Joseph Ardizzone - Academia.edu (original) (raw)

Papers by Joseph Ardizzone

Atmospheric and Environmental Remote Sensing Data Processing and Utilization VI: Readiness for GEOSS IV, 2010

ABSTRACT Since the 1970s, an extensive series of data impact studies has been performed to evalua... more ABSTRACT Since the 1970s, an extensive series of data impact studies has been performed to evaluate and enhance the impact of satellite surface wind data on ocean surface wind analyses and fluxes, atmospheric and oceanic modeling, and weather prediction. These studies led to the first beneficial impacts of scatterometer winds on numerical weather prediction (NWP), the development of the methodology to assimilate surface wind speeds derived from passive microwave radiometry, and the operational use of satellite surface winds by marine forecasters and NWP models. In recent years, the impact of these data on NWP has decreased as more competing data have become available; however, the results of our recent experiments still show a very significant impact of satellite surface winds on ocean surface wind analyses and on the prediction of selected storms over the oceans.

Ocean Remote Sensing: Methods and Applications, 2009

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008

A strategic goal of NASA's Science Mission Directorate is the development of... more A strategic goal of NASA's Science Mission Directorate is the development of highly advanced global Earth observing systems to help monitor and predict key elements of the Earth's ocean-atmosphere system. A new concept now being considered is the "sensor web", which would allow collaborative measurements to be made by linking together various spaced-based and in situ observations along with output

Laser Radar Technology and Applications VIII, 2003

Observing system simulation experiments (OSSE"s) provide an effective means to evaluate the ... more Observing system simulation experiments (OSSE"s) provide an effective means to evaluate the potential impact of a proposed observing system, as well as to determine tradeoffs in their design, and to evaluate data assimilation methodology. Great care must be taken to ensure realism of the OSSE"s, and in the interpretation of OSSE results. All of the OSSE"s that have been conducted to date have demonstrated tremendous potential for space-based wind profile data to improve atmospheric analyses, forecasts, and research. This has been true for differing data assimilation systems, analysis methodology, and model resolutions. OSSE"s clearly show much greater potential for observations of the complete wind profile than for single-level wind data or observations of the boundary layer alone.

Eos, Transactions American Geophysical Union, 2009

ABSTRACT A new cross-calibrated, multiplatform (CCMP) ocean surface wind product with wide-rangin... more ABSTRACT A new cross-calibrated, multiplatform (CCMP) ocean surface wind product with wide-ranging research applications in meteorology and oceanography became available at the Physical Oceanography Distributed Active Archive Center (PO.DACC) in May 2009. Data sets at three different levels of processing may be downloaded from http://podaac.jpl.nasa.gov/DATA_CATALOG/ccmpinfo.html. The principal data set, denoted as level 3.0, has global ocean coverage (except for the Arctic Ocean) with 25-kilometer resolution every 6 hours for more than 20 years, beginning in July 1987. Applying an enhanced variational analysis method (VAM) to multiple input data sources creates the level 3.0 data set. The VAM performs quality control and optimally combines wind observations from several individual satellite microwave radiometer and scatterometer sensors along with available conventional ship and buoy wind observations and European Centre for Medium-Range Weather Forecasts (ECMWF) analyses.

Journal of Geophysical Research, 2003

1] The ocean surface vector wind can be measured from space by scatterometers. For a set of measu... more 1] The ocean surface vector wind can be measured from space by scatterometers. For a set of measurements observed from several viewing directions and collocated in space and time, there will usually exist two, three, or four consistent wind vectors. These multiple wind solutions are known as ambiguities. Ambiguity removal procedures select one ambiguity at each location. We compare results of two different ambiguity removal algorithms, the operational median filter (MF) used by the Jet Propulsion Laboratory (JPL) and a two-dimensional variational analysis method (2d-VAR). We applied 2d-VAR to the entire NASA Scatterometer (NSCAT) mission, orbit by orbit, using European Centre for Medium-Range Weather Forecasts (ECMWF) 10m wind analyses as background fields. We also applied 2d-VAR to a 51-day subset of the NSCAT mission using National Centers for Environmental Prediction (NCEP) 1000-hPa wind analyses as background fields. This second data set uses the same background fields as the MF data set. When both methods use the same NCEP background fields as a starting point for ambiguity removal, agreement is very good: Approximately only 3% of the wind vector cells (WVCs) have different ambiguity selections; however, most of the WVCs with changes occur in coherent patches. Since at least one of the selections is in error, this implies that errors due to ambiguity selection are not isolated, but are horizontally correlated. When we examine ambiguity selection differences at synoptic scales, we often find that the 2d-VAR selections are more meteorologically reasonable and more consistent with cloud imagery.

Journal of Geophysical Research, 1999

A detailed geophysical evaluation of the initial NASA scatterometer (NSCAT) wind data sets was pe... more A detailed geophysical evaluation of the initial NASA scatterometer (NSCAT) wind data sets was performed in order to determine the error characteristics of these data and their applicability to ocean surface analysis and numerical prediction. The first component of this evaluation consisted of collocations of NSCAT data to ship and buoy wind reports, special sensor microwave imager wind observations, and National Centers for Environmental Prediction and Goddard Earth Observing System (GEOS) model wind analyses. This was followed by data assimilation experiments to determine the impact of NSCAT data on analysis and forecasting. The collocation comparisons showed the NSCAT wind velocity data to be of higher accuracy than operational ERS 2 wind data. The impact experiments showed that NSCAT has the ability to correct major errors in analyses over the oceans and also to improve numerical weather prediction. NSCAT data typically show the precise locations of both synoptic-scale and smaller-scale cyclones and fronts over the oceans. This often results in significant improvements to analyses. Forecast experiments using the GEOS model show approximately a 1-day extension of useful forecast skill in the southern hemisphere, in good agreement with the results of Observing System Simulation Experiments conducted prior to launch. 11,405 11,406 ATLAS ET AL.: GEOPHYSICAL VALIDATION OF NSCAT WINDS include those of ships and buoys and ERS 2. The analyses are those of the National Centers for Environmental Prediction (NCEP) and the Goddard Earth Observing System (GEOS). Second, limited data impact experiments are used to evaluate the relative effects of NSCAT, SSM/I, and ERS 2 winds using both the NCEP and GEOS data assimilation systems (DAS). A number of previous studies have examined the impact of scatterometer data in DAS. For example, Duffy and Atlas [ 1986], Stoffelen and Cats [ 1991 ], and Lenzen et al. [ 1993] examined the impact of Seasat scatterometer data on the simulation of the QE II storm, and Hoffman [1993] studied the impact of the ERS 1 scatterometer data on the European Centre for Medium-Range Weather Forecasts (ECMWF) DAS. Although experiments of this type are not generally used for geophysical validation, the comparison of the impact of NSCAT data with that predicted by Observing System Simulation Experiments (OSSEs) that were conducted prior to launch provides a very useful measure of the degree to which the expected performance of NSCAT has been achieved. The results of these experiments are evaluated objectively using conventional measures of analysis and forecast accuracy and subjectively by comparing analyses and forecast fields. Specific effects of the NSCAT data will be illustrated by examining specific cases.

Journal of Atmospheric and Oceanic Technology

... Wentz et al. (1984) from the Seasat dataset by matching the statistics of the observed σ 0 an... more ... Wentz et al. (1984) from the Seasat dataset by matching the statistics of the observed σ 0 and those simulated assuming that the ocean surface winds follow a one parameter Weibull distribution (Conradsen et al. 1984). The fitting ...

Journal of Atmospheric and Oceanic Technology, 2013

ABSTRACT The Desroziers diagnostics (DD) are applied to the cross-calibrated, multiplatform (CCMP... more ABSTRACT The Desroziers diagnostics (DD) are applied to the cross-calibrated, multiplatform (CCMP) ocean surface wind datasets to estimate wind speed errors of the ECMWF background, the microwave satellite observations, and the resulting CCMP analysis. The DD confirm that the ECMWF operational surface wind speed error standard deviations vary with latitude in the range 0.8-1.3 m s(-1) and that the cross-calibrated Remote Sensing Systems (RSS) wind speed retrievals' standard deviations are in the range 0.5-0.7 m s(-1). Further, the estimated CCMP analysis wind speed standard deviations are in the range 0.2-0.3 m s(-1). The results suggest the need to revise the parameterization of the errors of the first guess at appropriate time (FGAT) procedure. Errors for wind speeds <16 m s(-1) are homogeneous; however, for the relatively rare but critical higher wind speed situations, errors are much larger.

Bulletin of the American Meteorological Society, 1996

Bulletin of the American Meteorological Society, 2001

Satellite scatterometer observations of the ocean surface wind speed and direction improve the de... more Satellite scatterometer observations of the ocean surface wind speed and direction improve the depiction of storms at sea. Over the ocean, scatterometer surface winds are deduced from multiple measurements of reflected radar power made from several directions. In the nominal situation, the scattering mechanism is Bragg scattering from centimeterscale waves, which are in equilibrium with the local wind. These data are especially valuable where observations are otherwise sparse-mostly in the Southern Hemisphere extratropics and Tropics, but also on occasion in the North Atlantic and North Pacific. The history of scatterometer winds research and its application to weather analysis and forecasting is reviewed here. Two types of data impact studies have been conducted to evaluate the effect of satellite data, including satellite scatterometer data, for NWP. These are simulation experiments (or observing system simulation experiments or OSSEs) designed primarily to assess the potential impact of planned satellite observing systems, and real data impact experiments (or observing system experiments or OSEs) to evaluate the actual impact of available spacebased data. Both types of experiments have been applied to the series of satellite scatterometers carried on the Seasat, European Remote Sensing-1 and -2, and the Advanced Earth Observing System-1 satellites, and the NASA Quick Scatterometer. Several trends are evident: The amount of scatterometer data has been increasing. The ability of data assimilation systems and marine forecasters to use the data has improved substantially. The ability of simulation experiments to predict the utility of new sensors has also improved significantly.

Bulletin of the American Meteorological Society, 2011

The cross-calibrated, multi-platform (CCMP) ocean surface wind data sets are now available at the... more The cross-calibrated, multi-platform (CCMP) ocean surface wind data sets are now available at the Physical Oceanography Distributed Active Archive Center from July 1987 through December 2010. These data support wide-ranging air-sea research and applications. The main Level 3.0 data set has global ocean coverage (within 78S-78N) with 25-kilometer resolution every 6 hours. An enhanced variational analysis method (VAM) quality controls and optimally combines multiple input data sources to create the Level 3.0 data set. Data included are all available RSS DISCOVER wind observations, in situ buoys and ships, and ECMWF analyses. The VAM is set up to use the ECMWF analyses to fill in areas of no data and to provide an initial estimate of wind direction. As described in an article in the Feb. 2011 BAMS, when compared to conventional analyses and reanalyses, the CCMP winds are significantly different in some synoptic cases, result in different storm statistics, and provide enhanced high-spat...

Scatterometer observations of the ocean surface wind speed and direction improve the depiction an... more Scatterometer observations of the ocean surface wind speed and direction improve the depiction and prediction of storms at sea. These data are especially valuable where observations are otherwise sparse-mostly in the Southern Hemisphere extratropics and tropics, but also on occasion in the North Atlantic and North Pacific. From the history of scatterometer winds research and its application to weather analysis and forecasting, several trends are evident: The amount of scatterometer data has been increasing. The ability of data assimilation systems and marine forecasters to use the data has improved substantially. The ability of simulation experiments to predict the utility of new sensors has also improved significantly.

Atmospheric and Environmental Remote Sensing Data Processing and Utilization VI: Readiness for GEOSS IV, 2010

ABSTRACT Since the 1970s, an extensive series of data impact studies has been performed to evalua... more ABSTRACT Since the 1970s, an extensive series of data impact studies has been performed to evaluate and enhance the impact of satellite surface wind data on ocean surface wind analyses and fluxes, atmospheric and oceanic modeling, and weather prediction. These studies led to the first beneficial impacts of scatterometer winds on numerical weather prediction (NWP), the development of the methodology to assimilate surface wind speeds derived from passive microwave radiometry, and the operational use of satellite surface winds by marine forecasters and NWP models. In recent years, the impact of these data on NWP has decreased as more competing data have become available; however, the results of our recent experiments still show a very significant impact of satellite surface winds on ocean surface wind analyses and on the prediction of selected storms over the oceans.

Ocean Remote Sensing: Methods and Applications, 2009

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008

A strategic goal of NASA's Science Mission Directorate is the development of... more A strategic goal of NASA's Science Mission Directorate is the development of highly advanced global Earth observing systems to help monitor and predict key elements of the Earth's ocean-atmosphere system. A new concept now being considered is the "sensor web", which would allow collaborative measurements to be made by linking together various spaced-based and in situ observations along with output

Laser Radar Technology and Applications VIII, 2003

Observing system simulation experiments (OSSE"s) provide an effective means to evaluate the ... more Observing system simulation experiments (OSSE"s) provide an effective means to evaluate the potential impact of a proposed observing system, as well as to determine tradeoffs in their design, and to evaluate data assimilation methodology. Great care must be taken to ensure realism of the OSSE"s, and in the interpretation of OSSE results. All of the OSSE"s that have been conducted to date have demonstrated tremendous potential for space-based wind profile data to improve atmospheric analyses, forecasts, and research. This has been true for differing data assimilation systems, analysis methodology, and model resolutions. OSSE"s clearly show much greater potential for observations of the complete wind profile than for single-level wind data or observations of the boundary layer alone.

Eos, Transactions American Geophysical Union, 2009

ABSTRACT A new cross-calibrated, multiplatform (CCMP) ocean surface wind product with wide-rangin... more ABSTRACT A new cross-calibrated, multiplatform (CCMP) ocean surface wind product with wide-ranging research applications in meteorology and oceanography became available at the Physical Oceanography Distributed Active Archive Center (PO.DACC) in May 2009. Data sets at three different levels of processing may be downloaded from http://podaac.jpl.nasa.gov/DATA_CATALOG/ccmpinfo.html. The principal data set, denoted as level 3.0, has global ocean coverage (except for the Arctic Ocean) with 25-kilometer resolution every 6 hours for more than 20 years, beginning in July 1987. Applying an enhanced variational analysis method (VAM) to multiple input data sources creates the level 3.0 data set. The VAM performs quality control and optimally combines wind observations from several individual satellite microwave radiometer and scatterometer sensors along with available conventional ship and buoy wind observations and European Centre for Medium-Range Weather Forecasts (ECMWF) analyses.

Journal of Geophysical Research, 2003

1] The ocean surface vector wind can be measured from space by scatterometers. For a set of measu... more 1] The ocean surface vector wind can be measured from space by scatterometers. For a set of measurements observed from several viewing directions and collocated in space and time, there will usually exist two, three, or four consistent wind vectors. These multiple wind solutions are known as ambiguities. Ambiguity removal procedures select one ambiguity at each location. We compare results of two different ambiguity removal algorithms, the operational median filter (MF) used by the Jet Propulsion Laboratory (JPL) and a two-dimensional variational analysis method (2d-VAR). We applied 2d-VAR to the entire NASA Scatterometer (NSCAT) mission, orbit by orbit, using European Centre for Medium-Range Weather Forecasts (ECMWF) 10m wind analyses as background fields. We also applied 2d-VAR to a 51-day subset of the NSCAT mission using National Centers for Environmental Prediction (NCEP) 1000-hPa wind analyses as background fields. This second data set uses the same background fields as the MF data set. When both methods use the same NCEP background fields as a starting point for ambiguity removal, agreement is very good: Approximately only 3% of the wind vector cells (WVCs) have different ambiguity selections; however, most of the WVCs with changes occur in coherent patches. Since at least one of the selections is in error, this implies that errors due to ambiguity selection are not isolated, but are horizontally correlated. When we examine ambiguity selection differences at synoptic scales, we often find that the 2d-VAR selections are more meteorologically reasonable and more consistent with cloud imagery.

Journal of Geophysical Research, 1999

A detailed geophysical evaluation of the initial NASA scatterometer (NSCAT) wind data sets was pe... more A detailed geophysical evaluation of the initial NASA scatterometer (NSCAT) wind data sets was performed in order to determine the error characteristics of these data and their applicability to ocean surface analysis and numerical prediction. The first component of this evaluation consisted of collocations of NSCAT data to ship and buoy wind reports, special sensor microwave imager wind observations, and National Centers for Environmental Prediction and Goddard Earth Observing System (GEOS) model wind analyses. This was followed by data assimilation experiments to determine the impact of NSCAT data on analysis and forecasting. The collocation comparisons showed the NSCAT wind velocity data to be of higher accuracy than operational ERS 2 wind data. The impact experiments showed that NSCAT has the ability to correct major errors in analyses over the oceans and also to improve numerical weather prediction. NSCAT data typically show the precise locations of both synoptic-scale and smaller-scale cyclones and fronts over the oceans. This often results in significant improvements to analyses. Forecast experiments using the GEOS model show approximately a 1-day extension of useful forecast skill in the southern hemisphere, in good agreement with the results of Observing System Simulation Experiments conducted prior to launch. 11,405 11,406 ATLAS ET AL.: GEOPHYSICAL VALIDATION OF NSCAT WINDS include those of ships and buoys and ERS 2. The analyses are those of the National Centers for Environmental Prediction (NCEP) and the Goddard Earth Observing System (GEOS). Second, limited data impact experiments are used to evaluate the relative effects of NSCAT, SSM/I, and ERS 2 winds using both the NCEP and GEOS data assimilation systems (DAS). A number of previous studies have examined the impact of scatterometer data in DAS. For example, Duffy and Atlas [ 1986], Stoffelen and Cats [ 1991 ], and Lenzen et al. [ 1993] examined the impact of Seasat scatterometer data on the simulation of the QE II storm, and Hoffman [1993] studied the impact of the ERS 1 scatterometer data on the European Centre for Medium-Range Weather Forecasts (ECMWF) DAS. Although experiments of this type are not generally used for geophysical validation, the comparison of the impact of NSCAT data with that predicted by Observing System Simulation Experiments (OSSEs) that were conducted prior to launch provides a very useful measure of the degree to which the expected performance of NSCAT has been achieved. The results of these experiments are evaluated objectively using conventional measures of analysis and forecast accuracy and subjectively by comparing analyses and forecast fields. Specific effects of the NSCAT data will be illustrated by examining specific cases.

Journal of Atmospheric and Oceanic Technology

... Wentz et al. (1984) from the Seasat dataset by matching the statistics of the observed σ 0 an... more ... Wentz et al. (1984) from the Seasat dataset by matching the statistics of the observed σ 0 and those simulated assuming that the ocean surface winds follow a one parameter Weibull distribution (Conradsen et al. 1984). The fitting ...

Journal of Atmospheric and Oceanic Technology, 2013

ABSTRACT The Desroziers diagnostics (DD) are applied to the cross-calibrated, multiplatform (CCMP... more ABSTRACT The Desroziers diagnostics (DD) are applied to the cross-calibrated, multiplatform (CCMP) ocean surface wind datasets to estimate wind speed errors of the ECMWF background, the microwave satellite observations, and the resulting CCMP analysis. The DD confirm that the ECMWF operational surface wind speed error standard deviations vary with latitude in the range 0.8-1.3 m s(-1) and that the cross-calibrated Remote Sensing Systems (RSS) wind speed retrievals' standard deviations are in the range 0.5-0.7 m s(-1). Further, the estimated CCMP analysis wind speed standard deviations are in the range 0.2-0.3 m s(-1). The results suggest the need to revise the parameterization of the errors of the first guess at appropriate time (FGAT) procedure. Errors for wind speeds <16 m s(-1) are homogeneous; however, for the relatively rare but critical higher wind speed situations, errors are much larger.

Bulletin of the American Meteorological Society, 1996

Bulletin of the American Meteorological Society, 2001

Satellite scatterometer observations of the ocean surface wind speed and direction improve the de... more Satellite scatterometer observations of the ocean surface wind speed and direction improve the depiction of storms at sea. Over the ocean, scatterometer surface winds are deduced from multiple measurements of reflected radar power made from several directions. In the nominal situation, the scattering mechanism is Bragg scattering from centimeterscale waves, which are in equilibrium with the local wind. These data are especially valuable where observations are otherwise sparse-mostly in the Southern Hemisphere extratropics and Tropics, but also on occasion in the North Atlantic and North Pacific. The history of scatterometer winds research and its application to weather analysis and forecasting is reviewed here. Two types of data impact studies have been conducted to evaluate the effect of satellite data, including satellite scatterometer data, for NWP. These are simulation experiments (or observing system simulation experiments or OSSEs) designed primarily to assess the potential impact of planned satellite observing systems, and real data impact experiments (or observing system experiments or OSEs) to evaluate the actual impact of available spacebased data. Both types of experiments have been applied to the series of satellite scatterometers carried on the Seasat, European Remote Sensing-1 and -2, and the Advanced Earth Observing System-1 satellites, and the NASA Quick Scatterometer. Several trends are evident: The amount of scatterometer data has been increasing. The ability of data assimilation systems and marine forecasters to use the data has improved substantially. The ability of simulation experiments to predict the utility of new sensors has also improved significantly.

Bulletin of the American Meteorological Society, 2011

The cross-calibrated, multi-platform (CCMP) ocean surface wind data sets are now available at the... more The cross-calibrated, multi-platform (CCMP) ocean surface wind data sets are now available at the Physical Oceanography Distributed Active Archive Center from July 1987 through December 2010. These data support wide-ranging air-sea research and applications. The main Level 3.0 data set has global ocean coverage (within 78S-78N) with 25-kilometer resolution every 6 hours. An enhanced variational analysis method (VAM) quality controls and optimally combines multiple input data sources to create the Level 3.0 data set. Data included are all available RSS DISCOVER wind observations, in situ buoys and ships, and ECMWF analyses. The VAM is set up to use the ECMWF analyses to fill in areas of no data and to provide an initial estimate of wind direction. As described in an article in the Feb. 2011 BAMS, when compared to conventional analyses and reanalyses, the CCMP winds are significantly different in some synoptic cases, result in different storm statistics, and provide enhanced high-spat...

Scatterometer observations of the ocean surface wind speed and direction improve the depiction an... more Scatterometer observations of the ocean surface wind speed and direction improve the depiction and prediction of storms at sea. These data are especially valuable where observations are otherwise sparse-mostly in the Southern Hemisphere extratropics and tropics, but also on occasion in the North Atlantic and North Pacific. From the history of scatterometer winds research and its application to weather analysis and forecasting, several trends are evident: The amount of scatterometer data has been increasing. The ability of data assimilation systems and marine forecasters to use the data has improved substantially. The ability of simulation experiments to predict the utility of new sensors has also improved significantly.