Abstract

Interactions of reactive nitrogen (Nr) compounds between the atmosphere and the earth's surface play a key role in atmospheric chemistry and in understanding nutrient cycling of terrestrial ecosystems. While continuous observations of inert greenhouse gases through micrometeorological flux measurements have become a common procedure, information about temporal dynamics and longer-term budgets of Nr compounds is still extremely limited. Within the framework of the research projects NITROSPHERE and FORESTFLUX, field campaigns were carried out to investigate the biosphere-atmosphere exchange of selected Nr compounds over different land surfaces. The aim of the campaigns was to test and establish novel measurement techniques in eddy-covariance setups for continuous determination of surface fluxes of ammonia (NH3) and total reactive nitrogen (∑Nr) using two different analytical devices. While high-frequency measurements of NH3 were conducted with a quantum cascade laser (QCL) absorption spectrometer, a custom-built converter called Total Reactive Atmospheric Nitrogen Converter (TRANC) connected and operated upstream of a chemiluminescence detector (CLD) was used for the measurement of ∑Nr. As high-resolution data of Nr surface-atmosphere exchange are still scarce, but highly desired for testing and validating local inferential and larger scale models, we provide access to campaign data including concentrations, fluxes, and ancillary measurements of meteorological parameters. Campaigns (n = 4) were carried out in natural (forest) and semi-natural (peatland) ecosystem types. The published datasets stress the importance of recent advancements in laser spectrometry and help improve our understanding of the temporal variability of surface-atmosphere exchange in different ecosystems, thereby providing validation opportunities for inferential models simulating the exchange of reactive nitrogen. The dataset has been placed in the Zenodo repository (http://doi.org/10.5281/zenodo.4513854; Brümmer et al., 2021) and contains individual data files for each campaign.

Highlights

  • 30 The term ‘reactive nitrogen’ (Nr) describes all forms of nitrogen that are biologically, photochemically, and radiatively active

  • Both quantum cascade laser (QCL) inlet box and Total Reactive Atmospheric Nitrogen Converter (TRANC) were mounted on a separate boom at the north side of the anemometer, which was in all cases an infrequent (

  • A common approach for gap filling is the usage of statistical methods such as Look-Up Tables (LUT), Mean Diurnal Variation (MDV), or Non-Linear Regression (NLR) (Falge et al, 2001)

Read more

Summary

Introduction

30 The term ‘reactive nitrogen’ (Nr) describes all forms of nitrogen that are biologically, photochemically, and radiatively active. Land surface-atmosphere schemes (Massad et al, 2010; Wichink Kruit et al, 2010) can either be applied in local scale studies (e.g., Schrader et al, 2016) or within the framework of chemical transport models such as DEPAC (DEPosition of Acidifying Compounds) (Erisman et al, 1994) within LOTOS-EUROS (LOng Term Ozone Simulation – EURopean Operational Smog) (van Zanten et al, 2010; Manders et al, 2017) Outputs of these models help understand ecosystem functioning and can further be used for gap filling in order to compile total nitrogen budgets, which form the basis of national inventories of air pollutants and their assessment reports.

Bourtanger Moor site (WET)
Bavarian Forest site (FOR)
TRANC – Total Reactive Atmospheric Nitrogen Converter
QCL – Quantum Cascade Laser Spectrometer
Passive samplers
DELTA denuder and filter samplers
Instrumentation for meteorological measurements
Acquisition and flux calculation
High-frequency damping corrections
Gap filling
Model-based gap-filling (FOR- Nr only)
Dry deposition inferential modelling (WET-NH3 only)
Uncertainty estimation
Potential applications
Conclusions and outlook
Findings
FOR NH3
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.