BOON research
- Climate Research
- Oceanography
- Marine Ecology
Marine Atmospheric Boundary Layer (MABL)
Ian Faloona Ph.D., UC Davis Department of Land, Air and Water Resources
Stephen Lightfoote, Atmospheric Science Graduate Group
MABL Description:
During the summertime a sharp meteorological contrast is established in Northern California between the Pacific High pressure system offshore and the thermal low of California’s great central valley. The resultant along-shore winds and cold ocean waters along the coast are very important components of the local climate. Another atmospheric consequence of this contrast is the presence of a very strong temperature inversion separating warm and dry air subsiding aloft from the cool and moist, turbulent air near the ocean surface. This well-mixed layer over the ocean is known as the marine atmospheric boundary layer (MABL), and its vertical structure, depth, and temporal variability are important to a range of scientific interests. These include the dynamics of the alongshore winds and their consequent impact on ocean upwelling; the upwelling nutrient supply’s influence on the bountiful marine food web; the transport of chemical compounds from the ocean to the atmosphere; and the development of marine stratocumulus cloud layers, which are critical components of the regional climate. Of course, the environmental consequences of this meteorological setting are also important to operational interests such as to fishing vessels, small craft, and aviation. The height of the MABL is defined as the altitude of the base of the temperature inversion, and generally demarcates the depth to which atmospheric constituents are effectively mixed on short time scales.
Algorithm Description:
Measurement of the MABL height is derived from RASS (radio acoustic sounding system) virtual temperature soundings of the 915-MHz wind profiler operated by NOAA Environmental Technology Laboratory at BML (38.32N, 123.07W). The algorithm records the height of the initial positive jump in equivalent potential temperature (dΘv/dz) from the surface mixed layer to capping inversion. If there is no inversion layer present, the MABL height is not measured for that time period.
Download Matlab fig files of all processed years 04/05-07/07 [zipped archive]
Data Sources:
Data are retrieved from the ETL Download Database and from the BOON Data Access Portal (for information regarding access to the BML data sets, please refer to the BOON Data Usage Guidelines page). Data are uploaded on a monthly basis and plotted using MatLab Processing software.
Choose a panel to view a plot:
This data is courtesy of NOAA -Environmental Technology Laboratory: Regional Weather and Climate Applications Division - Boundary Layer Wind Profiler Studies
COast-to-Mountain Environmental Transect (COMET)
The COMET Project (for COast-to-Mountain Environmental Transect) is funded by the NSF Cyberinfrastructure for Environmental Observatories: Prototype Systems to Address Cross-Cutting Needs (CEO:P) initiative. The project team includes UC Davis faculty, researchers, and students from computer science, atmospherics sciences, environmental sciences, oceanography, and remote sensing.
The goal of the project is to develop a cyberinfrastructure prototype to facilitate the study of the way in which multiple environmental factors, including climate variability, affect major ecosystems along an elevation gradient from coastal California to the summit of the Sierra Nevada. An understanding of the coupling between the strength of the California upwelling system and terrestrial ecosystem carbon exchange is the central scientific question. Additional scientific goals are to better understand the way in which atmospheric dust is transported to Lake Tahoe and an examination of carbon flux in the coastal zone as moderated by upwelling processes. The geographic context is one in which there is a diversity of ecosystems that are believed to be sensitive to climatological changes.
The dispersion and complexity of the data needed to answer the scientific questions motivate the development of a state-of-the-art cyberinfrastructure to facilitate the scientific research. This cyberinfrastructure will be based around the integration of access to distributed and varied data collections and sensor data streams, semantic registration of data, models and analysis tools, semantically-aware data query mechanisms, and an orchestration system for advanced scientific workflows. Access to this cyberinfrastructure will be provided through a web-based portal.
Seasonal Flow Patterns
Silvia Piedracoba-Varela, Ph.D.
My work uses HF radar current analysis to determine typical surface flow patterns off Bodega Bay during the winter (Dec, Jan, Feb) of 2006/2007/2008. Surface trajectories show variable transport patterns depending on wind conditions (upwelling or relaxation) during the winter season. My research focuses on describing onshore/offshore and northward/southward transports and the onset, development and persistence of several structures (meanders). I am also interested in the relationship between currents and the most important winter season forcing factors (winds, continental runoff) as well as statistical differences between winter and summer seasons and the biological implications.
Fig. 1. Mean surface currents for January 2006. Vectors indicate mean current at that grid point. Black arrow shows mean wind velocity for January 2006 at the NDBC 46013 buoy.
Fig. 2. Median surface currents for January 2006. Vectors indicate mean current at that grid point. Black arrow shows mean wind velocity for January 2006 at the NDBC 46013 buoy.
Fig. 3. 3-Day average surface currents from 7 January 2006. Vectors indicate mean current at that grid point. Black arrow shows mean wind velocity for 7 January 2006 at the NDBC 46013 buoy. The figure shows an offshore/southward flow off Bodega Bay very close to the coast under moderate northerly winds of 7 Jan’06. A clockwise eddy north of Point Reyes has developed. Note the interaction between onshore and offshore flows off Bodega Bay.
Fig. 4. Four regions (northern/southern inshore and northern/southern onshore were defined to calculate the mean and median current (Fig. 5).
Fig. 5. a. Along-shelf and cross-shelf wind velocity. b.1, b.2, b.3. Daily average cross-shelf current (Ux), daily average along-shelf current (Uy) and daily total current , V=(Ux2+Uy2)1/2 and c.1, c.2, c.3 median cross-shelf current, median along-shelf currents and median total current for one of each regions defined in Fig.4.
Fig. 6. a) Monthly average chlorophyl a concentration (log [Chla]) and b) number of days used per position (according to thee availability of satellite images) for January 2006. c) Monthly average sea surface temperature (SST) and d) number of days per position used for the average.
Each dot is a 2 km ratio grid average approx.
Satellite ocean color data and sea surface temperature is from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor via NOAA's West Coast Regional Node.
Surface Currents and SST
Below are 2 movies of surface currents derived from long-range radar measurements. The system coverage and environmental conditions (wave height) are correlated. In this area, during the summer, wave height and wind speed are also correlated. The maximum long-range coverage is thus obtained during times of significant upwelling.
Long Range Daily Movie with SST June-Aug 2007 (10.7 Mb Quicktime movie):Sea surface temperature south of Point Arena, California, with surface currents measured by the long-range CODAR units superimposed. Winds as measured at NDBC buoy 46013 are also shown. The currents are daily estimates that have been smoothed over 3 days.
Long Range Hourly Movie June-Aug 2007 (78.4 Mb Quicktime movie): Hourly surface currents measured by the long-range CODAR units. Winds and significant wave height measured at NDBC buoy 46013 are also shown.
Long Range Hourly Movie ReadMe File 
This file contains a description of the symbols used in the movie of the hourly surface currents, as well as selected images of interesting current patterns.
Note: For optimal viewing please download the movies rather than play them in your browser window. To download: PC: right click on file name > save target as… Mac: option click on file name to download…
marine communities
We are investigating the effect of ocean conditions on year-class strength of marine invertebrates and fishes and the composition and structure of marine communities. Most marine species spend half their life cycle developing as microscopic larvae in the plankton, where they are susceptible to changes in ocean conditions. We are determining the effect temperature, light and tides on the timing of reproduction, which is critical for the survival of eggs and larvae being released into the water column by parents. We have made large strides in understanding the role of physics and behavior in regulating the transport of larvae between adult habitats and larval nursery areas. Multiple mechanisms regulate larval transport and recruitment to adult habitats, and these processes are identified by changing signatures of water masses (temperature, salinity, chlorophyll, turbidity) flowing through the region as a result of winds and tides. Wind conditions also affect the productivity of the ocean and whether offspring find enough food to survive. We are monitoring the effect of winds on ocean productivity to forecast year class strength of salmon and seabirds. Lastly, we are monitoring annual changes in temperature, oxygen and acidification to understand the effect of climate change on benthic and planktonic communities.