2019 - Robert's botanical adventures in Northern California

[Hoy]

The wildfires are in the news here. Hope they will not come your way.

It was a period with strong wind here also but north of us. (I think they said up to 35m/s (78mph) Happily we were not affected. This kind of strong wind hits the coast and mountains somewhere during the fall/winter every year. Once I was waiting in a tunnel in the mountains for 24 hours while the gale lasted (70mph). It was December, lots of snow, and impossible to drive of course.

The weather has dried up a bit here, which means less rain, not no rain! But we have sun or at least patches of blue sky now and then. One of these days we went for a walk in the hills nearby.



The aspens still keep their foliage. The birches have lost it.




Bracken and juniper.




Some plants like this Erica tetralix are still in flower.




Due east. It is snow on the mountains far east. Difficult to see in the picture. The rusty plant is Trichophorum cespitosum which is extremely common here.



Due south. The drinking water source for us and the city Haugesund which is very close to the right but behind the hills.

[Hoy]

The long time weather forecast says mild weather the next months. We shall see. Had one night with -1C a couple of days ago!



Hypochaeris radicata is another typical plant here. They flower all summer.




In a few years this will be forested. The birches and pines take over the open landscape. It is not the change of climate but change of use.




The bogs will also be covered by trees in 100 years.




Older forest. This one consists of pine, birch, rowan, oak, and firs and ilexes are popping up in the forest floor.
This was a pasture and possibly some of the pines and birches are natural, the other trees have arrived later.



Due west. Haugesund is behind the hills. The island (Røvær) is inhabited (86 persons) .https://rovar.no/english/

[Robert]

The recent pattern of strong, dry, northerly wind has ended. Placid weather with warm days, cool nights and slowly rebounding relative humidity looks in store for the next week or so.

Yesterday was an excellent opportunity for me to check on my high elevation data recording sites before the winter snow arrives and make any last minute adjustments and modifications. I did find a design flaw at one of my data recording sites. With some fairly simple modifications the operation of the sensors will be enhanced greatly. I will have to return to the site to finalize the modifications, but this is a pleasant prospect.

In the high country, most of the seasonal herbaceous vegetation has been pounded-down by the cold frosty nights. In many cases there is not much to see expect the freeze-dried remains of the plants and many bare stems on the deciduous shrubs. I find a great deal of beauty in the senescence. If one takes their time and looks closely there is still a great deal to see and learn during this seasonal transition.

As time permits, I have more photographs and details to share concerning this outing.

Until the next time…


Trond,

Some fantastic photographs! I will certainly comment on them at my next opportunity.

[Robert]

Hi Trond,

The countryside near your home is amazingly beautiful. Thank you so much for sharing the photographs. It is interesting that the rainy weather in your part of the world has paused at the same time that the North Atlantic Oscillation (NAO) has turned neutral/positive. I do follow the NAO, but for other reasons than the link to European weather. The NAO is a regional version of the AO (Arctic Oscillation). An outbreak of the Polar Vortex was responsible for our recent period of strong, dry, northerly winds (the AO briefly turned strongly negative). At one point there was strong cold air advection from the polar region in the general direction of California. The brunt of the cold air traveled down the backside (east side) of the Sierra Nevada Mountains, however we were not spared either. We experience the first frosty weather at the farm on 28 October. 40 years ago this was a typical first frost date at the farm, however with climate change this date now has shifted to 13 November, almost 2 weeks in only 40 years! The same is occurring at the other end of the spectrum. The last frost of the season was generally 1 May, however now mid-April is a much more common date. Oh, how our gardening environment is changing. Now we are entering a period of relatively warm and dry weather. I do not see any change in this general pattern into the foreseeable future. The next 1 to 3 months look dry and warm for the most part. More on this later.

The above photograph is of a mountain meadow I surveyed on my last outing. As you can see the vegetation is now dormant for the winter season. The meadow is not dry! As I walked across the meadow it was apparent that the standing water had turned to ice. In our region, it will take, most likely, thousands of years for coniferous trees to encroach into the waterlogged portions of this meadow (at that time it will no longer be waterlogged). There are very distinct ecohydrological niches in this region that support very distinct communities of plants. The dominant species within this meadow is Carex, with a sprinkling of Agrostis scabra, Camassia leichtlinii ssp. suksdorfii, Oreostemma alpigenum var. andersonii, etc. On slightly raised ground there are hummocks of Salix sp., mostly Salix orestera. In other locations within the meadow hummocks of Vaccinium uliginosum ssp. occidentale can be found. The diffusion of oxygen into the waterlogged soil is extremely limited to the top portions, which in turn strongly influences the redox potential and thus the soil chemistry. This is a very hostile environment for many plants (free Fe²⁺, anaerobic conditions, etc.) including the coniferous species found in this region. Reduced ionic species can form rapidly in waterlogged soils, sometimes within days, thus in our region very distinct ecohydrological niches can be observed based on the duration of flooding/waterlogged conditions at snow melt and into the late spring summer months.

I will have more comments a bit later. Thank you again for sharing the fine photographs and the discussion.

[Robert]

This is another interesting meadow within the same general area. The sloping terrain creates a situation where there are a variety of ecohydrological niches within this meadow. Not surprisingly, the duration and degree of waterlogging varies top to bottom along the grade of the slope. Despite the sloping terrain, much of the meadow remains waterlogged during the summer and autumn.



For many decades this meadow was a managed meadow ecosystem, part of a cattle (and other livestock) ranching operation. Many stumps still remain from the time when efforts were made to expand the pastureland area. Somewhat recently the ranch was sold to the U.S. government and is now public property under the stewardship of the U.S. Forest Service. At this time the meadow is unmanaged, and Lodgepole Pine, Pinus contorta spp. murrayana, are beginning to encroach into their former ecological space. This is a very common occurrence throughout the upper terrain of the Crystal Basin, both in relatively new unmanaged meadow sites, but also where extensive commercial logging occurred before the land was sold to the government. The overgrowth of Lodgepole Pine has now become a fire risk, as well as a forest management dilemma.

At home, I am anayizing the October meteorological data from the region. As I have mentioned in the past, I record data from my own recording sites high in the Sierra Nevada Mountains as well as synoptic scale sites surrounding our region, and the pertinent teleconnections beyond. October temperatures, in general, were 2.56 F below the 30-year average, but within the standard deviation of this time frame. As would be expected, the high mountain valleys (cold air basins) experienced very cold low temperatures during the last part of the month when the polar air arrived; temperatures in the lower “teens” F were not uncommon.

Looking into the future, the climatic indicators strongly suggest a continuation of our dry pattern into the foreseeable future. The likelihood of above average temperatures is strong too. Anomalous high SSTs (surface sea temperatures) in the northeastern Pacific Ocean are major consideration behind my extended forecast. Another consideration is the East Indian (Oopps) Asian Jetstream, which is now frequently weakening near the Hawaiian Islands and recently shows indications of wanting to split into a northern and southern branch. Although the MJO (Madden Julian Oscillation) is on the move again, it has also been inactive at times, as a general stagnant pattern seems to be persisting. Soon enough, I will be looking into the current conditions of the Indian Ocean Dipole (IOD), Tropical Instability Waves, as well as the down welling Oceanic Kelvin Wave to see I how these conditions are progressing and may be influencing our weather. There is plenty to keep me busy!

More later…

[Robert]

Yesterday 6 November was a beautiful day in the Sierra Nevada Mountains. As one can see from this photograph there is no snow on the high peaks of the Crystal Range. This is not unusual for this time of year, but it will be nice to see them covered with deep snow later this winter.

There is some good news concerning the mid-range weather patterns. SSTs in the northeastern Pacific have cooled a bit since the previous month. Cooler SSTs in the northeastern Pacific would be more conducive for a wet weather pattern on the west coast of the U.S.A. Other good news on the precipitation front: the Madden Julian Oscillation (MJO) has been very active and on the move over the last few days. It has stalled out as it has approached the western Pacific, however if it can remain active into the Pacific, this may shift the atmospheric pattern and increase the chances of precipitation in California (a more short term pattern shift). Even if we do not get any precipitation, stormy weather in the northeastern Pacific could help mix out the warm SSTs in this region. Warming SSTs in the eastern equatorial Pacific is also a good trend that is also conducive to changing our weather to a wet pattern (thank you down welling oceanic Kelvin wave). Lastly, the nose of the East Asian jet has reorganized and could begin to edge closer to the western U.S.A. All of this is good news concerning a change to a wetter pattern for our part of California. Currently, I do not believe that the general pattern of above average temperatures and below average precipitation will shift much during the next 30 days or so, however there are hints that the pattern could change in the mid to late December time period.

Stay tuned.

The plants in the Sierra Nevada may be dormant and ready for winter, but there is still a great deal for me to report, plant wise, from the Sierra Nevada Mountains. I will have more on this topic.

[ian mcdonald]

Robert, we could do with some dry weather here. It has rained all day today on already wet ground. I expect there will be flooding in some parts of the country.

[Robert]

Hi Ian,

I hope that most of town is on higher ground. It seems like much of “your patch” will be unscathed or even benefit from flooding.



This photograph is from last week, the last bit of autumn color on Populus tremuloides. Now all the leaves have dropped.



Most of the herbaceous plants have been pounded down by hard frost. This week the temperatures have turned very mild. Most mornings are not frosty, except on the east side of the Sierra Nevada Mountains. We could use some precipitation, as some plants at lower elevations are showing signs of stress (lack of moisture). Annual species that germinated after the September precipitation are showing the most stress. Most of these species have staggered germination. Other seeds will germinate as conditions change and precipitation returns. As an example, some native Diplacus species can either germinate immediately after rainfall, or will need varyingly amounts of vernalization before the seed will germinate. The staggered germination helps assure the survival of the species.

[Robert]

11 November 2019

It was a quiet, peaceful and beautiful day in the Sierra Nevada Mountains. While the eastern U.S. endures snow and frigid temperatures, our weather is extremely mild. Today’s high temperature at the elevation of 7,100 feet (2,164 meters) was 61 F (16.1 C)! The morning temperatures in the Sierra Nevada have been extremely mild too.  Except for the highest mountain valleys where cold air settles at night (cold air basins), overnight temperatures have been above freezing in our portion of the Sierra Nevada.

Our weather continues to be dry and the near term prospects appear to favor the continuation of our dry weather pattern. Presently, I do not see any indications that a wet weather pattern will be developing any time soon. The dynamics of the atmosphere can be challenging to interpret, but then this also makes atmospheric science incredibly fascinating. There is never a dull moment and there is always something new to learn and discover.



This temperature/relative humidity/dew point data recorder is at one of my high elevation study sites. In the autumn I extend the mast to 8 to 9 meters in height to keep the sensors above the height of the winter snow. I position the sensors on the lee side of the trees to prevent rime build up on the solar radiation shield. Instruments deployed in exposed sites above 7,500 feet elevation can experience rime accumulations. I discovered this last February.    Instruments recording soil temperatures (heat fluxes in and out of the soil) – moisture content, and stream flow - water temperature can be more or less left in place. This part is easy. Even easier is solar radiation, which I find on the internet (proxy data). 



Currently, I am very busy, however at the first opportunity I wish to open another discussion concerning our high elevation flora. I accomplished a great deal this season and there are many plant related topics to review. 

[ian mcdonald]

Hello Robert, many areas North of where I live are under water, making national news. Also areas to the west. Local authorities grant permission to build houses in low lying areas because these areas have not flooded for some years. Rain water is needed on the site to compensate for dry spells. It seems that the Jet Stream is further south than usual, allowing colder, wetter weather for us.

[Robert]

Hi Ian,

I definitely appreciate the update on your current weather conditions.

Here our dry weather pattern continues. In the short term the MJO may trigger a transient change to a wet pattern. This still remains to be seen, but based on the current conditions it is certainly a possibility. Currently, I do not see any definitive longer-term shift in our general dry weather pattern. I do run my model daily and continue to make improvements to it. I keep hoping for a change to a rainy weather pattern.

In the short term (the next 6 month) my primary concern is that we might return to a drought pattern. Currently, I cannot make a guess at this one way or another. Of much greater concern are the climatic shifts over the next 5 years or so. Earth’s oceans have absorbed a great deal of heat over the past decades. Radiative forcing is increasing and there is increasing evidence that more dramatic fluctuations in weather events will occur. I recently ran these ideas past a veteran atmospheric scientist. I proposed that the incidences of major windstorms, cycles of drought-flooding, extreme heat-extreme cold events, etc. in California would increase in frequency and severity in the near future. It is not much of a prediction, as these conditions appear to have already arrived. At least my reasoning behind these ideas is based on sound scientific principles. The bigger question is: are we approaching a climatic threshold where large and dramatic changes in the Earth’s climatic system will occur? Look at what is occurring in Alaska!

My current project is directly involved in determining the extent of change in specific ecosystems in our portion of the Sierra Nevada Mountains. Like your situation in the U.K., our land use decisions are frequently based more on economics than science. Our current attempts to deal with the recent destructive wildfires are fraught with complexities and major challenges. From my perspective the issue of invasive grasses is not being addressed, especially when it comes to “brush clearing”. At the lower elevations of interior California, our native bunchgrass ecosystem has been almost completely supplanted by non-native invasive grasses. The flash point of these grasses is extremely low and when ignited the flames spread rapidly, especially with high wind velocities. We saw this with the Camp Fire that destroyed the town of Paradise, California. The sparks that jumped the expanse of Lake Oroville did not ignite the native flora, but the invasive non-native grasses. Sadly, after brush clearing invasive grass species quickly invade the cleared terrain. The amount of fuel may have been reduced, however fires in non-native grasslands can spread quickly, and once in the crown of the tree canopy can be difficult to control, especially if there are high wind velocities. In addition, many native shrubs stump sprout quickly after being cut to the ground and before you know it there is a large fuel load again. And then we have not even considered the changes in the surface energy budget that profoundly affect the ecosystem. This is another subject. As you can see our challenges are immense.

Ian, please keep me posted as to the outcome of the flooding in your diary. I definitely will want to know the outcome.

[Robert]

13 November 2019

Our warm weather, with near record high temperatures, has continued through today. Today, I was working at the elevation of 6,725 feet (2,050 meters). The high temperature was 61 F (16.1 C)! So far to date, the average high temperature at this site is running 60.42 F (15.79 C). Remember this is at the elevation of 2,050 meters in the mountains. This is an extremely high average temperature for this time of year at this elevation.

Back at the farm…

For the month of November the average high temperature through the 13th is 75.69 F (24.27 C). The record average high temperature for the month of November is 70.40 F (21.33 C), set in 1986. It is well within the realm of possibilities that this record will be broken this November.



The high peaks of the Crystal Range are almost devoid of snow. The flow of Lyons Creek has been reduced to a trickle. This is not unusual for this time of year, but then, the weather has been very dry. The last measurable precipitation at this site was on 17 October, almost a month. There are strong discrepancies between the various forecasting models concerning the possibility of precipitation about a week from today. Given the stubbornness of the current weather pattern, I tend toward the dry forecast at this time. Temperatures are forecasted to cool a bit over the next few days, but I still think that a new record average high temperature will be set at the Placerville, California farm.

1300 UTC 14 November -

Contrary to the assemblage forecast models, my crude forecasting model agrees with the GFS, which suggests a chance of rain during the 20 November time period.

[Robert]

16 November 2019

Our persistent warm and dry weather pattern continues. Although in the short-term cooler temperatures and maybe a few sprinkles seem likely over the next 5 to 7 days, the longer term dynamics show little signs of change. The monthly average temperature for this November appears poised to be the warmest in the past 40-plus years. At one of my monitoring sites at 6,700 feet (2,042 meters) in the Sierra Nevada, the average high temperature through 15 November is 61.80 F (16.6 C). The average high temperature for the whole month over the past 15 years at this site is 46.69 F (8.2 C) and the current record average high temperature is 51.33 F (10.7 C). Unless there is a dramatic shift in the weather this record will easily be broken.

Sadly a dramatic shift in the weather over the next 30 days seems very unlikely. The prime concern in my mind is adequate precipitation this season. Given the precipitation totals to date, statistically the probability of average precipitation this season is extremely low, 20%. My experimental dynamic model is likely to be somewhat accurate out 30 to 45 days at the best, and currently the dynamics do not look promising at all. Unless there is significant precipitation over the next 30 days, catch-up in the precipitation department becomes increasingly problematic. I will hope for the best (precipitation wise), but at this point my bets would be on a dry rain/snow season with above average temperatures. We will see what actually happens.



At some point I wish to continue my discussion of plants in the Sierra Nevada Mountains. The site pictured above is very interesting in many respects. Despite the small size of this plot, only a few square meters, there is a great deal to learn by observing the dynamics and interactions of the variables as they influence the patterns and progression of growth into the spring and early summer season. If indeed this is a dry winter, a completely different vegetation pattern will emerge compared to last season. There is a great deal to learn from such transient changes.

[ian mcdonald]

Robert, I wish we could send you some of our rain. So far this year, and it is only a guess on my part, we have had more than average rain.

[Robert]

Hi Ian,

How will flooding impact your patch? Being a wetland ecosystem, it seems that the additional moisture could be beneficial. It is clear from your diary that the site is highly managed. I am sure that management choices have a high impact at the patch. (It might be best to answer the questions on your diary page – so others can follow easily).

As for the weather – The North Atlantic Oscillation (NAO) is a major teleconnection that influences the weather in Europe. By following the NAO and monitoring some other key variables one could get a good idea about the general trend of the weather in your part of the world. I follow the major teleconnections that influence our weather on the western coast of North America, however I use a much more dynamic approach to mid-range forecasting. As an example, I follow the ENSO (El Niño Southern Oscillation), but I do not directly use the index for forecasting. I am far more concerned about how the oceans and atmosphere respond to the changing patterns. A strong El Niño can result in either drought or heavy rainfall in our part of California. I am far more interested in how SSTs, Wind Stress, Ekman Transport, the East Asian Jetstream (both 300mb and 200mb), and much more dynamically interact together to influence our west coast weather.



A nice scene from my recent activities in the Sierra Nevada Mountains.