Frederick Iat-Hin Tam

Project Research Assistant

Curriculum vitae

[email protected]

Meteorology Building - C205
National Taiwan University
No.1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan

Identifying Critical Mechanisms Sustaining Nocturnal Storms: Role of Microphysics and Environmental Moisture (2016-2019; 2021-)

Scientific questions asked: 
  1. Why do some nocturnal MCSs live longer than others?
  2. What causes spatial variability in nocturnal environmental instability?
  3. Can we document the internal dynamic and microphysical processes in long-lived nocturnal MCSs?
In this first part of the project. Inter-comparison between field campaign observations, reanalysis data, and modeling outputs suggest that low-level jet (LLJ) provide the necessary ingredients, i.e., moisture, for storms to maintain overnight. We also performed some model sensitivity tests to show the sensitivity of a simulated nocturnal MCS to microphysical parameterization assumptions. Most of these work became the bulk of my M. S. thesis, submitted in early 2019.

In the second part of the project, we attempt to establish a link between moisture heterogeneity induced by LLJ and storm microphysical sensitivities. What motivated this subsequent work is that most storm microphysical sensitivity experiments assume uniform environment without temporal change. Interestingly, LLJ moisture heterogeneity seems to change the MCS sensitivities to rain fallout in unexpected ways. Preliminary findings suggest that how microphysical assumption feedbacks upon storm characteristics is governed by changes in storm thermodynamics through hydrometeor phase changes. It follows that the heating/cooling from phase change varies according to environmental moisture profiles, despite parameterization adjustments being identical. We intend to submit a journal article documenting these findings to Mon. Wea. Rev. later this year (2021).


Sensitivity of Simulated Nocturnal Convective Systems to Graupel Sedimentation Characteristics

Frederick Iat-Hin Tam, Ming-Jen Yang

Preprints. 2019 Conference of Weather Analysis and Forecast, Taiwan Geoscience Assembly (TGA), 2019 May

Microphysical and Near-Storm Environmental control on the Maintenance of Nocturnal Mesoscale Convective Systems: A Case Study

Frederick Iat-Hin Tam, Ming-Jen Yang, Wen-Chau Lee

National Taiwan University, M. S. thesis, 2019 Jan