Monday, 29 January 2024: 9:15 AM
328 (The Baltimore Convention Center)
Mineral dust impacts multiple Earth systems such as radiative budget, human health, and ecology. In higher latitudes, the presence of fine sediment in pro-glacial valleys and strong winds encourage dust emission when other limiting factors are absent. Many models for dust emission and transport do not utilize a fine enough resolution to capture dust emissions in characteristically steep walled proglacial valleys. Therefore, we utilized high resolution (from 0.67 to 2 km) Weather Research, and Forecasting Model (WRF) output to assess dust emission and transport in the A’ą̈y Chù (Slims River) valley, a proglacial valley in Yukon, Canada. We’ve adapted FLEXDUST, a dust emission model, to work with WRF input and use it to provide inputs for FLEXPART-WRF, a Lagrangian particle dispersion model, to assess dust transport and deposition. Furthermore, we utilized vertical dust concentration outputted by FLEXPART-WRF to estimate the radiative impacts of mineral dust over ecologically sensitive regions around Lhù’ààn Mân (Kluane Lake). Radiative impacts were estimated using libRadtran and compared to LIDAR and AERONET measurements.
This first application of FLEXDUST-WRF was tested at the study area during a large dust event from May 26th to May 29th, 2019. From these results, we identified two main emission sites: one in the upper part of the proglacial valley, and one at the mouth of the valley leading into Lhù’ààn Mân. This agrees with ground observations. We will focus on the emissions from the lower valley due to availability of field measurements for verification. Average emission in the upper valley was 2.0778·10-4 kg·m-2·day-1 over an emitting area of 1.65·107 m2 and 2.5195·10-4 kg·m-2·day-1 over an area of 9.50·106 m2 at the mouth of the valley. The majority of emissions from the lower valley were deposited around the shore of Lhù’ààn Mân, primarily in the southeast. In this study, we will summarize the process of adapting dust emission and transport models for proglacial dust sources, assess the agreement of the model with field observations, and discuss the impact of dust on the local region, and the implications for other high latitude dust sources.
This first application of FLEXDUST-WRF was tested at the study area during a large dust event from May 26th to May 29th, 2019. From these results, we identified two main emission sites: one in the upper part of the proglacial valley, and one at the mouth of the valley leading into Lhù’ààn Mân. This agrees with ground observations. We will focus on the emissions from the lower valley due to availability of field measurements for verification. Average emission in the upper valley was 2.0778·10-4 kg·m-2·day-1 over an emitting area of 1.65·107 m2 and 2.5195·10-4 kg·m-2·day-1 over an area of 9.50·106 m2 at the mouth of the valley. The majority of emissions from the lower valley were deposited around the shore of Lhù’ààn Mân, primarily in the southeast. In this study, we will summarize the process of adapting dust emission and transport models for proglacial dust sources, assess the agreement of the model with field observations, and discuss the impact of dust on the local region, and the implications for other high latitude dust sources.
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