Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Margaret A. Tolbert

Research Interests

I am a professor in Chemistry at the University of Colorado in Boulder. My research group focuses on clouds and aerosols in atmospheric chemistry. Research topics include stratospheric ozone depletion, cirrus cloud chemistry, tropospheric clouds and particles, the interaction between clouds and climate, and the chemistry of planetary atmospheres including Titan and Mars. Our work is laboratory-based; we use simulation chambers to identify key atmospheric aerosol processes important in different environments. Novel laboratory techniques include aerosol optical levitation, aerosol mass spectrometry, and aerosol optical techniques such as cavity ring down, photo acoustic and Raman spectroscopies. 

Current Research

Aqueous inorganic ions are a major component of atmospheric aerosols, typically comprising 25 to 75 percent of the dry aerosol mass. At sufficiently low relative humidity (RH), aqueous inorganic aerosols can undergo crystallization with the loss of particle-phase water (efflorescence), which alters the aerosol’s effect on global climate and many heterogeneous reactions that influence air quality. Because of the importance of the aerosol phase, the efflorescence behavior of aqueous inorganic aerosols has been studied for decades. Despite advances, there is still little agreement on how crystals nucleate and grow from an aqueous solution. In particular, the effect of collisions on particle phase remains largely unexplored.

We previously showed that collisions between aqueous droplets and soluble crystalline contact nuclei (CN) resulted in a nonequilibrium CN-droplet interface that persisted long enough for crystal nucleation to occur epitaxially (that is, oriented by CN crystal lattice structure), although CN dissolution was predicted from bulk thermodynamics. The question arises whether nonequilibrium effects may exist for collisions with other CN particle types, such as insoluble amorphous organics. Here, we studied the effect of collisions between aqueous inorganic microdroplets and insoluble (hydrophobic) amorphous organic aerosols. Experiments were performed using optically levitated microdroplets of sodium chloride (NaCl), ammonium chloride (NH4Cl), and sodium bromide (NaBr), which are important components of sea spray aerosol. In our optical levitation system, light-absorbing particles, such as soot, strongly absorb the trapping laser wavelength. Thus, to avoid these complications and to probe the potential relevance of ion-specific interactions on salt crystal nucleation, functionalized surfactant-free polystyrene latex spheres (PSLs), which are hydrophobic amorphous organic aerosols, with a range of surface functionality/net charge were used as CN proxies for atmospherically relevant insoluble organic aerosols. We found that collisions with PSLs induced crystallization of aqueous inorganic microdroplets at high RH, the effect of which was correlated with destabilizing water-mediated ion-specific surface interactions. These same organic aerosols did not induce crystallization once internally mixed in the droplet, pointing toward a previously unconsidered transient ion-specific crystal nucleation pathway that can promote aerosol crystallization via particle collisions.

An example of a collision induced contact efflorescence event is shown in the figure, where an aqueous droplet of NaCl is collided with a 400 nm PSL CN at 57% RH. In part A, the brightfield images of the NaCl particle are shown (scale bar 10 mm).  Frame 1 shows the aqueous droplet before contact, Frame 2 the droplet 20 ms after contact, and frames 3 and 4 the droplet 90 and 180 ms, respectively, after contact. Efflorescence begins immediately after contact, and as efflorescence proceeds, the loss of water causes the particle to move upward in the trap. Part B shows a different fully effloresced NaCl crystal levitated in the trap. Parts C and D show binary contrast images that allow the point of contact to be more visible (see arrow). This set of images clearly shows that it is the contact event with the amorphous organic CN that induced NaCl efflorescence at a relative humidity well above the homogeneous value of 47% RH. Ongoing studies will begin to probe contact ice nucleation, a process thought to be important in mixed phase clouds.



images of levitated droplets and collisions

An aqueous droplet of NaCl is collided with a 400 nm PSL CN at 57% RH. In part A, the brightfield images of the NaCl particle are shown (scale bar 10 μm). Frame 1 shows the aqueous droplet before contact, Frame 2 the droplet 20 ms after contact, and frames 3 and 4 the droplet 90 and 180 ms, respectively, after contact. Efflorescence begins immediately after contact, and as efflorescence proceeds, the loss of water causes the particle to move upward in the trap. Part B shows a different fully effloresced NaCl crystal levitated in the trap. Parts C and D show binary contrast images that allow the point of contact to be more visible (see arrow).

Honors and Awards

  • 2019 College Scholar Award, College of Arts and Sciences, CU Boulder
  • 2017 NASA Group Achievement Award, MSL Extended Mission Science Team
  • 2010 Distinguished Professor, University of Colorado
  • 2009 ACS National Award for Creative Advances in Environmental Science
  • 2009 Hazel Barnes Prize, CU Boulder
  • 2007 Guggenheim Fellowship
  • 2005 Elected to the National Academy of Sciences
  • 2003 NASA Group Achievement Award, Crystal-Face Science Team
  • 2001 NASA Group Achievement Award, SOLVE Experiment
  • 2001 Boulder Faculty Assembly Award for Excellence in Research, Scholarly and Creative Work, CU Boulder
  • 1994 Camille Dreyfus Teacher-Scholar
  • 1993 James B. Macelwane Medal, American Geophysical Union
  • 1993 Fellow of the American Geophysical Union

View Publications

  • Ushijima SB; Gough R; Tolbert MA. (Nov 2020). Probing Heterogeneous Efflorescence of Mars-Relevant Salts with an Optical Levitator. ACS Earth and Space Chemistry , 4(11), 1947-1956. 10.1021/acsearthspacechem.0c00161
  • Zhu Y; Toon OB; Jensen EJ; Bardeen CG; Mills MJ; Tolbert MA; Yu P; Woods S. (Sep 2020). Persisting volcanic ash particles impact stratospheric SO2 lifetime and aerosol optical properties. Nature Communications , 11(1). 10.1038/s41467-020-18352-5
  • De Haan DO; Hawkins LN; Jansen K; Welsh HG; Pednekar R; de Loera A; Jimenez NG; Tolbert MA; Cazaunau M; Gratien A. (Aug 2020). Glyoxal's impact on dry ammonium salts: fast and reversible surface aerosol browning. Atmospheric Chemistry and Physics , 20(15), 9581-9590. 10.5194/acp-20-9581-2020
  • Reed NW; Browne EC; Tolbert MA. (Jun 2020). Impact of Hydrogen Sulfide on Photochemical Haze Formation in Methane/Nitrogen Atmospheres. ACS Earth and Space Chemistry , 4(6), 897-904. 10.1021/acsearthspacechem.0c00086
  • Gough R; Nuding DL; Archer PD; Fernanders MS; Guzewich SD; Tolbert MA; Toigo AD. (Jun 2020). Changes in Soil Cohesion Due to Water Vapor Exchange: A Proposed Dry-Flow Trigger Mechanism for Recurring Slope Lineae on Mars. Geophysical Research Letters , 47(11). 10.1029/2020GL087618
  • De Haan DO; Jansen K; Rynaski AD; Sueme WRP; Torkelson AK; Czer ET; Kim AK; Rafla MA; De Haan AC; Tolbert MA. (Apr 2020). Brown Carbon Production by Aqueous-Phase Interactions of Glyoxal and SO2. Environmental Science and Technology (Washington) , 54(8), 4781-4789. 10.1021/acs.est.9b07852
  • Ugelow MS; Berry JL; Browne EC; Tolbert MA. (Mar 2020). The Impact of Molecular Oxygen on Anion Composition in a Hazy Archean Earth Atmosphere. Astrobiology , 20(5), 658-669. 10.1089/ast.2019.2145
  • Tolbert, M; Davis, R; Ushijima, S. (25-Aug 2019). Going through a phase: Particulate water in atmospheric aerosol. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 258.
  • Berry, JL; Ugelow, MS; Tolbert, MA; Browne, EC. (1-Nov 2019). The Influence of Gas-phase Chemistry on Organic Haze Formation. ASTROPHYSICAL JOURNAL LETTERS, 885(1). 10.3847/2041-8213/ab4b5b
  • Rannou, P; Curtis, D; Tolbert, MA. (13-Nov 2019). Adsorption isotherms and nucleation of methane and ethane on an analog of Titans photochemical aerosols. ASTRONOMY & ASTROPHYSICS, 631. 10.1051/0004-6361/201935777
  • Berry, JL; Ugelow, MS; Tolbert, MA; Browne, EC. (FEB 2019). Chemical Composition of Gas-Phase Positive Ions during Laboratory Simulations of Titans Haze Formation. ACS EARTH AND SPACE CHEMISTRY, 3(2), 202-211. 10.1021/acsearthspacechem.8b00139
  • Gough, RV; Primm, KM; Rivera-Valentin, EG; Martinez, GM; Tolbert, MA. (15-Mar 2019). Solid-solid hydration and dehydration of Mars-relevant chlorine salts: Implications for Gale Crater and RSL locations. ICARUS, 321, 1-13. 10.1016/j.icarus.2018.10.034
  • Primm, KM, V Gough, J Wong, G Rivera-Valentin, GM Martinez, JV Hogancamp, PD Archer, DW Ming and MA Tolbert. (AUG 2018). The Effect of Mars-Relevant Soil Analogs on the Water Uptake of Magnesium Perchlorate and Implications for the Near-Surface of Mars. JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, 123(8), 2076-2088. 10.1029/2018JE005540
  • Genareau, K, SM Cloer, K Primm, MA Tolbert and TW Woods. (JUL 2018). Compositional and Mineralogical Effects on Ice Nucleation Activity of Volcanic Ash. ATMOSPHERE, 9(7). 10.3390/atmos9070238
  • Rivera-Valentin, EG, RV Gough, VF Chevrier, KM Primm, GM Martinez and M Tolbert. (MAY 2018). Constraining the Potential Liquid Water Environment at Gale Crater, Mars. JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, 123(5), 1156-1167. 10.1002/2018JE005558
  • Horst, SM, C He, MS Ugelow, AM Jellinek, RT Pierrehumbert and MA Tolbert. (10-May 2018). Exploring the Atmosphere of Neoproterozoic Earth: The Effect of O-2 on Haze Formation and Composition. ASTROPHYSICAL JOURNAL, 858(2). 10.3847/1538-4357/aabd7d
  • Ugelow, MS, DO De Haan, SM Horst and MA Tolbert. (20-May 2018). The Effect of Oxygen on Organic Haze Properties. ASTROPHYSICAL JOURNAL LETTERS, 859(1). 10.3847/2041-8213/aac2c7
  • Creamean, JM, KM Primm, MA Tolbert, EG Hall, J Wendell, A Jordan, PJ Sheridan, J Smith and RC Schnell. (6-Jul 2018). HOVERCAT: a novel aerial system for evaluation of aerosol-cloud interactions. ATMOSPHERIC MEASUREMENT TECHNIQUES, 11(7), 3969-3985. 10.5194/amt-11-3969-2018
  • Ushijima, SB, RD Davis and MA Tolbert. (8-Feb 2018). Immersion and Contact Efflorescence Induced by Mineral Dust Particles. JOURNAL OF PHYSICAL CHEMISTRY A, 122(5), 1303-1311. 10.1021/acsjpca.7b12075
  • Horst, SM, YH Yoon, MS Ugelow, AH Parker, R Li, JA de Gouw and MA Tolbert. (FEB 2018). Laboratory investigations of Titan haze formation: In situ measurement of gas and particle composition. ICARUS, 301, 136-151. 10.1016/j.icarus.2017.09.039
  • Gough, RV, J Wong, JL Dickson, JS Levy, JW Head, DR Marchant and MA Tolbert. (15-Oct 2017). Brine formation via deliquescence by salts found near Don Juan Pond, Antarctica: Laboratory experiments and field observational results. EARTH AND PLANETARY SCIENCE LETTERS, 476, 189-198. 10.1016/j.epsl.2017.08.003
  • Nuding, DL, RV Gough, KJ Venkateswaran, JA Spry and MA Tolbert. (OCT 2017). Laboratory Investigations on the Survival of Bacillus subtilis Spores in Deliquescent Salt Mars Analog Environments. ASTROBIOLOGY, 17(10), 997-1008. 10.1089/ast.2016.1545
  • Davis, RD and MA Tolbert. (JUL 2017). Crystal nucleation initiated by transient ion-surface interactions at aerosol interfaces. SCIENCE ADVANCES, 3(7). 10.1126/sciadv.1700425
  • Primm, KM, RV Gough, VF Chevrier and MA Tolbert. (1-Sep 2017). Freezing of perchlorate and chloride brines under Mars-relevant conditions. GEOCHIMICA ET COSMOCHIMICA ACTA, 212, 211-220. 10.1016/j.gca.2017.06.012
  • Ugelow, MS, KJ Zarzana, DA Day, JL Jimenez and MA Tolbert. (15-Sep 2017). The optical and chemical properties of discharge generated organic haze using in-situ real-time techniques. ICARUS, 294, 1-13. 10.1016/j.icarus.2017.04.028
  • Primm, KM, GP Schill, DP Veghte, MA Freedman and MA Tolbert. (MAR 2017). Depositional ice nucleation on NX illite and mixtures of NX illite with organic acids. JOURNAL OF ATMOSPHERIC CHEMISTRY, 74(1), 55-69. 10.1007/s10874-016-9340-x
  • Hicks, RK, DA Day, JL Jimenez and MA Tolbert. (NOV 2016). Follow the Carbon: Isotopic Labeling Studies of Early Earth Aerosol. ASTROBIOLOGY, 16(11), 822-830. 10.1089/ast.2015.1436
  • Gough, RV, VF Chevrier and MA Tolbert. (15-Oct 2016). Formation of liquid water at low temperatures via the deliquescence of calcium chloride: Implications for Antarctica and Mars. PLANETARY AND SPACE SCIENCE, 131, 79-87. 10.1016/j.pss.2016.07.006
  • Hasenkopf, CA, DP Veghte, GP Schill, S Lodoysamba, MA Freedman and MA Tolbert. (AUG 2016). Ice nucleation, shape, and composition of aerosol particles in one of the most polluted cities in the world: Ulaanbaatar, Mongolia. ATMOSPHERIC ENVIRONMENT, 139, 222-229. 10.1016/j.atmosenv.2016.05.037
  • Schill, G. P., Genareau, K., Tolbert, M. A. (2015). Deposition and immersion mode nucleation of ice by three distinct samples of volcanic ash using Raman spectroscopy. Atmospheric Chemistry and Physics Discussions, 15(2). 10.5194/ACPD-15-1385-2015
  • Davis, RD, S Lance, JA Gordon, SB Ushijima and MA Tolbert. (29-Dec 2015). Contact efflorescence as a pathway for crystallization of atmospherically relevant particles. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 112(52), 15815-15820. 10.1073/pnas.1522860113
  • Schill, GP, K Genareau and MA Tolbert. (2015). Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash. ATMOSPHERIC CHEMISTRY AND PHYSICS, 15(13), 7523-7536. 10.5194/acp-15-7523-2015
  • Davis, RD, S Lance, JA Gordon and MA Tolbert. (16-Jun 2015). Long Working-Distance Optical Trap for in Situ Analysis of Contact-Induced Phase Transformations. ANALYTICAL CHEMISTRY, 87(12), 6186-6194. 10.1021/acs.analchem.5b00809
  • Nuding, DL, RD Davis, RV Gough and MA Tolbert. (MAR 2015). The aqueous stability of a Mars salt analog: Instant Mars. JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, 120(3), 588-598. 10.1002/2014JE004722
  • Hiranuma, N, S Augustin-Bauditz, H Bingemer, C Budke, J Curtius, A Danielczok, K Diehl, K Dreischmeier, M Ebert, F Frank, N Hoffmann, K Kandler, A Kiselev, T Koop, T Leisner, O Mohler, B Nillius, A Peckhaus, D Rose, S Weinbruch, H Wex, Y Boose, PJ DeMott, JD Hader, TCJ Hill, ZA Kanji, G Kulkarni, EJT Levin, CS McCluskey, M Murakami, BJ Murray, D Niedermeier, MD Petters, D OSullivan, A Saito, GP Schill, T Tajiri, MA Tolbert, A Welti, TF Whale, TP Wright and K Yamashita. (2015). A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques. ATMOSPHERIC CHEMISTRY AND PHYSICS, 15(5), 2489-2518. 10.5194/acp-15-2489-2015
  • Hicks, RK, DA Day, JL Jimenez and MA Tolbert. (3-Mar 2015). Elemental Analysis of Complex Organic Aerosol Using Isotopic Labeling and Unit-Resolution Mass Spectrometry. ANALYTICAL CHEMISTRY, 87(5), 2741-2747. 10.1021/ac504014g
  • Schill, GP and MA Tolbert. (18-Dec 2014). Heterogeneous Ice Nucleation on Simulated Sea-Spray Aerosol Using Raman Microscopy. JOURNAL OF PHYSICAL CHEMISTRY C, 118(50), 29234-29241. 10.1021/jp505379j
  • Nuding, DL, EG Rivera-Valentin, RD Davis, RV Gough, VF Chevrier and MA Tolbert. (15-Nov 2014). Deliquescence and efflorescence of calcium perchlorate: An investigation of stable aqueous solutions relevant to Mars. ICARUS, 243, 420-428. 10.1016/j.icarus.2014.08.036
  • Zarzana, KJ, CD Cappa and MA Tolbert. (2-Nov 2014). Sensitivity of Aerosol Refractive Index Retrievals Using Optical Spectroscopy. AEROSOL SCIENCE AND TECHNOLOGY, 48(11), 1133-1144. 10.1080/02786826.2014.963498
  • Sihvonen, SK, GP Schill, NA Lyktey, DP Veghte, MA Tolbert and MA Freedman. (25-Sep 2014). Chemical and Physical Transformations of Aluminosilicate Clay Minerals Due to Acid Treatment and Consequences for Heterogeneous Ice Nucleation. JOURNAL OF PHYSICAL CHEMISTRY A, 118(38), 8787-8796. 10.1021/jp504846g
  • Cable, ML, SM Horst, C He, AM Stockton, MF Mora, MA Tolbert, MA Smith and PA Willis. (1-Oct 2014). Identification of primary amines in Titan tholins using microchip nonaqueous capillary electrophoresis. EARTH AND PLANETARY SCIENCE LETTERS, 403, 99-107. 10.1016/j.epsl.2014.06.028
  • Robinson, CB, GP Schill and MA Tolbert. (JUN 2014). Optical growth of highly viscous organic/sulfate particles. JOURNAL OF ATMOSPHERIC CHEMISTRY, 71(2), 145-156. 10.1007/s10874-014-9287-8
  • Thalman, R, KJ Zarzana, MA Tolbert and R Volkamer. (NOV 2014). Rayleigh scattering cross-section measurements of nitrogen, argon, oxygen and air. JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, 147, 171-177. 10.1016/j.jqsrt.2014.05.030
  • Gough, RV, VF Chevrier and MA Tolbert. (1-May 2014). Formation of aqueous solutions on Mars via deliquescence of chloride-perchlorate binary mixtures. EARTH AND PLANETARY SCIENCE LETTERS, 393, 73-82. 10.1016/j.epsl.2014.02.002
  • Yoon, YH, SM Horst, RK Hicks, R Li, JA de Gouw and MA Tolbert. (1-May 2014). The role of benzene photolysis in Titan haze formation. ICARUS, 233, 233-241. 10.1016/j.icarus.2014.02.006
  • Schill, GP, DO De Haan and MA Tolbert. (4-Feb 2014). Heterogeneous Ice Nucleation on Simulated Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 48(3), 1675-1682. 10.1021/es4046428
  • Hawkins, LN, MJ Baril, N Sedehi, MM Galloway, DO De Haan, GP Schill and MA Tolbert. (18-Feb 2014). Formation of Semisolid, Oligomerized Aqueous SOA: Lab Simulations of Cloud Processing. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 48(4), 2273-2280. 10.1021/es4049626
  • Horst, SM and MA Tolbert. (20-Jan 2014). THE EFFECT OF CARBON MONOXIDE ON PLANETARY HAZE FORMATION. ASTROPHYSICAL JOURNAL, 781(1). 10.1088/0004-637X/781/1/53
  • Robinson, CB, GP Schill, KJ Zarzana and MA Tolbert. (3-Dec 2013). Impact of Organic Coating on Optical Growth of Ammonium Sulfate Particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 47(23), 13339-13346. 10.1021/es4023128
  • Baustian, KJ, ME Wise, EJ Jensen, GP Schill, MA Freedman and MA Tolbert. (2013). State transformations and ice nucleation in amorphous (semi-)solid organic aerosol. ATMOSPHERIC CHEMISTRY AND PHYSICS, 13(11), 5615-5628. 10.5194/acp-13-5615-2013
  • Horst, SM and MA Tolbert. (10-Jun 2013). IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS. ASTROPHYSICAL JOURNAL LETTERS, 770(1). 10.1088/2041-8205/770/1/L10
  • Schill, GP and MA Tolbert. (2013). Heterogeneous ice nucleation on phase-separated organic-sulfate particles: effect of liquid vs. glassy coatings. ATMOSPHERIC CHEMISTRY AND PHYSICS, 13(9), 4681-4695. 10.5194/acp-13-4681-2013
  • Trainer, MG, JA Sebree, YH Yoon and MA Tolbert. (20-Mar 2013). THE INFLUENCE OF BENZENE AS A TRACE REACTANT IN TITAN AEROSOL ANALOGS. ASTROPHYSICAL JOURNAL LETTERS, 766(1). 10.1088/2041-8205/766/1/L4
  • Schill, GP and MA Tolbert. (28-Jun 2012). Depositional Ice Nucleation on Monocarboxylic Acids: Effect of the O:C Ratio. JOURNAL OF PHYSICAL CHEMISTRY A, 116(25), 6817-6822. 10.1021/jp301772q
  • Connelly, BM, DO De Haan and MA Tolbert. (21-Jun 2012). Heterogeneous Glyoxal Oxidation: A Potential Source of Secondary Organic Aerosol. JOURNAL OF PHYSICAL CHEMISTRY A, 116(24), 6180-6187. 10.1021/jp211502e
  • Zarzana, KJ, DO De Haan, MA Freedman, CA Hasenkopf and MA Tolbert. (1-May 2012). Optical Properties of the Products of alpha-Dicarbonyl and Amine Reactions in Simulated Cloud Droplets. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 46(9), 4845-4851. 10.1021/es2040152
  • Trainer, MG, JL Jimenez, YL Yung, OB Toon and MA Tolbert. (APR 2012). Nitrogen Incorporation in CH4-N-2 Photochemical Aerosol Produced by Far Ultraviolet Irradiation. ASTROBIOLOGY, 12(4), 315-326. 10.1089/ast.2011.0754
  • Baustian, KJ, DJ Cziczo, ME Wise, KA Pratt, G Kulkarni, AG Hallar and MA Tolbert. (30-Mar 2012). Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 117. 10.1029/2011JD016784
  • Wise, ME, KJ Baustian, T Koop, MA Freedman, EJ Jensen and MA Tolbert. (2012). Depositional ice nucleation onto crystalline hydrated NaCl particles: a new mechanism for ice formation in the troposphere. ATMOSPHERIC CHEMISTRY AND PHYSICS, 12(2), 1121-1134. 10.5194/acp-12-1121-2012
  • Gough, RV, VF Chevrier, KJ Baustian, ME Wise and MA Tolbert. (15-Dec 2011). Laboratory studies of perchlorate phase transitions: Support for metastable aqueous perchlorate solutions on Mars. EARTH AND PLANETARY SCIENCE LETTERS, 312(4-Mar), 371-377. 10.1016/j.epsl.2011.10.026
  • Hasenkopf, CA, MA Freedman, MR Beaver, OB Toon and MA Tolbert. (MAR 2011). Potential Climatic Impact of Organic Haze on Early Earth. ASTROBIOLOGY, 11(2), 135-149. 10.1089/ast.2010.0541
  • De Haan, DO, LN Hawkins, JA Kononenko, JJ Turley, AL Corrigan, MA Tolbert and JL Jimenez. (1-Feb 2011). Formation of Nitrogen-Containing Oligomers by Methylglyoxal and Amines in Simulated Evaporating Cloud Droplets. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 45(3), 984-991. 10.1021/es102933x
  • Gough, RV, JJ Turley, GR Ferrell, KE Cordova, SE Wood, DO DeHaan, CP Mckay, OB Toon and MA Tolbert. (FEB 2011). Can rapid loss and high variability of Martian methane be explained by surface H2O2?. PLANETARY AND SPACE SCIENCE, 59(3-Feb), 238-246. 10.1016/j.pss.2010.09.018
  • DeWitt, HL, CA Hasenkopf, MG Trainer, DK Farmer, JL Jimenez, CP McKay, OB Toon and MA Tolbert. (OCT 2010). The Formation of Sulfate and Elemental Sulfur Aerosols under Varying Laboratory Conditions: Implications for Early Earth. ASTROBIOLOGY, 10(8), 773-781. 10.1089/ast.2009.9455
  • Freedman, MA, KJ Baustian, ME Wise and MA Tolbert. (1-Oct 2010). Characterizing the Morphology of Organic Aerosols at Ambient Temperature and Pressure. ANALYTICAL CHEMISTRY, 82(19), 7965-7972. 10.1021/ac101437w
  • Beaver, MR, MA Freedman, CA Hasenkopf and MA Tolbert. (8-Jul 2010). Cooling Enhancement of Aerosol Particles Due to Surfactant Precipitation. JOURNAL OF PHYSICAL CHEMISTRY A, 114(26), 7070-7076. 10.1021/jp102437q
  • Connelly, BM and MA Tolbert. (15-Jun 2010). Reaction of Isoprene on Thin Sulfuric Acid Films: Kinetics, Uptake, and Product Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 44(12), 4603-4608. 10.1021/es100708b
  • Hasenkopf, CA, MR Beaver, MG Trainer, HL Dewitt, MA Freedman, OB Toon, CP McKay and MA Tolbert. (JUN 2010). Optical properties of Titan and early Earth haze laboratory analogs in the mid-visible. ICARUS, 207(2), 903-913. 10.1016/j.icarus.2009.12.015
  • Gough, RV, MA Tolbert, CP McKay and OB Toon. (MAY 2010). Methane adsorption on a martian soil analog: An abiogenic explanation for methane variability in the martian atmosphere. ICARUS, 207(1), 165-174. 10.1016/j.icarus.2009.11.030
  • Wise, ME, KJ Baustian and MA Tolbert. (13-Apr 2010). Internally mixed sulfate and organic particles as potential ice nuclei in the tropical tropopause region. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 107(15), 6693-6698. 10.1073/pnas.0913018107
  • Trainer, MG, MA Tolbert, CP McKay and OB Toon. (JUL 2010). Limits on the trapping of atmospheric CH4 in martian polar ice analogs. ICARUS, 208(1), 192-197. 10.1016/j.icarus.2010.02.006
  • Baustian, KJ, ME Wise and MA Tolbert. (2010). Depositional ice nucleation on solid ammonium sulfate and glutaric acid particles. ATMOSPHERIC CHEMISTRY AND PHYSICS, 10(5), 2307-2317. 10.5194/acp-10-2307-2010
  • Freedman, MA, CA Hasenkopf, MR Beaver and MA Tolbert. (3-Dec 2009). Optical Properties of Internally Mixed Aerosol Particles Composed of Dicarboxylic Acids and Ammonium Sulfate. JOURNAL OF PHYSICAL CHEMISTRY A, 113(48), 13584-13592. 10.1021/jp906240y
  • De Haan, DO, AL Corrigan, MA Tolbert, JL Jimenez, SE Wood and JJ Turley. (1-Nov 2009). Secondary Organic Aerosol Formation by Self-Reactions of Methylglyoxal and Glyoxal in Evaporating Droplets. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 43(21), 8184-8190. 10.1021/es902152t
  • DeWitt, HL, MG Trainer, AA Pavlov, CA Hasenkopf, AC Aiken, JL Jimenez, CP McKay, OB Toon and MA Tolbert. (JUN 2009). Reduction in Haze Formation Rate on Prebiotic Earth in the Presence of Hydrogen. ASTROBIOLOGY, 9(5), 447-453. 10.1089/ast.2008.0289
  • De Haan, DO, MA Tolbert and JL Jimenez. (13-Jun 2009). Atmospheric condensed-phase reactions of glyoxal with methylamine. GEOPHYSICAL RESEARCH LETTERS, 36. 10.1029/2009GL037441
  • De Haan, DO, AL Corrigan, KW Smith, DR Stroik, JJ Turley, FE Lee, MA Tolbert, JL Jimenez, KE Cordova and GR Ferrell. (15-Apr 2009). Secondary Organic Aerosol-Forming Reactions of Glyoxal with Amino Acids. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 43(8), 2818-2824. 10.1021/es803534f
  • Wise, ME, KJ Baustian and MA Tolbert. (2009). Laboratory studies of ice formation pathways from ammonium sulfate particles. ATMOSPHERIC CHEMISTRY AND PHYSICS, 9(5), 1639-1646. 10.5194/acp-9-1639-2009
  • Trainer, MG, OB Toon and MA Tolbert. (12-Feb 2009). Measurements of Depositional Ice Nucleation on Insoluble Substrates at Low Temperatures: Implications for Earth and Mars. JOURNAL OF PHYSICAL CHEMISTRY C, 113(6), 2036-2040. 10.1021/jp805140p
  • Beaver, MR, RM Garland, CA Hasenkopf, T Baynard, AR Ravishankara and MA Tolbert. (OCT-DEC 2008). A laboratory investigation of the relative humidity dependence of light extinction by organic compounds from lignin combustion. ENVIRONMENTAL RESEARCH LETTERS, 3(4). 10.1088/1748-9326/3/4/045003
  • Curtis, DB, CD Hatch, CA Hasenkopf, OB Toon, MA Tolbert, CP McKay and BN Khare. (JUN 2008). Laboratory studies of methane and ethane adsorption and nucleation onto organic particles: Application to Titans clouds. ICARUS, 195(2), 792-801. 10.1016/j.icarus.2008.02.003
  • Hatch, CD, RV Gough, OB Toon and MA Tolbert. (17-Jan 2008). Heterogeneous nucleation of nitric acid trihydrate on clay minerals: Relevance to Type Ia polar stratospheric clouds. JOURNAL OF PHYSICAL CHEMISTRY B, 112(2), 612-620. 10.1021/jp075828n
  • Casale, MT, AR Richman, MJ Elrod, RM Garland, MR Beaver and MA Tolbert. (SEP 2007). Kinetics of acid-catalyzed aldol condensation reactions of aliphatic aldehydes. ATMOSPHERIC ENVIRONMENT, 41(29), 6212-6224. 10.1016/j.atmosenv.2007.04.002
  • Garland, RM, AR Ravishankara, ER Lovejoy, MA Tolbert and T Baynard. (4-Oct 2007). Parameterization for the relative humidity dependence of light extinction: Organic-ammonium sulfate aerosol. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 112(D19). 10.1029/2006JD008179
  • Hatch, CD, RV Gough and MA Tolbert. (2007). Heterogeneous uptake of the C-1 to C-4 organic acids on a swelling clay mineral. ATMOSPHERIC CHEMISTRY AND PHYSICS, 7(16), 4445-4458. 10.5194/acp-7-4445-2007
  • Gamblin, B, OB Toon, MA Tolbert, Y Kondo, N Takegawa, H Irie, M Koike, PK Hudson, JO Ballenthin, DE Hunton, TM Miller, AA Viggiano, BE Anderson, M Avery, GW Sachse, K Guenther, C Sorenson and MJ Mahoney. (27-Jun 2007). Nitric acid condensation on ice: 2. Kinetic limitations, a possible "cloud clock\ for determining cloud parcel lifetime. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 112(D12). 10.1029/2005JD006049
  • Shilling, JE, BM Connelly and MA Tolbert. (1-Jun 2006). Uptake of small oxygenated organic molecules onto ammonium nitrate under upper tropospheric conditions. JOURNAL OF PHYSICAL CHEMISTRY A, 110(21), 6687-6695. 10.1021/jp055940q
  • Beaver, MR, MJ Elrod, RM Garland and MA Tolbert. (4-Aug 2006). Ice nucleation in sulfuric acid/organic aerosols: implications for cirrus cloud formation. ATMOSPHERIC CHEMISTRY AND PHYSICS, 6, 3231-3242. 10.5194/acp-6-3231-2006
  • Garland, RM, MJ Elrod, K Kincaid, MR Beaver, JL Jimenez and MA Tolbert. (NOV 2006). Acid-catalyzed reactions of hexanal on sulfuric acid particles: Identification of reaction products. ATMOSPHERIC ENVIRONMENT, 40(35), 6863-6878. 10.1016/j.atmosenv.2006.07.009
  • Trainer, MG, AA Pavlov, HL DeWitt, JL Jimenez, CP McKay, OB Toon and MA Tolbert. (28-Nov 2006). Organic haze on Titan and the early Earth. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 103(48), 18035-18042. 10.1073/pnas.0608561103
  • Baynard, T, RM Garland, AR Ravishankara, MA Tolbert and ER Lovejoy. (24-Mar 2006). Key factors influencing the relative humidity dependence of aerosol light scattering. GEOPHYSICAL RESEARCH LETTERS, 33(6). 10.1029/2005GL024898
  • Shilling, JE, TJ Fortin and MA Tolbert. (17-Jun 2006). Depositional ice nucleation on crystalline organic and inorganic solids. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 111(D12). 10.1029/2005JD006664
  • Shilling, JE, MA Tolbert, OB Toon, EJ Jensen, BJ Murray and AK Bertram. (1-Sep 2006). Measurements of the vapor pressure of cubic ice and their implications for atmospheric ice clouds. GEOPHYSICAL RESEARCH LETTERS, 33(17). 10.1029/2006GL026671
  • Mashburn, CD, EK Frinak and MA Tolbert. (11-Aug 2006). Heterogeneous uptake of nitric acid on Na-montmorillonite clay as a function of relative humidity. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 111(D15). 10.1029/2005JD006525
  • Gamblin, B, OB Toon, MA Tolbert, Y Kondo, N Takegawa, H Irie, M Koike, JO Ballenthin, DE Hunton, TM Miller, AA Viggiano, BE Anderson, M Avery, GW Sachse, JR Podolske, K Guenther, C Sorenson and MJ Mahoney. (8-Nov 2006). Nitric acid condensation on ice: 1. Non-HNO3 constituent of NOY condensing cirrus particles on upper tropospheric. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 111(D21). 10.1029/2005JD006048
  • Garland, RM, ME Wise, MR Beaver, HL DeWitt, AC Aiken, JL Jimenez and MA Tolbert. (1-Aug 2005). Impact of palmitic acid coating on the water uptake and loss of ammonium sulfate particles. ATMOSPHERIC CHEMISTRY AND PHYSICS, 5, 1951-1961. 10.5194/acp-5-1951-2005
  • Curtis, DB, DL Glandorf, OB Toon, MA Tolbert, CP McKay and BN Khare. (24-Feb 2005). Laboratory studies of butane nucleation on organic haze particles: Application to Titans clouds. JOURNAL OF PHYSICAL CHEMISTRY A, 109(7), 1382-1390. 10.1021/jp045596h
  • Frinak, EK, CD Mashburn, MA Tolbert and OB Toon. (11-May 2005). Infrared characterization of water uptake by low-temperature Na-montmorillonite: Implications for Earth and Mars. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 110(D9). 10.1029/2004JD005647
  • Curtis, DB, B Rajaram, OB Toon and MA Tolbert. (1-Jul 2005). Measurement of the temperature-dependent optical constants of water ice in the 15-200 mu m range. APPLIED OPTICS, 44(19), 4102-4118. 10.1364/AO.44.004102
  • Hudson, PK and MA Tolbert. (2005 2005). Uptake of trace species by ice: Implications for cirrus clouds in the upper troposphere. ENVIRONMENTAL CATALYSIS, 157-175.
  • Trainer, MG, AA Pavlov, DB Curtis, CP McKay, DR Worsnop, AE Delia, DW Toohey, OB Toon and MA Tolbert. (WIN 2004). Haze aerosols in the atmosphere of early earth: Manna from heaven. ASTROBIOLOGY, 4(4), 409-419. 10.1089/ast.2004.4.409
  • Frinak, EK, SJ Wermeille, CD Mashburn, MA Tolbert and CJ Pursell. (4-Mar 2004). Heterogeneous reaction of gaseous nitric acid on gamma-phase iron(III) oxide. JOURNAL OF PHYSICAL CHEMISTRY A, 108(9), 1560-1566. 10.1021/jp030807o
  • Shilling, JE and MA Tolbert. (23-Dec 2004). Uptake of acetic acid on thin ammonium nitrate films as a function of temperature and relative humidity. JOURNAL OF PHYSICAL CHEMISTRY A, 108(51), 11314-11320. 10.1021/jp046135z
  • Gao, RS, PJ Popp, DW Fahey, TP Marcy, RL Herman, EM Weinstock, DG Baumgardner, TJ Garrett, KH Rosenlof, TL Thompson, PT Bui, BA Ridley, SC Wofsy, OB Toon, MA Tolbert, B Karcher, T Peter, PK Hudson, AJ Weinheimer and AJ Heymsfield. (23-Jan 2004). Evidence that nitric acid increases relative humidity in low-temperature cirrus clouds. SCIENCE, 303(5657), 516-520. 10.1126/science.1091255
  • Brooks, SD, OB Toon, MA Tolbert, D Baumgardner, BW Gandrud, EV Browell, H Flentje and JC Wilson. (30-Jan 2004). Polar stratospheric clouds during SOLVE/THESEO: Comparison of lidar observations with in situ measurements. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 109(D2). 10.1029/2003JD003463
  • Wise, ME, RM Garland and MA Tolbert. (9-Oct 2004). Ice nucleation in internally mixed ammonium sulfate/dicarboxylic acid particles. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 109(D19). 10.1029/2003JD004313
  • Trainer, MG, AA Pavlov, JL Jimenez, CP McKay, DR Worsnop, OB Toon and MA Tolbert. (11-Aug 2004). Chemical composition of Titans haze: Are PAHs present?. GEOPHYSICAL RESEARCH LETTERS, 31(17). 10.1029/2004GL019859
  • Kondo, Y, OB Toon, H Irie, B Gamblin, M Koike, N Takegawa, MA Tolbert, PK Hudson, AA Viggiano, LM Avallone, AG Hallar, BE Anderson, GW Sachse, SA Vay, DE Hunton, JO Ballenthin and TM Miller. (18-Feb 2003). Uptake of reactive nitrogen on cirrus cloud particles in the upper troposphere and lowermost stratosphere. GEOPHYSICAL RESEARCH LETTERS, 30(4). 10.1029/2002GL016539
  • Fortin, TJ, K Drdla, LT Iraci and MA Tolbert. (9-Jul 2003). Ice condensation on sulfuric acid tetrahydrate: Implications for polar stratospheric ice clouds. ATMOSPHERIC CHEMISTRY AND PHYSICS, 3, 987-997. 10.5194/acp-3-987-2003
  • Wise, ME, SD Brooks, RM Garland, DJ Cziczo, ST Martin and MA Tolbert. (31-Jul 2003). Solubility and freezing effects of Fe2+ and Mg2+ in H2SO4 solutions representative of upper tropospheric and lower stratospheric sulfate particles. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D19). 10.1029/2003JD003420
  • Brooks, SD, RM Garland, ME Wise, AJ Prenni, M Cushing, E Hewitt and MA Tolbert. (15-Aug 2003). Phase changes in internally mixed maleic acid/ammonium sulfate aerosols. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D15). 10.1029/2002JD003204
  • Wise, ME, JD Surratt, DB Curtis, JE Shilling and MA Tolbert. (23-Oct 2003). Hygroscopic growth of ammonium sulfate/dicarboxylic acids. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D20). 10.1029/2003JD003775
  • Brooks, SD, D Baumgardner, B Gandrud, JE Dye, MJ Northway, DW Fahey, TP Bui, OB Toon and MA Tolbert. (29-Oct 2003). Measurements of large stratospheric particles in the Arctic polar vortex. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D20). 10.1029/2002JD003278
  • Tolbert, MA. (JAN 2002). Expertise in nano-alignment aids photonics manufacturing. LASER FOCUS WORLD, 38(1), 161-+.
  • Hudson, PK, MA Zondlo and MA Tolbert. (28-Mar 2002). The interaction of methanol, acetone, and acetaldehyde with ice and nitric acid-doped ice: Implications for cirrus clouds. JOURNAL OF PHYSICAL CHEMISTRY A, 106(12), 2882-2888. 10.1021/jp012718m
  • Brooks, SD, ME Wise, M Cushing and MA Tolbert. (1-Oct 2002). Deliquescence behavior of organic/ammonium sulfate aerosol. GEOPHYSICAL RESEARCH LETTERS, 29(19). 10.1029/2002GL014733
  • Hudson, PK, JE Shilling, MA Tolbert and OB Toon. (24-Oct 2002). Uptake of nitric acid on ice at tropospheric temperatures: Implications for cirrus clouds. JOURNAL OF PHYSICAL CHEMISTRY A, 106(42), 9874-9882. 10.1021/jp020508j
  • Fortin, TJ, JE Shilling and MA Tolbert. (MAY 2002). Infrared spectroscopic study of the low-temperature phase behavior of ammonium sulfate. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 107(D10). 10.1029/2001JD000677
  • Northway, MJ, RS Gao, PJ Popp, JC Holecek, DW Fahey, KS Carslaw, MA Tolbert, LR Lait, S Dhaniyala, RC Flagan, PO Wennberg, MJ Mahoney, RL Herman, GC Toon and TP Bui. (SEP-OCT 2002). An analysis of large HNO3-containing particles sampled in the Arctic stratosphere during the winter of 1999/2000. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 107(D20). 10.1029/2001JD001079
  • Glandorf, DL, A Colaprete, MA Tolbert and OB Toon. (NOV 2002). CO2 snow on Mars and early Earth: Experimental constraints. ICARUS, 160(1), 66-72. 10.1006/icar.2002.6953
  • Prenni, AJ, ME Wise, SD Brooks and MA Tolbert. (16-Feb 2001). Ice nucleation in sulfuric acid and ammonium sulfate particles. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 106(D3), 3037-3044. 10.1029/2000JD900454
  • Hudson, PK, KL Foster, MA Tolbert, SM George, SR Carlo and VH Grassian. (1-Feb 2001). HBr uptake on ice: Uptake coefficient, H2O/HBr hydrate formation, and H2O desorption kinetics. JOURNAL OF PHYSICAL CHEMISTRY A, 105(4), 694-702. 10.1021/jp002700w
  • Nelson, CE, JW Elam, MA Tolbert and SM George. (1-Feb 2001). H2O and HCl adsorption on single crystal alpha-Al2O3(0001) at stratospheric temperatures. APPLIED SURFACE SCIENCE, 171(2-Jan), 21-33. 10.1016/S0169-4332(00)00536-5
  • Rajaram, B, DL Glandorf, DB Curtis, MA Tolbert, OB Toon and N Ockman. (1-Sep 2001). Temperature-dependent optical constants of water ice in the near infrared: new results and critical review of the available measurements. APPLIED OPTICS, 40(25), 4449-4462. 10.1364/AO.40.004449
  • Prenni, AJ and MA Tolbert. (JUL 2001). Studies of polar stratospheric cloud formation. ACCOUNTS OF CHEMICAL RESEARCH, 34(7), 545-553. 10.1021/ar950186k
  • Elam, JW, CE Nelson, MA Tolbert and SM George. (1-Apr 2000). Adsorption and desorption of HCl on a single-crystal alpha-Al2O3(0001) surface. SURFACE SCIENCE, 450(2-Jan), 64-77. 10.1016/S0039-6028(99)01247-9
  • Zondlo, MA, PK Hudson, AJ Prenni and MA Tolbert. (2000). Chemistry and microphysics of polar stratospheric clouds and cirrus clouds. ANNUAL REVIEW OF PHYSICAL CHEMISTRY, 51, 473-499. 10.1146/annurev.physchem.51.1.473
  • Prenni, AJ, RL Siefert, TB Onasch, MA Tolbert and PJ DeMott. (MAY 2000). Design and characterization of a fluidized bed aerosol generator: A source for dry, submicrometer aerosol. AEROSOL SCIENCE AND TECHNOLOGY, 32(5), 465-481. 10.1080/027868200303588
  • Barone, SB, MA Zondlo and MA Tolbert. (2-Dec 1999). Investigation of the heterogeneous reactivity of HCl, HBr, and HI on ice surfaces. JOURNAL OF PHYSICAL CHEMISTRY A, 103(48), 9717-9730. 10.1021/jp990400c
  • Onasch, TB, RL Siefert, SD Brooks, AJ Prenni, B Murray, MA Wilson and MA Tolbert. (20-Sep 1999). Infrared spectroscopic study of the deliquescence and efflorescence of ammonium sulfate aerosol as a function of temperature. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 104(D17), 21317-21326. 10.1029/1999JD900384
  • Tisdale, RT, AJ Prenni, LT Iraci, MA Tolbert and OB Toon. (15-Mar 1999). Variation of the infrared spectra of nitric acid hydrates with formation conditions: Impact on PSC identification. GEOPHYSICAL RESEARCH LETTERS, 26(6), 707-710. 10.1029/1999GL900090
  • Warshawsky, MS, MA Zondlo and MA Tolbert. (1-Apr 1999). Impact of nitric acid on ice evaporation rates. GEOPHYSICAL RESEARCH LETTERS, 26(7), 823-826. 10.1029/1999GL900120
  • Nelson, CE, JW Elam, MA Cameron, MA Tolbert and SM George. (30-Oct 1998). Desorption of H2O from a hydroxylated single-crystal alpha-Al2O3(0001) surface. SURFACE SCIENCE, 416(3), 341-353. 10.1016/S0039-6028(98)00439-7
  • Elam, JW, CE Nelson, MA Cameron, MA Tolbert and SM George. (3-Sep 1998). Adsorption of H2O on a single-crystal alpha-Al2O3(0001) surface. JOURNAL OF PHYSICAL CHEMISTRY B, 102(36), 7008-7015. 10.1021/jp981070j
  • Zondlo, MA, SB Barone and MA Tolbert. (16-Jul 1998). Condensed-phase products in heterogeneous reactions: N2O5, ClONO2, and HNO3 reacting on ice films at 185 K. JOURNAL OF PHYSICAL CHEMISTRY A, 102(29), 5735-5748. 10.1021/jp980131a
  • Iraci, LT, TJ Fortin and MA Tolbert. (20-Apr 1998). Dissolution of sulfuric acid tetrahydrate at low temperatures and subsequent growth of nitric acid trihydrate. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 103(D7), 8491-8498. 10.1029/98JD00281
  • Tisdale, RT, DL Glandorf, MA Tolbert and OB Toon. (20-Oct 1998). Infrared optical constants of low-temperature H2SO4 solutions representative of stratospheric sulfate aerosols. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 103(D19), 25353-25370. 10.1029/98JD02457
  • Prenni, AJ, TB Onasch, RT Tisdale, RL Siefert and MA Tolbert. (20-Nov 1998). Composition-dependent freezing nucleation rates for HNO3/H2O aerosols resembling gravity-wave-perturbed stratospheric particles. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 103(D21), 28439-28450. 10.1029/98JD02851
  • Tsias, A, AJ Prenni, KS Carslaw, TP Onasch, BP Luo, MA Tolbert and T Peter. (15-Sep 1997). Freezing of polar stratospheric clouds in orographically induced strong warming events. GEOPHYSICAL RESEARCH LETTERS, 24(18), 2303-2306. 10.1029/97GL02181
  • Zondlo, MA, TB Onasch, MS Warshawsky, MA Tolbert, G Mallick, P Arentz and MS Robinson. (11-Dec 1997). Experimental studies of vapor-deposited water-ice firms using grazing-angle FTIR-reflection absorption spectroscopy. JOURNAL OF PHYSICAL CHEMISTRY B, 101(50), 10887-10895. 10.1021/jp9709870
  • Tisdale, RT, AM Middlebrook, AJ Prenni and MA Tolbert. (13-Mar 1997). Crystallization kinetics of HNO3/H2O films representative of polar stratospheric clouds. JOURNAL OF PHYSICAL CHEMISTRY A, 101(11), 2112-2119. 10.1021/jp9624156
  • Foster, KL, MA Tolbert and SM George. (3-Jul 1997). Interaction of HCl with ice: Investigation of the predicted trihydrate, hexahydrate, and monolayer regimes. JOURNAL OF PHYSICAL CHEMISTRY A, 101(27), 4979-4986. 10.1021/jp970772q
  • Barone, SB, MA Zondlo and MA Tolbert. (13-Nov 1997). A kinetic and product study of the hydrolysis of ClONO2 on type Ia polar stratospheric cloud materials at 185 K. JOURNAL OF PHYSICAL CHEMISTRY A, 101(46), 8643-8652. 10.1021/jp971107k
  • Berland, BS, MA Tolbert and SM George. (18-Dec 1997). Surface sensitive studies of the reactive uptake of chlorine nitrate on ice. JOURNAL OF PHYSICAL CHEMISTRY A, 101(51), 9954-9963. 10.1021/jp971121x
  • Anthony, SE, TB Onasch, RT Tisdale, RS Disselkamp, MA Tolbert and JC Wilson. (20-May 1997). Laboratory studies of ternary H2SO4/HNO3/H2O particles: Implications for polar stratospheric cloud formation. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 102(D9), 10777-10784. 10.1029/96JD03129
  • DelNegro, LA, DW Fahey, SG Donnelly, RS Gao, ER Keim, RC Wamsley, EL Woodbridge, JE Dye, D Baumgardner, BW Gandrud, JC Wilson, HH Jonsson, M Loewenstein, JR Podolske, CR Webster, RD May, DR Worsnop, A Tabazadeh, MA Tolbert, KK Kelly and KR Chan. (20-Jun 1997). Evaluating the role of NAT, NAD, and liquid H2SO4/H2O/HNO3 solutions in Antarctic polar stratospheric cloud aerosol: Observations and implications. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 102(11D), 13255-13282. 10.1029/97JD00764
  • Iraci, LT and MA Tolbert. (20-Jul 1997). Heterogeneous interaction of formaldehyde with cold sulfuric acid: Implications for the upper troposphere and lower stratosphere. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 102(D13), 16099-16107. 10.1029/97JD01259
  • Zondlo, MA, SB Barone and MA Tolbert. (1-Jun 1997). Uptake of HNO3 on ice under upper tropospheric conditions. GEOPHYSICAL RESEARCH LETTERS, 24(11), 1391-1394. 10.1029/97GL01287
  • Disselkamp, RS, SE Anthony, AJ Prenni, TB Onasch and MA Tolbert. (23-May 1996). Crystallization kinetics of nitric acid dihydrate aerosols. JOURNAL OF PHYSICAL CHEMISTRY, 100(21), 9127-9137. 10.1021/jp953608g
  • Middlebrook, AM, MA Tolbert and K Drdla. (1-Aug 1996). Evaporation studies of model polar stratospheric cloud films. GEOPHYSICAL RESEARCH LETTERS, 23(16), 2145-2148. 10.1029/96GL01962
  • Berland, BS, KL Foster, MA Tolbert and SM George. (1-Oct 1996). UV absorption spectra of H2O/HNO3 films. GEOPHYSICAL RESEARCH LETTERS, 23(20), 2757-2760. 10.1029/96GL02610
  • TOON, OB and MA TOLBERT. (18-May 1995). SPECTROSCOPIC EVIDENCE AGAINST NITRIC-ACID TRIHYDRATE IN POLAR STRATOSPHERIC CLOUDS. NATURE, 375(6528), 218-221. 10.1038/375218a0
  • IRACI, LT, AM MIDDLEBROOK and MA TOLBERT. (20-Oct 1995). LABORATORY STUDIES OF THE FORMATION OF POLAR STRATOSPHERIC CLOUDS - NITRIC-ACID CONDENSATION ON THIN SULFURIC-ACID FILMS. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 100(D10), 20969-20977. 10.1029/95JD02267
  • ANTHONY, SE, RT TISDALE, RS DISSELKAMP, MA TOLBERT and JC WILSON. (1-May 1995). FTIR STUDIES OF LOW-TEMPERATURE SULFURIC-ACID AEROSOLS. GEOPHYSICAL RESEARCH LETTERS, 22(9), 1105-1108. 10.1029/95GL01031
  • Berland, BS, DE Brown, MA Tolbert and SM George. (15-Dec 1995). Refractive index and density of vapor-deposited ice. GEOPHYSICAL RESEARCH LETTERS, 22(24), 3493-3496. 10.1029/95GL03504
  • BERLAND, BS, DR HAYNES, KL FOSTER, MA TOLBERT, SM GEORGE and OB TOON. (21-Apr 1994). REFRACTIVE-INDEXES OF AMORPHOUS AND CRYSTALLINE HNO3/H2O FILMS REPRESENTATIVE OF POLAR STRATOSPHERIC CLOUDS. JOURNAL OF PHYSICAL CHEMISTRY, 98(16), 4358-4364. 10.1021/j100067a024
  • MIDDLEBROOK, AM, BS BERLAND, SM GEORGE, MA TOLBERT and OB TOON. (20-Dec 1994). REAL REFRACTIVE-INDEXES OF INFRARED-CHARACTERIZED NITRIC-ACID ICE FILMS - IMPLICATIONS FOR OPTICAL MEASUREMENTS OF POLAR STRATOSPHERIC CLOUDS. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 99(D12), 25655-25666. 10.1029/94JD02391
  • TOON, OB, MA TOLBERT, BG KOEHLER, AM MIDDLEBROOK and J JORDAN. (20-Dec 1994). INFRARED OPTICAL-CONSTANTS OF H2O ICE, AMORPHOUS NITRIC-ACID SOLUTIONS, AND NITRIC-ACID HYDRATES. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 99(D12), 25631-25654. 10.1029/94JD02388
  • WILLIAMS, LR, JA MANION, DM GOLDEN and MA TOLBERT. (JUL 1994). LABORATORY MEASUREMENTS OF HETEROGENEOUS REACTIONS ON SULFURIC-ACID SURFACES. JOURNAL OF APPLIED METEOROLOGY, 33(7), 785-790. 10.1175/1520-0450(1994)033<0785:LMOHRO>2.0.CO;2
  • MANION, JA, CM FITTSCHEN, DM GOLDEN, LR WILLIAMS and MA TOLBERT. (1994). HETEROGENEOUS REACTIONS OF CHLORINE NITRATE AND DINITROGEN PENTOXIDE ON SULFURIC-ACID SURFACES REPRESENTATIVE OF GLOBAL STRATOSPHERIC AEROSOL-PARTICLES. ISRAEL JOURNAL OF CHEMISTRY, 34(4-Mar), 355-363.
  • IRACI, LT, AM MIDDLEBROOK, MA WILSON and MA TOLBERT. (15-May 1994). GROWTH OF NITRIC-ACID HYDRATES ON THIN SULFURIC-ACID FILMS. GEOPHYSICAL RESEARCH LETTERS, 21(10), 867-870. 10.1029/94GL00916
  • TOLBERT, MA, J PFAFF, I JAYAWEERA and MJ PRATHER. (20-Feb 1993). UPTAKE OF FORMALDEHYDE BY SULFURIC-ACID-SOLUTIONS - IMPACT ON STRATOSPHERIC OZONE. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 98(D2), 2957-2962. 10.1029/92JD02386
  • KOEHLER, BG, LS MCNEILL, AM MIDDLEBROOK and MA TOLBERT. (20-Jun 1993). FOURIER-TRANSFORM INFRARED STUDIES OF THE INTERACTION OF HCL WITH MODEL POLAR STRATOSPHERIC CLOUD FILMS. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 98(D6), 10563-10571. 10.1029/93JD00586
  • MIDDLEBROOK, AM, LT IRACI, LS MCNEILL, BG KOEHLER, MA WILSON, OW SAASTAD, MA TOLBERT and DR HANSON. (20-Nov 1993). FOURIER TRANSFORM-INFRARED STUDIES OF THIN H2SO4/H2O FILMS - FORMATION, WATER-UPTAKE, AND SOLID-LIQUID PHASE-CHANGES. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 98(D11), 20473-20481. 10.1029/93JD02454
  • KOEHLER, BG, AM MIDDLEBROOK and MA TOLBERT. (30-May 1992). CHARACTERIZATION OF MODEL POLAR STRATOSPHERIC CLOUD FILMS USING FOURIER-TRANSFORM INFRARED-SPECTROSCOPY AND TEMPERATURE PROGRAMMED DESORPTION. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 97(D8), 8065-8074. 10.1029/91JD01844
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  • MIDDLEBROOK, AM, BG KOEHLER, LS MCNEILL and MA TOLBERT. (24-Dec 1992). FORMATION OF MODEL POLAR STRATOSPHERIC CLOUD FILMS. GEOPHYSICAL RESEARCH LETTERS, 19(24), 2417-2420. 10.1029/92GL02635
  • QUINLAN, MA, CM REIHS, DM GOLDEN and MA TOLBERT. (19-Apr 1990). HETEROGENEOUS REACTIONS ON MODEL POLAR STRATOSPHERIC CLOUD SURFACES - REACTION OF N2O5 ON ICE AND NITRIC-ACID TRIHYDRATE. JOURNAL OF PHYSICAL CHEMISTRY, 94(8), 3255-3260. 10.1021/j100371a007
  • REIHS, CM, DM GOLDEN and MA TOLBERT. (20-Sep 1990). NITRIC-ACID UPTAKE BY SULFURIC-ACID-SOLUTIONS UNDER STRATOSPHERIC CONDITIONS - DETERMINATION OF HENRY LAW SOLUBILITY. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 95(D10), 16545-16550. 10.1029/JD095iD10p16545
  • TOLBERT, MA and AM MIDDLEBROOK. (20-Dec 1990). FOURIER-TRANSFORM INFRARED STUDIES OF MODEL POLAR STRATOSPHERIC CLOUD SURFACES - GROWTH AND EVAPORATION OF ICE AND NITRIC-ACID ICE. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 95(D13), 22423-22431. 10.1029/JD095iD13p22423
  • TOLBERT, MA, MN SPENCER, DL HUESTIS and MJ ROSSI. (MAR 1988). HIGH-DENSITY CHEMI-LUMINESCENCE STUDIES - EXPLOSIVE DECOMPOSITION OF SOLID-PHASE TETRAMETHYLDIOXETANE. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 42(1), 73-85. 10.1016/1010-6030(88)80050-9
  • TOLBERT, MA, MJ ROSSI and DM GOLDEN. (20-May 1988). ANTARCTIC OZONE DEPLETION CHEMISTRY - REACTIONS OF N2O5 WITH H2O AND HCL ON ICE SURFACES. SCIENCE, 240(4855), 1018-1021. 10.1126/science.240.4855.1018
  • TOLBERT, MA, DL HUESTIS and MJ ROSSI. (14-Jul 1988). HIGH-TEMPERATURE DECOMPOSITION OF TETRAMETHYLDIOXETANE - MEASUREMENTS OF GAS-PHASE CHEMIEXCITATION YIELDS. JOURNAL OF PHYSICAL CHEMISTRY, 92(14), 4094-4099. 10.1021/j100325a022
  • TOLBERT, MA, MJ ROSSI and DM GOLDEN. (AUG 1988). HETEROGENEOUS INTERACTIONS OF CHLORINE NITRATE, HYDROGEN-CHLORIDE, AND NITRIC-ACID WITH SULFURIC-ACID SURFACES AT STRATOSPHERIC TEMPERATURES. GEOPHYSICAL RESEARCH LETTERS, 15(8), 847-850. 10.1029/GL015i008p00847
  • TOLBERT, MA, MJ ROSSI, R MALHOTRA and DM GOLDEN. (27-Nov 1987). REACTION OF CHLORINE NITRATE WITH HYDROGEN-CHLORIDE AND WATER AT ANTARCTIC STRATOSPHERIC TEMPERATURES. SCIENCE, 238(4831), 1258-1260. 10.1126/science.238.4831.1258
  • TOLBERT, MA, ML MANDICH, LF HALLE and JL BEAUCHAMP. (17-Sep 1986). ACTIVATION OF ALKANES BY RUTHENIUM, RHODIUM, AND PALLADIUM IONS IN THE GAS-PHASE - STRIKING DIFFERENCES IN REACTIVITY OF 1ST-ROW AND 2ND-ROW METAL-IONS. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 108(19), 5675-5683. 10.1021/ja00279a003
  • TOLBERT, MA and JL BEAUCHAMP. (9-Oct 1986). HOMOLYTIC AND HETEROLYTIC BOND-DISSOCIATION ENERGIES OF THE 2ND-ROW GROUP-8, GROUP-9, AND GROUP-10 DIATOMIC TRANSITION-METAL HYDRIDES - CORRELATION WITH ELECTRONIC-STRUCTURE. JOURNAL OF PHYSICAL CHEMISTRY, 90(21), 5015-5022. 10.1021/j100412a029
  • TOLBERT, MA and JL BEAUCHAMP. (26-Nov 1986). MECHANISTIC AND KINETIC-STUDY OF ALKANE ACTIVATION BY TI+ AND V+ IN THE GAS-PHASE - LIFETIMES OF REACTION INTERMEDIATES. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 108(24), 7509-7517. 10.1021/ja00284a012
  • WEBB, SP, SW YEH, LA PHILIPS, MA TOLBERT and JH CLARK. (1984). ULTRAFAST EXCITED-STATE PROTON-TRANSFER IN 1-NAPHTHOL. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 106(23), 7286-7288. 10.1021/ja00335a093
  • TOLBERT, MA and JL BEAUCHAMP. (1984). ACTIVATION OF CARBON HYDROGEN AND CARBON CARBON BONDS BY TRANSITION-METAL IONS IN THE GAS-PHASE - EXHIBITION OF UNIQUE REACTIVITY BY SCANDIUM IONS. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 106(26), 8117-8122. 10.1021/ja00338a019
  • SCOTT, GW, JH CLARK, MA TOLBERT, SP WEBB, AJ COX and G RENZ. (1983). SIMULTANEOUS DETERMINATION OF THE SPECTRAL AND TEMPORAL PROPERTIES OF TUNABLE, SINGLE, PICOSECOND PULSES FROM A SHORT CAVITY DYE-LASER. IEEE JOURNAL OF QUANTUM ELECTRONICS, 19(4), 544-550. 10.1109/JQE.1983.1071892
  • CHI, IC, LE LAUFE, SD GARDNER and MA TOLBERT. (1980). EPIDEMIOLOGIC-STUDY OF RISK-FACTORS ASSOCIATED WITH PREGNANCY FOLLOWING FEMALE STERILIZATION. AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY, 136(6), 768-773.