About

Anita Rapp is a Professor in the Department of Atmospheric Sciences at Texas A&M University, where she also serves as Graduate Committee Chair. Her research interests include remote sensing, clouds and precipitation, satellite meteorology, mesoscale meteorology, atmospheric radiation, and aerosol-cloud interactions. She holds a Ph.D. in Atmospheric Science from Colorado State University, earned in 2008, and a B.S. in Meteorology from Texas A&M University. Her educational background also includes an M.S. in Atmospheric Science from Colorado State University. Dr. Rapp has received several awards and honors, including a Visiting Postdoctoral Fellowship at the Cooperative Institute for Research in Environmental Sciences and NASA Earth System Science Fellowship. Her work involves analyzing atmospheric phenomena through observational data, contributing to understanding climate change impacts on the tropical hydrological cycle, mesoscale cloud behavior, and precipitation patterns.

Research topics

• Meteorology
• Climatology
• Atmospheric sciences
• Geography
• Geology
• Environmental science
• Physics

Selected publications

• Supplementary material to "Aerosol Vertical Distributions Shaped by Boundary Layer Dynamics in a Coastal Urban Environment: Insights from the TRACER Campaign"

  2026-04-02

  articleOpen access
  PublisherDOI

• Understanding aerosol properties in convective outflows during TRACER

  Figshare · 2026-01-01

  articleOpen access

  Convective outflow boundaries commonly form across the southeastern U.S., often originating from storms initiated along sea-breeze fronts. As outflows spread, merge, and collide, they frequently trigger secondary convection in air masses already modified by primary storm outflow. This resulting air mass carries a distinctive aerosol population, which can influence the development of secondary convective cells. During the U.S. DOE TRACER field campaign in summer 2022, we investigated how outflows affect aerosol size, composition, and hygroscopicity across Greater Houston, Texas. Using a novel detection algorithm, we identified and verified 72 outflow boundaries from surface meteorological observations. In the relatively simple continental environment northwest of Houston, a common relationship emerged between CCN-inferred hygroscopicity (<i>κ</i>) and size-resolved aerosol concentrations. The <i>κ</i> of aerosols typically decreased in size ranges where aerosol concentrations increased following outflow passage and increased where concentrations decreased. In contrast, at the Atmospheric Radiation Measurement’s (ARM) fixed site in La Porte, Texas, the aerosol response depended on outflow direction, shaped by concentrated industrial and shipping activity to the north and south/southeast along the Houston Ship Channel. Concurrent size distribution and composition changes suggested case-specific variability in <i>κ</i>, with either reinforcing or offsetting effects. Outflows passing over industrial/shipping sectors often promoted less hygroscopic aerosol populations while cleaner residential outflows often favored more hygroscopic aerosol populations. These results highlight key aerosol changes following outflow passage, providing a foundation for improved understanding of aerosol-cloud interactions related to secondary convection initiation along or in the wake of outflow boundaries.

  PublisherDOI

• Understanding aerosol properties in convective outflows during TRACER

  Figshare · 2026-01-01

  articleOpen access

  Convective outflow boundaries commonly form across the southeastern U.S., often originating from storms initiated along sea-breeze fronts. As outflows spread, merge, and collide, they frequently trigger secondary convection in air masses already modified by primary storm outflow. This resulting air mass carries a distinctive aerosol population, which can influence the development of secondary convective cells. During the U.S. DOE TRACER field campaign in summer 2022, we investigated how outflows affect aerosol size, composition, and hygroscopicity across Greater Houston, Texas. Using a novel detection algorithm, we identified and verified 72 outflow boundaries from surface meteorological observations. In the relatively simple continental environment northwest of Houston, a common relationship emerged between CCN-inferred hygroscopicity (<i>κ</i>) and size-resolved aerosol concentrations. The <i>κ</i> of aerosols typically decreased in size ranges where aerosol concentrations increased following outflow passage and increased where concentrations decreased. In contrast, at the Atmospheric Radiation Measurement’s (ARM) fixed site in La Porte, Texas, the aerosol response depended on outflow direction, shaped by concentrated industrial and shipping activity to the north and south/southeast along the Houston Ship Channel. Concurrent size distribution and composition changes suggested case-specific variability in <i>κ</i>, with either reinforcing or offsetting effects. Outflows passing over industrial/shipping sectors often promoted less hygroscopic aerosol populations while cleaner residential outflows often favored more hygroscopic aerosol populations. These results highlight key aerosol changes following outflow passage, providing a foundation for improved understanding of aerosol-cloud interactions related to secondary convection initiation along or in the wake of outflow boundaries.

  PublisherDOI

• Understanding aerosol properties in convective outflows during TRACER

  Aerosol Science and Technology · 2026-01-20

  articleOpen access

  Convective outflow boundaries commonly form across the southeastern U.S., often originating from storms initiated along sea-breeze fronts. As outflows spread, merge, and collide, they frequently trigger secondary convection in air masses already modified by primary storm outflow. This resulting air mass carries a distinctive aerosol population, which can influence the development of secondary convective cells. During the U.S. DOE TRACER field campaign in summer 2022, we investigated how outflows affect aerosol size, composition, and hygroscopicity across Greater Houston, Texas. Using a novel detection algorithm, we identified and verified 72 outflow boundaries from surface meteorological observations. In the relatively simple continental environment northwest of Houston, a common relationship emerged between CCN-inferred hygroscopicity (<i>κ</i>) and size-resolved aerosol concentrations. The <i>κ</i> of aerosols typically decreased in size ranges where aerosol concentrations increased following outflow passage and increased where concentrations decreased. In contrast, at the Atmospheric Radiation Measurement’s (ARM) fixed site in La Porte, Texas, the aerosol response depended on outflow direction, shaped by concentrated industrial and shipping activity to the north and south/southeast along the Houston Ship Channel. Concurrent size distribution and composition changes suggested case-specific variability in <i>κ</i>, with either reinforcing or offsetting effects. Outflows passing over industrial/shipping sectors often promoted less hygroscopic aerosol populations while cleaner residential outflows often favored more hygroscopic aerosol populations. These results highlight key aerosol changes following outflow passage, providing a foundation for improved understanding of aerosol-cloud interactions related to secondary convection initiation along or in the wake of outflow boundaries.

  PublisherDOI

• Transport to the Extratropical Stratosphere by Overshooting Storms in Idealized Simulations

  Journal of Geophysical Research Atmospheres · 2026-04-17

  articleOpen accessSenior author

  Abstract Deep convection is a significant source of water to the extratropical stratosphere which can alter radiative properties and contribute to ozone loss. Previous studies find it responsible for 40% of mid‐latitude water vapor above 380K. However, the amount of hydration from individual storms and the mechanisms that initiate mixing is less understood. We use an idealized large eddy simulation with 100 m horizontal and vertical grid spacing to simulate a multicell storm with several overshooting tops (OTs) extending up to 2.5 km above the tropopause. Our goals are to determine the amount of water vapor and ice added to the stratosphere by this storm complex, identify how varying grid spacing affects the amount of hydration, and investigate the processes leading to irreversible mixing into the stratosphere. We find that, relative to the base state, an additional 33.7 kilotons of ice and 4.2 kilotons of water vapor are present in the stratosphere at the end of the simulation. For hydration similar to the 100‐m baseline simulation, 300‐m horizontal and 100‐m vertical grid spacing are necessary. Finally, the mechanism leading to hydration from individual OTs is shown to occur only after the initial overshoots begin to collapse. A region of positive buoyancy develops where previously overshooting cloud has descended, which is followed by a secondary upward movement of moistened air disconnected from the initial updraft. This process, not direct detrainment and sublimation of ice from the initial overshoot itself, triggers irreversible mixing in each case we investigate.

  PublisherDOI

• Simulation of Water Vapor Transport to the Stratosphere by Overshooting Convection

  Journal of Geophysical Research Atmospheres · 2026-03-25

  articleOpen access

  Abstract Deep convection that penetrates the tropopause (overshooting convection) transports water vapor and other tropospheric constituents to the upper troposphere and lower stratosphere (UTLS). Overshooting convection has chemical and radiative impacts on the UTLS, including the downward transport of ozone and hydration of the stratosphere. Currently, water vapor transport due to overshooting convection is not well quantified. In this study the Weather Research and Forecasting model (WRF) is used to simulate a Mesoscale Convective System (MCS) that formed on 9 June 2022 and produced multiple overshoots over the course of 12 hr, with radar echo tops reaching up to 5 km above the ERA5 tropopause. Observations from the NEXRAD radar system are used along with in situ aircraft measurements from the Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) project to validate the simulated overshooting convection and horizontal transport of the water vapor plume. Isentropic back trajectories are used to match water vapor enhancements to individual overshoots and the mass of the plume is calculated by subtracting the stratospheric background. In total, the model estimates that this storm injected 121 kt of water vapor into the stratosphere: 56 kt into the 370–380 K layer, 30 kt into the 380–390 K layer, and 35 kt above 390 K with enhancements simulated as high as the 445 K isentrope.

  PublisherDOI

• Aerosol Vertical Distributions Shaped by Boundary Layer Dynamics in a Coastal Urban Environment: Insights from the TRACER Campaign

  2026-04-02

  articleOpen access

  Abstract. Aerosol vertical distributions are a major source of uncertainty in quantifying aerosol–cloud–climate interactions. Using observations collected during the 2022 TRACER campaign in Houston, Texas, we investigate how Atmospheric boundary layer dynamics shape the vertical structure of aerosol populations in a coastal urban environment. Our lidar retrieval combines micropulse lidar backscatter with ground-based aerosol measurements to obtain aerosol concentration profiles. We introduce a new parameterized fitting function that captures the characteristic S-shaped aerosol profiles associated with boundary layer processes. This parameterization is applied to case studies demonstrating how boundary-layer dynamics, including turbulent mixing, capping inversion strength, and sea-breeze circulations, govern aerosol vertical distributions. Finally, we estimate aerosol vertical profiles from boundary layer height and gradients in potential temperature profile using our proposed aerosol profile parameterization function. These findings provide a physically grounded parameterization for inferring aerosol vertical profiles in locations where aerosol sampling is limited to surface measurements.

  PublisherDOI

• Exploring Drivers of Unexpected Diurnal Variations in Tropical Oceanic Cold Cloud Production

  2026-03-14

  articleOpen access

  The diurnal cycle of cold cloud cover is underestimated within Earth system models (ESMs) with the greatest underestimation in the afternoon. To better understand the diurnal cycle of tropical oceanic cloud cover, the diurnal cycle of deep convective system (DCS) initiation and the subsequent contributions to cloud cover resulting from systems initiating at earlier times is analyzed using newly developed DCSs Lagrangian tracking methodologies. Satellite infrared-based Tracking Of Organized Convection Algorithm through 3D segmentatioN (TOOCAN) DCSs are matched to Global Precipitation Measurement (GPM) mission precipitation and diabatic heating products. Matched data are then binned by their hour of initiation (in local solar time) to evaluate morphological characteristics and contributions to rain and cloud cover diurnal cycles. Analysis reveals an unexpectedly large peak in daytime DCS initiation that produce subsequent afternoon cloud cover, thus suggesting that the discrepancy between ESMs and observations is likely due, in part, to ESM misrepresentation of initiation or maintenance of daytime-initiated DCSs. Results also show that daytime DCSs produce less precipitation, but relatively more cloud shield compared to DCS that initiate overnight. As a framework to understand these diurnal variations in cold cloud production, we will apply a semi-empirical source-sink cold cloud area growth model that includes a convective area source term and latent heating source term. Vertical latent heating profiles from GPM, DCS morphology from TOOCAN, and atmospheric lapse rates and density from ERA5 are fit to the semi-empirical model to estimate cloud growth and decay timescales. Observation-estimated timescales and the source term variations will be evaluated to understand key drivers in the differences in DCS cold cloud production across the diurnal cycle.

  PublisherDOI

• Aerosol Physicochemical Mixing State and Cloud Nucleation Potential during Tracking Aerosol Convection Interactions Experiment (TRACER) Campaign

  Environmental Science & Technology · 2025-07-18 · 5 citations

  article

  Aerosol-cloud interactions remain a major source of uncertainty in estimating global radiative forcing due to the complex nature of the aerosol physicochemical properties. This study investigates the physicochemical characteristics of aerosols collected during the DOE's TRacking Aerosol Convection interactions Experiment (TRACER) campaign, conducted from June to September 2022 in the Greater Houston area. Aerosols were sampled at coastal (Galveston) and inland (Hempstead and Jersey Village) sites during sea-breeze initiated convection and outflow events and analyzed using Raman microspectroscopy. Galveston's aerosols primarily consisted of organic compounds, while Hempstead featured mainly inorganic salts (e.g., ammonium sulfate) and secondary organic aerosols. Organic aerosols were more abundant in Galveston (73%) than in Hempstead (65%). Particles exhibited diverse morphologies including homogeneous, core-shell, and complex structures. Homogeneous particles dominated at both sites, though Hempstead showed a higher fraction of core-shell particles. Cloud condensation nuclei (CCN) concentrations were 5 times higher at the inland sites than at the coast at a supersaturation of 0.2%, and this difference increased to 13 times higher at a 1.2% supersaturation. During sampling of the outflow of convective storm systems, distinct changes in aerosol size, morphology, and mixing state led to a significant increase in CCN activity at the inland (Jersey Village) site. These findings emphasize the impacts of atmospheric processing on aerosols and highlight the need to incorporate physicochemical variability into models to improve predictions of aerosol-cloud interactions and climate effects.

  PublisherDOI

• Variability in Ice Nucleating Particles Across Greater Houston Texas

  Journal of Geophysical Research Atmospheres · 2025-08-18 · 2 citations

  articleOpen access

  Abstract The concentration and cloud‐forming potential of a region's ice nucleating particle (INP) population have uncertain impacts on deep convective clouds. Specifically, ice nucleating particles (INPs) may affect various cloud properties related to the formation, lifetime, and precipitation of deep convective clouds. As part of the U.S. Department of Energy's TRacking Aerosol and Convection interaction ExpeRiment (TRACER) campaign, researchers from Texas A&amp;M University deployed three Davis Rotating‐drum Universal‐size‐cut Monitoring (DRUM) samplers throughout Greater Houston, Texas from June through September 2022. Ambient particles, collected at the surface with the DRUM samplers in four aerodynamic diameter size ranges (&gt;3, 3–1.2, 1.2–0.34, and 0.34–0.15 μm), were analyzed in offline cold‐stage ice nucleation experiments. The INP population in Greater Houston is complex, varying by site and day, but can be generalized by a weak to moderately efficient mode of INPs at −24°C and an efficient mode at −15°C. Analysis reveals that supermicron particles are largely responsible for ice nucleation warmer than −20°C across the region while submicron particles dominate at temperatures colder than −20°C. Additionally, significant spatial diversity in the INP population was observed, with differences in mean nucleation temperature between sites for nearly every size cut. Although INP concentrations were typically ∼0.08 L −1 at −20°C throughout the campaign, a notable region‐wide increase in INP concentration for particles freezing at temperatures warmer than −20°C occurred from mid‐August to mid‐September. This comprehensive characterization of Greater Houston's INP population, including spatial, temporal, and particle size variations, can help constrain ice microphysics parameterizations in weather and climate models.

  PublisherOA PDFDOI

Recent grants

• RAPID: Evaluation of Climate Models in the Southeast Pacific Marine Stratocumulus Region

  NSF · $30k · 2011–2013

• Collaborative Research: Understanding Relationships between Dual-Polarimetric In-cloud Microphysics and Satellite-Observed Cumulus Cloud Properties to Predict Lightning Character

  NSF · $232k · 2013–2018

Frequent coauthors

• Tristan L’Ecuyer

  Cooperative Institute for Climate and Satellites

  12 shared

• Steven M. Quiring

  The Ohio State University

  12 shared

• K. Wodzicki

  11 shared

• Patrick Minnis

  Northern Health and Social Care Trust

  10 shared

• Kevin M. Smalley

  Jet Propulsion Laboratory

  9 shared

• Kenneth P. Bowman

  Texas A&M University

  9 shared

• William L. Smith

  8 shared

• Oliver W. Frauenfeld

  8 shared

Labs

• Atmospheric Sciences Research Lab at Texas A&M UniversityPI

Education

• Ph.D. Atmospheric Science, Department of Atmospheric Science

  Colorado State University

  2008

• M.S. Atmospheric Science, Department of Atmospheric Science

  Colorado State University

  2004

• B.S. Meteorology, Department of Meteorology

  Texas A&M University

  2000

Awards & honors

• NASA Earth System Science Fellowship (2005–2008)
• Superior Accomplishment Award, NASA Contractors Steering Cou…
• Superior Accomplishment Award, NASA Contractors Steering Cou…
• University Undergraduate Research Fellow, Texas A&M Universi…
• Cooperative Institute for Research in Environmental Sciences…