GEOMETRIC CHARACTERISTICS OF CLOUDS FROM CEILOMETER MEASUREMENTS AND RADIOSOUNDING METHODS Montserrat Costa Surós Dipòsit legal: Gi. 1888-2014 http://hdl.handle.net/10803/284084 http://creativecommons.org/licenses/by/4.0/deed.ca Aquesta obra està subjecta a una llicència Creative Commons Reconeixement Esta obra está bajo una licencia Creative Commons Reconocimiento This work is licensed under a Creative Commons Attribution licence GEOMETRIC CHARACTERISTICS OF CLOUDS FROM CEILOMETER MEASUREMENTS AND RADIOSOUNDING METHODS DOCTORAL THESIS Montserrat Costa Surós 2014 DOCTORAL THESIS GEOMETRIC CHARACTERISTICS OF CLOUDS FROM CEILOMETER MEASUREMENTS AND RADIOSOUNDING METHODS Montserrat Costa Surós 2014 Doctoral Programme in Experimental Sciences and Sustainability Supervisors: Josep Calbó Angrill José Abel González Gutiérrez Thesis submitted for the degree of Doctor of Philosophy by the University of Girona El Dr. Josep Calbó Angrill i el Dr. José Abel González Gutiérrez, professors titulars del Departament de Física de la Universitat de Girona, CERTIFIQUEN: Que aquest treball, titulat “Geometric characteristics of clouds from ceilometer measurements and radiosounding methods”, que presenta la Montserrat Costa Surós per a l’obtenció del títol de doctora, ha estat realitzat sota la seva direcció. I, perquè així consti i tingui els efectes oportuns, signen aquest document. Dr. Josep Calbó Angrill Dr. José Abel González Gutiérrez Girona, 29 de juliol de 2014. Un esforç total és una victòria completa M. Ghandi Acknowledgments First and the most important I would like to thank my supervisors Dr. Josep Calbó and Dr. Josep- Abel González for giving me the opportunity to begin my research career with them, which has led to this doctoral thesis, and for their guidance and support during these years. I am grateful to Ministry of Science and Innovation of the Spanish Government, currently Ministry of Economy and Competitiveness, for the FPI fellowship (Researcher Staff Formation, FPI BES-2008-003129). And for the two brief stay grants (EEBB-2011-44092 and EEBB-I-12 03669) which made possible the two training brief stays: in the Pacific Northwest National Laboratory (PNNL, Richland, WA, USA) in 2011, and in Vaisala Oyj. (Vantaa, Helsinki, Finland) in 2012. This thesis has also been possible thanks to Ministry of Science and Innovation which funded the research Projects: “Clouds and climate change: trends and variability of cloudiness and sunshine duration in the Iberian peninsula, and measurement and modeling of cloud radiative effects at the surface (NUCLIEREX)” (CGL2007-62664/CLI), and “Clouds and their effect on radiation: from studies of conditions at the local scale to climatological analyses of global extent. Interactions with the atmospheric aerosol (NUCLIERSOL)” (CGL2010-18546). I want to thank the Spanish Meteorological State Agency (AEMET) which kindly provided visual observations of cloudiness used for comparison in this thesis. Likewise, acknowledgements to the Atmospheric Measurements Research (ARM) Program Research facility (sponsored by the U.S. Department of Energy) for providing valuable long periods of data (ARSCL) and TSI animations from the Southern Great Plains (OK, USA). Also, acknowledgements to National Oceanic and Atmospheric Administration (NOAA) Comprehensive Large Array-data stewardship system (CLASS) to provide GOES images for research use. My sincere acknowledgments to the members of the projects: Dr. Javier Martín-Vide, especially because without his support regarding statistical analysis the thesis would have remained incomplete; Dr. Arturo Sanchez-Lorenzo, for being the fastest paper sender ever and for sharing his experiences with me; Dr. Antoni Viúdez, for his wise tips while we were sharing the office; and Dr. Jordi Badosa. To my brief stay advisors and mentors: Dr. Charles N. Long, for their high value contributions and comments to my manuscripts, and Victor Morris (from PNNL); Atte Salmi and Christopher Munkel (from Vaisala). And to Dr. Lydia Dimitrieva-Arrago for her explanations and interesting discussions while visiting the University of Girona in the frame of the UE Project CLIMSEAS (FP7-PEOPLE-2009-IRSES Proposal N. 247512). I also want to thank all my colleagues, Doctors and Professors, of the Department of Physics in the University of Girona, and specially my fellow Ph.D. students, for the friendship and good times: Dr. Dolors Pujol, Dr. Cristina Miàs, Dr. Jordi Colomer, Dr. Teresa Serra, Dr. Marianna Soler, Dr. Bruna Comas, Sandra Ricart, Nazha ElAllaui, Roger Arbusé, Lluís Calderer, Nitin Bharadwaj, Àlex Sànchez, Aaron Enríquez, Àlex Ros and Conxi Pau. Without forgetting the Service and Administration Personal (PAS) of the Department of Physics: Anna Espígol, Xevi Baca, Xicu Gómez, Marc Rodríguez, and Quico Pazo, as well as Natàlia Adell from UdG Technical Research Services. I would like to express my gratitude to reviewers for the valuable suggestions that allowed improving the published papers. And last but not least, I owe my deepest gratitude to all my family and friends who have given me their support in my choice of career and while preparing and writing this thesis. In particular, I want to thank Jaume Costa for his immensurable support and Xus López for his unconditional love, understanding and patience. There would be many other names worth mentioning here. I just hope I have been able to show my sincere gratitude because a part of this thesis belongs to them, and it wouldn’t be like this without them. Contents Publications and communications related to the thesis ............................................................... xiii List of acronyms and abbreviations ................................................................................................ xv List of figures ................................................................................................................................ xxiii List of tables.................................................................................................................................. xxix Abstract ........................................................................................................................................ xxxi Resum ......................................................................................................................................... xxxiii Resumen ...................................................................................................................................... xxxv 1. Introduction .................................................................................................................................. 1 1.1. Clouds and their classification ............................................................................................... 1 1.2. Current interest in clouds .................................................................................................... 14 1.3. Macroscopic detection, quantification and geometric characterization of clouds ............ 21 2. Goals ........................................................................................................................................... 27 3. Instruments, data and methodology .......................................................................................... 31 3.1. Cloud cover and cloud base height ..................................................................................... 31 3.1.1. Human observations .................................................................................................... 31 3.1.2. Sky cameras .................................................................................................................. 34 3.1.3. LIDAR technology and ceilometer measurements ....................................................... 38 3.1.4. Surface radiometry ....................................................................................................... 43 3.1.5. Satellite observations ................................................................................................... 50 3.2. Cloud vertical structure ....................................................................................................... 55 3.2.1. Remote sensing by active ground-based systems and value added products (ARSCL) 56 3.2.2. Satellite observations (the A-train) .............................................................................. 63 3.2.3. Aircraft in situ measurements ...................................................................................... 66 3.2.4. Radiosoundings ............................................................................................................ 67 3.3 Methodology ........................................................................................................................ 74 3.3.1 Cloud cover and cloud base height from ceilometer measurements (Girona) ............. 74 3.3.2. Cloud vertical structure from radiosoundings and ARSCL (Southern Great Plains) ..... 77 3.3.2-a. Selecting suitable cases (horizontal displacement of the radiosonde and GOES images) ............................................................................................................................... 78 3.3.2-b. Radiosounding methods for cloud vertical structure estimation ......................... 81 3.3.2-c. Classification of the situations .............................................................................. 90 4. Results and discussion ..............................................................................................................