Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E
description
Transcript of Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E
![Page 1: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/1.jpg)
Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E
Hyangsun Han and Hoonyol Lee
Kangwon National University, KOREA
![Page 2: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/2.jpg)
Contents
Introduction
Study Area and Data
Method
Radiation Characteristics of Glacial Ice
Conclusion
![Page 3: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/3.jpg)
Introduction
Glacial IceOriginated from fresh water (snow)Glaciers, Icebergs, Ice sheets, and Ice shelvesAir bubbles are small enough to cause Rayleigh scatteringCrystal size is very large because of slow recrystallizationThe GLACIAL ICE has different radiation characteristics from SEA ICE frozen from salty water
Importance of glacial ice studyGlacial ice changes coastal landform and environment of sea ice formation
![Page 4: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/4.jpg)
Introduction
Passive Microwave Sensorwidely used to study the polar ice
- sea ice concentration, snow depth, ice extent, …high temporal resolution, low spatial resolutionAMSR-E is a typical passive microwave sensor
Objective of studyEvaluation of accuracy of glacial ice on AMSR-E sea ice concentration in George V Coast, Southern AntarcticaAnalysis of microwave radiation characteristics of glacial ice
![Page 5: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/5.jpg)
Study Area
Radarsat-1 mosaic image of the Antarctic
George V CoastSouthern Antarctica
![Page 6: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/6.jpg)
ASAR Data and AMSR-E NT2 SIC Data
SIC
100%
50%
Ice sheet masked in AMSR-E NT2
SIC
Two ENVISAT ASAR Images
Wide Swath SLC/HH polarization2006/04/20, 2006/04/26
AMSR-E L1 data products
Brightness temperature, sea ice concentration 2006/04/20, 2006/04/26
ENVISAT ASAR image of the study area (2006/04/26, 100 km×100 km)
AMSR-E sea ice concentration of the study area (2006/04/26, 100 km×100 km)
Ice sheet
![Page 7: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/7.jpg)
Identification of Ice Type in ASAR
Most sea surface was covered with ice
Several icebergs
A ice tongue
Distinction between sea ice and ice shelf is difficult by only ASAR data
Ice sheet
Icebergs
Ice tongue
Sea ice Sea ice (new ice)
ENVISAT ASAR image of the study area (2006/04/26, 100 km×100 km)
![Page 8: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/8.jpg)
2006/04/29 2006/02/19 2005/12/17
2005/02/02 2004/03/08 2003/02/23
MODIS Imagery
MODIS time-series images
- A region of ice shelf is confirmed
![Page 9: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/9.jpg)
Comparing ASAR SIC with AMSR-E SIC
SIC
100%
50%
Ice sheet masked in AMSR-E NT2
SIC
Ice shelf
IcebergsSea ice
Sea ice
Ice shelf
IcebergsSea ice
Sea ice
Ice sheet
![Page 10: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/10.jpg)
ASAR Ice Concentration
Masking inland in ASAR images using land mask product of AMSR-E
Classifying ice type into sea ice, icebergs, and ice shelf by supervised classification and digitizing
Overall accuracy: 97.4% and 94.4% in each ASAR image
Calculating ice concentration of sea ice, icebergs, and ice shelf
Comparing with AMSR-E sea ice concentration
![Page 11: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/11.jpg)
AMSR-E Sea Ice Algorithm
AMSR-E6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz dual polarized channels Daily sea ice concentration with 12.5 km spatial resolution by using NASA Team2 Algorithm
NASA Team2 AlgorithmBetter spatial resolution and accuracy of sea ice concentration than NASA Team Algorithm Identifies Ice type A, B, C, and open water by data plotting in PR and GR domain
, ,
, ,B B
B B
T V T HPR
T V T H
1 21 2
1 2
, ,
, ,B B
B B
T p T pGR p p
T p T p
(Cavalieri et al., 1997)
![Page 12: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/12.jpg)
Comparing ASAR SIC with AMSR-E SIC
Difference between ASAR and AMSR-E SICSea ice: very small difference (RMSE 1.4%)Icebergs: AMSR-E NT2 SIC was underestimated (RMSE 29.5%)Ice shelf: AMSR-E NT2 SIC was underestimated (RMSE 23.3%) → analysis of microwave radiation characteristics of the glacial ice in PR and GR domain is needed
![Page 13: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/13.jpg)
PR(18)-GR(37V18V) Scattergram
Sea ice Icebergs Ice shelf
PR(18) 0.047 0.086 0.064
GR(37V18V) 0.006 0.024 0.027
![Page 14: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/14.jpg)
GR(89H18H)-GR(89V18V) Scattergram
Sea ice Icebergs Ice shelf
GR(89H18H) 0.048 0.117 0.124
GR(89V18V) 0.021 0.067 0.083
Ice type A-B line
100% Ice type A
100% Ice type B
Open water
100% Ice type C
![Page 15: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/15.jpg)
Conclusions
We evaluated AMSR-E NASA Team2 sea ice concentration in Antarctic glacial ice region
AMSR-E NT2 algorithm is very accurate in sea ice region
We found that AMSR-E NASA Team2 algorithm underestimates ice concentration in icebergs and ice shelf
Glacial ice has higher PR(18), GR(37V18V), GR(89V18V), and GR(89H18H) than those of sea ice
Microwave radiation characteristics of glacial ice are quite different from that of sea ice and open water
![Page 16: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/16.jpg)
Ongoing Study
Analysis of radiation characteristics of microwave from glacial ice in various seasons and regions
Improvement of the accuracy of AMSR-E NASA Team2 sea ice concentration by adding glacial ice concentration (GIC)
GIC can be used for- Improvement of land mask product from AMSR-E NASA Team2
algorithm- Icebergs tracking- Monitoring of coastal landform change by movement of glacial ice
![Page 17: Microwave Radiation Characteristics of Glacial Ice Observed by AMSR-E](https://reader036.fdocuments.in/reader036/viewer/2022062519/56814fc2550346895dbd7dff/html5/thumbnails/17.jpg)