The Demise of The West Antarctic Ice Sheet

On Wednesday, the New York times came out with an alarming article. It said that a new, high-resolution model was showing that the West Antarctic Ice Sheet (WAIS), a massive ice sheet west of the "Transantarctic Mountains" that divides the continent into eastern and western sections, could melt far faster than previously thought, with sea levels rising as much as 6 feet by the end of the century. This is twice as high as what other models, such as those used in the reports given by the Intergovernmental Panel on Climate Change, were showing for a similar emissions scenario.

I am always skeptical of these types of articles. New York Times likely wouldn't publish a story like this if sea-level rise with this new model was a meter or less. That's simply not an exciting story to write. And the problem with publishing these types of articles is that it gives the impression to the public that a significant portion of the scientific community believes that the sea level could rise higher than Russell Wilson by the end of the century when, in reality, this is just one study in a field where a lot of uncertainty currently exists.

Credit: NASA

I minored in oceanography at the University of Washington and was pondering double majoring in it and atmospheric sciences, but I ultimately decided to simply go for the atmospheric sciences major because doing both of these wonderful majors would require me to stay at the UW for two additional years. Still, I took plenty of oceanography classes, and in multiple classes, my professors stressed the importance of the WAIS in deciding how much our sea-level could rise by the end of the century. 

Like many glaciers and ice caps around the world, the WAIS has been shrinking since the end of the "Little Ice Age," and global warming has accelerated this process. However, there is a lot of uncertainty as to how the WAIS will react to warming in the future. This is because large parts of Antarctica, including much of the WAIS, actually lie below sea level due to the massive weight of the ice above the continent weighing it down in a process known as isostatic depression.

Subglacial topography and bathymetry of Antarctica.
Credit: Paul V. Heinrich

As the picture above shows, land generally slopes downward as you go inland in West Antarctica due to isostatic depression. In fact, some inland areas are actually over a mile below sea level. Because of this unique feature, the ice sheet is unstable, meaning that even a little bit of a retreat of the WAIS could start a destabilization process that would lead to a collapse of the WAIS. Our current computer models do not have the capabilities to simulate this process, and significant uncertainty in the scientific community exists as to how quickly the WAIS will continue to melt, and if there ever will be a catastrophic collapse of a large section of the ice sheet.

As such, sea-level rise estimates span a pretty darn wide range, even for given "emissions forecasts" looking into the future. As shown below, there is a degree of overlap between the sea level rise with RCP 8.5 (the high-emissions scenario) and RCP 2.6 (the low-emissions scenario), suggesting that there is considerable uncertainty in how much the sea level will rise over the next century. And much of this uncertainty has to do with our poor handle on how the WAIS will behave in the future.

Credit: IPCC 5th Assessment Report

The New York Times article was based on this study on the "Contribution of Antarctica to past and future sea-level rise recently published in Nature. In the study, scientists showcased the results of a new, high resolution model that attempted to correctly model the response of the WAIS to subtle shifts in temperature. With this model, scientists were able to correctly reproduce the sea levels around 125,000 years ago, which are estimated to have been between 20 and 30 feet higher than today. Once they modeled this correctly, they used this model to forecast how the sea level would change in the future. According to the study, Antarctica alone has the potential to contribute one meter of sea-level rise by 2100 and over 15 meters (50 feet!) by 2500 if we continue to pump greenhouse gases into the atmosphere at the current rate.

Credit: Deconto and Pollard, 2016

Even more startling is the predicted rate of sea-level-rise. Since 1950, the sea level has been rising at about an inch per decade. Under the high-emissions (RCP 8.5) scenario, this new Antarctic model predicts that sea levels could rise as much as a foot per decade by the middle of the 22nd century. This would have tremendous impacts around the world, and while many large cities such as Miami, New Orleans, and New York City would be able to adapt to the increasing sea levels, it would be cost-prohibitive to build a seawall around the entire United States to protect all coastal areas from flooding. Donald Trump likes walls, but I believe our biggest threat in the future is from the ocean, not from our neighbors to the south. Developing countries would have an even harder time adapting.

Even though this all sounds very scary, it is important to remember that this is just one study. It is a very important study because it offers new insight into the fate of the WAIS, but in the coming years, more accurate, higher resolution models will be created, and we'll see if they come to similar conclusions. One thing is for sure - we need to decrease our CO2 emissions immediately, because we are just digging ourselves into a deeper and deeper hole. Honestly, when you consider the impact on future generations, I think it is quite selfish of us to be as lackadaisical as we have been. Global warming can't be avoided, but it can be mitigated. 

My challenge to you is to think about one thing you could do every day that would reduce your carbon footprint. Maybe it's taking the bus instead of driving to that doctor's appointment, or maybe it's wearing a sweater in the winter and turning down the thermostat a bit. Maybe it's simply going for a walk instead of watching TV, or maybe it is educating other people about climate change, ocean acidification, and sea level rise. Although our individual impacts on Earth's climate are negligible, we are having a profound impact on the Earth as a whole, so if we could all just work together to try and decrease that impact, that would be awesome.

Thanks for reading!!!

Charlie

Beautiful Week Ahead!

I had meant to get to this earlier, but then a funnel cloud occurred over Mill Creek and I had to write about that. Believe it or not, there are people who prefer stormy days with funnel clouds to beautiful, clear, warm sunny days, and I belong to that unique group. However, I'm a big fan of sun as well. In the words of John Ruskin, "there is no such thing as bad weather, only different kinds of good weather," so let's talk about the good weather ahead.

Well, on second thought, let's just talk about the good weather now. It is calm as can be on Lake Washington as I look outside my window, and the only clouds I see are some harmless cirrus clouds. Mt. St. Helens is always spectacular, but right now it is downright gorgeous. I'd love to hit the slopes of the Cascade volcanoes sometime.

Credit: US Forest Service

Right now, we have a HUGE ridge of high pressure over us. Those of you who read my blog regularly know how much I love the satellite images from the MODIS instruments aboard the AQUA and TERRA polar-orbiting satellites, so I'll post one here showing how clear it is over the West Coast. Even if you have no idea what the last sentence just meant, I'm sure you'll understand the picture.

High pressure over our area as seen from NASA's TERRA Satellite. Credit: NASA

Yeah, it's clear. By the way, that diagonal line you see simply shows the boundary of one passage around the pole of this satellite. The satellites that we usually use for meteorology are called "geostationary" satellites and are very useful because they orbit the Earth at the same velocity that the Earth is rotating, so they always stay above a single point on the equator. This allows them to get continuous shots of nearly every place on the globe. However, in order to be geostationary, they must be about 22,326 miles above sea level. Polar orbiting satellites do not have the advantage of remaining stationary over a single point, but they are only several hundred miles above the planet and can thus get much higher-resolution images.

The weather models show this too - the current UW flagship WRF-GFS model shows a massive ridge of high pressure over the Eastern Pacific.

Valid 05:00 pm PDT, Wed 30 Mar 2016 - 12hr Fcst
Credit: University of Washington Atmospheric Sciences

 

Also, notice how there are areas of low pressure on either side of the high - this pattern is known as an "omega block" because the flow resembles the Greek Letter omega - and it is a very hard pattern to break.

Idealized Omega Block
Credit: University Corporation for Atmospheric Research

This omega block will live up to its reputation, and won't go anywhere for the remainder of the week. 24 hours from now, the omega block has hardly moved at all.

Valid 05:00 pm PDT, Thu 31 Mar 2016 - 36hr Fcst
Credit: University of Washington Atmospheric Sciences

I don't think we'll be breaking any records, but highs on Thursday and Friday have a good chance of breaking the 70-degree mark for many areas in Western Washington, especially Friday. We "cool down" to the low 60s for the weekend, still well above our average high of 56, and turn rainy by next week. Still, we do not look stormy by any means. Spring arrived a little late this year, but I think it's safe to say that it is finally here.

Get outside, and don't forget to wear sunscreen!

Cheers,
Charlie

Funnel Cloud Over Mill Creek!

Credit: NASA AQUA Satellite, ~2pm on Easter Sunday, March 27, 2016

Yesterday was definitely a crazy day for weather! For much of the day, a pretty strong Puget Sound Convergence Zone set up shop in the Northern and Central Puget Sound regions, waxing and waning in intensity and shifting northward and southward as the day went on. The convergence zone ventured further south than usual, actually making it south of Seattle at times. The above satellite picture not only shows a well-defined convergence zone but also shows clearing to the north and south of the zone due to sinking air on either side of it, and lots of scattered clouds (popcorn) offshore denoting little showers and indicating an unstable atmosphere. An unstable atmosphere means there is a large decrease in temperature with height, and as Mother Nature would have it, Sea-Tac had a high of 55 yesterday while Snoqualmie Pass has picked up 8 inches of snow in the last 24 hours. There's still a ton of snow up there, go and get it before it all melts away by the end of this week (but that's for another blog).

Credit: Travis Miller

In addition to bringing gobs of snow to Stevens and Snoqualmie Passes, yesterday's convergence zone actually brought a funnel cloud to Mill Creek! Interestingly enough, funnel clouds are not all that uncommon with strong convergence zones. However, these are called "cold core" funnel clouds and are due to localized areas of circulation due to wind shear within the convergence zone. They are NOT like the funnel clouds and tornadoes common in the Great Plains, which are formed from supercell thunderstorms and are much larger and stronger. For comparison, take a look at the F5 tornado below from Manitoba. Yup, even Canadians get tornadoes!

Category F5 tornado approaching Elie, Manitoba on June 22, 2007
Retrieved from Wikipedia

Huge difference. Even so, even our little cold-core funnel clouds can become tornadoes, and when they do, they can cause quite a bit of destruction.

Supercells are large, severe thunderstorms with a rotating updraft, or mesocyclone. The mesocyclone forms when wind shear caused by relatively light winds at the surface and strong winds aloft creates a spinning vortex of air, and then strong updrafts tilt this updraft so that it is vertical. Both these pictures were taken from a powerpoint presentation I saved from my atmospheric sciences 452 (advanced synoptic meteorology and forecasting lab) class at the UW, and the credit goes to Nick Bond.

The difference in wind strength in the vertical can be quite high, especially in areas near the surface that are sheltered from the wind. I remember one time in December 2007 (the "Great Coastal Gale," to be exact), when winds around a mile up were an astounding 100 knots, while winds away from the immediate coast weren't even at advisory levels. The coast was a different story, and this was arguably the strongest storm on record for some parts of northwest Oregon and southwest Washington - even surpassing the Columbus Day storm!

While supercells get their rotation from differences in wind strength in the vertical, our tiny cold-core funnel clouds and tornadoes are formed from differences in wind strength in the horizontal. With convergence zones, you have winds coming from the south and winds coming from the north, and this can spin up small, localized vortices that manifest themselves as cold-core funnel clouds. I couldn't find a picture of this online, so I drew one myself. This is a picture of the convergence zone around the time that the funnel cloud was sighted, and the pinwheel represents a vortex formed by wind shear from the converging air streams. In this case, the pinwheel is over Mill Creek, which is where people spotted the funnel cloud.

In case you want to learn more about supercell thunderstorms, I have a much more detailed post here. I must of had a lot of time on my hands when I wrote it!!!

Thanks for reading!!!
Charlie

Should Seattle Close Its Parks During Windstorms?

There's nothing a Pacific Northwest meteorologist likes more than a big windstorm. Flooding rains are interesting, but they make for terrible skiing (something many meteorologists like to do!) and are not nearly as vicious and intense as a windstorm. Snowstorms are awesome because they are so rare, and there's nothing more beautiful than Seattle with a fresh coat of snow on it, but they still lack the intense cyclogenesis that weather geeks rave about. I personally prefer snowstorms to windstorms (skiing down a hill is more fun than living without power), but when it comes to weather events that meteorologists go ga-ga over, windstorms generally take the cake.

However, I'm beginning to feel a little apprehensive about wishing for these big windstorms. It seems like every windstorm that hits us results in at least one tragic fatality. Recently, most of these have been due to falling trees, but I recall back during the Hanukkah Eve Storm that the majority of deaths were actually due to carbon monoxide poisoning in the days after the storm, as people left their generators running inside their homes and carbon monoxide built up throughout the house. Regardless, I am no fan of any windstorm when it results in loss of life. Damage is inevitable, but loss of life can usually be avoided.

The windstorm on March 13th killed somebody in Seward Park when they were crushed by a falling Douglas Fir, and this has sparked concerns over whether Seattle should close its parks during these windstorms. One of my friends actually went to Seward Park to go storm chasing, and although he planned to get there well ahead of the storm and set up in an area clear of trees, the storm moved faster than expected and he got there right about the time that this fatality occurred. Many trees were down throughout the park, and based on the damage, he estimated that gusts were reaching 55-60 mph. He recorded a gust to 49 mph, so winds above the surface impacting the trees were likely higher.

Credit: Seattle Times

On Thursday, I read an interesting article in the Seattle Times. The article stated that while many other parks and cities close their parks when severe weather strikes, Seattle does not. Seward Park remained open throughout the storm, while other parks like Olympic National Park closed well before the storm hit and others like Point Defiance Park in Tacoma closed as soon as the winds picked up. This begs the question: does it make sense to close parks in Seattle like Seward Park when the winds get too high? Or is this not necessary, and should we let people decide on their own if they want to go to parks during a storm?

My opinions are mixed. I identify as a liberal who likes small government. I am not a libertarian by any means, but in my opinion, government and public agencies should be as streamlined and efficient as possible while still fulfilling certain basic needs. I don't consider deciding whether to keep parks open or not a basic need. On the other hand, organizations like the Washington State Department of Transportation close roads when they are deemed unsafe (ex: the 520 bridge, which was closed during the height of this storm). The Coast Guard can close certain ports to prevent ships from going out if there are rough ocean conditions. The Forest Service can close certain trails, like they did last summer with the Big Four trail near Mt. Baker due to people illegally venturing into the ice caves there and being killed by collapsing ice. So, why shouldn't Seattle Parks and Recreation close certain parks during severe weather?

Credit: Washington Trails Association

It would be hard to enforce these closures, especially on places like the Burke-Gilman trail, which according to UW professor Cliff Mass is one of the most hazardous places to be in a windstorm. So I don't think that closing the parks is the most efficient way to go about solving this problem.

Cliff Mass actually got to this topic before I did, and he suggested that Seattle develop a "Seattle Environmental Hazard App" that would warn you of any threats of severe weather based on your exact location. I think this would be a good idea, and if it is done I'd definitely check it out.

However, at this point, I think the main thing we should be doing is educating people about what to do during severe weather. People should know not to drive or walk in areas with lots of trees when there is high wind, and they should not be out in small boats. For example, last spring, a group of kayakers were caught unaware by strong westerly winds coming down the Strait of Juan de Fuca, even though models predicted the winds perfectly. And that's another thing - we need to be better at communicating what the weather forecast is to the public (I could write a dozen blogs about this).

The number one weather-related killer in the Pacific Northwest is roadway ice, and it is how I almost died while traveling near Blewett Pass when I was 5 years old. But with our large, shallow-rooted trees and often-saturated soils, falling trees are a real danger to lives and property, and we must be better at limiting the frequency of these tragic deaths, because we have had far too many over the past year.

Rest in peace.

Sneezing Up A Storm

Wednesday, March 23, 2016
2:28 pm

Every year, around the first week of March, springtime allergies hit me harder than a bottle of caffeine pills. For the majority of the winter, I'm totally fine, and then suddenly, my eyes are the wettest they've been since stupidly eating some absurdly hot chili pepper in Indonesia. Ten to thirty percent of the world has seasonal allergies, and I am one of those people. In fact, I almost sneezed as I was just typing that sentence. Now, I'll be yearning for a sneeze for the rest of the day.

I'm allergic to cats (though we still had one) and mildly allergic to dogs (though I love my dog and wouldn't give him up for the world), but I'm incredibly allergic to horses. Put me on a horse, and I'll sneeze, cry, and punch my nose like you wouldn't believe. I love riding horses too - I just need to take a ton of allergy medicine well beforehand - it takes weeks for the medicine to fully get into my system and have a noticeable effect on my horse allergies.

Luckily for me, my allergies are just an inconvenience. I do not have life-threatening allergic reactions to peanuts or bee stings. But even though those allergies are much more severe, the basic mechanism behind all allergic reactions is the same. So before we get specifically into hay fever, let's talk about how allergic reactions work.

Allergic reactions occur when the body's immune system identifies a normally harmless substance as a hazard to the body's health. When a person is exposed to an allergen for the very first time, they generally do not experience a severe allergic reaction. However, some individuals develop antibodies to these allergens, and the next time an allergen enters the body, the antibodies produce "histamines," which then act on various areas of the body and create different types of allergic reactions. Some allergies, like hay fever, are relatively harmless in the grand scheme of things, while others, like nut allergies, can cause the body to experience a rapid drop in blood pressure and go into anaphylactic shock. In these cases, a shot of epinephrine (an Epi-Pen) must be administered immediately, as the sufferer could die in as little as 15 minutes after being exposed to the allergen. Allergies are not just found in humans; even man's best friend can go into anaphylactic shock if they are exposed to a particular allergen.

A scanning electron microscope image of pollen grains from sunflower, morning glory, prairie hollyhock, oriental lily, evening primrose, and castor bean. Credit: Dartmouth College

Hay fever is caused by the body's immune response to pollen. The severity of hay fever symptoms varies among different people, but it is extremely rare for a person to go into anaphylactic shock because they have been exposed to pollen. That's a good thing, because pollen is pretty much everywhere!

Pollen itself is a powdery substance composed of individual pollen grains, or microgametophytes. Though we usually don't think of plants as having a certain sex, pollen grains produce sperm cells, and therefore are the "male" part of the plant as a whole. This is why bees are so important... they allow plants to reproduce by depositing the pollen grains on the female receptacles, or megagametophytes. In a flower, the microgametophytes are found on the stamen, while the megagametophytes are found on the stigma. So ladies, next time you get ambushed by hay fever, find one of your guy friends and blame him and all his microgametophyte friends for making you sneeze!

Credit: American Museum of Natural History

In the springtime, trees are the most common source of pollen. Particularly notorious trees in my neck of the woods include Cedar and Maple, especially Maple. In summer, grasses are the most prevalent source of pollen, and by autumn, weeds are the main offenders. Although pollen decreases in the winter, some people are still allergic to mold and dust, and indoor air is generally dirtier than outdoor air. Allergies are generally worst on breezy days when lots of pollen has been knocked off of plants, but if it is too windy, cleaner air from the upper atmosphere will get mixed down and pollen concentrations will decrease. Pollen concentrations are usually lowest if it is raining cats and dogs, as raindrops capture pollen and other aerosols and remove them from the atmosphere.

There are a variety of medications you can use to mitigate hay fever. Many are "antihistamines," which reduce the amount of histamines your body produces so you don't have as much of an allergic reaction. Some, like Benadryl, cause drowsiness, while others, like Claritin, keep you perfectly awake. However, in recent years, prescription nasal sprays such as Flonase have become available over-the-counter, and I've had better success with these. These are steroids instead of antihistamines, and are stronger and longer lasting than most antihistamines. If springtime has got you feeling under the weather, get a nasal spray, and you'll be back to feeling better in no time.

Thanks for reading!

Charlie