This study evaluates the impact of land surface models (LSMs) and urban heterogeneity [using local climate zones (LCZs)] on air temperature simulated by the Weather Research and Forecasting model (WRF) during a regional extreme event. We simulated the 2017 heatwave over Europe considering four scenarios, using WRF coupled with two LSMs (i.e., Noah and Noah‐MP) with default land use/land cover (LULC) and with LCZs from the World Urban Database and Access Portal Tools (WUDAPT). The results showed that implementing the LCZs significantly improves the WRF simulations of the daily temperature regardless of the LSMs. Implementing the LCZs altered the surface energy balance partitioning in the simulations (i.e., the sensible heat flux was reduced and latent heat flux was increased) primarily due to a higher vegetation feedback in the LCZs. The changes in the surface flux translated into an increase in the simulated 2‐m relative humidity and 10‐m wind speed as well as changed air temperature within cities section and generated a temperature gradient that affected the temperatures beyond the urban regions. Despite these changes, the factor separation analysis indicated that the impact of LSM selection was more significant than the inclusion of LCZs. Interestingly, the lowest bias in temperature simulations was achieved when WRF was coupled with the Noah as the LSM and used WUDAPT as the LULC/urban representation.
Technical note: AQMEII4 Activity 1: evaluation of wet and dry deposition schemes as an integral part of regional-scale air quality models
Abstract. We present in this technical note the research protocol for phase 4 of theAir Quality Model Evaluation International Initiative (AQMEII4). Thisresearch initiative is divided into two activities, collectively having threegoals: (i) to define the current state of the science with respect torepresentations of wet and especially dry deposition in regional models,(ii) to quantify the extent to which different dry depositionparameterizations influence retrospective air pollutant concentration andflux predictions, and (iii) to identify, through the use of a common set ofdetailed diagnostics, sensitivity simulations, model evaluation, andreduction of input uncertainty, the specific causes for the current range ofthese predictions. Activity 1 is dedicated to the diagnostic evaluation ofwet and dry deposition processes in regional air quality models (describedin this paper), and Activity 2 to the evaluation of dry deposition pointmodels against ozone flux measurements at multiple towers with multiyearobservations (to be described in future submissions as part of the specialissue on AQMEII4). The scope of this paper is to present the scientificprotocols for Activity 1, as well as to summarize the technical informationassociated with the different dry deposition approaches used by theparticipating research groups of AQMEII4. In addition to describing allcommon aspects and data used for this multi-model evaluation activity, mostimportantly, we present the strategy devised to allow a common process-levelcomparison of dry deposition obtained from models using sometimes verydifferent dry deposition schemes. The strategy is based on adding detaileddiagnostics to the algorithms used in the dry deposition modules of existingregional air quality models, in particular archiving diagnostics specific to land use–land cover(LULC) and creating standardized LULC categories tofacilitate cross-comparison of LULC-specific dry deposition parameters andprocesses, as well as archiving effective conductance and effective flux asmeans for comparing the relative influence of different pathways towards thenet or total dry deposition. This new approach, along with an analysis ofprecipitation and wet deposition fields, will provide an unprecedentedprocess-oriented comparison of deposition in regional air quality models.Examples of how specific dry deposition schemes used in participating modelshave been reduced to the common set of comparable diagnostics defined forAQMEII4 are also presented.
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- Award ID(s):
- 1848372
- PAR ID:
- 10336337
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Date Published:
- Journal Name:
- Atmospheric Chemistry and Physics
- Volume:
- 21
- Issue:
- 20
- ISSN:
- 1680-7324
- Page Range / eLocation ID:
- 15663 to 15697
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/acp-21-15663-2021
