellation' missions or 'formation flying' with 'sensorcraft', 'sensor webs', autonomous operation of satellites, more on-board processing and delivery to individual users, data synthesis and analysis in real-time, etc. are being considered. With the data now having been and soon to be received plus the very real possibilities of further advances in use and applicability of data the potential for very significant gains in knowledge for Earth studies and applications looks quite high in the next decade or two.

Predicting daily PM2.5 concentrations in Texas using high-resolution satellite aerosol optical depth.

PubMed

Zhang, Xueying; Chu, Yiyi; Wang, Yuxuan; Zhang, Kai

2018-08-01

The regulatory monitoring data of particulate matter with an aerodynamic diameter <2.5μm (PM 2.5 ) in Texas have limited spatial and temporal coverage. The purpose of this study is to estimate the ground-level PM 2.5 concentrations on a daily basis using satellite-retrieved Aerosol Optical Depth (AOD) in the state of Texas. We obtained the AOD values at 1-km resolution generated through the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm based on the images retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellites. We then developed mixed-effects models based on AODs, land use features, geographic characteristics, and weather conditions, and the day-specific as well as site-specific random effects to estimate the PM 2.5 concentrations (μg/m 3 ) in the state of Texas during the period 2008-2013. The mixed-effects models' performance was evaluated using the coefficient of determination (R 2 ) and square root of the mean squared prediction error (RMSPE) from ten-fold cross-validation, which randomly selected 90% of the observations for training purpose and 10% of the observations for assessing the models' true prediction ability. Mixed-effects regression models showed good prediction performance (R 2 values from 10-fold cross validation: 0.63-0.69). The model performance varied by regions and study years, and the East region of Texas, and year of 2009 presented relatively higher prediction precision (R 2 : 0.62 for the East region; R 2 : 0.69 for the year of 2009). The PM 2.5 concentrations generated through our developed models at 1-km grid cells in the state of Texas showed a decreasing trend from 2008 to 2013 and a higher reduction of predicted PM 2.5 in more polluted areas. Our findings suggest that mixed-effects regression models developed based on MAIAC AOD are a feasible approach to predict ground-level PM 2.5 in Texas. Predicted PM 2.5 concentrations at the 1-km resolution on a daily basis can be used for epidemiological studies to investigate short- and long-term health impact of PM 2.5 in Texas. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterizing the Vertical Profile of Aerosol Particle Extinction and Linear Depolarization over Southeast Asia and the Maritime Continent: The 2007-2009 View from CALIOP

NASA Technical Reports Server (NTRS)

Campbell, James R.; Reid, Jeffrey S.; Westphal, Douglas L.; Zhang, Jianglong; Tackett, Jason L.; Chew, Boon Ning; Welton, Ellsworth J.; Shimizu, Atsushi; Sugimoto, Nobuo; Aoki, Kazuma;

Sulfur plumes off Namibia

NASA Technical Reports Server (NTRS)

2002-01-01

Sulfur plumes rising up from the bottom of the ocean floor produce colorful swirls in the waters off the coast of Namibia in southern Africa. The plumes come from the breakdown of marine plant matter by anaerobic bacteria that do not need oxygen to live. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on April 24, 2002 Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Submicrometer Particle Sizing by Multiangle Light Scattering following Fractionation

PubMed

Wyatt

1998-01-01

The acid test for any particle sizing technique is its ability to determine the differential number fraction size distribution of a simple, well-defined sample. The very best characterized polystyrene latex sphere standards have been measured extensively using transmission electron microscope (TEM) images of a large subpopulation of such samples or by means of the electrostatic classification method as refined at the National Institute of Standards and Technology. The great success, in the past decade, of on-line multiangle light scattering (MALS) detection combined with size exclusion chromatography for the measurement of polymer mass and size distributions suggested, in the early 1990s, that a similar attack for particle characterization might prove useful as well. At that time, fractionation of particles was achievable by capillary hydrodynamic chromatography (CHDF) and field flow fractionation (FFF) methods. The latter has proven most useful when combined with MALS to provide accurate differential number fraction size distributions for a broad range of particle classes. The MALS/FFF combination provides unique advantages and precision relative to FFF, photon correlation spectroscopy, and CHDF techniques used alone. For many classes of particles, resolution of the MALS/FFF combination far exceeds that of TEM measurements. Copyright 1998 Academic Press. Copyright 1998Academic Press

Multipole expansion method for supernova neutrino oscillations

DOE PAGES

Duan, Huaiyu; Shalgar, Shashank

2014-10-31

Here, we demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.

Data processing technique for multiangle lidar sounding of poorly stratified polluted atmospheres: Theory and experiment

Treesearch

Cyle E. Wold; Vladimir A. Kovalev; Alexander P. Petkov; Wei Min Hao

2012-01-01

Scanning elastic lidar, which can operate in different slant directions, is the most appropriate remote sensing tool for investigating the optical properties of smoke-polluted atmospheres. However, the commonly used methodologies of multiangle measurements are based on the assumption of horizontal stratification of the searched atmosphere1,2. When working in real...

Profiling of poorly stratified smoky atmospheres with scanning lidar

Treesearch

Vladimir Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

2012-01-01

The multiangle data processing technique is considered based on using the signal measured in zenith (or close to zenith) as a core source for extracting the information about the vertical atmospheric aerosol loading. The multiangle signals are used as the auxiliary data to extract the vertical transmittance profile from the zenith signal. Simulated and experimental...

Modified technique for processing multiangle lidar data measured in clear and moderately polluted atmospheres

Treesearch

Vladimir Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

2011-01-01

We present a modified technique for processing multiangle lidar data that is applicable for relatively clear atmospheres, where the utilization of the conventional Kano-Hamilton method meets significant issues. Our retrieval algorithm allows computing the two-way transmission and the corresponding extinction-coefficient profile in any slope direction searched during...

Profiling of poorly stratified atmospheres with scanning lidar

Treesearch

C. E. Wold; V. A. Kovalev; A. P. Petkov; W. M. Hao

2012-01-01

The direct multiangle solution may allow inversion of the scanning lidar data even when the requirement of the horizontally stratified atmosphere is poorly met. The solution is based on two principles: (1) The signal measured in zenith is the core source for extracting the information about the atmospheric aerosol loading, and (2) The multiangle signals are used as...

Post-hurricane forest damage assessment using satellite remote sensing

Treesearch

W. Wang; J.J. Qu; X. Hao; Y. Liu; J.A. Stanturf

2010-01-01

This study developed a rapid assessment algorithm for post-hurricane forest damage estimation using moderate resolution imaging spectroradiometer (MODIS) measurements. The performance of five commonly used vegetation indices as post-hurricane forest damage indicators was investigated through statistical analysis. The Normalized Difference Infrared Index (NDII) was...

Coupled Retrieval of Aerosol Properties and Surface Reflection Using the Airborne Multi-angle SpectroPolarimetric Imager (AirMSPI)

NASA Astrophysics Data System (ADS)

Xu, F.; van Harten, G.; Kalashnikova, O. V.; Diner, D. J.; Seidel, F. C.; Garay, M. J.; Dubovik, O.

2016-12-01

The Airborne Multi-angle SpectroPolarimetric Imager (AirMSPI) [1] has been flying aboard the NASA ER-2 high altitude aircraft since October 2010. In step-and-stare operation mode, AirMSPI acquires radiance and polarization data at 355, 380, 445, 470*, 555, 660*, 865*, and 935 nm (* denotes polarimetric bands). The imaged area covers about 10 km by 10 km and is observed from 9 view angles between ±67° off of nadir. We have developed an efficient and flexible code that uses the information content of AirMSPI data for a coupled retrieval of aerosol properties and surface reflection. The retrieval was built based on the multi-pixel optimization concept [2], with the use of a hybrid radiative transfer model [3] that combines the Markov Chain [4] and adding/doubling methods [5]. The convergence and robustness of our algorithm is ensured by applying constraints on (a) the spectral variation of the Bidirectional Polarization Distribution Function (BPDF) and angular shape of the Bidirectional Reflectance Distribution Function (BRDF); (b) the spectral variation of aerosol optical properties; and (c) the spatial variation of aerosol parameters across neighboring image pixels. Our retrieval approach has been tested using over 20 AirMSPI datasets having low to moderately high aerosol loadings ( 0.02550-nm< 0.45) and acquired during several field campaigns. Results are compared with AERONET aerosol reference data. We also explore the benefits of AirMSPI's ultraviolet and polarimetric bands as well as the use of multiple view angles. References[1]. D. J. Diner, et al. Atmos. Meas. Tech. 6, 1717 (2013). [2]. O. Dubovik et al. Atmos. Meas. Tech. 4, 975 (2011). [3]. F. Xu et al. Atmos. Meas. Tech. 9, 2877 (2016). [4]. F. Xu et al. Opt. Lett. 36, 2083 (2011). [5]. J. E. Hansen and L.D. Travis. Space Sci. Rev. 16, 527 (1974).

Preliminary design study. Shuttle modular scanning spectroradiometer

NASA Technical Reports Server (NTRS)

1975-01-01

Fundamental concepts on which to base a detailed design for a Shuttle Modular Scanning Spectroradiometer were developed, and a preliminary design is presented. The recommended design features modularity and flexibility. It includes a 75-cm f/1.7-telescope assembly in an all-reflective Schmidt configuration, a solid state scan system (pushbroom) with high resolution over a 15 deg field of view, and ten detector channels covering the spectral range from 0.45 to 12.5 micrometers. It uses charge transfer device techniques to accommodate a large number of detector elements for earth observation measurements. Methods for in-flight radiometric calibration, for image motion compensation, and for data processing are described. Recommendations for ground support equipment are included, and interfaces with the shuttle orbiter vehicle are illustrated.

Huge Super Typhoon Meranti Over Taiwan Spotted by NASA MISR

NASA Image and Video Library

2016-09-14

On Sept. 14, 2016, the eye of Super Typhoon Meranti passed just south of Taiwan. The enormous storm, classified as a Category 5 typhoon at the time, still caused much disruption on the island. Nearly 500,000 homes lost power, schools were closed, and most flights were cancelled. Maximum wind speeds were 180 miles per hour (290 kilometers per hour) as the storm passed, and more than 25 inches (64 centimeters) of rain fell on some areas of the country. However, the storm did not pass over Taiwan's mountainous landscape, which would have weakened it. That means it will remain strong as it heads toward mainland China, unlike Super Typhoon Nepartak in July, which weakened from a Category 5 typhoon to a tropical storm after crossing Taiwan. Meranti is currently maintaining Category 4 strength and is expected to make landfall near Shantou, Guangdong province, on Thursday, September 15. The coast of China is more vulnerable to storm surges than Taiwan due to shallower coastal waters and recent rainfall. There is risk of substantial flooding. On Sept. 14, at 10:45 AM local time, the Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite passed directly over the eye of Meranti. On the left is a natural-color image from MISR's nadir-pointing camera. At this time the eye of Meranti was just off the southern tip of Taiwan, which is invisible under the clouds. The coast of China is barely visible through the clouds in the upper left portion of the image. The small eye and dense high clouds are both markers of the storm's power. MISR's nine cameras, each pointed at a different angle, can be used to determine the heights of clouds based on geometric shifts among the nine images. The middle panel shows these stereo-derived cloud top heights superimposed on the natural color image. The clouds of the central core of Typhoon Meranti have heights ranging between 16 and 20 kilometers (10 and 12.5 miles). It takes about seven minutes for all nine cameras to image the same location on the ground, and wind velocity can be calculated from the motion of the clouds over this seven-minute period. The right panel plots these wind velocities as vectors which indicate both direction and speed. The length of the arrow corresponds to the wind speed, which can be compared to the reference 20 meters per second (45 miles per hour) arrow in the key. Hurricanes and typhoons in the Northern Hemisphere rotate counterclockwise due to the Earth's rotation, but these wind vectors mainly show motion outward from the eye at the storm tops. This is due to the fact that hurricanes draw in moist air at low altitudes, which then flows upwards and outwards around the eye reversing direction. These data were acquired during Terra orbit 88865. http://photojournal.jpl.nasa.gov/catalog/PIA17309

Nile River Fluctuations Near Khartoum, Sudan

NASA Image and Video Library

2001-08-29

Throughout history, the rising and falling waters of the mighty Nile River have directly impacted the lives of the people who live along its banks. These images of the area around Sudan's capital city of Khartoum capture the river's dynamic nature. Acquired by the Multi-angle Imaging SpectroRadiometer's nadir (vertical-viewing) camera, they display the extent of the Nile waters before and after the onset of the rainy seasons of 2000 (top pair) and 2001 (bottom pair). The images are displayed in "false color," using the camera's near-infrared, green, and blue bands. With this particular spectral combination, water appears in shades of blue and turquoise, and highly vegetated areas show up as bright red. Originating in Uganda and Ethiopia, respectively, the waters of the White Nile (western branch) and Blue Nile (eastern branch) converge at Khartoum (about half-way between image center and the left-hand side), and continue to flow northward as the Great Nile. Although the most obvious feature in these images is the increased width of the White Nile between spring and summer, careful inspection shows that the Great Nile is at its widest in August 2001 (note in particular the area between the clouds near the top of this panel). Heavy rains in the Blue Nile catchment area of the Ethiopian highlands led to a rapid overflow of the river's floodwaters into the main stream of the Great Nile, leading to extensive flooding, the worst effects of which occurred north of Khartoum. According to the Food and Agriculture Organization of the United Nations, tens of thousands of people have fled their homes, and the number of people in need of urgent food assistance in Sudan, estimated at three million earlier in the year, was likely to increase with the onset of these floods. South of the confluence of the White Nile and the Blue Nile, the area of a cross-hatched appearance is the irrigated plain of El Gezira. The Gezira irrigation scheme uses water from the Makwar Dam (now called the Sennar Dam), located across the Blue Nile south of Khartoum. Among the main agricultural products of this region are cotton, millet, peanuts and fodder crops. Overall prospects for Sudan's 2001 grain crop were already poor prior to the flooding due to a late start of the rainy season in parts of the country. Following two consecutive years of serious drought, precipitation arrived too late to save the grain harvest that normally begins in late August. Lower harvests for the past two years coupled with depletion of stocks have led to a rise in cereal prices, reducing access to food for the Sudan's poorer citizens, already suffering from the effects of Africa's longest running civil war. Each of these images represents an area of about 130 kilometers x 150 kilometers. The data were obtained during Terra orbits 1922, 3553, 7281, and 8912. http://photojournal.jpl.nasa.gov/catalog/PIA03420

Growing Crack in Antarctica Larsen C Ice Shelf Spotted by NASA MISR

NASA Image and Video Library

2016-08-31

Project MIDAS, a United Kingdom-based group that studies the Larsen Ice Shelf in Antarctica, reported Aug. 18, 2016, that a large crack in the Larsen C shelf has grown by another 13 miles (22 kilometers) in the past six months. The crack is now more than 80 miles (130 kilometers) long. Larsen C is the fourth largest ice shelf in Antarctica, with an area of about 19,300 square miles (50,000 square kilometers), greater than the size of Maryland. Computer modeling by Project MIDAS predicts that the crack will continue to grow and eventually cause between nine and twelve percent of the ice shelf to collapse, resulting in the loss of 2,300 square miles (6,000 square kilometers) of ice -- more than the area of Delaware. This follows the collapse of the Larsen B shelf in 2002 and the Larsen A shelf in 1995, which removed about 1,255 square miles (3,250 square kilometers) and 580 square miles (1,500 square kilometers) of ice, respectively. The Multiangle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite flew over Larsen C on Aug. 22, 2016. The MISR instrument views Earth with nine cameras pointed at different angles, which provides information about the texture of the surface. On the left is a natural-color image of the shelf from MISR's vertical-viewing camera. Antarctica is slowly emerging from its polar night, and the low light gives the scene a bluish tint. The Larsen C shelf is on the left, while thinner sea ice is present on the right. A variety of cracks are visible in the Larsen C shelf, all appearing roughly the same. The image is about 130 by 135 miles (210 by 220 kilometers) in size. On the right is a composite image made by combining data from MISR's 46-degree backward-pointing camera (plotted as blue), the vertical-pointing camera (plotted as green), and the 46-degree forward-pointing camera (plotted as red). This has the effect of highlighting surface roughness; smooth surfaces appear as blue-purple, while rough surfaces appear as orange. Clouds near the upper left appear multi-hued because their elevation above the surface causes the different angular views to be slightly displaced. In this composite, the difference between the rough sea ice and the smoother ice shelf is immediately apparent. An examination of the cracks in the ice shelf shows that the large crack Project MIDAS is tracking (indicated by an arrow) is orange in color, demonstrating that it is actively growing. These data were acquired during Terra orbit 88717 http://photojournal.jpl.nasa.gov/catalog/PIA20894

NASA MISR Tracks Growth of Rift in the Larsen C Ice Shelf

NASA Image and Video Library

2017-04-11

A rift in Antarctica's Larsen C ice shelf has grown to 110 miles (175 km) long, making it inevitable that an iceberg larger than Rhode Island will soon calve from the ice shelf. Larsen C is the fourth largest ice shelf in Antarctica, with an area of almost 20,000 square miles (50,000 square kilometers). The calving event will remove approximately 10 percent of the ice shelf's mass, according to the Project for Impact of Melt on Ice Shelf Dynamics and Stability (MIDAS), a UK-based team studying the ice shelf. Only 12 miles (20 km) of ice now separates the end of the rift from the ocean. The rift has grown at least 30 miles (50 km) in length since August, but appears to be slowing recently as Antarctica returns to polar winter. Project MIDAS reports that the calving event might destabilize the ice shelf, which could result in a collapse similar to what occurred to the Larsen B ice shelf in 2002. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite captured views of Larsen C on August 22, 2016, when the rift was 80 miles (130 km) in length; December 8, 2016, when the rift was approximately 90 miles (145 km) long; and April 6, 2017. The MISR instrument has nine cameras, which view the Earth at different angles. The overview image, from December 8, shows the entire Antarctic Peninsula -- home to Larsen A, B, and C ice shelves -- in natural color (similar to how it would appear to the human eye) from MISR's vertical-viewing camera. Combining information from several MISR cameras pointed at different angles gives information about the texture of the ice. The accompanying GIF depicts the inset area shown on the larger image and displays data from all three dates in false color. These multiangular views -- composited from MISR's 46-degree backward-pointing camera, the nadir (vertical-viewing) camera, and the 46-degree forward-pointing camera -- represent variations in ice texture as changes in color, such that areas of rough ice appear orange and smooth ice appears blue. The Larsen C shelf is on the left in the GIF, bordered by the Weddell Sea on the upper right. The ice within the rift is orange, indicating movement, and the end of the rift can be tracked across the shelf between images. In addition, between December and April, the rift widened, pushing the future iceberg away from the shelf at its southern end. These data were acquired during Terra orbits 88717, 90290 and 92023. https://photojournal.jpl.nasa.gov/catalog/PIA21581

Fire in the Land of 100,000 Lakes

NASA Technical Reports Server (NTRS)

2001-01-01

Fire season in Manitoba, Canada lasts from April until October, and numerous smoke plumes caused by lightning strikes are captured in these Multi-angle Imaging SpectroRadiometer (MISR) views of the northwestern part of the province. The data were acquired on June 20, 2001 during Terra orbit 8015.

On the left is a true-color image acquired by MISR's vertical-viewing (nadir) camera. The area covered measures 232 kilometers X 80 kilometers. The greenish area on the right-hand side of the image, partially obscured by clouds, is Southern Indian Lake. This landscape is predominantly boreal, and contains deciduous and evergreen conifer forests, deciduous broadleaved forests, fens, and lakes. Tree species found within the area include white and black spruce, jack pine, tamarack, willow, and birch. Human population density is sparse, averaging about 1 person per 10 square kilometers.

During the fire season, information is updated daily on the Manitoba Conservation website (http://www.gov.mb.ca/natres/fire/). The large plume northwest of Big Sand Lake, above image center, was reported to be under control on June 20, whereas the plume at lower left, to the west of Gold Sand Lake, was classified 'out of control.' In the next two days, an additional 27 out-of-control fires in the area were started by lightning strikes arriving with as low-moving northerly cold front. By June 29, all but six of the fires had been brought under control.

The picture on the right is a height field derived using automated computer processing of the data from several of MISR's cameras. The results indicate that the smoke plumes reach altitudes a few kilometers above the surface terrain, nearly as high as the cumulus cloud field in the lower right quadrant. The height retrievals make use of geometric parallax associated with observing the features at multiple angles. A few artifacts are visible in this early version of the MISR stereoscopic product, e.g., linear discontinuities in the elevation field, isolated elevation 'spikes' (appearing as red), and black areas where no result was obtained. Nevertheless, this first version of the algorithm, which is designed to operate autonomously and rapidly without human intervention, is doing a good job at detecting the smoke plumes and cloud field. Improvements are anticipated in the future. The product was generated as part of operational processing at the NASA Langley Atmospheric Sciences Data Center.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

MODTRAN Radiance Modeling of Multi-Angle Worldview-2 Imagery

DTIC Science & Technology

2013-09-01

this thesis, multi-angle CHRIS data has been used to validate canopy BRDF models generated using PROSPECT and SAILH radiative transfer models (D’Urso...67 1. MODTRAN Modeling using BRDF Algorithms .............................67 2. MODTRAN Modeling of Hyperspectral Data...associated with BRDF , and (2) develop software- 2 based atmospheric models , using parameters similar to those found in the imagery, for comparison to

INDICATOR OF EUTROPHICATION AND SEDIMENT LOAD: HYPERSPECTRAL TECHNIQUE FOR CONTINUOUS COVERAGE OF DEEP RIVERS

EPA Science Inventory

Remote sensing techniques were used to characterize and quantify spatial and temporal variation in water quality of the Great Miami River in Ohio. An initial feasibility study was conducted in the summer of 1999 using a non-imaging hand-held spectroradiometer to ascertain the pr...

Satellite-based peatland mapping: potential of the MODIS sensor.

Treesearch

D. Pflugmacher; O.N. Krankina; W.B. Cohen

2006-01-01

Peatlands play a major role in the global carbon cycle but are largely overlooked in current large-scale vegetation mapping efforts. In this study, we investigated the potential of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to capture extent and distribution of peatlands in the St. Petersburg region of Russia.

Terrestrial Carbon Sinks in the Brazilian Amazon and Cerrado Region Predicted from MODIS Satellite Data and Ecosystem Modeling

EPA Science Inventory

A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2004. Pr...

HYPERSPECTRAL CHANNEL SELECTION FOR WATER QUALITY MONITORING ON THE GREAT MIAMI RIVER, OHIO

EPA Science Inventory

During the summer of 1999, spectral data were collected with a hand-held spectroradiometer, a laboratory spectrometer and airborne hyperspectral sensors from the Great Miami River (GMR), Ohio. Approximately 80 km of the GMR were imaged during a flyover with a Compact Airborne Sp...

Sub-Pixel Mapping of Tree Canopy, Impervious Surfaces, and Cropland in the Laurentian Great Lakes Basin Using MODIS Time-Series Data

EPA Science Inventory

This research examined sub-pixel land-cover classification performance for tree canopy, impervious surface, and cropland in the Laurentian Great Lakes Basin (GLB) using both timeseries MODIS (MOderate Resolution Imaging Spectroradiometer) NDVI (Normalized Difference Vegetation In...

HYPERSPECTRAL TECHNIQUE AS AN INDICATOR OF EUTROPHICATION AND SEDIMENT LOAD FOR DEEP RIVERS

EPA Science Inventory

Remote sensing techniques were used to characterize and quantify spatial and temporal variation in water quality of the Great Miami River in Ohio. An initial feasibility study was conducted in the summer of 1999 using a non-imaging hand-held spectroradiometer to ascertain the pre...

REFINING FIRE EMISSIONS FOR AIR QUALITY MODELING WITH REMOTELY-SENSED FIRE COUNTS: A WILDFIRE CASE STUDY

EPA Science Inventory

This paper examines the use of Moderate Resolution Imaging Spectroradiometer (MODIS) observed active fire data (pixel counts) to refine the National Emissions Inventory (NEI) fire emission estimates for major wildfire events. This study was motivated by the extremely limited info...

Analysis of the moderate resolution imaging spectroradiometer contextual algorithm for small fire detection

Treesearch

W. Wang; J.J. Qu; X. Hao; Y. Liu

2009-01-01

In the southeastern United States, most wildland fires are of low intensity. Asubstantial number of these fires cannot be detected by the MODIS contextual algorithm. Toimprove the accuracy of fire detection for this region, the remote-sensed characteristics ofthese fires have to be systematically...

Monitoring NEON terrestrial sites phenology with daily MODIS BRDF/albedo product and landsat data

USDA-ARS?s Scientific Manuscript database

The MODerate resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) and albedo products (MCD43) have already been in production for more than a decade. The standard product makes use of a linear “kernel-driven” RossThick-LiSparse Reciprocal (RTLSR) BRDF m...

LINKING IN SITU TIME SERIES FOREST CANOPY LAI AND PHENOLOGY METRICS WITH MODIS AND LANDSAT NDVI AND LAI PRODUCTS

EPA Science Inventory

The subject of this presentation is forest vegetation dynamics as observed by the TERRA spacecraft's Moderate-Resolution Imaging Spectroradiometer (MODIS) and Landsat Thematic Mapper, and complimentary in situ time series measurements of forest canopy metrics related to Leaf Area...

SATELLITE REMOTE SENSING AND GROUND-BASED ESTIMATES OF FOREST BIOMASS AND CANOPY STRUCTURE

EPA Science Inventory

MODIS (Moderate Resolution Imaging Spectroradiometer) launched in 1999 is the first satellite sensor to provide the kind of data necessary to intensively probe the global landscape for LAl. Because it is a new sensor, its data products must be validated with ground data. This res...

East Siberian Sea, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

The winter sea ice in the east Siberian Sea is looking a bit like a cracked windshield in these true-color Moderate Resolution Imaging Spectroradiometer (MODIS) images from June 16 and 23, 2002. North of the thawing tundra, the sea ice takes on its cracked, bright blue appearance as it thins, which allows the reflection of the water to show through. Numerous still-frozen lakes dot the tundra. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Wildfires, smoke, and burn scars, near Yakutsk, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

The Lena River in central Siberia is hidden beneath a veil of smoke from multiple wildfires burning around the city of Yakutsk, Russia. Fires have been burning in the region off and on since late May 2002, and may be agricultural in cause. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on July 23, 2002. In the false=-color image, vegetation is bright green, smoke is blueish-white, and burned areas are reddish-brown. In both images, fire detections are marked with red outlines. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

MODIS: Moderate-resolution imaging spectrometer. Earth observing system, volume 2B

NASA Technical Reports Server (NTRS)

1986-01-01

The Moderate-Resolution Imaging Spectrometer (MODIS), as presently conceived, is a system of two imaging spectroradiometer components designed for the widest possible applicability to research tasks that require long-term (5 to 10 years), low-resolution (52 channels between 0.4 and 12.0 micrometers) data sets. The system described is preliminary and subject to scientific and technological review and modification, and it is anticipated that both will occur prior to selection of a final system configuration; however, the basic concept outlined is likely to remain unchanged.

Typhoon Chataan off Japan

NASA Technical Reports Server (NTRS)

2002-01-01

Slowly winding its way down, Typhoon Chataan had dropped to tropical storm status by Thursday, July 11, 2002, when this image from the Moderate Resolution Imaging Spectroradiometer (MODIS) was captured. In the image, the storm is located off the east coast of central Japan in the Pacific Ocean. The storm is much less organized than it was in the previous day's image. Through a gap in the clouds to the southwest of the storm's eye, Tokyo can be seen as a grayish cluster of pixels surrounding a small bay or inlet that protrudes into the island of Honshu. Credit: Image courtesy Jesse Allen, NASA Earth Observatory; data provided by the MODIS Land Rapid Response Team

Absorption Properties of Mediterranean Aerosols Obtained from Multi-year Ground-based and Satellite Remote Sensing Observations

NASA Technical Reports Server (NTRS)

Mallet, M.; Dubovik, O.; Nabat, P.; Dulac, F.; Kahn, R.; Sciare, J.; Paronis, D.; Leon, J. F.

2013-01-01

Aerosol absorption properties are of high importance to assess aerosol impact on regional climate. This study presents an analysis of aerosol absorption products obtained over the Mediterranean Basin or land stations in the region from multi-year ground-based AERONET and satellite observations with a focus on the Absorbing Aerosol Optical Depth (AAOD), Single Scattering Albedo (SSA) and their spectral dependence. The AAOD and Absorption Angstrom Exponent (AAE) data set is composed of daily averaged AERONET level 2 data from a total of 22 Mediterranean stations having long time series, mainly under the influence of urban-industrial aerosols and/or soil dust. This data set covers the 17 yr period 1996-2012 with most data being from 2003-2011 (approximately 89 percent of level-2 AAOD data). Since AERONET level-2 absorption products require a high aerosol load (AOD at 440 nm greater than 0.4), which is most often related to the presence of desert dust, we also consider level-1.5 SSA data, despite their higher uncertainty, and filter out data with an Angstrom exponent less than 1.0 in order to study absorption by carbonaceous aerosols. The SSA data set includes both AERONET level-2 and satellite level-3 products. Satellite-derived SSA data considered are monthly level 3 products mapped at the regional scale for the spring and summer seasons that exhibit the largest aerosol loads. The satellite SSA dataset includes the following products: (i) Multi-angle Imaging SpectroRadiometer (MISR) over 2000-2011, (ii) Ozone Monitoring Instrument (OMI) near-UV algorithm over 2004-2010, and (iii) MODerate resolution Imaging Spectroradiometer (MODIS) Deep-Blue algorithm over 2005-2011, derived only over land in dusty conditions. Sun-photometer observations show that values of AAOD at 440 nm vary between 0.024 +/- 0.01 (resp. 0.040 +/- 0.01) and 0.050 +/- 0.01 (0.055 +/- 0.01) for urban (dusty) sites. Analysis shows that the Mediterranean urban-industrial aerosols appear "moderately" absorbing with values of SSA close to approximately 0.94-0.95 +/- 0.04 (at 440 nm) in most cases except over the large cities of Rome and Athens, where aerosol appears more absorbing (SSA approximately 0.89-0.90 +/- 0.04). The aerosol Absorption Angstrom Exponent (AAE, estimated using 440 and 870 nm) is found to be larger than 1 for most sites over the Mediterranean, a manifestation of mineral dust (iron) and/or brown carbon producing the observed absorption. AERONET level-2 sun-photometer data indicate the existence of a moderate East-West gradient, with higher values over the eastern basin (AAEEast. = 1.39/AAEWest. = 1.33) due to the influence of desert dust. The North-South AAE gradient is more pronounced, especially over the western basin. Our additional analysis of AERONET level-1.5 data also shows that organic absorbing aerosols significantly affect some Mediterranean sites. These results indicate that current climate models treating organics as nonabsorbing over the Mediterranean certainly underestimate the warming effect due to carbonaceous aerosols. Acomparative analysis of the regional SSA variability has been attempted using satellite data. OMI and MODIS data show an absorbing zone (SSA approximately 0.90 at 470-500 nm) over Northeastern Africa that does not appear in the MISR retrievals. In contrast, MISR seems able to observe the East-West SSA gradient during summer, as also detected by AERONET. Also, the analysis of SSA provided by satellites indicates that the aerosol over the Mediterranean Sea appears less absorbing during spring (MAM) than summer (JJA).

Lena River Delta and East Siberian Sea

NASA Technical Reports Server (NTRS)

2002-01-01

The winter sea ice in the east Siberian Sea is looking a bit like a cracked windshield in these true-color Moderate Resolution Imaging Spectroradiometer (MODIS) images from June 16 and 23, 2002. North of the thawing tundra, the sea ice takes on its cracked, bright blue appearance as it thins, which allows the reflection of the water to show through. Numerous still-frozen lakes dot the tundra. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Rapid mapping of hurricane damage to forests

Treesearch

Erik M. Nielsen

2009-01-01

The prospects for producing rapid, accurate delineations of the spatial extent of forest wind damage were evaluated using Hurricane Katrina as a test case. A damage map covering the full spatial extent of Katrina?s impact was produced from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery using higher resolution training data. Forest damage...

Evaluation of MODIS NPP and GPP products across multiple biomes.

Treesearch

David P. Turner; William D. Ritts; Warren B. Cohen; Stith T. Gower; Steve W. Running; Maosheng Zhao; Marcos H. Costa; Al A. Kirschbaum; Jay M. Ham; Scott R. Saleska; Douglas E. Ahl

2006-01-01

Estimates of daily gross primary production (GPP) and annual net primary production (NPP) at the 1 km spatial resolution are now produced operationally for the global terrestrial surface using imagery from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. Ecosystem-level measurements of GPP at eddy covariance flux towers and plot-level measurements of...

Monitoring start of season in Alaska with GLOBE, AVHRR, and MODIS data

Treesearch

Jessica Robin; Ralph Dubayah; Elena Sparrow; Elissa Levine

2008-01-01

This work evaluates whether continuity between Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) is achievable for monitoring phenological changes in Alaska. This work also evaluates whether NDVI can detect changes in start of the growing season (SOS) in this region....

Use of Normalized Difference Water Index for monitoring live fuel moisture

Treesearch

D.A. Roberts; P.E. Dennison; S.H. Peterson; J. Rechel

2006-01-01

Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) were compared for monitoring live fuel moisture in a shrubland ecosystem. Both indices were calculated from 500m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance data covering a 33-month period from 2000 to 2002. Both NDVI and NDWI were...

East Asian dust storm in May 2017: observations, modelling and its influence on Asia-Pacific region

USDA-ARS?s Scientific Manuscript database

A severe dust storm event originated from the Gobi Desert in Central and East Asia during 2-7 May, 2017. Based on moderate resolution imaging spectroradiometer (MODIS) satellite products, hourly environmental monitoring measurements from 367 Chinese cities and more than 2000 East Asian meteorologica...

Moderate Resolution Imaging Spectroradiometer (MODIS) MOD21 Land Surface Temperature and Emissivity Algorithm Theoretical Basis Document

NASA Technical Reports Server (NTRS)

Hulley, G.; Malakar, N.; Hughes, T.; Islam, T.; Hook, S.

2016-01-01

This document outlines the theory and methodology for generating the Moderate Resolution Imaging Spectroradiometer (MODIS) Level-2 daily daytime and nighttime 1-km land surface temperature (LST) and emissivity product using the Temperature Emissivity Separation (TES) algorithm. The MODIS-TES (MOD21_L2) product, will include the LST and emissivity for three MODIS thermal infrared (TIR) bands 29, 31, and 32, and will be generated for data from the NASA-EOS AM and PM platforms. This is version 1.0 of the ATBD and the goal is maintain a 'living' version of this document with changes made when necessary. The current standard baseline MODIS LST products (MOD11*) are derived from the generalized split-window (SW) algorithm (Wan and Dozier 1996), which produces a 1-km LST product and two classification-based emissivities for bands 31 and 32; and a physics-based day/night algorithm (Wan and Li 1997), which produces a 5-km (C4) and 6-km (C5) LST product and emissivity for seven MODIS bands: 20, 22, 23, 29, 31-33.