ATS Release 1.5.1

This release fixes several minor bugs in ATS and supporting code:

1. fixes a bug in ats_xdmf.py's centroid calculation
2. fixes a bug in hydraulic redistribution in the new transpiration distribution evaluator
3. adds code to construct MeshInfo files, needed for tile drain work
4. renames rooting_depth_fraction --> root_fraction in the input spec converter from 1.4 to 1.5
5. fixes the name of the input spec converter from 1.4 to 1.5

ATS Release 1.5.0

This release contains a few significant additions in process capability in ATS:

1. A new transpiration reduction function (TRF) was added. In previous versions, transpiration was reduced in dry conditions by an empirical function that was a function of water potential (based on CLM 4.5 technical note). The downside of this method is that it ignored soil properties; in some collections of van Genuchten water retention models, the TRF would still allow transpiration when there was very little water available in the soil. This would result in very small time steps. The new model is a simpler for of including plant hydraulics, and computes a plant water potential; this model reduces transpiration in all soils as needed.
2. New capabilities were added for managed water systems, including tile drains and evaluators to map tiles to drainage ditches.
3. New relative permeability models for freezing soils were added to support Arctic hillslope simulations.
4. Preferential snow distribution was recovered -- it existed in older versions, but was not maintained and not included in the previous few releases.

Additionally, multiple bugs were fixed including in canopy evapotranspiration, and several evaluators were refactored to make them more flexible, particularly in splitting the radiation balance to be used in multiple configurations of surface energy.

ATS Release 1.4.2

This patch release fixes a bug in the aspect calculation, where NW-facing aspects got negative values.

ATS Release 1.4.1

This release fixes a bug in the Priestley-Taylor computation of evapotranspiration, introduced in 1.4, which incorrectly set ET to a high value because of a units mistake in the function for the slope of the vapor pressure curve.

ATS Release 1.4.0

ATS version 1.4.0 is a major new release, with a complete revision of significant infrastructure within Amanzi and ATS. Little physics has changed, but the underlying multiphysics infrastructure has changed substantially, so this release affects developers more than users (though input files have changed substantially as well in this release).

• The new State model in Amanzi fundamentally changes what can be stored in State.
• The new Tag system in Amanzi required a rewrite of all ATS PKs to use Tags instead of multiple copies of State to deal with time-slices, subcycling etc.
• DomainSets were completely rewritten and updated to allow PKs to work on subdomains robustly. This is particularly important for multiscale and multidimensional models (e.g. the Arctic Intermediate Scale Model, the ADELS transport model for hyporheic exchange, etc)
• A complete pass through (nearly) all PKs and Evaluators was completed, standardizing a lot of documentation, use of the input spec, use of State and Evaluators, use of Keys and Tags, and more.
• Subcycling was generalized and now works with any PK/MPC.

ATS Release 1.3.0

ATS version 1.3.0 introduces a significant number of bug fixes, more robust implementations of transport, reactive transport, and Priestley-Taylor evapotranspiration models, and salinity transport and its effects on flow. Many of these are not brand new this release, but made much more robust. This is also the first version that is well-integrated with Watershed Workflow as a tool for setting up ATS simulations.

ATS 1.2.0

This release includes major refactoring of land surface processes for enabling improved evapotranspiration models.

1. New options for "land cover types," conceptually similar to Plant Functional Types in ESM land models or to National Land Cover Indices, these allow partitioning the surface for use in various processes, typically governing evapotranspiration.
2. Updated Arctic evaporation to use this new concept, but also making evaporation in ice-rich conditions much more robust than previously. The old model is still available, and is documented in tests, but demos will migrate to the newer model.
3. Addition of a few Priestley-Taylor models, including a basic one based on PRMS (this existed previously but is improved here) and a new one allowing canopy, snow and bare ground evaporation, along with transpiration from the rooting zone.

Note that this version is the version of the code to be used in the Sept 2021 workshop training on ATS.
Also, updating release notes (no change to code) to establish DOI with Zenodo.

ATS version 1.1

This release, which parallels Amanzi release 1.1, adds significant new functionality in a variety of physics spaces. The big new capabilities include:

1. Reliable integrated (surface and subsurface) transport, including 1st and 2nd order schemes for transport, molecular diffusion, dispersion (including tensor dispersion) and more.
2. Reactive transport through the Alquimia geochemical interface, allowing access to PFloTran and Crunch reaction networks. This is coupled with transport, allowing geochemical constraints on sources and boundary conditions, linear and nonlinear sorption, and more.
3. Much-improved support for multi scale models, including subgrid models of in-stream hyporheic exchange.
4. Support for the transport of salinity, including the effects of salinity on liquid density.
5. Preliminary support for sediment transport.

This release also includes significant improvements to the documentation of existing capabilities, and improved integration of tests through continuous integration (in the ate-regression-tests repository), and added examples (in the ats-demos repository).

ATS Release 1.0.0

Release 1.0 brings together major changes that have happened from 0.88, including improved evapotranspiration models, greatly improved documentation and example problems, and ongoing work in sediment and other development areas. We're also very excited as we're ready to call the base capabilities of hydrology, freeze/thaw, and ecohydrology on watersheds mature enough to be 1.0. This release partners with Amanzi's release 1.0.

This is a big milestone for Amanzi and ATS development teams -- thank you all so much for all of your hard work!

ATS Release 0.88

This release adds new stable functionality in:

• deformation, allowing volumetric change of grid cells to allow for a deforming mesh
• subgrid parameterizations in evaporation and the surface energy balance
• fixed major issues in assumptions about energy transport with evaporative fluxes. 0.87's evaporation model should not be trusted. While 0.86 is still a supported release, 0.87 should now be considered a deprecated/legacy release and will not be supported.

Additionally, there was significant cleanup of the surface energy balance in preparation for future work (hopefully for ATS-0.89?) on transpiration in temperate environments. These did not change physics, but changed code significantly.