A microwave radiometer (MWR) at NOAA-CESSRST in Manhattan, NYC has experienced interference from nearby sources operating in the 5G FR2 n257 band (26.50--29.50 GHz). In this poster, we produce interference using a mobile 28 GHz IBM Phased Array Antenna Module (PAAM). The mobile PAAM leverages a software-defined radio which offers flexibility in varying center frequency, modulation, gain, bandwidth, time schedule, and more. In this poster, we show preliminary experiments which successfully created controlled interference to a MWR's 28 GHz channel which lead to distortion in some of the MWR final products, such as water vapor profile. We transmitted a 10 MHz bandwidth OFDM signal with varying amplitude, observing the highly sensitive MWR voltage response to fractional dB increments of the transmitter gain. The mobile PAAM is characterized in an anechoic chamber and MWR measurements are taken at various azimuth angles to help estimate the MWR antenna pattern. Future work will develop a Spectrum Consumption Model to help enable coexistence of MWRs and Beyond-5G networks.

A 1.5-μm all-fiber coherent Doppler lidar system for wind sensing was developed and characterized. The system design and implementation is presented. The system employs a 20-kHz pulse repetition rate transmitter and samples return signals at 400 MHz. A field-programmable gate array is programmed to generate and accumulate real-time periodograms representing average power spectra of the Doppler shifted echo from a series of more than 60 range gates, where each range gate is 48 m. The accumulated periodograms are streamed to a host computer for subsequent processing to yield the line-of-sight wind velocity. Wind velocity estimates with a precision value of 0.08 m/s can be made under nominal aerosol loading and nominal atmospheric turbulence conditions for ranges up to 3 km. Wind velocities and aerosol profiles are obtained while scanning the pointing direction of the lidar, thus producing both horizontal and vertical representations of the wind vectors.

Sun photometric measurements are an important method of measuring the column amount and optical properties of atmospheric aerosols and are frequently used to better understand the impact of aerosols on the Earth's radiative budget. This paper assesses two calibration techniques used for multifilter rotating shadowband radiometers (MFRSRs) and presents the results obtained at Long Island, NY, during the July 2011 Aerosol Life Cycle Intensive Operational Period (IOP) campaign. The instrument calibration constants are validated internally against each other and against an independent quantitative technique based on the solar irradiance at the top of the atmosphere, convolved with the MFRSR filter response. In addition, the aerosol optical parameters obtained from the MFRSR are assessed against the same parameters retrieved with a recently calibrated CIMEL sun/sky radiometer collocated with the MFRSR instrument. These comparisons indicate generally good agreement between the two instruments for both calibration techniques. The advantages and disadvantages of the two techniques are presented. Additionally, an analysis of the optical and physical properties of aerosols from the MFRSR and their chemical compositions obtained by an in situ high-resolution time-of-flight aerosol mass spectrometer, together with back trajectories, indicate that the principal source of high concentrations of fine aerosols observed during July 18-24 was forest fires in western Canada.

Urban areas suffer from high pollutant loadings due to their proximity to emission sources as well as transported aerosols. Therefore it is essential to have an accurate technique for measuring the pollutants and evaluate their effect. Since the atmosphere mixing height (MH) defines the total volume available for the pollutant transport and dispersion, it is important that air-quality models can provide realistic estimates. This paper studies multiple instruments for MH determination and their potential for validating air-quality model forecasts such as WRF. In addition, use of automated PBL height retrieval using wavelet analysis is briefly described and long term statistical comparisons of MH and WRF mixing height are obtained.

In this paper, we demonstrate a regional approach to Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) retrieval over urban scenes. By using simultaneous MODIS and AErosol RObotic NETwork (AERONET) sky radiometer data, we show that for urban scenes, the surface reflectance ratios between the visible (VIS) (0.47- and 0.66-¿m) and shortwave-infrared (2.12-¿m) channels used in the MODIS Collection 5 (C005) retrieval are significantly underestimated. This leads to an underestimate in the VIS ground albedos resulting in a significant overestimate of the AOD in the VIS channels. Since the dependence on scattering geometry is weak, revised surface reflectance ratio maps at spatial resolutions down to 1.5 km can be developed, permitting aerosol retrievals at these resolutions. Applying this procedure results in significant reductions in MODIS-retrieved AOD bias in comparison to AERONET. As an example, for New York City, at the operational 10-km resolution, the MODIS-AERONET regression using C005 is ¿MODIS= 1.24 ¿AERONET+ 0.11,R2= 0.85 , while for the regional method, we apply results in ¿MODIS= 1.02 ¿AERONET+ 0.04,R2= 0.92 . This improved performance is maintained even for high-resolution retrieval down to 1.5 km with a regression of ¿MODIS= 0.96 ¿AERONET+ 0.02,R2= 0.88. In addition, we show that this method can be extended to other urban scenes such as Mexico City with similar results and discuss the implications of C005 AOD overestimates on PM2.5 monitoring. Furthermore, comparisons with distributed PM2.5 sensors in the region confirm that the high estimates of AOD from C005 cannot be explained by excess urban emissions.

Information about global distributions of aerosol optical thickness (AOT) and size categorization is necessary to quantify the aerosol radiative forcing as well as a method to monitor air-quality such as fine particulate matter. The development of suitable radiometer networks is central to this effort. Modern robotic solar instruments for retrievals of aerosols optical depth and other microphysical parameter retrievals, such as the CIMEL Sky Scanning Radiometers part of the Aeronet Network are crucial to this effort but are unfortunately quite sparse and expensive. It has been proposed that the use of more cost effective devices likes the Multi-Filter Rotating Shadow-band Radiometer in a network might prove sufficient. Direct observations of the effects of aerosols are quite limited even with current advances in satellite base aerosols remote sensing.

In this paper, the usefulness of multi-wavelength lidar measurements to study the interaction of aerosols in the PBL with long range advected aerosol plumes is presented. Lidar's measurements are used to determine the plume angstrom exponent, which is used to differentiate smoke events from dust events, as well as partitioning the total aerosol optical depth obtained from a CIMEL sky radiometer between the PBL and the high altitude plumes. Furthermore, the correlation between the lidar derived PBL aerosol optical depth and surface PM2.5 is high, only if the optical depth from the upper level plumes is taken into account. In addition, the dynamic interaction of high altitude plumes interacting with the PBL result a dramatic rise in surface PM10 concentrations without a corresponding dramatic rise in PM2.5 concentrations. These observations strongly suggest the deposition of large particulates into the PBL which is consistent with both lidar angstrom coefficient measurements and back-trajectory analysis.

Chlorophyll Fluorescence Line Height [FLH] is analyzed based on the spatial similarity between MODIS [Chl] and FLH maps. FLH and [Chl] data of areas with high degree of spatial similarity were extracted from the whole scene and compared with the simple theoretical model of the expected variations of fluorescence magnitude with variations in chlorophyll concentration, absorption of non-algal particles, photosynthetically available radiation as well as solar zenith and viewing angles. Extracted data show good agreement with the model. Based on the model and satellite FLH data, fluorescence quantum yield is estimated.

Improvement of algorithms for the retrieval of inherent optical properties (IOPs) as well as concentrations of chlorophyll (CHL) and minerals from the recorded reflectance spectra remains an important issue in the analysis of water quality in coastal zones. It is expected that the retrievals could be improved if both UV and NIR channels are added to the existing VIS bands. This paper examines the performance of over constrained linear matrix inversion with statistical selection algorithm when additional information from UV and NIR channels is added to the retrievals for both synthetic and field data.

In this paper, we focus on the use of simultaneous MODIS and AERONET sky radiometer data to regionally refine the MODIS surface albedo models which are used for the AOD retrieval over land and improve on the current operational retrieval. In particular, we show that the correlation coefficient assumption used in the MODIS Collection (5) model between the VIS and MIR channels used for surface reflection parameterization are still severely optical depth. When applying the new VIS/MIR surface reflectance ratio model, we show the MODIS and AERONET derived optical thickness agreement is significantly improved for the operational 10 km resolution product. Furthermore, we show the high resolution surface model allows us to improve the resolution of the retrieved AOD to 1.5 km. We find the AOD spatial variability from the improved MODIS retrievals is in far better underestimated in an urban area in comparison with high spatial resolution imagery data from Hyperion thereby leading to an underestimate in the VIS ground albedos and explaining the subsequent overestimation of the VIS aerosol.

Polarized solar radiation reflected from water bodies contains useful additional information on inherent optical properties, concentrations and size distributions of water constituents if compared with unpolarized data. We report the use of a modified hyperspectral radiance sensor with very high sensitivity in order to study in detail polarization characteristics of reflectance from field measurements in coastal waters. To compare multi-angular hyperspectral field measurements with theory, radiative transfer computations of the water-leaving radiance were performed. Good agreement between simulation and angularly-resolved field measurements was observed in a certain angular range, which can be considered less affected by Sun glint. The results of the analysis are also used to develop design criteria for effective polarization sensors aimed to measure above and underwater characteristics of polarized light in coastal regions.

To provide reasonable forcasts of near surface PM2.5 levels, it necessary that satellite measurments provide a reasonable estimator of PM2.5 which can be coupled to a transport model Unfortunately this requires that the aerosol be homogeneously mixed and that the extent of the PBL be sufficiently accurate. For example, the IDEA product (Infusing satellite Data into Environmental Applications) used by the EPA relies on a static relationship connecting PM2.5 to MODIS aerosol optical depth (AOD) which relies on a static model of the PBL aerosol height. In this paper, we show that the PBL height is far from static and by taking the variable PBL into account, a far better prediction of PM2.5 from the MODIS (AOD) measurements is obtained.

The need for accurate calibration is apparent for accurate retrievals of backscatter at 1064nm. Due to the low molecular scattering in comparison to the aerosol component, it is not possible to use a rayleigh calibration procedure which is suitable for the 355 and 532nm channels and aan alternative approach is needed. In particular,a modified cirrus cloud calibration method is considered which uses the fact that the ciurrus cloud scatter is spectrally independent together with an approach to properly estimate the backscatter at cloud base. We find that the calibration accuracy can be takenm within 15% which is reasonable agreement with the uncertainry in the backscatter color ratio between 532nm and 1064nm

Variations of bidirectional reflectance effects in coastal waters are analyzed based on extensive radiative transfer simulations of remote sensing reflectances and field data, which are compared with existing models. Improved relationships are proposed which better accounts for BRDF effects but should be further verified for a broader range of synthetic data with various sun, viewing and azimuth angles as well as insitu datasets.

The collection 5 MODIS aerosol algorithm was designed to be more robust in handling surface reflection by differentiating different surfaces. When compared to the old collection 4 algorithm, we found that although there was some improvement, the MODIS retrievals were still biased high. This result was traced to the fact that the correlation coefficient in collect 5 was still too low compared to results from Hyperion. To address this issue, a regional surface albedo model is obtained based on matchups of CIMEL sunphotometer and MODIS retrievals. Given the optical depth measurments and utilizing the urban aerosol phase function (tuned by AOD) , we obtained a set of reflectance measurements which were than regressed against the scattering angle. Using this surface model, we recalculated the AOD using MODIS over a different set of measurments and saw a significant reduction in bias.

Water vapor is an important greenhouse gas due to its high concentration in the atmosphere (parts per thousand) and its interaction with tropospheric aerosols particles. The upward convection of water vapor and aerosols due to intense heating of the ground leads to aggregation of water particles or ice on aerosols in the air forming different types of clouds at various altitudes. The condensation of water vapor on aerosols is affecting their size, shape, refractive index and chemical composition. The warming or cooling effect of the clouds hence formed are both possible depending on the cloud location, cover, composition and structure. The effect of these clouds on radiative global forcing and therefore on the short and long term global climate is of high interest in the scientific world. A major interest is manifested in obtaining accurate vertical water vapor profiles simultaneously with aerosol extinction and backscatter in the meteorological and remote sensing fields all around the globe in an effort to understand the hygroscopic properties of aerosols. In previous work, simultaneous measurements of RH with backscatter measurements from a surface nephelometer were used to probe the hygroscopic properties of aerosols. However, most of these measurements were not able to probe the high RH domain since such high RH is rare for surface altitudes. For this reason, experiments using a 355nm raman water vapor and aerosol lidar at the ARM site were used. Capable of providing simultaneous backscatter and RH profiles, and performing the experiments under low altitude cloud decks insured stable well mixed layers as well as probing RH profiles to above 95% which is required for the differentiation of different aerosol hygroscopic models.

Performance of fluorescence height algorithms is analyzed based on synthesized and field data. In this paper we analyze performance of these algorithms for coastal waters conditions, using results of comprehensive measurements of the water parameters in the Chesapeake Bay in July 2005. Underwater upwelling radiances near water surface were measured by a GER spectroradiometer in the fiber optic mode which has 512 channels in the wavelength range from 300 to 1100 nm, normalized by the reflection from a Spectralon plate. Optical water characteristics were measured by a WET Labs package, which included an acs instrument (absorption and attenuation at 82 wavelengths) and a bb9 instrument (7 channels for backscattering in wavelength range from 400 to 715 nm, chlorophyll fluorescence and CDOM fluorescence).

We examine the use, characteristics and potential of polarization discrimination techniques developed by us in which the polarization properties of elastically scattered light and the unpolarized nature of any fluorescence excited are utilized to separate the fluorescence component from the reflectance spectra of algae. These techniques are applied here to seawater algae in a variety of conditions both in the laboratory and in the field. We show that they are effective for extracting the chlorophyll fluorescence in the 685 nm region from reflectance spectra dominated by chlorophyll pigments for different types of algae with the illumination by polarized and unpolarized light