13 results on '"snowfall detection"'
Search Results
2. The two-layered radiative transfer model for snow reflectance and its application to remote sensing of the Antarctic snow surface from space
- Author
-
Alexander Kokhanovsky, Maximilian Brell, Karl Segl, Dmitry Efremenko, Boyan Petkov, Giovanni Bianchini, Robert Stone, and Sabine Chabrillat
- Subjects
cryosphere and climate ,radiative transfer ,light scattering ,snowfall detection ,ice crystals ,remote sensing ,Environmental sciences ,GE1-350 - Abstract
The two-LAyered snow Radiative Transfer (LART) model has been proposed for snow remote sensing applications. It is based on analytical approximations of the radiative transfer theory. The geometrical optics approximation has been used to derive the local snow optical parameters, such as the probability of photon absorption by ice grains and the average cosine of single light scattering in a given direction in a snowpack. The application of the model to the selected area in Antarctica has shown that the technique is capable of retrieving the snow grain size both in the upper and lower snow layers, with grains larger in the lower snow layer as one might expect due to the metamorphism processes. Such a conclusion is confirmed by ground measurements of the vertical snow grain size variability in Antarctica.
- Published
- 2024
- Full Text
- View/download PDF
3. A Snowfall Detection Algorithm for Fengyun-3D Microwave Sounders with Differentiated Atmospheric Temperature Conditions.
- Author
-
Ji, Qingwen, Ma, Ziqiang, Xu, Jintao, Yan, Songkun, and Li, Xiaoqing
- Subjects
ATMOSPHERIC temperature ,WEATHER ,MICROWAVES ,BRIGHTNESS temperature ,RANDOM forest algorithms ,SNOW cover - Abstract
Precipitation in different phases has varying effects on runoff. However, monitoring surface snowfall poses a significant challenge, highlighting the importance of developing a snowfall detection algorithm. The objective of this study is develop a snowfall detection algorithm for the Microwave Temperature Sounder-2 (MWTS-II) and the Microwave Humidity Sounder-2 (MWHS-II) onboard the FY-3D satellite while considering the differentiated atmosphere temperature conditions. The results show that: (1) The brightness temperature (TB) of MWTS Channel 3 is well-suited for pre-classifying atmospheric temperatures, and significant differences in TB distribution exist between the two pre-classification subsets. (2) Among six machine classifiers examined, the random forest classifier exhibits favorable classification performance on both the validation set (accuracy: 0.76, recall: 0.76, F1 score: 0.75) and test set (accuracy: 0.80, recall: 0.44, F1 score: 0.44). (3) The application of the snowfall detection algorithm showcases a reasonable spatial distribution and outperforms the IMERG and ERA5 snowfall data. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. A 1DVAR-Based Snowfall Rate Algorithm for Passive Microwave Radiometers
- Author
-
Meng, Huan, Kongoli, Cezar, Ferraro, Ralph R., Stoffel, Markus, Series Editor, Cramer, Wolfgang, Advisory Editor, Luterbacher, Urs, Advisory Editor, Toth, F., Advisory Editor, Levizzani, Vincenzo, editor, Kidd, Christopher, editor, Kirschbaum, Dalia B., editor, Kummerow, Christian D., editor, Nakamura, Kenji, editor, and Turk, F. Joseph, editor
- Published
- 2020
- Full Text
- View/download PDF
5. A Snowfall Detection Algorithm for Fengyun-3D Microwave Sounders with Differentiated Atmospheric Temperature Conditions
- Author
-
Qingwen Ji, Ziqiang Ma, Jintao Xu, Songkun Yan, and Xiaoqing Li
- Subjects
snowfall detection ,Fengyun-3D ,MWTS ,MWHS ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Precipitation in different phases has varying effects on runoff. However, monitoring surface snowfall poses a significant challenge, highlighting the importance of developing a snowfall detection algorithm. The objective of this study is develop a snowfall detection algorithm for the Microwave Temperature Sounder-2 (MWTS-II) and the Microwave Humidity Sounder-2 (MWHS-II) onboard the FY-3D satellite while considering the differentiated atmosphere temperature conditions. The results show that: (1) The brightness temperature (TB) of MWTS Channel 3 is well-suited for pre-classifying atmospheric temperatures, and significant differences in TB distribution exist between the two pre-classification subsets. (2) Among six machine classifiers examined, the random forest classifier exhibits favorable classification performance on both the validation set (accuracy: 0.76, recall: 0.76, F1 score: 0.75) and test set (accuracy: 0.80, recall: 0.44, F1 score: 0.44). (3) The application of the snowfall detection algorithm showcases a reasonable spatial distribution and outperforms the IMERG and ERA5 snowfall data.
- Published
- 2023
- Full Text
- View/download PDF
6. A Snowfall Detection Algorithm for Fengyun-3D Microwave Sounders with Differentiated Atmospheric Temperature Conditions
- Author
-
Li, Qingwen Ji, Ziqiang Ma, Jintao Xu, Songkun Yan, and Xiaoqing
- Subjects
snowfall detection ,Fengyun-3D ,MWTS ,MWHS - Abstract
Precipitation in different phases has varying effects on runoff. However, monitoring surface snowfall poses a significant challenge, highlighting the importance of developing a snowfall detection algorithm. The objective of this study is develop a snowfall detection algorithm for the Microwave Temperature Sounder-2 (MWTS-II) and the Microwave Humidity Sounder-2 (MWHS-II) onboard the FY-3D satellite while considering the differentiated atmosphere temperature conditions. The results show that: (1) The brightness temperature (TB) of MWTS Channel 3 is well-suited for pre-classifying atmospheric temperatures, and significant differences in TB distribution exist between the two pre-classification subsets. (2) Among six machine classifiers examined, the random forest classifier exhibits favorable classification performance on both the validation set (accuracy: 0.76, recall: 0.76, F1 score: 0.75) and test set (accuracy: 0.80, recall: 0.44, F1 score: 0.44). (3) The application of the snowfall detection algorithm showcases a reasonable spatial distribution and outperforms the IMERG and ERA5 snowfall data.
- Published
- 2023
- Full Text
- View/download PDF
7. A hybrid snowfall detection method from satellite passive microwave measurements and global forecast weather models.
- Author
-
Kongoli, Cezar, Meng, Huan, Dong, Jun, and Ferraro, Ralph
- Subjects
- *
WEATHER forecasting , *REMOTE sensing , *SNOW measurement , *MICROWAVE measurements , *HUMIDITY - Abstract
Despite significant progress made in snowfall estimation from space, methods utilizing passive microwave measurements continue to be plagued by low detectability compared to those that estimate rainfall. This article presents a hybrid snowfall detection algorithm that combines the output from a statistical algorithm utilizing satellite passive microwave measurements with the output from a statistical algorithm trained with in situ data that uses meteorological variables derived from a global forecast model as predictors. The satellite algorithm computes the probability of snowfall over land using logistic regression and the principal components of the high‐frequency brightness‐temperature measurements at AMSU/MHS and ATMS channel frequencies 89 GHz and above. In a separate investigation, analysis of modelled data derived from NOAA's Global Forecast System (GFS) showed that cloud thickness and relative humidity at 1 to 3 km height were the best predictors of snowfall occurrence. A statistical logistical regression model that combined cloud thickness, relative humidity and vertical velocity was selected among statistically significant variants as the one with the highest overall classification accuracy. Next, the weather‐based and satellite model outputs were combined in a weighting scheme to produce a final probability of snowfall output, which was then used to classify a weather event as "snowing" or "not snowing" based on an a priori threshold probability. Statistical analysis indicated that a scheme with equal weights applied to the weather‐based and satellite model significantly improved satellite snowfall detection. Example applications of the hybrid algorithm over continental USA demonstrated the improvement for a major snowfall event and for an event dominated by lighter snowfall. The article presents a hybrid approach to satellite snowfall detection that can improve the performance of satellite‐based methods and increase their utility in operational weather and hydrological forecasting. It presents an analysis and new insights into modelled meteorological variables that are related to snowfall occurrence, and a weather‐based snowfall detection algorithm using modelled data from a global weather forecast system. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
8. CloudSat-Based Assessment of GPM Microwave Imager Snowfall Observation Capabilities.
- Author
-
Panegrossi, Giulia, Rysman, Jean-François, Casella, Daniele, Marra, Anna Cinzia, Sanò, Paolo, and Kulie, Mark S.
- Subjects
- *
METEOROLOGICAL precipitation measurement , *SNOW , *REMOTE sensing , *MICROWAVE imaging , *REGRESSION trees - Abstract
The sensitivity of Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channels to snowfall at higher latitudes (around 60N/S) is investigated using coincident CloudSat observations. The 166 GHz channel is highlighted throughout the study due to its ice scattering sensitivity and polarization information. The analysis of three case studies evidences the important combined role of total precipitable water (TPW), supercooled cloud water, and background surface composition on the brightness temperature (TB) behavior for different snow-producing clouds. A regression tree statistical analysis applied to the entire GMI-CloudSat snowfall dataset indicates which variables influence the 166 GHz polarization difference (166 DTB) and its relation to snowfall. Critical thresholds of various parameters (sea ice concentration (SIC), TPW, ice water path (IWP)) are established for optimal snowfall detection capabilities. The 166 DTB can identify snowfall events over land and sea when critical thresholds are exceeded (TPW > 3.6 kg.m-2, IWP > 0.24 kg.m-2 over land, and SIC > 57%, TPW > 5.1 kg.m-2 over sea). The complex combined 166 DTB-TB relationship at higher latitudes and the impact of supercooled water vertical distribution are also investigated. The findings presented in this study can be exploited to improve passive microwave snowfall detection algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
9. SLALOM: An All-Surface Snow Water Path Retrieval Algorithm for the GPM Microwave Imager
- Author
-
Jean-François Rysman, Giulia Panegrossi, Paolo Sanò, Anna Cinzia Marra, Stefano Dietrich, Lisa Milani, and Mark S. Kulie
- Subjects
snowfall detection ,snow water path retrieval ,supercooled droplets detection ,GPM Microwave Imager ,Science - Abstract
This paper describes a new algorithm that is able to detect snowfall and retrieve the associated snow water path (SWP), for any surface type, using the Global Precipitation Measurement (GPM) Microwave Imager (GMI). The algorithm is tuned and evaluated against coincident observations of the Cloud Profiling Radar (CPR) onboard CloudSat. It is composed of three modules for (i) snowfall detection, (ii) supercooled droplet detection and (iii) SWP retrieval. This algorithm takes into account environmental conditions to retrieve SWP and does not rely on any surface classification scheme. The snowfall detection module is able to detect 83% of snowfall events including light SWP (down to 1 × 10−3 kg·m−2) with a false alarm ratio of 0.12. The supercooled detection module detects 97% of events, with a false alarm ratio of 0.05. The SWP estimates show a relative bias of −11%, a correlation of 0.84 and a root mean square error of 0.04 kg·m−2. Several applications of the algorithm are highlighted: Three case studies of snowfall events are investigated, and a 2-year high resolution 70°S–70°N snowfall occurrence distribution is presented. These results illustrate the high potential of this algorithm for snowfall detection and SWP retrieval using GMI.
- Published
- 2018
- Full Text
- View/download PDF
10. CloudSat-Based Assessment of GPM Microwave Imager Snowfall Observation Capabilities
- Author
-
Giulia Panegrossi, Jean-François Rysman, Daniele Casella, Anna Cinzia Marra, Paolo Sanò, and Mark S. Kulie
- Subjects
snowfall detection ,GPM ,CloudSat ,CPR ,CALIPSO ,high latitudes ,passive microwave ,remote sensing of precipitation ,Science - Abstract
The sensitivity of Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channels to snowfall at higher latitudes (around 60°N/S) is investigated using coincident CloudSat observations. The 166 GHz channel is highlighted throughout the study due to its ice scattering sensitivity and polarization information. The analysis of three case studies evidences the important combined role of total precipitable water (TPW), supercooled cloud water, and background surface composition on the brightness temperature (TB) behavior for different snow-producing clouds. A regression tree statistical analysis applied to the entire GMI-CloudSat snowfall dataset indicates which variables influence the 166 GHz polarization difference (166 ∆TB) and its relation to snowfall. Critical thresholds of various parameters (sea ice concentration (SIC), TPW, ice water path (IWP)) are established for optimal snowfall detection capabilities. The 166 ∆TB can identify snowfall events over land and sea when critical thresholds are exceeded (TPW > 3.6 kg·m−2, IWP > 0.24 kg·m−2 over land, and SIC > 57%, TPW > 5.1 kg·m−2 over sea). The complex combined 166 ∆TB-TB relationship at higher latitudes and the impact of supercooled water vertical distribution are also investigated. The findings presented in this study can be exploited to improve passive microwave snowfall detection algorithms.
- Published
- 2017
- Full Text
- View/download PDF
11. Active and passive microwave observations of snowfall from space
- Author
-
Casella D., Panegrossi G., Sanò P., Marra A. C., Dietrich S., Kulie M. S., and Johnson B. T.
- Subjects
microwave ,dpr ,cpr ,snowfall detection ,precipitation ,radiometer ,atms ,gmi - Abstract
One of the main goals of the Global Precipitation Measurement (GPM) mission is to improve snowfall retrieval accuracy, as snowfall is, the predominant component of the global precipitation amount at mid and high latitudes. The GPM Core Observatory (GPM-CO) is equipped with two instruments: the GMI, the most advanced conical precipitation radiometer with respect to both channel assortment and spatial resolution; and the Dual-frequency Precipitation Radar (DPR) [composed of two radars, a Ku-band Precipitation Radar (KuPR) (13.6-GHz) and a Ka-band (35.5-GHz) Precipitation Radar (KaPR)]. Advancements in snowfall detection and accuracy in quantitative estimates of snowfall rates at mid-high latitudes is expected from both the GMI and DPR. Moreover, thanks to the exploitation of the high-frequency channels (> 100 GHz) available on most of radiometers in the GPM constellation, providing very good coverage at mid-high latitudes (hourly or less), snowfall monitoring is now possible. Among these radiometers, the Advanced Technology Microwave Sounder (ATMS) onboard Suomi-NPP is the most advanced cross track radiometer with 22 channels, 5 of which in the 183 GHz oxygen absorption band. On the other hand, CloudSat carries the W-band (94GHz) Cloud Profiling Radar (CPR) that has collected data since its 2006 launch. While CPR was designed as primarily a cloud remote sensing mission, its high-latitude coverage (up to ;82° latitude) and hi gh radar sensitivity (~-28dBZ) make it very suitable for snowfall-related research. We will show the results of a study where CPR is used to: 1) assess snowfall detection and estimate capabilities of DPR; 2) analyze snowfall signatures in the high frequency channels of the passive microwave radiometers in relation to fundamental environmental conditions. A number of global datasets made of coincident observations of snowfall producing clouds from the spaceborne radars DPR and CPR and from the most advanced radiometers available (GMI and ATMS) are analyzed. We have assessed the snowfall detection and estimation capabilities of DPR, comparing its observations and precipitation products with those available from CPR. We have estimated that DPR radars miss a very large fraction of snowfall precipitation (more than 90% of the events and around 70% of the precipitating snowfall mass). This is due mostly to the sensitivity limits of the DPR radar and secondly to the effect of the DPR radar side lobe clutter. An algorithm that combines the measured reflectivities from the two Ku-band and Ka-band radars exploiting the weak signals related to snowfall has been developed. Results from this study will be presented, showing improved DPR detection capabilities up to more than 50% of the snowfall mass obtained with the newly developed algorithm. Moreover the coincident observations of ATMS - CPR and of the GMI - DPR have been analyzed in order to study the multichannel brightness temperature signal related to snowfall. The main results of this study show that the high frequency channels (and the 183 GHz band channels in particular) can be successfully used in order to identify and quantify snowfall. The degree of success strongly depends on the type of surface background which requires proper detection and identification. Moreover, some ancillary data must be used (i.e. the columnar water vapor content is of paramount importance) for the correct use of the measurements towards snowfall detection. In this context an algorithm for surface classification of snow over land and ice over ocean using primarily the PMW low frequency channels is proposed and will be presented.
- Published
- 2016
12. CloudSat-Based Assessment of GPM Microwave Imager Snowfall Observation Capabilities
- Author
-
Paolo Sanò, Giulia Panegrossi, Jean-François Rysman, Mark S. Kulie, Daniele Casella, and Anna Cinzia Marra
- Subjects
010504 meteorology & atmospheric sciences ,CALIPSO ,0211 other engineering and technologies ,snowfall detection ,GPM ,CloudSat ,CPR ,high latitudes ,passive microwave ,remote sensing of precipitation ,02 engineering and technology ,01 natural sciences ,Latitude ,Statistical analysis ,lcsh:Science ,Sea ice concentration ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Precipitable water ,Snow ,Climatology ,Brightness temperature ,General Earth and Planetary Sciences ,Environmental science ,lcsh:Q ,Global Precipitation Measurement ,Microwave - Abstract
The sensitivity of Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channels to snowfall at higher latitudes (around 60°N/S) is investigated using coincident CloudSat observations. The 166 GHz channel is highlighted throughout the study due to its ice scattering sensitivity and polarization information. The analysis of three case studies evidences the important combined role of total precipitable water (TPW), supercooled cloud water, and background surface composition on the brightness temperature (TB) behavior for different snow-producing clouds. A regression tree statistical analysis applied to the entire GMI-CloudSat snowfall dataset indicates which variables influence the 166 GHz polarization difference (166 ∆TB) and its relation to snowfall. Critical thresholds of various parameters (sea ice concentration (SIC), TPW, ice water path (IWP)) are established for optimal snowfall detection capabilities. The 166 ∆TB can identify snowfall events over land and sea when critical thresholds are exceeded (TPW > 3.6 kg·m−2, IWP > 0.24 kg·m−2 over land, and SIC > 57%, TPW > 5.1 kg·m−2 over sea). The complex combined 166 ∆TB-TB relationship at higher latitudes and the impact of supercooled water vertical distribution are also investigated. The findings presented in this study can be exploited to improve passive microwave snowfall detection algorithms.
- Published
- 2017
13. SLALOM: An All-Surface Snow Water Path Retrieval Algorithm for the GPM Microwave Imager.
- Author
-
Rysman, Jean-François, Panegrossi, Giulia, Sanò, Paolo, Marra, Anna Cinzia, Dietrich, Stefano, Milani, Lisa, and Kulie, Mark S.
- Subjects
- *
METEOROLOGICAL precipitation measurement , *MICROWAVE imaging , *MICROWAVE imaging equipment , *SNOW analysis , *ALGORITHMS - Abstract
This paper describes a new algorithm that is able to detect snowfall and retrieve the associated snow water path (SWP), for any surface type, using the Global Precipitation Measurement (GPM) Microwave Imager (GMI). The algorithm is tuned and evaluated against coincident observations of the Cloud Profiling Radar (CPR) onboard CloudSat. It is composed of three modules for (i) snowfall detection, (ii) supercooled droplet detection and (iii) SWP retrieval. This algorithm takes into account environmental conditions to retrieve SWP and does not rely on any surface classification scheme. The snowfall detection module is able to detect 83% of snowfall events including light SWP (down to 1 × 10−3 kg·m−2) with a false alarm ratio of 0.12. The supercooled detection module detects 97% of events, with a false alarm ratio of 0.05. The SWP estimates show a relative bias of −11%, a correlation of 0.84 and a root mean square error of 0.04 kg·m−2. Several applications of the algorithm are highlighted: Three case studies of snowfall events are investigated, and a 2-year high resolution 70°S–70°N snowfall occurrence distribution is presented. These results illustrate the high potential of this algorithm for snowfall detection and SWP retrieval using GMI. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.