Probabilistic Quantitative Precipitation Estimation with Geostationary Satellites
Interest:
The low latency and high space/time resolution from geostationary satellites (e.g. GOES-16/17, Himawari-8) are essential for monitoring and predicting precipitation processes occurring over short space and time scales and for driving hydrometeorological hazards such as flash floods and landslides.
Hydrometeorological applications require more than just one deterministic precipitation “best estimate” to adequately cope with the intermittent, highly skewed distribution that characterizes precipitation. However current geostationary quantitative precipitation estimates (QPE) are deterministic despite the indirect information provided by (near-)infrared passive radiances on surface precipitation rates.
objectives:
We propose to advance the interpretation of GOES-16/17 observations for hydrometeorological applications with the use of probability as an integral part of QPE. Probabilistic information provides the needed ingredients to advance ensemble hydrologic applications through assimilation and data fusion with other precipitation products, and enables to quantify the likelihood of observing extreme precipitation cases for risk analysis (Kirstetter et al. 2018).
The overarching goal of this research project is to leverage reliable ground sensors (radar and gauges) with the Ground-Validation Multi-Radar/Multi-Sensor (GV-MRMS) quantitative precipitation estimates to geostationary missions and synergize CONUS-wide GOES-16/17 precipitation enhancement.
Approach and Progress:
We are addressing the probabilistic QPE challenge in two stages. In Stage I we identify precipitation types from ABI sensor onboard GOES-16 using insights from GV-MRMS. In Stage II probabilistic QPE modeling will be applied using these insights.
I. Classifying precipitation: Prognostic and Diagnostic Modeling
A machine learning-based classification model is developed by deriving a comprehensive set of features using five ABI channels and numerical weather prediction observations. The developed prognostic model shows promising results in identifying the occurrence/non-occurrence of precipitation as well as precipitation processes from ground radars with overall accuracy of around 75%. It is suggested to utilize probabilities instead of deterministically separating precipitation types especially in regions with uncertain classifications. Ultimately, this effort will aid towards improved precipitation characterization and retrievals from space.
Peering into the model shows satellite observations are important in separating Rain and No-Rain areas. For stratiform precipitation types, predictors related to atmospheric moisture content, such as relative humidity and precipitable water, are the most important predictors, while for convective types, predictors such as 850-500hPa lapse-rate and Convective Available Potential Energy (CAPE) are more important. The diagnostic analysis confirms the benefit of spatial textures derived from ABI observations to improve the classification accuracy. It is recommended to combine the heritage water vapor channel T6.2 with the IR T11.2 channel for improved precipitation classification. There is more than 10% improvement in detection of stratiform and tropical precipitation types compared to using T11.2 alone.
II. Quantifying precipitation : Preliminary Analysis
Modeling precipitation types showed significance of deriving several new satellite predictors and combining this information with NWP based environmental predictor in improving detection of different precipitation types from GOES-16. Continuing this effort, the impact of these predictors on precipitation quantification is studied. A new QPE algorithm is proposed for GOES-16 satellite observations using random forest ML technique with novelty in exploring several new predictors and combining this information with NWP based environmental predictors. Further to improve quantification accuracy we use probabilities predicted by the classification model and study its impact.
Relevant publications:
- Kirstetter, P. E., Karbalaee, N., Hsu, K., & Hong, Y. (2018). Probabilistic precipitation rate estimates with space‐based infrared sensors. Quarterly Journal of the Royal Meteorological Society, 144, 191-205.
- Upadhyaya, S. A., Kirstetter, P. E., Gourley, J. J., & Kuligowski, R. J. (2020). On the propagation of satellite precipitation estimation errors: from passive microwave to infrared estimates. Journal of Hydrometeorology, 21(6), 1367-1381.
- Upadhyaya, S., Kirstetter, P. E., Kuligowski, R. J., Gourley, J. J., & Grams, H., (2021). Classifying precipitation from GEO Satellite Observations: Prognostic Model. (Submitted to Quarterly Journal of the Royal Meteorological Society)
- Upadhyaya, S., Kirstetter, P. E., Kuligowski, R. J., & Searls (2021). Classifying precipitation from GEO Satellite Observations: Diagnostic Model. (Submitted to Quarterly Journal of the Royal Meteorological Society)
Projects/Funding sources
Funding for this research was provided by the GOES-R Series Risk Reduction program, which provided support to the Cooperative Institute for Mesoscale Meteorological Studies at the University of Oklahoma under Grant NA16OAR4320115
Team
Pierre-Emmanuel Kirstetter
Shruti A. Upadhyaya
Collaborators: Robert J. Kuligowski, Jonathan J. Gourley