Andrew J. Ansorge

Graduate Research

Summary of the Multi-Regional climate model Ensemble Downscaling (MRED) Project funded by NOAA and CPPA An objective of the MRED project is to determine if dynamic downscaling using regional climate models (RCMs) can produce skillful seasonal predictions compared to the global model (NCEP Climate Forecast System version 1) and observations. To assess this objective, we are calculating the frequency and intensity of daily precipitation over several regions of the continental United States. These regions were chosen because they have known ENSO influences on precipitation, are regions that other collaborators are investigating or have topographically varying terrain where dynamic downscaling should have added value to predictions. Analysis of the central Rockies has shown that dynamic downcaling using RCMs adds value to the forecast. The RCMs are able to simulate extreme precipitation (50mm/day or higher), albeit too frequently when compared to observations. In contrast, the global model has little or no extreme precipitation compared to observations. The RCMs are distributing precipitation to higher intensities (may or may not be extreme) while the global model are distributing to lower intensities. Additional regions are currently being examined.

Presentations
* indicates presenter
Ansorge, A. J., R. W. Arritt*, and The MRED Team, 2012: Precipitation intensity in an ensemble of downscaled seasonal forecasts. European Geosciences Union General Assembly 2012 Meeting EGU2012-12832. [Abstract | PDF]

Ansorge, A. J.*, and R. W. Arritt, 2012: Distribution and intensity of extreme winter precipitation in seasonal forecasts. 26th Conference on Hydrology, New Orleans, LA P366. [Abstract | PDF]

Arritt, R. W.*, A. J. Ansorge, and L. L. De Haan, 2011: Ensemble downscaling of winter seasonal forecasts over the United States. 26th Conference on Hydrology, New Orleans, LA A33H-04. [Abstract]

Ansorge, A. J.*, R. W. Arritt, and the MRED team, 2011: Distribution and intensity of extreme winter precipitation in seasonal forecasts. AGU Fall Meeting 2011, San Francisco, CA A23C-0176. [Abstract | PDF]

Arritt, R. W.*, A. J. Ansorge, and L. L. De Haan, 2011: Ensemble downscaling of winter seasonal forecasts over the United States. AGU Fall Meeting 2011, San Francisco, CA A33H-04. [Abstract]

Arritt, R. W., L. L. De Haan, and M. Kanamitsu for the MRED team, 2011: MRED: Seasonal forecasting for climate applications. Climate Prediction Applications Science Workshop 2011 P16. (presented by A. J. Ansorge*) [PDF]

Undergraduate Research
Summary My senior research thesis investigated how the Betts-Miller-Janjic (BMJ) and Kain-Fritsch (KF) cumulus parameterization schemes performed in simulated convective propagating precipitation over the central United States by using the WRF model. The diurnal cycle showed that the BMJ‘s precipitation is driven by the non-convective scheme whereas the KF favors the convective scheme in precipitation amount. Propagating precipitation streaks that were in the observations were best simulated in the KF convective and total precipitation while the BMJ produced precipitation over a widespread area with no propagating precipitation streaks. This project was guided by James Correia, Jr. and Adam Clark, two Ph.D. students at the time.

Presentations
* indicates presenter
Ansorge, A. J.*, J. Correia, and A. J. Clark, 2007: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. 22nd Conference on Weather Analysis and Forecasting/18th Conference on Numerical Weather Prediction, Park City, Utah P2.26. [Abstract | PDF]

Ansorge, A. J.*, J. Correia, and A. J. Clark, 2007: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. 1st Annual Iowa State University Undergraduate Symposium, Ames, Iowa II.A.1. [PDF]

Ansorge, A. J.*, J. Correia, and A. J. Clark, 2007: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. 11th Annual Central Iowa National Weather Association Severe Storms and Doppler Radar Conference, Des Moines, Iowa Poster Session. [PDF]

Ansorge, A. J.*, J. Correia, and A. J. Clark, 2007: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. Research in the Capitol, Des Moines, Iowa P7. [PDF]

Ansorge, A. J.*, J. Correia, and A. J. Clark, 2006: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. 14th Annual Iowa State University Atmospheric Science Undergraduate Research Symposium, Ames, IA [14.4 | Paper]

Ansorge, A. J.*, J. Correia, and A. J. Clark, 2006: Coherence of rainfall propagation as simulated in the WRF model using two difference convective scheme. Atmospheric Sciences Seminar Series - Graduate and Undergraduate, Ames, IA Poster Session. [PDF]