Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2012 Comparison Between Satellite Observed and Dropsonde Simulated Surface Sensitive Microwave Channel Observations within and Around Hurricane Ivan Katherine Moore Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES COMPARISON BETWEEN SATELLITE OBSERVED AND DROPSONDE SIMULATED SURFACE SENSITIVE MICROWAVE CHANNEL OBSERVATIONS WITHIN AND AROUND HURRICANE IVAN By KATHERINE MOORE A Thesis submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science Degree Awarded: Summer Semester, 2012 Katherine Moore defended this thesis on June 28, 2012. The members of the supervisory committee were: Xiaolei Zou Professor Directing Thesis Mark A. Bourassa Committee Member Vasubandhu Misra Committee Member The Graduate School has verified and approved the above-named committee members, and certifies that the thesis has been approved in accordance with university requirements. ii ACKNOWLEDGEMENTS I would first like to thank my advisor Dr. Zou for giving me the opportunity to work for her as a graduate student and for all of the many lessons she has taught me in and out of the classroom. I am also grateful for my committee members, Dr. Bourassa and Dr. Misra, for imparting much knowledge to me in their classrooms and further committing their time to me as committee members. I would like to thank James Wang and Dr. Shengpeng Yang for helping me immensely with running the Community Radiative Transfer Model (CRTM). I want to thank Dr. Zou and Dr. Yang for providing me with insightful and invaluable guidance throughout the process of researching for my thesis. I also want to thank Hui Wang for the hours of help she has given me in using MATLAB to process images as well as spending time reviewing my manuscript for assessment. I want to thank Bradley Schaaf and Brian Nguyen for reviewing my manuscript for assessment as well. I’d like to thank Dr. Jun Zhang of the NOAA AOML group for providing me with the dropsonde data, assistance with storm selection, data processing, and advice early in the process. I would also like to thank all of the members of Dr. Zou’s lab for their help and encouragement throughout my time here. Finally, I want to thank my friends and family for their support and encouragement. iii TABLE OF CONTENTS List of Tables ...................................................................................................................................v List of Figures ................................................................................................................................ vi Abstract ............................................................................................................................................x 1. INTRODUCTION ...................................................................................................................1 1.1 Motivation ......................................................................................................................1 1.2 Previous Studies .............................................................................................................2 1.3 Objectives ......................................................................................................................6 2. DATA ......................................................................................................................................7 2.1 JCSDA CRTM ...............................................................................................................7 2.2 Dropsonde Data .............................................................................................................9 2.3 GFS Model Data ..........................................................................................................13 2.4 AMSU-A Microwave Data ..........................................................................................14 3. METHODS ............................................................................................................................19 3.1 Preparing the Atmospheric Profile Data for Input to CRTM ......................................19 3.1.1 Calculating Mixing Ratios ...............................................................................20 3.1.2 Calculating Layer Averages .............................................................................20 3.2 Preparing the AMSU-A Data for Comparison .............................................................21 3.3 Strategy for Comparison ..............................................................................................22 3.3.1 Collocation of Simulations to Observation Space ...........................................22 3.3.2 Cloudy and Clear Sky Identification ................................................................22 4. DESCRIPTION OF HURRICANE IVAN (2004) ................................................................23 5. SIMULATION PERFORMANCE ANALYSIS ...................................................................30 5.1 O-B Histogram Analysis ..............................................................................................30 5.2 Scatter Plot Analysis ....................................................................................................35 5.3 O-B Scatter Plots Grouped by FOV.............................................................................45 5.4 O-B Scatter Plots Grouped by Latitude .......................................................................51 5.5 O-B Statistical Analysis ...............................................................................................56 6. SUMMARY AND CONCLUSIONS ....................................................................................62 REFERENCES ..............................................................................................................................64 BIOGRAPHICAL SKETCH .........................................................................................................67 iv LIST OF TABLES Table 1. Time in minutes it takes (on average) for a dropsonde to fall to sea level as dropped from various pressure levels. (Hock and Franklin, 1999). .............................................................10 Table 2. The specifications of the NCAR GPS dropsonde as given by the manufacturer. (Hock and Franklin, 1999). .......................................................................................................................12 Table 3. Estimated error in NCAR GPS dropsonde observations. (Hock and Franklin, 1999). ....13 Table 4. The frequencies of channels 1-15 of AMSU-A and of channels 1-5 of AMSU-B, in GHz, are displayed below. The frequencies are denoted as x±y±z, where x is the center/nadir frequency, y is the distance between the center frequency and the center of two pass bands (for cases when the center frequency is not sensed, but there are two bands sensed on both sides of the nadir frequency), and z is the width of the two pass bands for the same case as y is valid for. (Kidder et al., 1998). ......................................................................................................................17 Table 5. The minimum and maximum values of brightness temperatures (TB) for each channel, for the dropsonde and GFS simulations and the AMSU-A observations. Values are rounded to the nearest hundredth. ....................................................................................................................57 Table 6. The mean, median, and mode values of brightness temperatures (TB) for each channel, for the dropsonde and GFS simulations and the AMSU-A observations. Values are rounded to the nearest hundredth. ....................................................................................................................58 Table 7. The mean and median values of brightness temperature errors for each channel, for the dropsonde (top, O-Bsonde) and GFS (bottom, O-BGFS) simulations calculated for all points where data was available for both the simulation and the observation. Values are rounded to the nearest hundredth. ......................................................................................................................................59 Table 8. The mean and median values of brightness temperature errors for each channel, for the dropsonde (top, O-Bsonde) and GFS (bottom, O-BGFS) simulations calculated at only the clear sky observation points. Values are rounded to the nearest hundredth. ................................................60 Table 9. The mean and median values of brightness temperature errors for each channel, for the dropsonde (top, O-Bsonde) and GFS (bottom, O-BGFS) simulations calculated at only the cloudy sky observation points. Values are rounded to the nearest hundredth. ..........................................60 v LIST OF FIGURES Figure 1. Clear sky weighting function (top) for AMSU-A based on optical depth profiles output by the CRTM using the U.S. standard atmosphere profile (bottom). ............................................18 Figure 2. Track of Hurricane Ivan from 2-24 September 2004. The color of the track indicates the strength of the storm at that time and location. The green circles indicate the locations of the dropsondes released from the