Hawaiian volcano inspired vocabulary

Here is a fun video about how Hawaiian volcanoes have affected our vocabulary.

A very bad week for vog

For the past few days the trade winds have failed to clear the air. The air in Kona is in the Orange range, while Waikoloa is not faring much better. On the bright side, this is typical Kona vog, high in PM2.5 but low in SO2. The weak trade winds should continue for a few days more.

The trade winds normally come from a high pressure system to the northeast of Hawaii. But three low pressure systems to the east are pulling the trade winds away from Hawaii. This is a unusual situation and we can hope for better conditions while we are on the Big Island in July.

The wind map below came from Earth Nullschool.

How to predict Vog for the Big Island

During a volcanic eruption, the vog on the Big Island is primarily determined by the direction of the wind. If you can visualize the overall wind patterns for the island, you can see the wind passing over the volcanic emission and where it will go on the island. A tool which allows you to see future wind patterns, will allow you to predict the vog in your area. There is such a tool on the web called Windy.com.

The wind typically blow from the east. When it hits the Big Island eastern point, the wind splits into a northern stream and a southern stream. The southern steam will pass over the volcanic eruptions and typically carry the emission out to sea, while the northern stream stays clean. Both streams may wrap back toward the west coast once they get around the island. The vog at any point along the west coast will be determined by which stream dominates at a certain time and place.

Waikoloa is on the northern part of the west coast will typically get the good air from the northern stream. But changing wind patterns may allow the vog from the southern stream to reach Waikoloa. When there is vog at Waikoloa, it will be just in the Yellow range, even if the vog further south is in the Orange or Red range.

How to find the AQI of Waikoloa

If you googled AQI for Waikoloa, you may get to the Weather Underground for Waikoloa webpage. It will show you an AQI for PM2.5 and claims its source is EPA AirNow. If you go to the AirNow for Hawaii webpage, you will see that there are only five AQI PM2.5 monitoring stations on the Big Island. The closest station to Waikoloa is Kona. You will see that the Weather Underground AQI for Waikoloa is identical to the AirNow AQI for Kona. So when you google the AQI for Waikoloa, you are actually getting the AQI for Kona.

Under normal wind conditions, the emissions from Kilauea are blown south out to sea but wrap around to the southwest coast. The AQI for PM2.5 on the southwest coast is typically worst that the rest of the island, even for places closer to Kilauea. Waikoloa is on the the northwest coast, 27 miles north of Kona, and should have better air quality, but there are no EPA stations above Kona to confirm this.

However, there is a private AQI network, called Purple Air which sells cheap PM2.5 monitors and makes the readings from their customers available on the internet. There are several Purple Air monitors spread across the island, one in Waikoloa and many around Kona. The readings from the Kona monitors show that the Purple Air monitors are consistent among themselves. When the Kona monitors are compared to the Waikoloa monitor, it shows that the air in Waikoloa is much better than in Kona on a day with typical trade winds. But on days that the trade winds fail, the AQI readings in Waikoloa is about the same as in Kona. The reading below was taken on 6/10/18 had typical trade winds.

Note that the Purple Air monitor in near to the AirNow Kona station does not agree with the official AQI reading. Also the Purple Air monitor in Waikoloa sometimes behave erratically.

How reliable are the trade winds

The trade winds died down starting Monday. For two days, there were intervals of high SO2 levels around the island. But today the trade winds returned and cleared the air by blowing the SO2 out to sea. Since the eruptions started 27 days ago, there have been only three days that the trade winds failed to clear the air from most of the island, May 17, 28 and 29.

The reliability of the trade winds varies with each month. As it turns out the most reliable month is July, the time of our reunion. If we get unlucky and the trade winds fail while we are there, we can expect the trade winds to return within a day or two.

Keep in mind that the SO2 does not mix evenly in the air. Bad air comes in pockets and last in an area for about an hour. For example, Hilo received no more than 75 minutes of SO2 in the Orange range on each of its three bad air days.

For where we are staying on the Kona side, the loss of trade winds means that SO2 can take a direct route across the island. But it is still over twice the distance to Hilo. The worst SO2 event in Kona was a 30 minute interval on May 28 of SO2 in the Yellow range. Remember that there is still a PM2.5 vog problem in Kona which was discuss in previous blog posts. In Kona, if the SO2 quality is in the Yellow range, then the PM2.5 quality could be in the Red range, unhealthy but not dangerous. So pollution masks should help.

One final thing, the trade winds are predicted several days in advance. The start and duration of bad air days are part of the weather forecast. The possible loss of trade winds should not be a concern for our trip.

Will masks help with vog

From the very start of the eruptions, the media has warned the public that masks would not work for SO2 gas. THIS report from CNN is typical. The gist of the article is, "the Hawaii Department of Health says no commercial mask sold in stores would actually do residents any good".

This is obviously not completely true since we see emergency workers using face masks with filter cartridges. These masks can be bought on Amazon for about $30. So certainly some commercially available masks will work.

What they meant by "store masks" was probably simple dust masks or surgical masks. These types of mask will not work on SO2 or PM2.5 sulfates. But what about high quality dust masks designed for heavy urban pollution? These types of masks do not work on gas, but do filter the PM2.5 particles which are the primary component of the kind of vog in Kona.

The Hawaii DOH advisory was intended for residents near the eruptions where gaseous SO2 is still present. For areas, like Kona, far away from the eruption, the vog was not considered bad enough to consider a mask. However, the advisory did not include people with breathing problems that might have trouble with the moderate level of vog found in Kona during the eruptions. Pollution masks that can filter PM2.5 should help.

Good pollution masks are certified by the National Institute for Occupational Safety and Health, NIOSH, as N95 or N99. Several brands of NIOSH certified masks are sold on Amazon. N95 masks filter 95% of particles larger that 0.3 um, while N99 filters 99%. PM2.5 are particles smaller than 2.5 um, so there may still be some particles smaller than 0.3 um. These masks may not be completely effective in very high levels of PM2.5. We do not expect dangerously high levels of PM2.5 in Kona.

"Kona" refers the city of Kailua Kona or the region nearby, which could include Waikoloa if the term is used broadly. The Kona air quality monitor is in Kealakekua, which is nine mile south of Kailua Kona. Our condo in Waikoloa is 27 miles north of Kealakekua, so the air there should be better that the Kona AQI readings.

Hula at Pahoa

Pahoa is a small town just a couple of mile away from the lava eruptions in Leilani Estates. Yet it is considered safe since it is off the rift where fissures might form, upslope from the lava flow, and upwind from the SO2 gas emissions. Here is a heartwarming video of Pahoa Elementary School's late celebration of May Day with hula dancing.