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Lubin, D, Jensen EH.  1997.  Satellite mapping of solar ultraviolet radiation at the earth's surface. Solar ultraviolet radiation : modelling, measurements, and effects. ( Zerefos CS, Bais AF, Eds.)., Berlin; New York: Springer Abstract
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Satheesh, SK, Lubin D.  2003.  Short wave versus long wave radiative forcing by Indian Ocean aerosols: Role of sea-surface winds. Geophysical Research Letters. 30   10.1029/2003gl017499   AbstractWebsite

[1] Recent observations over the Indian Ocean have demonstrated aerosol short wave absorption as high as 20 to 25 W m(-2). The aerosol net radiative forcing reduces substantially while considering the broad spectrum including the long wave region (due to large infrared forcing which is opposite in sign). At highwinds, presence of large amounts of sea-salt aerosols (absorbing in infrared) enhances the infrared forcing; hence reduces the net radiative forcing. In this paper, we examine the role of sea-surface winds (which enhance sea-salt aerosols) on long wave aerosol forcing. Even at moderate winds (6-10 m s(-1)), the short wave forcing reduces by similar to45% due to the dominance of sea-salt aerosols. At high winds (>10 m s(-1)), a major fraction of the long wave forcing is contributed by sea-salt (more than 70%). Our studies show that neglecting aerosol long wave radiative forcing can cause large errors in climate models.

Lubin, D, Ricchiazzi P, Payton A, Gautier C.  2002.  Significance of multidimensional radiative transfer effects measured in surface fluxes at an Antarctic coastline. Journal of Geophysical Research-Atmospheres. 107   10.1029/2001jd002030   AbstractWebsite

[1] At a coastal high-latitude site, multiple reflection of photons between the high albedo surface and an overlying cloud can enhance the downwelling shortwave flux out over the adjacent open water to a distance of several kilometers. This coastal albedo effect has been predicted by theoretical radiative transfer studies and has also been measured under ideal conditions. In this study, three multispectral solar ultraviolet radiometers were deployed in the vicinity of Palmer Station, Antarctica (64degrees 46'S, 64degrees 04'W) to determine the prevalence of the coastal albedo effect under the region's natural variability in cloud cover. One radiometer was deployed near the base of a glacier, and the other two radiometers were deployed on Janus Island and Outcast Island, islets similar to2.8 km (1.5 nautical miles) and 5.6 km (3 nautical miles) distant from Palmer Station, respectively. The radiometers were operated simultaneously for 16 days during late December 1999 and January 2000. Under all cloudy sky conditions sampled by this experiment the coastal albedo effect is seen in the data 60% of the time, in the form of a decreasing gradient in surface flux from Palmer Station through Janus and Outcast Islands. During the other 40% of the cloudy sky measurements, local cloud inhomogeneity obscured the coastal albedo effect. The effect is more apparent under overcast layers that appear spatially uniform and occurs 86% of the time under the low overcast decks sampled. The presence of stratus fractus of bad weather, under higher overcast layers, obscures the coastal albedo effect such that it occurs only 43% of the time. A wavelength dependence is noted in the data under optically thin cloud cover: the ratio of a flux measured at an islet to that measured at the station increases with wavelength. This wavelength dependence can be explained by plane-parallel radiative transfer theory.

Morrow, E, Scheeres DJ, Lubin D.  2001.  Solar sail orbit operations at asteroids. Journal of Spacecraft and Rockets. 38:279-286.   10.2514/2.3682   AbstractWebsite

The inherent capabilities of solar sails and that they need no onboard supplies of fuel for propulsion make them well suited for use in long-term, multiple-objective missions. They are especially well suited for the exploration of asteroids, where one spacecraft could rendezvous with a number of asteroids in succession. The orbital mechanics of solar sail operations about an asteroid, however, have not yet been studied in detail. Building an previous studies, we find both hovering points and orbiting trajectories about various sized asteroids using equations of motion for a solar sail spacecraft. The orbiting trajectories are stable and offer good coverage of the asteroid surface, although restrictions on sail acceleration are needed for smaller asteroids.

Holm-Hansen, O, Lubin D.  1994.  Solar ultraviolet radiation: effect on rates of CO2 fixation in marine phytoplankton. Regulation of atmospheric CO2 and O2 by photosynthetic carbon metabolism. ( Tolbert NE, Preiss J, Eds.).:55-74., New York; Oxford: Oxford University Press Abstract
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Lubin, D, Cutchin D, Conant W, Grassl H, Schmid U, Biselli W.  1995.  Spectral Longwave Emission in the Tropics - Ftir Measurement at the Sea-Surface and Comparison with Fast Radiation Codes. Journal of Climate. 8:286-295.   10.1175/1520-0442(1995)008<0286:sleitt>2.0.co;2   AbstractWebsite

Longwave emission by the tropical western Pacific atmosphere has been measured at the ocean surface by a Fourier Transform Infrared (FTIR) spectroradiometer deployed aboard the research vessel John Vickers as part of the Central Equatorial Pacific Experiment. The instrument operated throughout a Pacific Ocean crossing, beginning on 7 March 1993 in Honiara, Solomon Islands, and ending on 29 March 1993 in Los Angeles, and recorded longwave emission spectra under atmospheres associated with sea surface temperatures ranging from 291.0 to 302.8 K. Precipitable water vapor abundances ranged from 1.9 to 5.5 column centimeters. Measured emission spectra (downwelling zenith radiance) covered the middle infrared (5-20 mu m) with one inverse centimeter spectral resolution. FTIR measurements made under an entirely clear field of view are compared with spectra generated by LOWTRAN 7 and MODTRAN 2, as well as downwelling flux calculated by the NCAR Community Climate Model (CCM-2) radiation code, using radiosonde profiles as input data for these calculations. In the spectral interval 800-1000 cm(-1), these comparisons show a discrepancy between FTIR data and MODTRAN 2 having an overall variability of 6-7 mW m(-2) sr(-1) cm and a concave shape that may be related to the representation of water vapor continuum emission in MODTRAN 2. Another discrepancy appears in the spectral interval 1200-1300 cm(-1), where MODTRAN 2 appears to overestimate zenith radiance by 5 mW m(-2) sr(-1) cm. These discrepancies appear consistently; however, they become only slightly larger at the highest water vapor abundances. Because these radiance discrepancies correspond to broadband (500-2000 cm(-1)) flux uncertainties of around 3 W m(-2), there appear to be no serious inadequacies with the performance of MODTRAN 2 or LOWTRAN 7 at high atmospheric temperatures and water vapor abundances. On average, CCM-2 flux calculations agree to within 1 W m(-2) with downwelling flux estimates from the FTIR data over all sea surface temperatures, although this result has a scatter of +/-12 W m(-2) at high sea surface temperatures.

Lubin, D, Li W, Dustan P, Mazel CH, Stamnes K.  2001.  Spectral signatures of coral reefs: Features from space. Remote Sensing of Environment. 75:127-137.   10.1016/s0034-4257(00)00161-9   AbstractWebsite

The special signatures of coral reefs and related scenes, as they would be measured above the Earth's atmosphere, are calculated using a coupled atmosphere-ocean discrete ordinates radiative transfer model. Actual measured reflectance spectra from field work are used as input data. Four coral species are considered, to survey the natural range of coral reflectance: Montastrea cavernosa, Acropora palmata, Dichocoenia stokesii, and Siderastrea siderea. Four noncoral objects associated with reefs are also considered: sand, coralline algae, green macroalgae, and algal turf. The reflectance spectra as would be measured at the top of the atmosphere are substantially different from the in situ spectra, due to differential attenuation by the water column and, most importantly, by atmospheric Rayleigh scattering. The result is that many of the spectral features that can be used to distinguish coral species from their surroundings or from one another, which have been used successfully with surface or aircraft data, would be obscured in spectral measurements from a spacecraft. However, above the atmosphere, the radiance contrasts between most coral species and most brighter noncoral objects remain noticeable for water column depths up to 20 m. Over many spectral intervals, the reflectance from dark coral under shallow water is smaller than that of deep water. The maximum top-of-atmosphere radiances, and maximum contrasts between scene types, occur between 400 nm and 600 nm. This study supports the conclusions of recent satellite reef mapping exercises, suggesting that coral reef identification should be feasible using satellite remote sensing, but that detailed reef mapping (e.g., species identification) may be more difficult. (C) Elsevier Science Inc., 2001.

Xiong, XZ, Stamnes K, Lubin D.  2002.  Surface albedo over the Arctic Ocean derived from AVHRR and its validation with SHEBA data. Journal of Applied Meteorology. 41:413-425.   10.1175/1520-0450(2002)041<0413:saotao>2.0.co;2   AbstractWebsite

A method is presented for retrieving the broadband albedo over the Arctic Ocean using advanced very high resolution radiometer (AVHRR) data obtained from NOAA polar-orbiting satellites. Visible and near-infrared albedos over snow and ice surfaces are retrieved from AVHRR channels 1 and 2, respectively, and the broadband shortwave albedo is derived through narrow-to-broadband conversion (NTBC). It is found that field measurements taken under different conditions yield different NTBC coefficients. Model simulations over snow and ice surfaces based on rigorous radiative transfer theory support this finding. The lack of a universal set of NTBC coefficients implies a 5%-10% error in the retrieved broadband albedo. An empirical formula is derived for converting albedo values from AVHRR channels 1 and 2 into a broadband albedo under different snow and ice surface conditions. Uncertain calibration of AVHRR channels 1 and 2 is the largest source of uncertainty, and an error of 5% in satellite-measured radiance leads to an error of 5%-10% in the retrieved albedo. NOAA-14 AVHRR data obtained over the Surface Heat Budget of the Arctic Ocean (SHEBA) ice camp are used to derive the seasonal variation of the surface albedo over the Arctic Ocean between April and August of 1998. Comparison with surface measurements of albedo by Perovich and others near the SHEBA ice camp shows very good agreement. On average, the retrieval error of albedo from AVHRR is 5%-10%.

Kerr, J, Seckmeyer G, Bais AF, Bernhard G, Blumthaler M, Diaz SB, Krotkov NA, Lubin D, Mckenzie RL, Sabziparvar AA, Verdebout J.  2002.  Surface Ultraviolet Radiation: Past and Future. Scientific assessment of ozone depletion, 2002. Executive summary. ( Organization W, Ed.).:5.1-5.46., [Washington, D.C.]; [Nairobi, Kenya]; [Geneva, Switzerland]; [Brussels, Belgium]: National Oceanic and Atmospheric Administration : National Aeronautics and Space Administration ; United Nations Environment Programme ; World Meteorological Organization ; European Commission Abstract
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Bais, AF, Lubin D, Arola A, Bernhard G, Blumthaler M, Chubarova N, Erlick C, Gies HP, Krotkov NA, Lantz K, Mayer B, Mckenzie RL, d. Piacentini R, Seckmeyer G, Slusser JR, Zerefos CZ.  2007.  Surface Ultraviolet Radiation: Past, Present, and Future. Scientific assessment of ozone depletion: 2006. ( Organization W, Ed.)., Geneva, Switzerland: World Meteorological Organization Abstract
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