The Experts below are selected from a list of 3999 Experts worldwide ranked by ideXlab platform
Fuzhong Weng - One of the best experts on this subject based on the ideXlab platform.
-
remote sensing of tropical cyclone thermal structure from satellite Microwave Sounding instruments impacts of background profiles on retrievals
Journal of meteorological research, 2019Co-Authors: Fuzhong Weng, H U Hao, Yang Han, Yihong DuanAbstract:A variational retrieval system often requires background atmospheric profiles and surface parameters in its minimization process. This study investigates the impacts of specific background profiles on retrievals of tropical cyclone (TC) thermal structure. In our Microwave Retrieval Testbed (MRT), the K-means clustering algorithm is utilized to generate a set of mean temperature and water vapor profiles according to stratiform and convective precipitation in hurricane conditions. The Advanced Technology Microwave Sounder (ATMS) observations are then used to select the profiles according to cloud type. It is shown that the cloud-based background profiles result in better hurricane thermal structures retrieved from ATMS observations. Compared to the Global Positioning System (GPS) dropsonde observations, the temperature and specific humidity errors in the TC inner region are less than 3 K and 2.5 g kg–1, respectively, which are significantly smaller than the retrievals without using the cloud-based profiles. Further experiments show that all the ATMS observations could retrieve well both temperature and humidity structures, especially within the inner core region. Thus, both temperature and humidity profiles derived from Microwave Sounding instruments in hurricane conditions can be reliably used for evaluation of the storm intensity with a high fidelity.
-
remote sensing of tropical cyclone thermal structure from satellite Microwave Sounding instruments impacts of optimal channel selection on retrievals
Journal of meteorological research, 2018Co-Authors: Yang Han, Fuzhong WengAbstract:Accurate information on atmospheric temperature of tropical cyclones (TCs) is important for monitoring and prediction of their developments and evolution. For hurricanes, temperature anomaly in the upper troposphere can be derived from Advanced Microwave Sounding Unit (AMSU) and Advanced Technology Microwave Sounder (ATMS) through either regression-based or variational retrieval algorithms. This study investigates the dependency of TC warm core structure on emission and scattering processes in the forward operator used for radiance computations in temperature retrievals. In particular, the precipitation scattering at ATMS high-frequency channels can significantly change the retrieval outcomes. The simulation results in this study reveal that the brightness temperatures at 183 GHz could be depressed by 30–50 K under cloud ice water path of 1.5 mm, and thus, the temperature structure in hurricane atmosphere could be distorted if the ice cloud scattering was inaccurately characterized in the retrieval system. It is found that for Hurricanes Irma, Maria, and Harvey that occurred in 2017, their warm core anomalies retrieved from ATMS temperature Sounding channels 4–15 were more reasonable and realistic, compared with the retrievals from all other channel combinations and earlier hurricane simulation results.
-
developing vicarious calibration for Microwave Sounding instruments using lunar radiation
IEEE Transactions on Geoscience and Remote Sensing, 2018Co-Authors: Hu Yang, Fuzhong Weng, Jun Zhou, Ninghai Sun, Kent Anderson, Quanhua Liu, Edward KimAbstract:Accurate global observations from space are critical for global climate change study. However, atmospheric temperature trend derived from spaceborne Microwave instruments remains a subject of debate, due mainly to the uncertainty in characterizing the long-term drift of instrument calibration. Thus, a highly stable target with a well-known Microwave radiation is required to evaluate the long-term calibration stability. This paper develops a new model to simulate the lunar emission at Microwave frequencies, and the model is then used for monitoring the stability of the Advanced Technology Microwave Sounder (ATMS) onboard Suomi NPP satellite. It is shown that the ATMS cold space view of lunar radiation agrees well with the model simulation during the past five years and this instrument is capable of serving the reference instrument for atmospheric temperature trending studies, and connecting the previous generation of Microwave sounders from NOAA-15 to the future Joint Polar Satellite System Microwave Sounder onboard NOAA-20 satellite.
-
connecting the time series of Microwave Sounding observations from amsu to atms for long term monitoring of climate
Journal of Atmospheric and Oceanic Technology, 2014Co-Authors: Xiaolei Zou, Fuzhong Weng, Hu YangAbstract:AbstractThe measurements from the Microwave Sounding Unit (MSU) and the Advanced Microwave Sounding Unit-A (AMSU-A) on board NOAA polar-orbiting satellites have been extensively utilized for detecting atmospheric temperature trend during the last several decades. After the launch of the Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite on 28 October 2011, MSU and AMSU-A time series will be overlapping with the Advanced Technology Microwave Sounder (ATMS) measurements. While ATMS inherited the central frequency and bandpass from most of AMSU-A Sounding channels, its spatial resolution and noise features are, however, distinctly different from those of AMSU. In this study, the Backus–Gilbert method is used to optimally resample the ATMS data to AMSU-A fields of view (FOVs). The differences between the original and resampled ATMS data are demonstrated. By using the simultaneous nadir overpass (SNO) method, ATMS-resampled observations are collocated in space and time with AMSU-A data. The inters...
-
retrieval of snow surface Microwave emissivity from the advanced Microwave Sounding unit
Journal of Geophysical Research, 2008Co-Authors: Banghua Yan, Fuzhong Weng, Huan MengAbstract:[1] Satellite data assimilation in numerical weather prediction systems requires information on Microwave snow surface emissivity in a wide wavelength range. However, the existing models perform poorly for stratified snow or aged snow especially at high frequencies such that they are inapplicable for various snow types. The brightness temperatures at the window channels of the advanced Microwave Sounding unit (AMSU) are characterized strongly by surface emissivity and are thus used in this study to retrieve snow surface emissivity from 23.8 to 150 GHz under both clear and cloudy conditions. This algorithm uses an iteration scheme associated with a two-stream radiative transfer model. The accuracy of the AMSU-retrieved snow emissivity using this algorithm is first assessed against a set of satellite-observed emissivity under clear skies and a set of simulated emissivity under cloudy conditions. The algorithm is then assessed by its application to seven consecutive snow events observed at Hagerstown, Maryland, in February 2003 and to a set of mountainous snowpacks observed at the Local Scale Observation Site of the Cold Land Processes Field Experiment in northern Colorado in February and March of 2002 and 2003. Results show that the AMSU-retrieved snow emissivity spectra are consistent with the snow emissivity model simulations of the snow events in both Maryland and Colorado. Furthermore, the impact of the AMSU-retrieved snow emissivity on global satellite data assimilation systems is investigated by applying the algorithm to the National Centers for Environmental Prediction (NCEP) Gridpoint Statistical Interpolation (GSI) system. Compared to the existing analytic land emissivity model used in the GSI system, the retrieved emissivity significantly improves the use of the AMSU Sounding data in the NCEP GSI system. Therefore, the AMSU-based snow emissivity retrieval algorithm has demonstrated its potential use in the global satellite data assimilation systems.
Norman C Grody - One of the best experts on this subject based on the ideXlab platform.
-
relationship between snow parameters and Microwave satellite measurements theory compared with advanced Microwave Sounding unit observations from 23 to 150 ghz
Journal of Geophysical Research, 2008Co-Authors: Norman C GrodyAbstract:[1] A theoretical model is used to examine the relationship between snow parameters and satellite-based Microwave radiometer measurements between 23 and 150 GHz. The model is based on the two-stream radiative transfer equation whose optical parameters are obtained from dense media theory. Model simulations are used to show how the grain size, density, snow depth, and an ice crust affect the emissivity and brightness temperatures measured by the Advanced Microwave Sounding Unit (AMSU). The AMSU channels at 23, 31, 89, and 150 GHz are shown to be more sensitive to grain size variations than the other snow parameters. For ice particle diameters less than 1 mm the emissivity and brightness temperatures are found to decrease continuously up to 150 GHz. However, for larger particles, the emissivity and brightness temperature results in a flatter frequency response beyond 89 GHz as the wavelength approaches the particle size. Model results are tested using AMSU measurements for snow events over the central United States during a 2-week period in the late fall. In agreement with model simulations, the brightness temperature is shown to decrease continuously up to 150 GHz for the small grain size associated with new snow, whereas the brightness temperature no longer decreases beyond 89 GHz as the snow ages and larger grains form owing to snow metamorphosis. Most importantly, the difference between the 89 and 150 GHz AMSU measurements is shown to provide a unique signature for identifying and separating new from aged snow. Consequently, it is now possible to identify four different snow types (wet, new, aged, and stratified snow) from AMSU.
-
recalibration of Microwave Sounding unit for climate studies using simultaneous nadir overpasses
Journal of Geophysical Research, 2006Co-Authors: Chengzhi Zou, Mitchell D Goldberg, Norman C Grody, Zhaohui Cheng, Jerry Sullivan, Changyong Cao, Dan TarpleyAbstract:[1] The measurements from Microwave Sounding unit (MSU) on board different NOAA polar-orbiting satellites have been extensively used for detecting atmospheric temperature trend during the last several decades. However, temperature trends derived from these measurements are under significant debate, mostly caused by calibration errors. This study recalibrates the MSU channel 2 observations at level 0 using the postlaunch simultaneous nadir overpass (SNO) matchups and then provides a well-merged new MSU 1b data set for climate studies. The calibration algorithm consists of a dominant linear response of the MSU raw counts to the Earth-view radiance plus a smaller quadratic term. Uncertainties are represented by a constant offset and errors in the coefficient for the nonlinear quadratic term. A SNO matchup data set for nadir pixels with criteria of simultaneity of less than 100 s and within a ground distance of 111 km is generated for all overlaps of NOAA satellites. The simultaneous nature of these matchups eliminates the impact of orbital drifts on the calibration. A radiance error model for the SNO pairs is developed and then used to determine the offsets and nonlinear coefficients through regressions of the SNO matchups. It is found that the SNO matchups can accurately determine the differences of the offsets as well as the nonlinear coefficients between satellite pairs, thus providing a strong constraint to link calibration coefficients of different satellites together. However, SNO matchups alone cannot determine the absolute values of the coefficients because there is a high degree of colinearity between satellite SNO observations. Absolute values of calibration coefficients are obtained through sensitivity experiments, in which the percentage of variance in the brightness temperature difference time series that can be explained by the warm target temperatures of overlapping satellites is a function of the calibration coefficient. By minimizing these percentages of variance for overlapping observations, a new set of calibration coefficients is obtained from the SNO regressions. These new coefficients are significantly different from the prelaunch calibration values, but they result in bias-free SNO matchups and near-zero contaminations by the warm target temperatures in terms of the calibrated brightness temperature. Applying the new calibration coefficients to the Level 0 MSU observations, a well-merged MSU pentad data set is generated for climate trend studies. To avoid errors caused by small SNO samplings between NOAA 10 and 9, observations only from and after NOAA 10 are used. In addition, only ocean averages are investigated so that diurnal cycle effect can be ignored. The global ocean-averaged intersatellite biases for the pentad data set are between 0.05 and 0.1 K, which is an order of magnitude smaller than that obtained when using the unadjusted calibration algorithm. The ocean-only anomaly trend for the combined MSU channel 2 brightness temperature is found to be 0.198 K decade -1 during 1987-2003.
-
noaa operational hydrological products derived from the advanced Microwave Sounding unit
IEEE Transactions on Geoscience and Remote Sensing, 2005Co-Authors: Ralph Ferraro, Norman C Grody, Fuzhong Weng, Limin Zhao, Huan Meng, Cezar Kongoli, Paul Pellegrino, Shuang Qiu, Charles DeanAbstract:With the launch of the NOAA-15 satellite in May 1998, a new generation of passive Microwave sounders was initiated. The Advanced Microwave Sounding Unit (AMSU), with 20 channels spanning the frequency range from 23-183 GHz, offers enhanced temperature and moisture Sounding capability well beyond its predecessor, the Microwave Sounding Unit (MSU). In addition, by utilizing a number of window channels on the AMSU, the National Oceanic and Atmospheric Administration (NOAA) expanded the capability of the AMSU beyond this original purpose and developed a new suite of products that are generated through the Microwave Surface and Precipitation Products System (MSPPS). This includes precipitation rate, total precipitable water, land surface emissivity, and snow cover. Details on the current status of the retrieval algorithms (as of September 2004) are presented. These products are complimentary to similar products obtained from the Defense Meteorological Satellite Program Special Sensor Microwave/Imager (SSMI) and the Earth Observing Aqua Advanced Microwave Scanning Radiometer (AMSR-E). Due to the close orbital equatorial crossing time between NOAA-16 and the Aqua satellites, comparisons between several of the MSPPS products are made with AMSR-E. Finally, several application examples are presented that demonstrate their importance to weather forecasting and analysis, and climate monitoring.
-
calibration of multisatellite observations for climatic studies Microwave Sounding unit msu
Journal of Geophysical Research, 2004Co-Authors: Norman C Grody, Mitchell D Goldberg, Konstantin Y Vinnikov, Jerry Sullivan, Dan J TarpleyAbstract:[1] The Microwave Sounding Units (MSU) aboard the NOAA series of polar orbiting satellites has been used by three groups to monitor the very small trend in the global tropospheric temperature over the 25-year satellite record. To obtain a homogeneous data set, each group made different calibration corrections of the MSUs in the form of fixed biases, and in some cases temperature-dependent adjustments, to each of the nine satellite instruments using data during the overlap periods. Up until now, however, the adjustments are empirically based. To improve the accuracy as well as our understanding of the error sources, this paper develops an alternate, physical approach for intercalibrating the MSU instruments. The paper develops a calibration model for the MSU instrument that includes the errors in the cold space and warm target measurements, as well as the nonlinear factor. Corrections for these calibration errors are estimated using a least squares minimization where the predictors are the differences between all 12 overlapping satellite measurements at low and high latitudes. After applying the calibration corrections, the zonally averaged differences between satellite instruments are no larger than 0.03 K, independent of latitude. It is also found that the tropospheric temperature trend derived from MSU measurements is nearly the same as the surface trend. Furthermore, it now appears that much of the earlier inconsistency between the satellite and surface measurements arises from errors in the MSU calibration correction procedure, which can artificially suppress the temperature trend.
-
global warming trend of mean tropospheric temperature observed by satellites
Science, 2003Co-Authors: Konstantin Y Vinnikov, Norman C GrodyAbstract:We have analyzed the global tropospheric temperature for 1978 to 2002 with the use of passive Microwave Sounding data from the NOAA series of polar orbiters and the Earth Observing System Aqua satellite. To accurately retrieve the climatic trend, we combined the satellite data with an analytic model of temperature that contains three different time scales: a linear trend and functions that define the seasonal and diurnal cycles. Our analysis shows a trend of +0.22° to 0.26°C per 10 years, consistent with the global warming trend derived from surface meteorological stations.
Laurence Eymard - One of the best experts on this subject based on the ideXlab platform.
-
A comparison of ocean emissivity models using the Advanced Microwave Sounding Unit, the Special Sensor Microwave Imager, the TRMM Microwave Imager, and airborne radiometer observations
2020Co-Authors: W J Ellison, S J English, K Lamkaouchi, A Balana, Estelle Obligis, G Deblonde, Tim J Hewison, Peter Bauer, Graeme Kelly, Laurence EymardAbstract:[1] New measurements of the permittivity of saline water at millimeter wavelengths have the potential to improve the accuracy of ocean surface emissivity models for use with Microwave and millimeter-wave imaging and Sounding instruments. Recent radiative transfer models employing a range of different treatments of surface ocean emissivity are compared with observations from the following Microwave radiometers: Advanced Microwave Sounding Unit, Special Sensor Microwave Imager, TRMM Microwave Imager, Microwave Airborne Radiometer Scanning System, and Deimos. Emissivity models using the new permittivity model fit these observations more closely than those models which use the Klein and Swift extrapolation model. INDEX TERMS: 333
-
on the use of advanced Microwave Sounding unit a and b measurements for studying the monsoon variability over west africa
Journal of Geophysical Research, 2010Co-Authors: Laurence Eymard, Fatima Karbou, Serge Janicot, N Chouaib, Francoise PinsardAbstract:The advanced Microwave Sounding unit (AMSU) ‐A and ‐B sensors provide observations of humidity and temperature that are relevant for meteorological and climate studies. The use of these observations in numerical weather prediction models has increased in the past 10 years because of some improvements in data assimilation. However, an appropriate use of AMSU measurements apart from assimilation context is rather difficult and depends for the most part on how successfully the instrumental characteristics are accounted for. In particular, atmosphere humidity and temperature variations can be completely hidden by features because of the effect of the observation zenith angle. In this paper, 8 years of AMSU‐A and ‐B observations have been corrected from the observations zenith angle effect and have been used to study temperature and humidity variations over West Africa. Comparisons have been made between AMSU observations and selected atmospheric fields from European Centre for Medium‐Range Weather Forecasts analyses as well as outgoing longwave radiation estimates. It has been found that observations from AMSU‐A channel 5 can be used to monitor the heat low evolution and that AMSU‐B observations from channels 3 and 5 are well adapted to study the humidity variations in direct link with the African monsoon from intraseasonal to interannual scales.
-
a comparison of ocean emissivity models using the advanced Microwave Sounding unit the special sensor Microwave imager the trmm Microwave imager and airborne radiometer observations
Journal of Geophysical Research, 2003Co-Authors: W J Ellison, Stephen English, K Lamkaouchi, A Balana, Estelle Obligis, G Deblonde, Tim J Hewison, Peter Bauer, Graeme Kelly, Laurence EymardAbstract:[1] New measurements of the permittivity of saline water at millimeter wavelengths have the potential to improve the accuracy of ocean surface emissivity models for use with Microwave and millimeter-wave imaging and Sounding instruments. Recent radiative transfer models employing a range of different treatments of surface ocean emissivity are compared with observations from the following Microwave radiometers: Advanced Microwave Sounding Unit, Special Sensor Microwave Imager, TRMM Microwave Imager, Microwave Airborne Radiometer Scanning System, and Deimos. Emissivity models using the new permittivity model fit these observations more closely than those models which use the Klein and Swift extrapolation model.
Mitchell D Goldberg - One of the best experts on this subject based on the ideXlab platform.
-
error structure and atmospheric temperature trends in observations from the Microwave Sounding unit
Journal of Climate, 2009Co-Authors: Mitchell D GoldbergAbstract:Abstract The Microwave Sounding Unit (MSU) onboard the National Oceanic and Atmospheric Administration polar-orbiting satellites measures the atmospheric temperature from the surface to the lower stratosphere under all weather conditions, excluding precipitation. Although designed primarily for monitoring weather processes, the MSU observations have been extensively used for detecting climate trends, and calibration errors are a major source of uncertainty. To reduce this uncertainty, an intercalibration method based on the simultaneous nadir overpass (SNO) matchups for the MSU instruments on satellites NOAA-10, -11, -12, and -14 was developed. Due to orbital geometry, the SNO matchups are confined to the polar regions, where the brightness temperature range is slightly smaller than the global range. Nevertheless, the resulting calibration coefficients are applied globally to the entire life cycle of an MSU satellite. Such intercalibration reduces intersatellite biases by an order of magnitude compared to...
-
recalibration of Microwave Sounding unit for climate studies using simultaneous nadir overpasses
Journal of Geophysical Research, 2006Co-Authors: Chengzhi Zou, Mitchell D Goldberg, Norman C Grody, Zhaohui Cheng, Jerry Sullivan, Changyong Cao, Dan TarpleyAbstract:[1] The measurements from Microwave Sounding unit (MSU) on board different NOAA polar-orbiting satellites have been extensively used for detecting atmospheric temperature trend during the last several decades. However, temperature trends derived from these measurements are under significant debate, mostly caused by calibration errors. This study recalibrates the MSU channel 2 observations at level 0 using the postlaunch simultaneous nadir overpass (SNO) matchups and then provides a well-merged new MSU 1b data set for climate studies. The calibration algorithm consists of a dominant linear response of the MSU raw counts to the Earth-view radiance plus a smaller quadratic term. Uncertainties are represented by a constant offset and errors in the coefficient for the nonlinear quadratic term. A SNO matchup data set for nadir pixels with criteria of simultaneity of less than 100 s and within a ground distance of 111 km is generated for all overlaps of NOAA satellites. The simultaneous nature of these matchups eliminates the impact of orbital drifts on the calibration. A radiance error model for the SNO pairs is developed and then used to determine the offsets and nonlinear coefficients through regressions of the SNO matchups. It is found that the SNO matchups can accurately determine the differences of the offsets as well as the nonlinear coefficients between satellite pairs, thus providing a strong constraint to link calibration coefficients of different satellites together. However, SNO matchups alone cannot determine the absolute values of the coefficients because there is a high degree of colinearity between satellite SNO observations. Absolute values of calibration coefficients are obtained through sensitivity experiments, in which the percentage of variance in the brightness temperature difference time series that can be explained by the warm target temperatures of overlapping satellites is a function of the calibration coefficient. By minimizing these percentages of variance for overlapping observations, a new set of calibration coefficients is obtained from the SNO regressions. These new coefficients are significantly different from the prelaunch calibration values, but they result in bias-free SNO matchups and near-zero contaminations by the warm target temperatures in terms of the calibrated brightness temperature. Applying the new calibration coefficients to the Level 0 MSU observations, a well-merged MSU pentad data set is generated for climate trend studies. To avoid errors caused by small SNO samplings between NOAA 10 and 9, observations only from and after NOAA 10 are used. In addition, only ocean averages are investigated so that diurnal cycle effect can be ignored. The global ocean-averaged intersatellite biases for the pentad data set are between 0.05 and 0.1 K, which is an order of magnitude smaller than that obtained when using the unadjusted calibration algorithm. The ocean-only anomaly trend for the combined MSU channel 2 brightness temperature is found to be 0.198 K decade -1 during 1987-2003.
-
calibration of multisatellite observations for climatic studies Microwave Sounding unit msu
Journal of Geophysical Research, 2004Co-Authors: Norman C Grody, Mitchell D Goldberg, Konstantin Y Vinnikov, Jerry Sullivan, Dan J TarpleyAbstract:[1] The Microwave Sounding Units (MSU) aboard the NOAA series of polar orbiting satellites has been used by three groups to monitor the very small trend in the global tropospheric temperature over the 25-year satellite record. To obtain a homogeneous data set, each group made different calibration corrections of the MSUs in the form of fixed biases, and in some cases temperature-dependent adjustments, to each of the nine satellite instruments using data during the overlap periods. Up until now, however, the adjustments are empirically based. To improve the accuracy as well as our understanding of the error sources, this paper develops an alternate, physical approach for intercalibrating the MSU instruments. The paper develops a calibration model for the MSU instrument that includes the errors in the cold space and warm target measurements, as well as the nonlinear factor. Corrections for these calibration errors are estimated using a least squares minimization where the predictors are the differences between all 12 overlapping satellite measurements at low and high latitudes. After applying the calibration corrections, the zonally averaged differences between satellite instruments are no larger than 0.03 K, independent of latitude. It is also found that the tropospheric temperature trend derived from MSU measurements is nearly the same as the surface trend. Furthermore, it now appears that much of the earlier inconsistency between the satellite and surface measurements arises from errors in the MSU calibration correction procedure, which can artificially suppress the temperature trend.
-
recalibration of the noaa Microwave Sounding unit
Journal of Geophysical Research, 2001Co-Authors: Mitchell D Goldberg, David S Crosby, Zhaohui ChengAbstract:The Microwave Sounding unit (MSU) prelaunch thermal-vacuum chamber test data for eight MSU flight models that flew on TIROS-N, NOAA 7 through NOAA 12, and NOAA 14 were reanalyzed using an improved calibration algorithm, originally designed for the advanced Microwave Sounding unit-A (AMSU-A) operations. The new calibration algorithm can automatically adjust for any channel gain shift in operation. Adoption of this calibration algorithm as the MSU calibration procedure in the recalibration project will make the data sets from the MSU and the AMSU-A more consistent. This will be useful for future blending of the climate trends generated from the MSU and AMSU-A data. A single nonlinearity parameter u, which appears in the new calibration algorithm, was obtained for each channel from analysis of the prelaunch calibration test data. A software package for implementing this new calibration algorithm was developed and applied to calculate the MSU time series for improvement of the accuracy of the climate record. Sample calculations of MSU antenna temperatures with the new calibration algorithm were made for two satellites and are compared with similar results obtained from the old MSU calibration algorithm. Significant differences are observed, and strong evidence indicates that the new calibration procedure will provide a more accurate quantification of climate trends.
-
satellite analysis of tropical cyclones using the advanced Microwave Sounding unit amsu
Bulletin of the American Meteorological Society, 2000Co-Authors: Stanley Q Kidder, Mitchell D Goldberg, Norman C Grody, Mark Demaria, Raymond M Zehr, James F W Purdom, Christopher S Velden, Sheldon J KusselsonAbstract:The first Advanced Microwave Sounding Unit (AMSU) was launched aboard the NOAA-15 satellite on 13 May 1998. The AMSU is well suited for the observation of tropical cyclones because its measurements are not significantly affected by the ice clouds that cover tropical storms. In this paper, the following are presented: 1) upper-tropospheric thermal anomalies in tropical cyclones retrieved from AMSU data, 2) the correlation of maximum temperature anomalies with maximum wind speed and central pressure, 3) winds calculated from the temperature anomaly field, 4) comparison of AMSU data with GOES and AVHRR imagery, and 5) tropical cyclone rainfall potential. The AMSU data appear to offer substantial opportunities for improvement in tropical cyclone analysis and forecasting.
Ralph Ferraro - One of the best experts on this subject based on the ideXlab platform.
-
a prototype hail detection algorithm and hail climatology developed with the advanced Microwave Sounding unit amsu
Atmospheric Research, 2015Co-Authors: Ralph Ferraro, James Beauchamp, Daniel J Cecil, Gerald M HeymsfieldAbstract:Abstract In previous studies published in the open literature, a strong relationship between the occurrence of hail and the Microwave brightness temperatures (primarily at 37 and 85 GHz) was documented. These studies were performed with the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and most recently, the Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sensor. This led to climatologies of hail frequency from TMI and AMSR-E, however, limitations included geographical domain of the TMI sensor (35 S to 35 N) and the overpass time of the Aqua satellite (130 am/pm local time), both of which reduce an accurate mapping of hail events over the global domain and the full diurnal cycle. Nonetheless, these studies presented exciting, new applications for passive Microwave sensors. NOAA and EUMETSAT have been operating the Advanced Microwave Sounding Unit (AMSU-A and -B) and the Microwave Humidity Sounder (MHS) on several operational satellites since 1998: NOAA-15 through NOAA-19; MetOp-A and -B. With multiple satellites in operation since 2000, the AMSU/MHS sensors provide near global coverage every 4 h, thus, offering a much larger time and temporal sampling than TRMM or AMSR-E. With similar observation frequencies near 30 and 85 GHz, one at 157 GHz, and additionally three at the 183 GHz water vapor band, the potential to detect strong convection associated with severe storms on a more comprehensive time and space scale exists. In this study, we develop a prototype AMSU-based hail detection algorithm through the use of collocated satellite and surface hail reports over the continental US for a 10-year period (2000–2009). Compared with the surface observations, the algorithm detects approximately 40% of hail occurrences. The simple threshold algorithm is then used to generate a hail climatology based on all available AMSU observations during 2000–2011 that is stratified in several ways, including total hail occurrence by month (March through September), total annual, and over the diurnal cycle. Independent comparisons are made compared to similar data sets derived from other satellite, ground radar and surface reports. The algorithm was also applied to global land measurements for a single year and showed close agreement with other satellite based hail climatologies. Such a product could serve as a prototype for use with a future geostationary based Microwave sensor such as NASA's proposed PATH mission.
-
noaa operational hydrological products derived from the advanced Microwave Sounding unit
IEEE Transactions on Geoscience and Remote Sensing, 2005Co-Authors: Ralph Ferraro, Norman C Grody, Fuzhong Weng, Limin Zhao, Huan Meng, Cezar Kongoli, Paul Pellegrino, Shuang Qiu, Charles DeanAbstract:With the launch of the NOAA-15 satellite in May 1998, a new generation of passive Microwave sounders was initiated. The Advanced Microwave Sounding Unit (AMSU), with 20 channels spanning the frequency range from 23-183 GHz, offers enhanced temperature and moisture Sounding capability well beyond its predecessor, the Microwave Sounding Unit (MSU). In addition, by utilizing a number of window channels on the AMSU, the National Oceanic and Atmospheric Administration (NOAA) expanded the capability of the AMSU beyond this original purpose and developed a new suite of products that are generated through the Microwave Surface and Precipitation Products System (MSPPS). This includes precipitation rate, total precipitable water, land surface emissivity, and snow cover. Details on the current status of the retrieval algorithms (as of September 2004) are presented. These products are complimentary to similar products obtained from the Defense Meteorological Satellite Program Special Sensor Microwave/Imager (SSMI) and the Earth Observing Aqua Advanced Microwave Scanning Radiometer (AMSR-E). Due to the close orbital equatorial crossing time between NOAA-16 and the Aqua satellites, comparisons between several of the MSPPS products are made with AMSR-E. Finally, several application examples are presented that demonstrate their importance to weather forecasting and analysis, and climate monitoring.
-
determination of precipitable water and cloud liquid water over oceans from the noaa 15 advanced Microwave Sounding unit
Journal of Geophysical Research, 2001Co-Authors: Norman C Grody, Ralph Ferraro, Fuzhong Weng, Jiang Zhao, R BoersAbstract:The advanced Microwave Sounding unit (AMSU) was finally launched in May 1998 aboard the NOAA 15 satellite. Algorithms are provided for retrieving the total precipitable water (TPW) and cloud liquid water (CLW) over oceans using the AMSU measurements at 23.8 and 31.4 GHz. Extensive comparisons are made between the AMSU retrievals of CLW and TPW and those obtained using other satellite instruments (Special Sensor Microwave Imager (SSM/I) and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI)) and ground-based radiometers. The AMSU TPW is also compared against radiosonde data, where all of the results are in good agreement with rms differences less than 3 mm and biases less than 1 mm over the range between 5 and 60 mm. The CLW comparisons show greater variability, although the time series of the AMSU and ground-based sensors follow each other and cover the same dynamic range of 0 - 0.5 mm. The AMSU CLW also compares well with the other satellite measurements, although a bias exists between AMSU and TMI when the CLW exceeds 0.5 mm.