Past IEM Features tagged: eclipse
Eclipse Solar Radiation
20 Apr 2024 08:03 AMFor the 8 April eclipse, the ISU Soil Moisture Network put its southeastern most station (near West Point, IA) into a rapid scan mode to observe atmospheric variables at a 15 second interval. This station subsequently suffered a communications outage and did not come back online until yesterday! So with this data in hand now, a daily featured chart should at least be made. The chart focuses in on the eclipse period and attempts to address the question if the percentage of the sun covered by the moon is linear to the decrease in received solar radiation. The black line shows the 15 second observations, the red lines denote the period of the eclipse, the green line is an estimate of received radiation if the sky was clear and there was not an eclipse, the blue line is the eclipse coverage percentage, and the black dashed line represents the linear model. So while the relationship looks good and intuitive, it is not exact as the impact of received radiation is very nuanced with lots of small effects causing small variances in this linear model. If you want details on the minutia involved, ask Google Scholar.
Voting:
Good: 19
Bad: 0
Tags: eclipse
Inversion Data During Eclipse
09 Apr 2024 05:41 AMThe featured chart is from the inversion station near Crawfordsville on the ISU Southeast Farm. The plot focuses in on the period around the eclipse yesterday afternoon. The top panel traces air temperature at 1.5, 5, and 10 feet above the ground surface. The second panel differences the 10 and 1.5 foot values. The bottom panel plots wind speed and gusts at 10 foot. This beautiful plot shows what happens when the eclipse starts rapidly decreasing solar energy as the near surface temperature cools more quickly than levels further away. A temperature inversion then sets up with the 10 foot value warmer than 1.5. This period also features a decrease in wind speed as vertical mixing decreases. Once the eclipse period ends, the various data traces return to about how they were prior to the eclipse.
Voting:
Good: 15
Bad: 0
Tags: eclipse
Eclipse in weather models
08 Apr 2024 06:17 AMThe eclipse is finally at hand and hopefully you are able to see it wherever you may or may not have traveled to. While the eclipse at totality only lasts a few minutes, the shadow effects while the moon is partially blocking the sun lasts for an hour or two. The HRRR model includes special code to account for the change in received solar radiation during the eclipse. With instantaneous solar radiation output from the model at 15 minute resolution, the featured lapse nicely shows the impact of the eclipse. You may be wondering about the darkened areas already on the map. That is the effect of clouds reducing the solar radiation received at earth's surface.
Voting:
Good: 10
Bad: 0
Tags: eclipse hrrr
Eclipse Cloud Cover Forecast
07 Apr 2024 08:09 AMThe featured map is courtesy of an excellent website by Tomer Burg. The map shows a cloud cover forecast for Monday afternoon from the NWS National Blend of Models. Blue colors indicate less clouds and gray indicate more. There is still plenty of time for this forecast to change, but southern Illinois (and then adjusting on Monday as traffic allows) continues to look like the safest bet for any Iowans that are still wondering where the go. Given the consistent and poor forecast in Texas, the traffic situation seems problematic for areas to the north and east as some of those folks attempt to move in that direction. If you don't wish to leave Iowa, the far southeastern tip continues to look optimistic for being able to see a near full eclipse (~90% coverage) from that location!
Voting:
Good: 6
Bad: 0
Tags: eclipse
Decision Time
21 Aug 2017 05:39 AMYou may have heard that there will be an eclipse today and if you are still deciding on where to go, the featured map presents the latest NWS forecast for sky coverage at 1 PM. The darker areas on the map represent the lowest sky coverage (least amount of clouds). It would still seem like Nebraska is the best bet for Iowans, but caveats galore with the amount of traffic likely on the roads today and the ongoing storms this morning complicating the forecast. If you are sticking around Iowa today, clouds look to be a problem for most of the state. Whatever you do, good luck and enjoy!
Voting:
Good: 9
Bad: 0
Tags: eclipse
Eclipse Sky Coverage Forecast
18 Aug 2017 05:34 AMThere is great excitement for the full solar eclipse that will transverse the entire CONUS on Monday. The featured map presents a recent NWS forecast of sky coverage at 1 PM CDT on Monday and the path of eclipse totality. For this chart, the darker areas represent locations with fewer clouds forecasted. At this point, the best eclipse viewing would appear to be over the northwestern US. If you are looking for somewhere closer to drive from Iowa, Nebraska appears to be a better bet at this time. Suffice it to say, there has never been this much interest nor forecaster attention given to a sky coverage forecast!
Voting:
Good: 14
Bad: 1
Tags: eclipse
Great evening for an eclipse
20 May 2012 09:04 PMThe clouds cleared out in time for most Iowans to get a glimpse of the partial solar eclipse this evening. The featured image is from the ISUAg Farm webcam showing an internal webcam reflection of the eclipse of the sun. I was not expecting to get this kind of view, but will certainly take it!
Voting:
Good: 46
Bad: 11
Tags: eclipse