The North Dakota Agricultural Weather Network (NDAWN) provides current weather data, climatological records, and is the backbone of growth and development models in North Dakota and Northwest Minnesota. This, for example, includes the orange wheat blossom midge emergence model and the small grains disease development risk models. This summer a new tool is being added to the suite of NDAWN applications, namely a temperature inversion alert.
Inversions are areas of the atmosphere where temperature increases with height. This stable air mass results in low wind speeds and horizontal flow. When spray droplets are dispersed in this environment, the smallest drops may not make it to the ground and can end up floating for long distances before settling in an entirely different area, including someone else’s field.
This meteorological phenomenon can be a headache when applying pesticides. in particular herbicides. Even though many of you are aware of the existence of inversions, it is not that easy to determine if they are happening.
After nearly a year of testing, NDAWN has begun installing their inversion instrumentation across the NDAWN network. Currently the Fargo, Carrington and Langdon NDAWN sites are equipped to detect temperature inversions, with six more being added later this year. The instrumentation consist of tall pole with thermometers mounted at approximately ground level, 3 and 18 ft. The difference in temperatures will allow inversions to be recognized, and the corresponding data will then be instantly published on the NDAWN website.
To access, users should go to the “NDAWN Center” page and click on the “Show tower measurements” checkbox. Users will have access to the temperatures and be notified with a red number and “!” symbolizing that an inversion is in place and they should act appropriately. The network’s real-time data stream will allow users access to these updates every five minutes.
Although the system can identify an temperature inversions at the NDAWN station your conditions in your field may differ. This information is a decision-support tool and you need to evaluate local conditions in your field to ensure that you can apply the pesticides safely and according to the label directions.