► Nocturnal subcanopy flow regimes are observed beneath a tall forest canopy. ► Missing carbon dioxide is coincident with decoupled downslope flow. ► The inferred advection terms often dominate the carbon dioxide budget.
► Major impacts of decadal climate variability on hydro-meteorology in Missouri River Basin (MRB). ► Major impacts of decadal climate variability (DCV) on yields of corn, and spring and winter wheat. ► Potentially dramatic, combined effects of DCV phenomena on agricultural production in the MRB. ► Perhaps the first study of modeling DCV impacts on crop yields in the world.
► Multivariate statistical monitoring approach to estimate ETowhen no local climatic inputs are available. ► Principal components analysis (PCA) useful tool to characterize similarities among weather stations. ► Four principal components are enough to describe systematic variability of ETodata. ► PC regression approach allows EToestimations using geographical inputs with AARE around 10%.
► Monthly estimation of CO2sources of soil respiration was conducted using bomb-14C signatures. ► We observed large differences in seasonal patterns among sources of soil respiration. ► SOC decomposition was the most responsive to a rise in soil temperature. ► Autotrophic respiration appeared to correlate strongly with vegetation phenology.
Digital repeat photography for phenological research in forest ecosystemsOriginal Research Article Agricultural and Forest Meteorology, Volume 152, 15 January 2012, Pages 159-177 Oliver Sonnentag, Koen Hufkens, Cory Teshera-Sterne, Adam M. Young, Mark Friedl, Bobby H. Braswell, Thomas Milliman, John O’Keefe, Andrew D. Richardson
Highlights
► The green chromatic coordinate (gcc) suppresses changes in scene illumination. ► We proposeper90to further minimize these effects in time series ofgcc. ► Digital camera and file format choice are not critical for phenological research. ► Comparison of different cameras is limited to the timing of key phenological events.
► Data quality and energy balance tests show that eddy covariance can be used in ‘belt and alley’ landscapes. ► Inclusion of tree belts in farming systems increases carbon sequestration. ► Inclusion of tree belts in farming systems increases water use, potentially reducing the risk of dryland salinity.
► Martian valley network formation timescales constrain early atmospheric conditions. ► Formation timescales of large Martian valley networks range from 105to 107yr. ► These networks require longer durations of precipitation than impacts can provide. ► Valley-forming precipitation was limited to the Late Noachian/Early Hesperian.
Crop science experiments designed to inform crop modelingOriginal Research Article Agricultural and Forest Meteorology, Available online 28 September 2011 Peter Q. Craufurd, Vincent Vadez, S.V. Krishna Jagadish, P.V. Vara Prasad, M. Zaman-Allah
Highlights
► Development, heat tolerance and transpiration are key processes for crop models. ► We describe types of experiments used to understand and quantify these processes. ► Transfer experiments are used to define sensitive stages of development to stresses. ► Mini-lysimeter experiments quantify transpiration and key thresholds for water use. ► More investment in physiology for phenotyping is required for modeling.
► Hydrophobic annatto dye was intercalated in alkyl trimethylammonium montmorillonite. ► The intercalated annatto dye showed enhanced stability against visible light. ► Using ethanol–water mixtures in the adsorption process increased the dye adsorbed.
► We use multi-spectral retrievals to retrieve lowermost tropospheric ozone. ► Simulations are performed for 16 cloud- and aerosol free atmospheric profiles. ► Combination of visible (VIS) and ultraviolet (UV) measurements has good sensitivity to lowermost tropospheric ozone. ► Combination of UV and thermal infrared (TIR) measurements significantly improves total and lowermost tropospheric degrees of freedom for signal (DFS).
► Particle in-situ pH could be estimated by a single linear regression equation of two parameters. ► In-situ pH estimation indicates fine particles are highly acidic in Hong Kong. ► The diurnal variation in relative humidity could drive
► Maximum precipitation accumulated in the left side of the MALA cyclone. ► Turbulent, diapycnal mixing play role in sea-surface cooling and deepening of MLD. ► High enthalpy occur on the right side of the track of MALA cyclone.
► We examine the reliability of two surface renewal methods to estimate sensible heat flux. Input requirements are contrasting. ► The apparent advantages (simplicity and affordability) attributed to one method were not clear. ► Significant differences were found in terms of robustness and reliability which are mandatory for method selection.
► Unheated greenhouses in mild winter areas suffer winter microclimate limitations. ► Three soil surface treatments: non-mulched (NM), transparent (TM) and black (BM) mulch. ► Soil heat flux, ground net radiation and air and soil temperatures were highest in BM. ► Greenhouse ventilation reduced negatively the benefits of plastic mulching. ► BM+greenhouse was a simple and low-cost passive heating system in winter.
► Eddy covariance flux measurements of stable CO2isotopologues over a forest canopy. ►18O discrimination is reduced after rain events reflecting18O exchange with water. ► The low signal-to-noise ratio makes EC isotopologue flux measurements challenging. ► Inherent noise from EC method rather than the instrument precision is the limiting factor.
