Today was pretty rough. Most of the time we spent at the beach was characterised by intermediate rain alternated by a few heavy showers, and a fairly strong and persistent SSW-wind. The first things we noticed when entering the beach were the remarkable alternating patches of dark moist and light coloured dry sand. Aeolian saltation was abundant even during these wet conditions, probably due to the large fetch length as a consequence of the alongshore directed wind. There was absolutely no reason not to deploy our SalDecS (Saltation Detection Systems)! At least, that is what we thought.
In the end, we had deployed two SalDecS, one on the - in the meantime almost entirely merged -sandbar and the other a bit higher up the beach. It was just after we had finished installing all equipment that we realised it was not feasible to keep the sensor elements free from dirt for a decent amount of time, as the wet conditions greatly enhanced the cohesiveness of the sand. We could only hope for the sensor elements to detect most of the impacting grains and collect as much data as possible. Fortunately, once back at our base camp - at first sight - they appeared to have done just that. In fact, the only disappointment was that the record of one small sensor array of one of the SalDecS could not be found back on the memory card. Perhaps this error was due to a wrongly connected wire during the measuring period.
Besides recording sand spray intensities, we also measured the soil moisture on the sandbar in both streamwise and spanwise direction with respect to the SalDecS. This was done with the idea of obtaining a two-dimensional record of the drying of the top sand layer. Normally, we would also have placed sand catchers near each SalDecS, but these do not work properly together with (intense) rainfall.
In the days to come, we will try to collect as much data on aeolian streamers as possible, as the right weather conditions prove to be scarce and time is slowly running out!
- JWB
In the end, we had deployed two SalDecS, one on the - in the meantime almost entirely merged -sandbar and the other a bit higher up the beach. It was just after we had finished installing all equipment that we realised it was not feasible to keep the sensor elements free from dirt for a decent amount of time, as the wet conditions greatly enhanced the cohesiveness of the sand. We could only hope for the sensor elements to detect most of the impacting grains and collect as much data as possible. Fortunately, once back at our base camp - at first sight - they appeared to have done just that. In fact, the only disappointment was that the record of one small sensor array of one of the SalDecS could not be found back on the memory card. Perhaps this error was due to a wrongly connected wire during the measuring period.
Besides recording sand spray intensities, we also measured the soil moisture on the sandbar in both streamwise and spanwise direction with respect to the SalDecS. This was done with the idea of obtaining a two-dimensional record of the drying of the top sand layer. Normally, we would also have placed sand catchers near each SalDecS, but these do not work properly together with (intense) rainfall.
In the days to come, we will try to collect as much data on aeolian streamers as possible, as the right weather conditions prove to be scarce and time is slowly running out!
- JWB