Changelog

fieldClim 1.2.0

Added a Bulk-Residual heat-flux workflow with sensible_bulk(), latent_bulk_residual() and turb_flux_bulk_residual().
sensible_bulk() estimates sensible heat flux from the temperature difference between two heights and a simplified aerodynamic resistance.
latent_bulk_residual() computes latent heat flux as rad_bal - soil_flux - sensible.
Added optional Richardson-number screening for Bulk-Residual via stability_method = "ri_guard".
The Richardson guard attaches bulk_Ri_g and bulk_stability attributes and returns NA for invalid, weak-shear or very stable profile cases.
The default Bulk-Residual behaviour remains the neutral, unguarded estimate with stability_method = "none".

Added energy_balance_closure() to inspect how existing heat-flux output fields relate to available energy, rad_bal - soil_flux.
For paired sensible/latent heat methods, the diagnostic reports closure_residual = rad_bal - soil_flux - sensible - latent and closure_ratio = (sensible + latent) / (rad_bal - soil_flux).
For Penman, the diagnostic reports unresolved_complement = rad_bal - soil_flux - latent_penman; this complement is not a paired sensible heat flux.
Monin-Obukhov/Profile residuals are reported as diagnostic differences and are not treated as automatic errors or forced to close the balance.
Added plot_energy_balance_closure() to plot diagnostic residuals, Penman unresolved complements and closure ratios. Formal closure is not presented as physical validation.
Clarified Bulk-Residual documentation: the sensible-heat estimate may use mean-wind, profile-derived friction velocity, or roughness-derived friction velocity, while latent heat remains a residual closure term.

Corrected the Penman vapour-pressure-deficit term by converting saturation and actual vapour pressure from hPa to kPa before use.
This fixes a unit mismatch in latent_penman() and can substantially change Penman latent-heat estimates.
Aerodynamic-resistance handling in latent_penman() is now elementwise; invalid log arguments, invalid wind and non-finite aerodynamic states return NA with a warning.
latent_penman.weather_station() now uses hum1 when available and falls back to rh; missing humidity input produces an explicit failure instead of an unclear downstream error.

Sensible and latent Bowen paths now use the same guarded denominator logic for 1 + beta.
Finite, uncapped Bowen cases still close the available energy rad_bal - soil_flux.
Non-finite Bowen ratios or non-finite denominators now return NA elementwise with warnings.
Near-singular capped cases are treated as guarded outputs and are not interpreted as exact energy-balance closure.
The exported Bowen implementation remains the documented fieldClim beta path based on gamma_code * dpot / dah.

Corrected sensible_monin() to use the documented vertical gradient denominator z2 - z1 instead of log(z2 - z1).
sensible_monin() and latent_monin() now return controlled values for critical profile cases: zero temperature gradient gives zero sensible heat flux, and zero moisture gradient gives zero latent heat flux.
Invalid heights, invalid wind input, weak shear and non-finite profile states return NA with warnings.
Monin-Obukhov/Profile outputs remain profile-based estimates. They are not forced to close rad_bal - soil_flux.

Priestley-Taylor sensible and latent heat formulas remain unchanged.
Warning checks were made more robust for vectors containing NA.
Documentation now clarifies the package implementation and sign convention for Priestley-Taylor outputs.

sol_hour_angle() and sol_azimuth() now handle POSIXct and POSIXlt datetime inputs consistently.
trans_air_mass_rel() now returns NA with a warning for non-positive or invalid solar elevation instead of leaking NaN.
Valid positive-elevation transmittance calculations keep the previous formula.
Radiation-balance formulas were not changed in this release.

soil_heat_flux() now returns NA with a warning for invalid depth pairs, including non-finite, negative or equal depths.
Valid soil_heat_flux() calculations keep the existing sign convention: positive soil_flux means heat flux into the soil.
Corrected soil_attenuation() to call soil_thermal_cond(texture, moisture) in the documented argument order.

hum_precipitable_water() now handles POSIXct input safely by converting internally to POSIXlt before extracting month information.
This fixes failures in the rad_sw_in() -> trans_vapor() -> hum_precipitable_water() path when datetime input is POSIXct.
Existing POSIXlt input remains supported.

turb_flux_calc() now includes Bulk-Residual outputs in the full workflow.
Added pt_only = TRUE to compute only the Priestley-Taylor sensible and latent heat fluxes for a restricted workflow.
Penman failures inside turb_flux_calc() are now caught and represented as NA output instead of stopping the whole workflow.
as.data.frame.weather_station() is more robust for objects without a $measurements field.

Removed/disabled weather-station missing-data completion behavior from the package API. fieldClim no longer creates replacement time-series columns or performs internal gap treatment.
inspect_weather_station_inputs() remains as a read-only inspection and quality-control helper. It reports missingness, gap runs, variable classes, selected QC flags and heat-flux method input availability.
Missing-data treatment must be performed outside fieldClim with documented provenance; package heat-flux methods continue to require their actual measured/input fields.

Roxygen documentation was updated for formulas, units, sign conventions, examples, source references and guard behaviour.
The documentation now separates energy-balance-closing methods from profile-based estimates and latent-heat-only paths.
Help pages and vignettes document the method-family context and package implementation choices. Remaining scientific validation should be added through benchmark datasets, published numerical examples and explicit table-value audits where needed.

Added method equation-contract tests for radiation balance, soil heat flux, Priestley-Taylor, Bulk-Residual, Bowen, Penman and Monin-Obukhov/Profile equations.
Added helper equation-contract tests for documented humidity, pressure, temperature, boundary-layer and turbulent-flux helper equations.
Added weather_station API parity tests for direct calls versus weather_station methods.
Added workflow tests for turb_flux_calc() including pt_only, full workflow output, Penman fallback and Bulk-Residual Richardson-guard pass-through.
Current validation status: devtools::test(): 812 passed, 4 intentional skips devtools::check(): 0 errors, 0 warnings, 0 notes