Timothy Logan

Timothy Logan

Assistant Professor

Director of the Houston Lightning Mapping Array Network

Aerosol-cloud Interactions, Aerosol Chemistry, Biomass Burning Smoke, Atmospheric Electricity

  tlogan52@tamu.edu

  (979) 845-2004

  Eller O&M 1009A

Research

My current research consists of the following projects:

(1) Aerosol impacts on low-level cloud development which is funded by a NSF Collaborative Research Grant (2017-2020). My contribution to the study deals with using surface-based Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) retrievals from 2007-2017 and NASA Modern Era Retrospective Reanalysis for Research (MERRA-2) data for the 1981-2018 period. I am responsible for processing all aerosol physical and chemical data and discerning how various aerosol types can influence cloud microphysical processes such as cloud development, precipitation, and electrification. There is a specific interest in investigating aerosols derived from biomass burning.

(2) Texas A&M University Tier One Proposal (TOPS) grant (2018-2021) where I analyze aerosol transport and aerosol impacts on boundary layer clouds using a portable micropulse LIDAR (MPL). The MPL has captured several Saharan dust intrusions over the Bryan/College Station area as well as smoke/pollution emissions from local and long-range transport sources. During May 2019, the MPL was part of a two week field excursion where it sampled boundary layer aerosols during several instances of deep convection in the Southern Great Plains regions. The McCook, Nebraska tornado was thoroughly sampled including the bounded weak echo region (BWER) and TVS just before the tornado was observed.

(3) NOAA Grant (2017-2019) to validate the Geostationary Lightning Mapper sensor data using the Houston Lightning Mapping Array (HLMA). Current projects include impacts of Hurricane Harvey, Hurricane Barry, and other catastrophic flooding events in and around the Houston Metropolitan and Bryan/College Station Micropolitan areas.

(4) The Houston Lightning Mapping Array will be used in the 2021 TRACER-Ex field campaign that will be conducted over the Houston Metropolitan Area. Funding for graduate work is pending.

Future research will incorporate laser spectroscopy to investigate the physical and radiative properties of aerosols such as mineral dust and ash/soot that are derived from local and long-range transport sources.

My primary research goals are to (1) discern the possible impacts of carbonaceous aerosols on severe weather and lightning, (2) investigate the relationship between cloud electrification processes and precipitation/flooding events (especially over Southeast Texas), (3) analyze long-term aerosol impacts on low-level and deep convective cloud development, and (4) analyze aerosol scattering properties and their impacts on cloud development by using theoretical radiative transfer calculations and in situ measurements (e.g., micropulse lidar and laser spectroscopy).

ADDITIONAL NOTES
I am actively seeking graduate students at the Masters and Doctoral levels. Students having a diverse interdisciplinary background of geoscience (meteorology, hydrology, and geology) plus any of the following: physics, chemistry, math, programming/machine learning skills, and GIS skills, are preferred. My active research areas include:

Processing HLMA data along with other lightning datasets to investigate the feasibility of using lightning activity to predict the severity of deep convection;

Comparing/contrasting the behavior of lightning over continental and marine regions;

Analyzing data from the TAMU micropulse lidar and laser spectroscope as well as other instrument platforms and field campaigns to determine how aerosol physical and radiative properties can influence cloud development.

Impact

The HLMA provides a service to the surrounding community by providing timely and reliable lightning data to make informed decisions in regards to public safety interests while providing quality data for collaborative, interdisciplinary research within the university community and for K-12 STEM projects.

Selected Publications

Logan, T., B. Xi, X. Dong, R. Obrecht, Z. Li, and M. Cribb (2010), A Study of Asian Dust Plumes Using Satellite, Surface, and Aircraft Measurements during the INTEX-B Field Experiment, J. Geophy. Res., 115, D00K25, doi:10.1029/2010JD014134.

Logan, T., B. Xi, X. Dong, Z. Li, and M. Cribb (2013), Classification and Investigation of Asian Aerosol Properties, Atmos. Chem. Phys., 13, 2253-2265, www.atmos-chem-phys.net/13/2253/2013/doi:10.5194/acp-13-2253-2013.

Logan, T., B. Xi, and X. Dong (2013), A Comparison of the Mineral Dust Absorptive Properties from Two Asian Dust Events, Atmosphere, 4(1), 1-16; doi:10.3390/atmos4010001.

Logan, T., B. Xi, and X. Dong (2013), Biomass Burning Aerosol Properties over the Northern Great Plains during the 2012 Warm Season, Atmos. Chem. Phys. Discuss., 13, 32269–32289, www.atmos-chem-phys-discuss.net/13/32269/2013/doi:10.5194/acpd-13-32269-2013.

Mao, F., W. Gong, and T. Logan (2013), Linear Segmentation Algorithm for Detecting Layer Boundary with LIDAR, Optics Express, 21(22), doi:10.1364/oe.21.026876.

Logan, T., B. Xi, and X. Dong (2014), Aerosol properties and their influences on marine boundary layer cloud condensation nuclei at the ARM mobile facility over the Azores, J. Geophys. Res., 119, doi:10.1002/2013JD021288.

Wang W., L. Sheng, X. Dong, W. Qu, J. Sun, H. Jin, and T. Logan (2016), Dust aerosol impact on the retrieval of cloud top height from satellite observations of CALIPSO, CloudSat and MODIS. J. Quant. Spectrosc. Radiat. Transfer, http://dx.doi.org/10.1016/j.jqsrt.2016.03.034.

Tian P., X. Cao, L. Zhang, N. Sun, L. Sun, T. Logan, J. Shi, Y. Wang, Y. Ji, Y. Lin, Z. Huang, T. Zhou, Y. Shi, and R. Zhang (2017), Seasonal and spatial variations in aerosol vertical distribution and optical properties over China from long-term satellite and ground-based remote sensing. Atmos. Chem. Phys., 17, 2509-2523, http://www.atmos-chem-phys.net/17/2509/2017/doi:10.5194/acp-17-2509-2017.

Logan, T., X. Dong, and B. Xi (2018), Aerosol properties and their impacts on surface CCN at the ARM Southern Great Plains site during the 2011 Midlatitude Continental Convective Clouds Experiment. Adv. Atmos. Sci., 35(2), 224–233, https://doi.org/10.1007/s00376-017-7033-2.

Logan, T. (2018), Anomalous Lightning Behavior during the 26-27 August 2007 Northern Great Plains Severe Weather Event. J. Geophys. Res. Atmos., 123, https://doi.org/10.1002/2017JD027750.

Li, R., G. Tang, J. Ding, T. Logan, S. D. Brooks, D. R. Collins, P. Yang and G. W. Kattawar (2018), Laboratory measurements of light scattering properties of kaolinite dust at 532 nm, Aerosol Sci. Tech., doi:10.1080/02786826.2018.1444729, 1-13.

Bowen P., Y. Wang, J. Hu, Y. Lin, J.-S. Hsieh, T. Logan, X. Feng, J. H. Jiang, Y. Yung, and R. Zhang, (2018), Impacts of Saharan Dust on Regional Climate and Tropical Cyclogenesis over the Atlantic, J. Clim., https://doi.org/10.1175/JCLI-D-16-0776.1.

Pan Z., F. Mao, W. Wang, T. Logan, J. Hong (2018), Examining Intrinsic Aerosol-Cloud Interactions in South Asia through Multiple Satellite Observations, J. Geophys. Res. Atmos., 123, https://doi.org/10.1029/2017JD028232, 1-15.

Zhang, Y., J. Fan, T. Logan, Z. Li, and C. R. Homeyer (2019), Wildfire impact on environmental thermodynamics and severe convective storms, Geophys. Res. Lett., 46. https://doi.org/10.1029/2019GL084534

Education

B.A. IN ENVIRONMENTAL SCIENCE FROM UNIVERSITY OF VIRGINIA

M.S. IN ATMOSPHERIC SCIENCE FROM UNIVERSITY OF NORTH DAKOTA

PH. D. IN ATMOSPHERIC SCIENCE FROM UNIVERSITY OF NORTH DAKOTA

Awards

2015: TAMU Atmospheric Science Department Outstanding Faculty Teaching Award

2015: Hubei Province, China Scientific Paper Award “Mao, F., W. Gong, and T. Logan (2013), Linear Segmentation Algorithm for Detecting Layer Boundary with LIDAR, Optics Express, 21(22), doi:10.1364/oe.21.026876.”

2014: American Meteorological Society Best Student Poster Award

2011: National Science Foundation East Asian and Pacific Summer Institutes (EAPSI) in China Fellowship

2009: North Dakota Space Grant Consortium Fellowship

Links

Houston Lightning Mapping Array Network
*Website is under construction. The link will be provided as soon as the new design is complete.*

Texas A&M University Micropulse LIDAR

 

Courses

ATMO 201 – Weather and Climate – introductory meteorology class
ATMO 291/491 – Independent Undergraduate Research – processing HLMA and MPL data; students present findings at national conferences (e.g., AMS and AGU)
GEOS 101 – First Year Experience (Hullabaloo U): Science Can Be A Real Disaster
GEOS 681 – Graduate Seminar

Additional Information

Texas A&M Professor Collected Unique Data With Mobile LIDAR During Storm Chase – College of Geoscience News
https://geonews.tamu.edu/news/2019/10/tim-logan-storm-chase-with-cace-lidar

A&M Professor Studies Effects of Aerosols – The Battalion (Texas A&M University)
https://www.thebatt.com/science-technology/a-m-professor-studies-effects-of-aerosols/article_d4428638-0fa4-11e8-a18b-6bd02484ef4d.html

Lightning Safety Story – The Eagle (Bryan, TX)
https://www.theeagle.com/news/local/tips-can-reduce-risk-of-being-hit-by-lightning/article_6afd1962-52f2-5929-bd40-3e11b3f177ef.html

Saharan Dust Story – The Star-Telegram (Fort Worth, TX)
https://www.star-telegram.com/news/weather/article215252090.html

Why You Can Smell Rain
https://theconversation.com/why-you-can-smell-rain-101507

 

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