Multi-Sensor Improved Lake Surface Temperature Year 1: Review Lake SST Erik Tavis Crosman(1) (1) University of Utah Department of Atmospheric Sciences Salt Lake City Utah, Email: erik.crosman@utah.edu ABSTRACT The first year’s MISST2 task (1.3) of reviewing current lake temperature algorithms and other sources of error associated with satellite-derived lake water surface temperature (WST) has been mostly completed. The results for the review also aided in the development of improved land masking, QC, bias-correction, quality-control, temporal compositing, spatial hole filling and spatial smoothing techniques have been presented in a paper recently accepted for publication in the Journal of Atmospheric and Oceanic Technology. Next year’s MISST2 task will be to validate existing and improved NAVO-implemented lake temperature products. 1. Lake Temperature Algorithm Review (1980-2012) and New Techniques Suggested Over 50 papers relating to remote sensing of WST were reviewed and are listed in the References section. Figure 1a-c. Summarizes the observed RMSE and Bias between in situ and satellite-derived WST for a number of WST studies. The observed biases between lake WST’s and in situ measurements range from +/2 ⁰C, while the observed RMSE between lake WST’s and in situ measurements have been observed to be as high as 1.9 ⁰C. In general, the bias and RMSE decrease for larger lakes (Figure 1a-b), although there are a lack of data for small lakes. For instrument platform, the mean biases (~0.45) and RMSE (~1.7) associated with the AVHRR instrument are higher than MODIS (bias ~ 0.1; RMSE ~ 0.7) or the AATSR (bias ~-0.05; RMSE~0.5). In addition, night biases and RMSE are reported to be significantly lower than during daytime, supporting other findings that suggest using only nighttime satellite retrievals over lakes (Fig. 1c-d). Studies of satellite-derived lake temperature have historically overwhelmingly used split-window algorithms. These algorithms used either generic SST coefficients or derived coefficients via regressions with in situ buoy data. However, a lack of in situ data (lake buoy temperature and atmospheric profiles) over many lakes results in using split-window coefficients developed for the oceans and that are inappropriate for lakes in many cases. Figure 1. Observed biases (a, c) and RMSE (b, d) reported in lake SST studies between 1980-2013 as a function of lake area (a-b) and satellite platform (c-d). Recent work by Hulley et al. 2011 and McCallum and Merchant 2012 have used radiative transfer models using ECMWF or NCEP reanalyses to estimate atmospheric profiles over various lakes to estimate the atmospheric variability observed in different lake locations, resulting in improved lake WST. Hulley et al. 2011 developed an Inland Water-body Surface Temperature (IWbST) split-window algorithm while McCallum and Merchant developed a sophisticated Optimal Estimation techniques to provide lake surface wather temperature. These recent developments have resulted in RMSE of 0.1-0.4 K which is significantly improved over the average RMSE of most previous lake temperature studies shown in Figure 1. In addition to the need for improved split-window techniques and situ data for developing and tuning better algorithms, review of lake SST literature indicated persistent problems in the quality of the cloud masks, land masks, temporal compositing techniques and QC parameters available over lakes. Table 1. Summarizes many of these issues and possible solutions discussed in the literature. The author also aided in the development of improved land masking, QC, bias-correction, quality-control, temporal compositing, spatial hole filling and spatial smoothing techniques have been presented in the following paper recently accepted for publication in the Journal of Atmospheric and Oceanic Technology. Techniques for Using MODIS Data to Remotely Sense Lake Water Surface Temperature. J.A. Grim, J.C. Knievel, and E.T. Crosman, Journal of Atmospheric and Oceanic Technology (accepted) Topic Satellite-derived Problems Cloud Mask Manual inspection to remove retrievals used for many lakes cloud-contaminated SST-designed cloud masks not appropriate. Cloud masks and QC flags specifically designed for lakes needed. Land Near-shoreline land contamination of lake LWST a common problem. Current shoreline databases insufficient for fluctuating lakes and reservoirs. Removal of all pixels within 1-2 pixel width of shoreline or more complex sub-pixel estimations. Satellite visible reflectance-based time-varying shoreline database. Biases of standard split-window algorithms highly variable between lakes even within the same region. Lack of in situ data to derive regression coefficients and a lack of atmospheric temperature and moisture profiles for input into transfer model calculations. More research comparing the relative improvement of a full radiative transfer model to regional split-window algorithms for lakes. Increased in situ lake temperature monitoring. Possible use of atmospheric reanalysis data in radiative transfer model. Geolocation and Orthorectification For some satellites, geolocation errors can be 1-2 pixels widths, resulting in problems in shoreline placement. In addition, for lakes more than several hundred meters above sea level orthorectification will also be needed to correctly place satellite image. Verify that satellite data has been geolocated or orthorectified if possible. Sampling Frequency In many mid-latitude locales clouds preclude regular satellite observation. Lake temperature, particularly in shallower waters, changes rapidly. Use a multi-sensor approach to increase sampling frequency. Quantification of mean annual cloud cover as function of lake would help to estimate reliability of satellite-derived data. Air-water Interactions and Diurnal Effects Large air-water temperature differences reduce accuracy of split-window algorithms and also rapidly cool or warm shallow regions of lake, contributing error to a priori lake temperature based on earlier satellite image. Large skin vs. bulk water temperatures are observed. Develop satellite spatial climatological LWST maps to use as first guess field if certain time has passed. Develop relationships relating skin and bulk lake temperature for biological applications. Time Satellite Pass Many studies found large diurnal variations in LWST. Thus a single-sensor or single time approach may have biases associated with time of day. Incorporate satellite retrievals during spectrum of times during both day and night to sample diurnal and inter-diurnal variations in LWST. Processing and QC Many higher-level SST products produced over lakes are at too coarse of resolution (4 km) to be of use in smaller lakes or near shoreline. Reprocess higher-level SST product at native satellite pixel resolution. Validation Outside of a few lakes, in situ data to rigorously validate satellite-derived lake temperature is lacking Expand current in situ lake monitoring observations and number of validation (task for next year) Lake State High salinity decreases the surface emissivity and low water clarity increases the diurnal warming Derive monthly maps of current salinity and water clarity to incorporate into sophisticated algorithms. Mask Retrieval Algorithm of Lake Surface Temperature Suggested Solutions Table 1: Summary of the challenges, and reported problems in the literature of lake SST retrievals 2. Plans for Next Year Work for the next year will involve validating existing and improved NAVO-implemented lake temperature products. At the GHRSST meeting the appropriate lake SST products to be validated will be chosen as well as the selection of appropriate validation of in situ data. 3. References Adrian, R.A., O’Reilly C.M.,Zagarese H., Baines S.B., Hessen D.O., K. Wendel, Livingstone D.M., Sommaruga R, S. Dietmar, Van Donk E., Weyhenmeyer G.A., & Winderl M. (2009). Lakes as sentinels of climate change. Limnol. Oceanogr.,54(6, part 2), 2009, 2283–2297 Alcantara, E., Stech, J., Lorenzzetti, J., Bonnet, M., Casamitjana, X., Assireu, A., and Novo, E.: Remote sensing of water surface temperature and heat flux over a tropical hydroelectric reservoir, Remote Sens. Environ., 114, 2651–2665, 2010. Alsdorf, D. E., & Lettenmaier, D. P. (2003). Tracking fresh water from space. Science, 301, 1491-1494 Austin, J.A., & Colman, S.M. (2007). Lake superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback. Geophyical Research Letters, 34, L06604, doi:10.1029/2006GL029021. Barton, I., & Takashima, T. (1986). An AVHRR investigation of surface emissivity near Lake Eyre, Australia. Remote Sensing of Environment, 20, 153-163. Becker, M.W., & Daw, A. (2005). Influence of lake morphology and clarity on water surface temperature as measured by EOS ASTER. Remote Sensing of Environment, 99, 288-294. Bolgrien, D., Granin, N., & Levin, L. (1995). Surface temperature dynamics of Lake Baikal observed from AVHRR images. Photogrammetric Engineering and Remote Sensing, 61, 211-216. Bussieres, N., & Schertzer, W. (2003). The evolution of AVHRR-derived water temperatures over lakes in the Mackenzie Basin and hydrometeorological applications. Journal of Hydrometeorolology, 4, 660-672. Bussières, N., and R. J. Granger. 2007. Estimation of Water Temperature of Large Lakes in Cold Climate Regions during the Period of Strong Coupling between Water and Air Temperature Fluctuations, Journal of Atmospheric and Oceanic Technology, Vol. 24, pp. 285-296. Cardona, M.C., Steissberg, T.E., S.G. Schladow, S.G., and Hook, S.J. (2008). Relating fish kills to and wind patterns in the Salton Sea. Hydrobiologia, 604, 85-95, doi: 10.1007/s10750-008-9315-2 Chavula, G., Brezonik, P., Thenkabail, P., Johnson, T., and Bauer, M. 2009. Estimating the surface temperature of Lake Malawi using AVHRR and MODIS satellite imagery. Physics and Chemistry of the Earth, Parts A/B/C, Vol. 34, No. 13-16, pp. 749-754. Crosman, E. T., and J. D. Horel (2009), MODIS-derived surface temperature of the Great Salt Lake, Remote Sens. Environ., 113, 73–81, Fang, X. and H.G. Stefan. 1999. Projections of climate change effects on water temperature characteristics of small lakes in the contiguous U.S. Climatic Change 42: 377-412. Hondzo, M. and H.G. Stefan. 1991. Three case studies of lake temperature and stratification response to warmer climate. Water Resources Research 27: 1837-1846. Hook, S., Prata, F., Alley, R., Abtahi, A., Richards, R., Schladow, S., & Palmarson, S. (2003). Retrieval of lake bulk and skin temperature using Along-Track Scanning Radiometer (ATSR-2) data: A case study using Lake Tahoe, California. Journal of Atmospheric and Oceanic Technology, 20, 534-548. Hook, S.J., Vaughnan, R.G., Tonooka, H., & Schladow, S.G. (2007). Absolute radiometric in-flight validation of mid infrared and thermal infrared data from ASTER and MODIS on the Terra Spacecraft using the Lake Tahoe, CA/NV, USA, automated validation site. IEEE Transactions on Geosciences and Remote Sensing, 45(6), 1798-1807. Hulley, G.C., S.J. Hook & P. Schneider, (2011), Optimized split-window coefficients for deriving surface temperatures from inland water bodies, Remote Sensing of Environment, 115, 3758-3769 Kay, J. E., Kampf, S. K., Handcock, R. N., Cherkauer, K. A., Gillespie, A. R., & Burges, S. J. (2005). Accuracy of lake and stream temperatures determined from atmospherically corrected thermal-infrared imagery. Journal of theAmerican Water Resource Association, 41, 1161−1175. Li, X., Pichel, W., Clemente-Colon, P., Krasnopolsky, V., & Sapper, J. (2001). Validation of coastal sea and lake surface temperature measurements derived from NOAA/AVHRR data. International Journal of Remote Sensing, 22, 1285-1303. Long, Z., W. Perrie, J. Gyakum, D. Caya, R. Laprise, 2007: Northern lake impacts on local seasonal climate. J. Hydrometeor, 8, 881–896. Lofgren, B.M., & Zhu, Y. (2000). Surface energy fluxes on the Great Lakes based on satellite-observed surface temperatures 1992 to 1995. Journal of Great Lakes Research, 26(3), 305-314. Jingshi Liu, Siyuan Wang, Shumei Yu, Daqing Yang, Lu Zhang, Climate warming and growth of high-elevation inland lakes on the Tibetan Plateau, Global and Planetary Change, Volume 67, Issues 3–4, June 2009, Pages 209-217 MacCallum, S.N., and C.J. Merchant (2012). Surface Water Temperature Observations of Large Lakes by Optimal Estimation. MacCallum. Can J Remote Sensing, 38(1), 25 - 45 Mogilev, N., & Gnatovsky, R. (2003). Satellite imagery in the study of Lake Baikal surface temperatures. Mapping Sciences and Remote Sensing, 40, 41-50. Nehorai, R., I. M. Lensky, N. G. Lensky, and S. Shiff (2009), Remote sensing of the Dead Sea surface temperature, J. Geophys. Res., 114, C05021. Oesch, D,C., Jaquet, J.M., Hauser, A., & Wunderle, S. (2005). Lake surface water temperature retrieval using advanced very high resolution and Moderate Resolution Imaging Spectroradiometer data: Validation and feasibility study. Journal of Geophysical Research, 110, C12014, doi:10.1029/2004JC002857. Oesch, D,C., Jaquet, J.M., Klaus, R, Schenker, P (2008). Multi-scale thermal pattern monitoring of a large lake (Lake Geneva) using a multi-sensor approach. Int. Journal of Remote Sensing. 29(20), 5785-5808. Plattner, S., Mason, D.M., Leshkevitch, G.A., Schwab, D.J., & Rutherford, E.S. (2006). Classifying and forecasting coastal upwellings in Lake Michigan using satellite derived temperature images and buoy data. Journal of Great Lakes Research, 32, 63-76. Politi, E, M.J. Cutler, and J.S. Rowan, 2012. Using the NOAA Advanced Very High Resolution Radiometer to Characterize temporal and spatial trends in water temperature of large European lakes. Remote Sensing Environment. 126, 1-11. Reinart, A., & Reinhold, M. (2008). Mapping surface temperature in large lakes with MODIS data. Remote Sensing of Environment, 112, 603-611. Sahoo, G. B., & Schladow, S. G. (2008). Impacts of climate change on lakes and reservoirs dynamics and restoration policies. Sustainability Science, 3(2), 189–199. Schwab, D.J., Leshkevich, G.A., and Muhr, G.C. 1992. Satellite measurements of surface water temperature in the Great Lakes: Great Lakes CoastWatch. J. Great Lakes Res. 18(2):247–258. Schwab, D.J., Leshkevich, G.A., & Muhr, G.C. (1999). Automated mapping of surface water temperature in the Great Lakes. Journal of Great Lakes Research, 25, 468-481. Schneider, P., Hook, S. J., Radocinski, R. G., Corlett, G. K., Hulley, G. C., Schladow, S. G., and Steissberg, T. E. 2009. Satellite observations indicate rapid warming trend for lakes in California and Nevada, Geophysical Research Letters, Vol. 36, No. 22. Schneider, P., & Hook, S. J. (2010). Space observations of inland water bodies show rapid surface warming since 1985. Geophysical Research Letters, 37. Steissberg, T.E., Hook, S.J., & Schladow, S.G. (2005). Characterizing partial upwellings and surface circulation at Lake Tahoe, California—Nevada, USA with thermal infrared images. Remote Sensing of Environment, 99, 2-15. Thiemann, S., & Schiller, H. (2003). Determination of the bulk temperature from NOAA/AVHRR satellite data in a midlatitude lake. International Journal of Applied Earth Observation and Geoinformation, 4, 339−349. Tomlinson, C. J., Chapman, L., Thornes, J. E. and Baker, C. (2011), Remote sensing land surface temperature for meteorology and climatology: a review. Met. Apps, 18: 296–306. Ward, B. (2006). Near-surface ocean temperature. Journal of Geophysical Research, 111, C02004, doi:10.1029/2004JC002689. Wen Yau, L., Field, R.T., Gantt, R., & Klemas, V. (1987). Measurement of the surface emissivity of turbid waters. Remote Sensing of Environment, 21, 97-109. Wooster, M., Patterson, G., Loftie, R., Sear, C., 2001. Derivation and validation of the seasonal thermal structure of lake Malawi using multi-satellite AVHRR observations International Journal of Remote Sensing 22 (15), 2953–2972. Wu, X., & Smith, W.L. (1997). Emissivity of rough sea surface for 8-13 µm: modeling and verification. Applied Optics, 36, 2609-2619. Warner, T. T., M. N. Lakhtakia, J. D. Doyle, and R. A. Pearson, 1990: Marine atmospheric boundary layer circulations forced by Gulf Stream sea surface temperature gradients. Mon. Wea. Rev., 118, 309–323. Wright, D. M., D. J. Posselt, and A. L. Steiner, 2013: Sensitivity of lake-effect snowfall to lake ice cover and temperature in the Great Lakes region. Mon. Wea. Rev., (accepted). Zhao, L., J. Jin, S.-Y. Wang, and M. B. Ek, 2012: Integration of remote-sensing data with WRF to improve lake-effect precipitation simulations over the Great Lakes region, J. Geophys. Res., 117, D09102