# A new, long-term root zone soil moisture dataset for operational agricultural drought monitoring over Africa

## TL;DR

A new dataset tracks soil moisture in Africa to help monitor agricultural drought, using rainfall and satellite data.

## Contribution

The paper introduces TAMSAT-SM, a long-term root zone soil moisture dataset for Africa.

## Key findings

- TAMSAT-SM reliably captures soil moisture patterns across Africa.
- The dataset improves agricultural drought monitoring when compared to other products.
- Vegetation health data supports the usefulness of TAMSAT-SM.

## Abstract

Quantifying root zone soil moisture (RZSM) is critical for assessing water availability to crops and identifying agricultural drought across Africa, with access to reliable and timely RZSM data essential for informed decision-making. While rainfall is frequently used to assess crop growing conditions, it alone may not reliably reflect crop water availability due to the impact of evapotranspiration on soil moisture and rainfall not always reflective of concurrent soil water content at rooting depth. To provide robust information on agricultural drought, this paper describes a new, operational RZSM dataset, called TAMSAT soil moisture (TAMSAT-SM), available from 1983-present at 0.25° spatial resolution. TAMSAT-SM is derived using the JULES land surface model, forced with TAMSAT rainfall estimates and other meteorological variables from the NCEP reanalysis, and tuned to SMAP satellite soil moisture observations. Comparison against other RZSM products and independent satellite-derived vegetation health data show TAMSAT-SM can reliably capture the spatial and temporal RZSM and vegetation health patterns across Africa and can be a useful tool to support existing agricultural drought monitoring efforts.