Online Links:
Online Links:
| Range of values | |
|---|---|
| Minimum: | 1.85 |
| Maximum: | 14.65 |
| Units: | hours per day |
USGS Land Change Science, Cooperative Institute for Research on the Atmosphere, California Landscape Conservation Cooperative, TBC3 -Pepperwood Preserve, and Gordon and Betty Moore Foundation.
Fog and low cloud cover (FLCC) is very important for coastal California. During the seasonally arid summer months of the northern hemisphere Mediterranean climate zones (June to September), the stratus and stratocumulus clouds that form over the ocean advect onshore. When these low clouds touch the earth they are called fog although many people will also call the higher overcast clouds fog. When fog touches needles or other surfaces the fog water droplets coalesce becoming fog drip. Overcast clouds form a shield that reflects solar radiation bringing relief from summer heat. The added water from fog and reduced temperatures from low clouds can be critical for coastal species such as endangered coho salmon that require cool flowing streams during late summer. FLCC is highly variable across the landscape and throughout the summer resulting in many different climate regimes just a short distance from each other. Precisely located fog belt zones can help natural resource managers and others quantify the impacts of FLCC on ecosystem dynamics. A summertime FLCC dataset was developed as a Pacific Coastal Fog Project partnership between the US Geological Survey and the Cooperative Institute for Research on the Atmosphere (CIRA). The project goal is to quantify coastal ecosystem response to summertime patterns of marine stratus and stratocumulus cloud. A first step toward that goal is quantifying the FLCC patterns. We used 26,000 cloud maps, generated by CIRA from hourly weather satellite imagery to generate raster grids of average summertime FLCC. The images were collected from 1999 to 2009 and were subset into several temporal periods: decadal, annual, and monthly. By compressing large quantities of FLCC data into manageable units we sought to simplify the complex FLCC meteorological phenomenon into coherent FLCC indices applicable to landscape-level analysis. For more details see the publication, GOES-derived fog and low cloud indices for coastal north and central California ecological analyses, Earth and Space Science, 3, doi:10.1002/2015EA000119. The dataset uses hours per day (h/d) as the unit of analysis. This metric, like percent cover, gives a relative measure of cover however rather than a base of 100 it uses a base of 24 hours. Either measure could be used however our use of h/d is intended to facilitate an intuitive grasp of the amount of FLCC affecting the ecological process-of-interest on a daily time-step. Other indices in the series include the nighttime and daytime patterns and two measures of variation: standard deviation and coefficient of variation.
Online Links:
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Please use the following citation when using this dataset: Torregrosa, A., C. Combs, and J. Peters (2016), GOES-derived fog and low cloud indices for coastal north and central California ecological analyses, Earth and Space Science, 3, doi:10.1002/2015EA000119.
Distributor assumes no liability for misuse of data.
| Data format: | Raster Digital Data Set |
|---|---|
| Network links: |
http://climate.calcommons.org/datasets/summertime-fog |