Brazilian Experimental datasets for MUlti-Scale interactions in the critical zone under Extreme Drought (BEMUSED)

This IOF proposal, entitled "Brazilian Experimental datasets for MUlti-Scale interactions in the critical zone under Extreme Drought" (BEMUSED), is a partnership between the University of Bristol (UoB) and University of Sao Paulo (USP) [RCUK-FAPESP Lead Agency Agreement is applied]. BEMUSED recognizes that a more scale-integrated view of the role of soil moisture in the critical zone (the earth's outer layer from vegetation canopy to the soil and groundwater that sustains life) is of great importance in South America. Soil moisture is a key environmental variable of the hydrological cycle connecting the rapid changes in atmospheric conditions near the surface with slower subsurface processes. However, our understanding of key soil moisture controlling factors has been limited due to a lack of soil moisture measurements directly compatible to so-called "hyper-resolution" hydrological models. Recently, the development of new Cosmic-Ray Sensors (CRS) technology for monitoring soil moisture at unprecedented sub-kilometer scales provides the missing link between traditional point-scale sensors and large-scale satellite remote sensing products. In recent years, networks of CRS have been established worldwide but not yet for tropical hydrological studies (e.g., in South America). In addition, limited representation of key hydrological processes (including subsurface-surface interactions) in current Earth System Models poses extreme challenges for prediction and adaptation strategies. This is important for predicting extreme events such as droughts, especially in data scarce regions such as in tropical areas. The recent (2013-2014) extreme drought event that occurred in southeast Brazil severely affected water resources in the region including the Cantareira Reservoir System (one of the largest in the world) which supplies water to more than 9 million people in Sao Paulo metropolitan area. Lack of accurately representing the role of soil moisture in connecting the subsurface to surface water dynamics will continue to undermine our predictability skills, consequently providing sub-optimal information for adaptation strategies in important economic-social region in South America and globally.

This opportunity is very timely because it will allow both groups to mutually exploit the hydrological model developments from our current NERC New Investigator "A MUlti-scale Soil moisture - Evapotranspiration Dynamics study" (AMUSED) project using locally available data from an experimental catchment in southeast Brazil which has recently experienced an extreme drought event. This provides a unique opportunity to further evaluate our current model developments (i.e., preferential water flow in soils, and groundwater dynamics) in a challenging tropical region. Also importantly, BEMUSED will allow the UoB to engage in knowledge and skills transfer associated with the use of CRS particularly in a tropical South America region where it has never been tested. A CRS is scheduled to be installed at the experimental catchment in 2018, hence we propose to test our CRS deployment/calibration guidelines and data processing approaches, developed under AMUSED, in tropical South America for the first time, and further engage with AMUSED's original Pathways to Impact activities in promoting knowledge transfer and dissemination of new measurement technology by offering a short-course on "Soil Moisture Measurements using Cosmic-Ray Sensors" in Brazil. Finally, a workshop will be held in Brazil to discuss on strategies for improvement of Brazil's national capability for large-scale hydrometeorological monitoring and modeling with the aim to enhance response to future hydroclimatic variability and natural hazards.

The impacts from this IOF project, entitled "Brazilian Experimental datasets for MUlti-Scale interactions in the critical zone under Extreme Drought" (BEMUSED), are summarized as follows:

Societal and economic impacts:
The general public is directly affected by hydrometeorological events such as floods, droughts, and extreme weather. In Brazil, extreme events have devastating socio-economic impacts, especially in densely-populated regions such as southeast Brazil, which relies immensely on water resources for domestic, agriculture, and industry. BEMUSED will benefit government agencies, industry, and policy/decision makers, stakeholders and public in general in providing a better understanding of soil moisture dynamics using new technology and better representation of key hydrological processes in numerical models. Improving predictability skills of extreme events such as droughts can significantly affect how water resources are monitored and how adaptation strategies are put in effect in this sensitive socio-economic region. This will allow for better water resources management and adaptation strategies (link to government agencies, industry, policy/decision makers, and stakeholders) due to extreme events which directly impact the society and economy of the region (link to general public).

University of Sao Paulo (USP; International Partner): USP will benefit from data-knowledge exchange and improved understanding of the use of new Cosmic-Ray Sensor (CRS) technology for hydrological studies in South America for the first time. Training provided in BEMUSED to Brazilian early-career researchers will allow the technology to be disseminated in Brazil and South America, resulting in future (multi-national) collaboration. Modeling developments and testing under BEMUSED will also benefit our partners. The adopted land surface model in BEMUSED (the Joint UK Land Environment Simulator, JULES), in its original version, is the same currently implemented in the Brazilian Regional Atmospheric System (BRAMS) mesoscale atmospheric numerical model used at USP. In addition, the BRAMS is one of the main operational models used by Brazilian National Center for Weather and Climate Studies (CPTEC) at the internationally-recognized Institute for Space Research (INPE), and used by the Center for Monitoring of Natural Disasters (CEMADEN). Hence, improvements obtained with BEMUSED pilot study can quickly reach national level impact given its relevance to both operational centers.

UK Met Office (UKMO) and Centre for Ecology and Hydrology (CEH): Model's of Earth's weather and climate require accurate fluxes (e.g., momentum, energy, water) across the land-atmosphere interface to solve the equations of atmospheric physics and dynamics. Improvements on how soil moisture is simulated by the JULES model, and its interaction with a newly implemented preferential flow and groundwater parameterizations in the model, will ultimately make significant impact on the overall JULES development strategy by UKMO and CEH, including recent efforts towards the UK Earth System Modeling capabilities. The UKMO and CEH will also benefit from a comprehensive evaluation of JULES under extreme drought conditions compared to a suite of ground-based observations from (usually) data-scarce regions.

BEMUSED PI: Of importance, the nature of this funding will ultimately impact the project PI of this proposal by ensuring the appropriate financial support to expand his research portfolio, currently established with his New Investigator grant, to catchment scale studies in South America, enhancing his international reputation and increasing his network of collaboration significantly. This will allow the PI to further establish himself as a researcher leader in the subject in future years.