Data / Science Data Products / VAPs

PRECIPBE

Precipitation Best Estimate

Evaluation VAP

The Precipitation Best Estimate value-added product (PrecipBE VAP) streamlines both process understanding and model evaluation studies using ARM precipitation data. The VAP processing is performed on a per-precipitation-event basis, leveraging existing ARM measurement capabilities depending on instrument availability for a site/deployment while incorporating ARM Data Quality Reports and data validity considerations. This approach enhances the robustness of the data product, enabling users to integrate uncertainty metrics into their analyses.

PrecipBE includes two daily datastreams: precipbetseries, which provides time-series data of (evolving, per-event) cumulative precipitation and precipitation rates at one-minute resolution; and precipbestats, which includes per-event statistics in an easy-to-use, one-dimensional (tabular) format. The precipbestats datastream also includes ancillary atmospheric-state data corresponding to each event, such as temperature, relative humidity, and a selected set of drop size distribution moments derived from ARM disdrometer quantities VAPs (where available).

PrecipBE’s processing method of isolating distinct precipitation events simplifies the use of this VAP. The time-series datastream (precipbetseries) provides the temporally evolving instrument-mean, minimum, maximum, and standard deviation of cumulative precipitation and one-minute precipitation rates, equipping users interested in specific case studies with robust benchmarks. For bulk analyses, the statistics datastream (precipbestats) provides essential quantities such as event period, mean precipitation rate, one-minute maximum precipitation rate, and event total amount. VAP users can also leverage the ancillary event quantities included in this datastream.

A Jupyter Notebook demonstrating use of the PrecipBE VAP is available on the ARM-Notebooks GitHub repository.

The accuracy of precipitation measurements is influenced by factors such as strong winds or subfreezing temperatures, with some instruments being more susceptible to some effects than others. While PrecipBE includes flags indicating the occurrence of such events, users are advised to leverage the complete set of statistics this VAP provides to mitigate these effects. Regarding the influence of atmospheric temperatures, future updates to PrecipBE will incorporate measurement data specific to solid water phase (snow) precipitation.