Planned Deployment for TEA Bill Swanson with Palmer Long-Term Ecological Research (LTER) at Palmer Station leave PA: 12 November arrive Palmer: 18 Nov leave Palmer: 20Dec arrive PA: 24Dec _____________________________________________ To: bswanson@socorro.k12.tx.us cc: karen, mwallace@socorro.k12.tx.us Subject: Re: Information on Projects and PI's Date: Tue, 02 May 2000 07:43:17 -0700 From: Karen Baker 1) A brief description of the project you will be undertaking written so that high school students can understand it. Phytoplankton, the microscopic plants of the ocean, are the basis of the marine food web, all life in the sea, and they play an important role in the global biogeochemical cycles. The ocean covers nearly 3/4ths of the earths surface, a vast area which is poorly sampled by conventional shipboard techniques, so satellite sensors have been deployed to sample the oceans of the world. An important satellite sensor is the SeaWiFS (Sea-viewing Wide Field-of-view Sensor) ocean color sensor. Ocean waters vary from deep marine blue to a more turbid green color. Deep marine blue is the color of sea water itself, which becomes increasingly green as the concentration of phytoplankton suspended in the water increases. This principle, blue for low biomass and increasingly green for higher biomass concentrations, is used by the SeaWiFS ocean color satellite sensor for the estimation from space of oceanic chlorophyll, a measure of phytoplankton biomass. The overall objectives and the basic principles of this project are relatively simple. The actual implementation of receiving a satellite signal in space, relating it to a water leaving reflectance, and linking that reflectance to the in-water chlorophyll concentration requires attention to a number of important details. For our work at Palmer and the Southern Ocean these details include: determining and understanding the reasons for the unique biological and optical (bio-optical) characteristics of these waters in the Southern Ocean; making detailed observations using in-water optical instruments and water samples for chlorophyll analysis that will permit accurate modeling of the bio-optical properties of these waters; understanding how these observations relate to the actual signal observed by the SeaWiFS satellite in orbit. Each study of the "details" is a project. The final output will be calibrated satellite images of the abundance and distribution of phytoplankton biomass for the Palmer region and the Southern Ocean. 2) Project Information PI Name: Dr. Raymond C. Smith PI's Institution and Address: Institution Name: University of California at Santa Barbara (UCSB) Street: Institute for Computational Earth System Science (ICESS) Street: 6832 Ellison Hall County/State/Zip: Santa Barbara, CA 93105 PI's Phone Number: 805-893-4709 PI's E-Mail Address: 805-893-2578 Dates in the Field (please be as precise as possible): 12 Nov-24 Dec 2000 Location(s) in Field: Palmer Station Is E-Mail Available at the Field Site? yes. swansowi@palmer.usap.nsf.gov Is phone communication available at the Field Site? Limited. Project Title: Palmer Long-Term Ecological Research Program ******************************************************************* To: bswanson@socorro.k12.tx.us cc: karen Subject: Palmer LTER project text Date: Mon, 24 Jul 2000 07:10:05 -0700 From: Karen Baker Bill: Here's the information about the field work. -karen _________________________________________________ High Latitude Sunphotometer Observations at Palmer Station Project Description Revisited Published estimates of Southern Ocean primary production vary by about an order of magnitude. These data also indicate that the Southern Ocean contributes between 3 to 9% to total oceanic primary production and is highly variable in time and space [Longhurst et al., 1995; Antoine et al., 1996; Behrenfeld & Falkowski, 1997; Smith et al., 1998; Arrigo et al., 1998]. The Southern Ocean is large, the environment hostile, and ship operations limited. In spite of problems associated with low solar elevations and persistent cloud cover, satellite observations coupled with systematic surface observations hold promise of increased accuracy for the estimation of phytoplankton biomass and subsequent estimation of phytoplankton production for these waters and such observations are essential for comprehensive and accurate global estimates. Further, the Antarctic marine ecosystem, it's role in the carbon cycle and potential for change under environmental change scenarios [Smith et al., 1999] are significant per se. Time series observations spanning years and several generations of satellite sensors will be necessary in order to establish baselines, accurately infer trends, and investigate causative factors influencing long-term variability. Ocean Considerable evidence now exists to show that the bio-optical properties of the Southern Ocean (SO) are significantly different than at lower latitudes. Early workers [Mitchell and Holm-Hansen, 1991; and Mitchell 1992] found significantly different bio-optical algorithms for Antarctic Peninsula waters compared to reported descriptions for low latitudes [Smith & Baker, 1978; Gordon et al., 1983; Morel, 1988]. More recently, we [Dierssen & Smith, accepted JGR] have shown that the remote sensing reflectance is significantly different for WAP waters than for those published for more temperate latitudes. As a consequence of these spectral differences, the application of general processing algorithms for SeaWiFS to Antarctic waters results in an underestimation of chlorophyll by roughly a factor of two. We are currently adding absorption and backscattering observations to our ongoing time series LTER program to directly test the various hypotheses concerning the distinct bio-optical properties of SO waters. Atmosphere Another important issues in developing accurate algorithms for ocean color sensors is that of the atmospheric correction necessary to obtain the water leaving radiances needed for computing chlorophyll concentration from remotely sensed observations. Correcting for the atmospheric effects on satellite ocean color measurements is a key component towards obtaining quality oceanic bio-optical products. Scattering and absorption due to atmospheric gases, clouds and aerosol, but also sea foam, affect the upwelling radiance from the ocean measured by a satellite sensor. At the typical wavelengths selected for observing ocean color, many of the effects of atmospheric constituents are small (e.g., gaseous absorption), or can be accurately modeled (e.g., Rayleigh scattering). Correcting for the effects of aerosols, however, represent a more formidable challenge since their radiative properties vary spectrally depending on their chemical composition and on atmospheric humidity, and because their spatial distribution is highly variable. In the Southern Ocean regions, the problem is compounded by the lack of available observations of aerosol radiative properties and aerosol concentration. We propose to start building a ground-based data base of aerosol optical depth observations for the Southern Oceans and develop an atmospheric correction algorithm more adapted to these remote, low illumination oceanic regions characterized by high winds. We will make use of a Micro Tops II Sunphotometer. This instrument is a stand alone 5 channel hand-held sunphotometer for measuring aerosol optical thickness and total water vapor easily, accurately and dependably. Direct solar ultraviolet radiation at 5 discrete wavelengths (440,500,675,870,936 nm) are measured and stored. These data can be directly compared with the BioSpherical Instruments full spectral information. This database will constitute the start of a ground-based aerosol study in the region and a long-term sampling program whose data will be available for surface validation of atmospheric retrievals and correction algorithms for ocean color satellite algorithms.