Manitou Experimental Forest Observatory


The Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen (BEACHON) project was initiated by the National Center for Atmospheric Research (NCAR)as well as research collaborators from the university community to investigate ecosystem-atmosphere exchange of trace gases and aerosols and their potential feedbacks between biogeochemical and water cycles. One of the project’s primary objectives is to improve the predictability of earth-system models over time scales ranging from minutes to decades. BEACHON is now an ongoing component of atmospheric research sponsored by the National Science Foundation. This interdisciplinary research program integrates local and regional model simulations with remote sensing, regional network observations, and canopy- to regional-scale field measurements. BEACHON includes investigations of atmospheric, ecological and hydrological processes including concentration and flux measurements of energy, CO2, H2O, volatile organic compounds, aerosols, nitrogen compounds, hydrological parameters and feedback processes that are relevant to atmospheric chemistry. Rocky Mountain ecosystems are important for providing water and other resources in the western United States, but contain only a limited number of long-term monitoring sites. This region is predominantly arid or semi-arid resulting in biogeochemical cycles that are water-limited. Since the area contains some of the fastest growing population centers, water limitations (combined with a climate that is projected to be warmer and potentially drier) pose significant societal vulnerabilities (Vorosmarty et al., 2010).

The Manitou Experimental Forest Observatory (MEFO) was established in 2008, in an area representative of a middle-elevation (~2000 - 2500 m ASL). It is a semi-arid, ponderosa pine ecosystem that is common throughout the Rocky Mountain West, but not adequately characterized.


Quick facts:

Chemistry Tower Configuration

For more information, click here to download the comprehensive review paper



If you use this data we recommend this citation:

If you use this data, please use this citation:
National Center for Atmospheric Research Atmospheric Chemistry Observations and Modeling (NCAR-ACOM): Manitou Experimental Forest Observatory Field Site, Accessed on [date]



Site Description

This forest’s elevation ranges from 2280 to 2840m ASL, and vegetation is primarily composed of forests of ponderosa pine, Douglas fir, mixed conifer and aspen. Soils underlying the tower site and the surrounding area are classified as deep, well-drained sandy loams and sandy gravelly loams originating from alluvial deposits weathered from underlying arkosic sandstone formations as well as nearby granite formations (Soil Conservation Service, 1992). The terrain slope is asymmetric across this valley with the east side of the valley being steeper and the west side being more gradual (gradient between 3 and 8%). The National Weather Service has been monitoring precipitation at MEFO since 1940 (Station Woodland Park 8 NNW, Coop ID: 059210), and US Forest Service staff have been collecting meteorological data including air and soil temperature, precipitation and wind speed since 1998.

Measurement Timeline

MEFO Timeline Download the Manitou Measurements Timeline


Publications & Presentations

For a list of papers and publications, click here.

For an overview of the experiment, please download this PowerPoint





John Ortega



Battaglia, M. A., Rocca, M. E., Rhoades, C. C., and Ryan, M. G.: Surface fuel loadings within mulching treatments in Colorado coniferous forests, Forest Ecol. Manag., 260, 15571566, doi:10.1016/j.foreco.2010.08.004, 2010.

Berkelhammer, M.J., J. Hu, A. Bailey, D. C. Noone, C. J. Still, H. Barnard, D. Gochis, G. S. Hsiao, T. Rahn, and A. Turnipseed, The nocturnal water cycle in an open-canopy forest, J. Geophys. Res. Atmos., 118, 10,22510,242, doi:10.1002/jgrd.50701, 2013

Brüggemann, M, Vogel, A.L., Hoffman, T.. Analysis of organic aerosols using a micro-orifice volatilization impactor (MOVI) coupled to an atmospheric-pressure chemical ionization mass spectrometer (APCI-MS). European Journal of Mass Spectrometry. 20(1), pp. 31-41, 2014. (DOI:10.1255/ejms.1260)

Chan, A. W. H., Kreisberg, N. M., Hohaus, T., Campuzano-Jost, P., Zhao, Y., Day, D. A., Kaser, L., Karl, T., Hansel, A., Teng, A. P., Ruehl, C. R., Sueper, D. T., Jayne, J. T., Worsnop, D. R., Jimenez, J. L., Hering, S. V., and Goldstein, A. H.: Speciated measurements of semivolatile and intermediate volatility organic compounds (S/IVOCs) in a pine forest during BEACHON-RoMBAS 2011, Atmos. Chem. Phys., 16, 1187-1205, doi:10.5194/acp-16-1187-2016, 2016.

Crawford, I., N. H. Robinson, M. J. Flynn, V. E. Foot, M. W. Gallagher, J. A. Huffman, W. R. Stanley, and P. H. Kaye. Characterisation of bioaerosol emissions from a Colorado pine forest: results from the BEACHON-RoMBAS experiment, Atmos. Chem. Phys., 14, 8559-8578, doi:10.5194/acp-14-8559-2014, 2014

Cui, Y. Y., Hodzic, A., Smith, J. N., Ortega, J., Brioude, J., Matsui, H., Levin, E. J. T., Turnipseed, A., Winkler, P., and de Foy, B.: Modeling ultrafine particle growth at a pine forest site influenced by anthropogenic pollution during BEACHON-RoMBAS 2011, Atmos. Chem. Phys., 14, 11011-11029, doi:10.5194/acp-14-11011-2014, 2014.

DiGangi, J. P., Henry, S. B., Kammrath, A., Boyle, E. S., Kaser, L., Schnitzhofer, R. et al. 2012. Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry. Atmospheric Chemistry and Physics 12, 9529-9543.

DiGangi, J. P., Boyle, E. S., Karl, T., Harley, P., Turnipseed, A., Kim, S. et al. 2011. First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources. Atmospheric Chemistry and Physics 11, 10565-10578.

Eidhammer, T., Barth, M. C., Petters, M. D., Wiedinmyer, C. and Prenni, A. J. 2014. Aerosol microphysical impact on summertime convective precipitation in the Rocky Mountain region. Journal of Geophysical Research-Atmospheres 119, 11709-11728.

Eller, A.S.D., P. Harley, and R.K. Monson, Potential contribution of exposed resin to ecosystem emissions of monoterpenes Atmos. Environ., 2013

Fornwalt, P. J., Kaufmann, M. R., and Stohlgren, T. J.: Impacts of mixed severity wildfire on exotic plants in a Colorado ponderosa pine-Douglas-fir forest, Biol. Invasions, 12, 26832695, doi:10.1007/s10530-009-9674-2, 2010.

Fry, J.L., D.C. Draper, K.J. Zarzana, P. Campuzano-Jost, D.A. Day, J.L. Jimenez, S.S. Brown, R.C. Cohen, L. Kaser, A. Hansel, L. Cappellin, T. Karl, A. Hodzic Roux, A. Turnipseed, C. Cantrell, B.L. Lefer, and N. Grossberg. Observations of gas- and aerosol-phase organic nitrates at BEACHON-RoMBAS 2011 ACP, 2013

Gary, H. L.: A summary of research at the Manitou Experimental Forest in Colorado, 19371983, US Department of Agriculture, Forest Service Publication, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO, 1985.

Gosselin, M. I., Rathnayake, C. M., Crawford, I., Pöhlker, C., Fröhlich-Nowoisky, J., Schmer, B., Després, V. R., Engling, G., Gallagher, M., Stone, E., Pöschl, U., and Huffman, J. A.: Fluorescent bioaerosol particle, molecular tracer, and fungal spore concentrations during dry and rainy periods in a semi-arid forest, Atmos. Chem. Phys., 16, 15165-15184, doi:10.5194/acp-16-15165-2016, 2016.

Huffman, J.A., C. Pöhlker, A.J. Prenni, P.J. DeMott, R.H. Mason, N.H. Robinson, J. Fröhlich-Nowoisky, Y. Tobo, V.R. Després, E. Garcia, D.J. Gochis, E. Harris, I. Müller-Germann, C. Ruzene, B. Schmer, B. Sinha, D.A. Day, M.O. Andreae, J.L. Jimenez, M. Gallagher, S.M. Kreidenweis, A.K. Bertram, and U. Pöschl. High concentrations of biological aerosol particles and ice nuclei during and after rain ACP, 2013

Hunter, J.F., Day, D.A., Palm,B.B.,Yatavelli,R.L.N., Chan,A.W.H., Kaser, L., Cappellin,L., Hayes, P.L., Cross, E.S., Carrasquillo, A.J., Campuzano-Jost, P., Stark, H., Zhao,Y., Hohaus, T., Smith, J.N., Hansel, J., Karl, T., Goldstein, A.H., Guenther, A., Worsnop, D.R., Thornton, J.A., Heald,C.L., Jimenez,J.L., Kroll,J.H., Comprehensive characterization of atmospheric organic carbon at a forested site, Nature Geoscience, doi:10.1038/ngeo3018, 2017.

Karl, T., Kaser, L. and Turnipseed, A. 2014. Eddy covariance measurements of isoprene and 232-MBO based on NO+ time-of-flight mass spectrometry. International Journal of Mass Spectrometry 365, 15-19.

Karl, T., A. Hansel, L. Cappellin, L. Kaser, I. Herdlinger, and W. Jud. Selective measurements of isoprene and 2-methyl-3-buten-2-ol based on NO+ ionization mass spectrometry. Atmos. Chem. Phys., 12, 11877-11884, doi:10.5194/acpd-12-19349-2012, 2012

Kaser, L., Karl, T., Guenther, A., Graus, M., Schnitzhofer, R., Turnipseed, A. et al. 2013. Undisturbed and disturbed above canopy ponderosa pine emissions: PTR-TOF-MS measurements and MEGAN 2.1 model results. Atmospheric Chemistry and Physics 13, 11935-11947.

Kim, S., Wolfe, G. M., Mauldin, L., Cantrell, C., Guenther, A., Karl, T. et al. 2013. Evaluation of HOx sources and cycling using measurement-constrained model calculations in a 2-methyl-3-butene-2-ol (MBO) and monoterpene (MT) dominated ecosystem. Atmospheric Chemistry and Physics 13, 2031-2044.

Kim, S., Karl, T., Guenther, A., Tyndall, G., Orlando, J., Harley, P. et al. 2010. Emissions and ambient distributions of Biogenic Volatile Organic Compounds (BVOC) in a ponderosa pine ecosystem: interpretation of PTR-MS mass spectra. Atmospheric Chemistry and Physics 10, 1759-1771.

Linkhart, B. D. and Reynolds, R. T., Lifetime reproduction of Flammulated Owls in Colorado, J. Raptor Res., 40,2937, doi:10.3356/0892-1016(2006)40[29:lrofoi];2, 2006.

Linkhart, B. D. and Reynolds, R. T.: Return rate, fidelity, and dispersal in a breeding population of flammulated owls (Otus flammeolus), Auk, 124, 264275, doi:10.1642/00048038(2007)124[264:rrfadi];2, 2007.

Levin, E.J.T., A.J. Prenni1, B.B. Palm, D.A. Day, P. Campuzano-Jost, P.M. Winkler, S.M. Kreidenweis, P.J. DeMott, J.L. Jimenez, and J.N. Smith. Size-resolved aerosol composition and its link to hygroscopicity at a forested site in Colorado, Atmos. Chem. Phys., 14, 26572667, doi:10.5194/acp-14-2657-2014, 2014

Levin, E. J. T., Prenni, A. J., Petters, M. D., Kreidenweis, S. M., Sullivan, R. C., Atwood, S. A. et al. 2012. An annual cycle of size-resolved aerosol hygroscopicity at a forested site in Colorado. Journal of Geophysical Research-Atmospheres 117.

Lezberg, A. L., Battaglia, M. A., Shepperd, W. D., and Schoettle, A. W.: Decades-old silvicultural treatments influence surface wildfire severity and post-fire nitrogen availability in a ponderosa pine forest, Forest Ecol. Manag., 255, 4961, doi:10.1016/j.foreco.2007.08.019, 2008.

Massman, W. J., Frank, J. M., and Mooney, S. J.: Advancing investigation and physical modeling of first-order fire effects on soils, Fire Ecology, 6, 3654, doi:10.4996/fireecology.0601036, 2010.

Nakashima, Y., Kato, S., Greenberg, J., Harley, P., Karl, T., Turnipseed, A. et al. 2014. Total OH reactivity measurements in ambient air in a southern Rocky mountain ponderosa pine forest during BEACHON-SRM08 summer campaign. Atmospheric Environment 85, 1-8.

Ortega, J., A. Turnipseed, A.B. Guenther, T.G. Karl,D.A. Day, D. Gochis, J.A. Huffman, A.J. Prenni, E.J.T. Levin,S.M. Kreidenweis, P.J. DeMott, Y. Tobo, E.G. Patton, A. Hodzic,Y. Cui, P.C. Harley, R.H. Hornbrook, E.C. Apel, R.K. Monson,A. S. D. Eller, J. P. Greenberg, M. Barth, P. Campuzano-Jost,B.B. Palm, J.L. Jimenez, A.C. Aiken, M.K. Dubey, C. Geron,J. Offenberg, M.G. Ryan, P.J. Fornwalt, S.C. Pryor, F.N. Keutsch,J.P. DiGangi, A.W.H. Chan, A.H. Goldstein, G.M. Wolfe, S. Kim,L. Kaser, R. Schnitzhofer, A. Hansel, C.A. Cantrell, R.L. Mauldin III,and J.N. Smith. Overview of the Manitou Experimental Forest Observatory: site description and selected science results from 2008 to 2013, Atmos. Chem. Phys., 14, 6345-6367, doi:10.5194/acp-14-6345-2014, 2014.

Palm, B. B., Campuzano-Jost, P., Day, D. A., Ortega, A. M., Fry, J. L., Brown, S. S., Zarzana, K. J., Dube, W., Wagner, N. L., Draper, D. C., Kaser, L., Jud, W., Karl, T., Hansel, A., Gutiérrez-Montes, C., and Jimenez, J. L. Secondary organic aerosol formation from in situ OH, O3, and NO3 oxidation of ambient air in an oxidation flow reactor, Atmos. Chem. Phys. 17, 5331-5354, doi:10.5194/acp-17-5331-2017, 2017.

Palm, B. B., Campuzano-Jost, P., Ortega, A. M., Day, D. A., Kaser, L., Jud, W., Karl, T., Hansel, A., Hunter, J. F., Cross, E. S., Kroll, J. H., Peng, Z., Brune, W. H., and Jimenez, J. L.: In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor, Atmos. Chem. Phys., 16, 2943-2970, doi:10.5194/acp-16-2943-2016, 2016.

Prenni, A.J., Y. Tobo, E. Garcia, P.J. DeMott, J.A. Huffman, C.S. McCluskey, S.M. Kreidenweis, J.E. Prenni, C. Pöhlker, U. Pösch The impact of rain on ice nuclei populations at a forested site in Colorado GRL, 2013

Pryor, S.C., R.J. Barthelmie, and K.E. Hornsby. Size-Resolved Particle Fluxes and Vertical Gradients over and in a Sparse Pine Forest AS&T, 2013

Rhew, R. C., Deventer, M. J., Turnipseed, A. A., Warneke, C., Ortega, J., Shen, S., Martinez, L., Koss, A., Lerner, B. M., Gilman, J. B., Smith, J. N., Guenther, A. B., and de Gouw, J. A.: Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by relaxed eddy accumulation, Atmos. Chem. Phys., 17, 13417-13438,, 2017.

Rhoades, C. C., Battaglia, M. A., Rocca, M. E., and Ryan, M. G.: Short- and medium-term effects of fuel reduction mulch treatments on soil nitrogen availability in Colorado conifer forests, Forest Ecol. Manag., 276, 231238, doi:10.1016/j.foreco.2012.03.028, 2012.

Robinson, N.H., J.D. Allan, J.A. Huffman, P.H. Kaye, V.E. Foot, and M. Gallagher. Cluster analysis of WIBS single particle bioaerosol data. Atmos. Meas. Tech., 6, 337-347, 2012, doi:10.5194/amt-6-337-2013, 2013

Roskamp, M.J., W. Luo, J.F. Pankow, T.R. Rosenstiel, P.C. Harley, A.A. Turnipseed, K.C. Barsanti. Characterization of Biogenic Volatile Organic Compounds (BVOCs) in a Pine Forest by Two-Dimensional Gas Chromatography-Time of Flight Mass Spectrometry (GCxGC-TOFMS), In Prep, Ph.D Thesis

Schumacher, C. J., Pöhlker, C., Aalto, P., Hiltunen, V., Petäjä, T., Kulmala, M., Pöschl, U., and Huffman, J. A.: Seasonal cycles of fluorescent biological aerosol particles in boreal and semi-arid forests of Finland and Colorado, Atmos. Chem. Phys., 13, 11987-12001, doi:10.5194/acp-13-11987-2013, 2013.

Soil Conservation Service: Soil Survey of Pike National Forest, Eastern Part, Colorado, Parts of Douglas, El Paso, Jefferson and Teller Counties. United States Department of Agriculture, Forest Service and Soil Conservation Service, 106 pp., 1992.

Tobo, Y., A.J. Prenni, P.J. DeMott, J.A. Huffman, C.S. McCluskey, G. Tian, C. Pohlker, U. Poschl, and S.M. Kreidenweis. Biological aerosol particles as a key determinant of ice nuclei populations in a forest ecosystem J. Geophys. Res. Atmos., 118, 10,10010,110, doi:10.1002/jgrd.50801, 2013

Vorosmarty, C. J., McIntyre, P. B., Gessner, M. O., Dudgeon, D., Prusevich, A., Green, P., Glidden, S., Bunn, S. E., Sullivan, C.A., Liermann, C. R., and Davies, P. M.: Global threats to human water security and river biodiversity, Nature, 467, 555561, doi:10.1038/nature09440, 2010.

Wolfe, G. M., Cantrell, C., Kim, S., Mauldin, R. L., Karl, T., Harley, P. et al. 2014. Missing peroxy radical sources within a summertime ponderosa pine forest. Atmospheric Chemistry and Physics 14, 4715-4732.

Yatavelli, R. L. N., Claudia Mohr, Harald Stark, Douglas A. Day, Samantha L. Thompson, Felipe D. Lopez-Hilfiker, Pedro Campuzano-Jost, Brett B. Palm, Alexander L. Vogel, Thorsten Hoffmann, Liine Heikkinen, Mikko Äijälä, Nga L. Ng, Joel R. Kimmel, Manjula R. Canagaratna, Mikael Ehn, Heikki Junninen, Michael J. Cubison, Tuukka Petäja, Markku Kulmala, John T. Jayne, Douglas R. Worsnop, and Jose L. Jimenez. Estimating the contribution of organic acids to northern hemispheric continental organic aerosol, Geophys. Res. Lett., 42, doi:10.1002/2015GL064650, 2015

Yatavelli, R.L.N., H. Stark, S.L. Thompson, J.R. Kimmel, M.J. Cubison, D.A. Day, P. Campuzano-Jost, B.B. Palm, J.A. Thornton, J.T. Jayne, D.R. Worsnop, and J.L. Jimenez. SemiContinuous Measurements of Gas/Particle Partitioning of Organic Acids in a ponderosa pine Forest Using a MOVI-HRToF-CIMS. Atmospheric Chemistry and Physics, 14, 1527-1546, doi:10.5194/acp-14-1527-2014, 2014.

Zhang, H., Z. Zhang, T. Cui, Y.H. Lin, N.A. Bhathela, J. Ortega, D.R. Worton, A.H. Goldstein, A. Guenther, J.L. Jimenez, A. Gold, and J.D. Surratt. Secondary Organic Aerosol Formation from 2-Methyl-3-Buten-2-ol (MBO) Photooxidation: Evidence for Acid-Catalyzed Reactive Uptake of Epoxides, Environ. Sci. Technol. Lett., 2014, 1 (4), pp 242247, doi: 10.1021/ez500055f, 2014

Zhang, H., D.R. Worton, M. Lewandowski, J. Ortega, C.L. Rubitschun, J.H. Park, K. Kristensen, P. Campuzano-Jost, D.A. Day, J.L. Jimenez, M. Jaoui, J.H. Offenberg, T.E. Kleindienst, J. Gilman, W.C. Kuster, J. de Gouw, C.H. Park, G.W. Schade, A.A. Frossard, L. Russell, L. Kaser, W. Jud, A. Hansel, L. Cappellin, T. Karl, M. Glasius, A. Guenther, A.H. Goldstein, J.H. Seinfeld, A. Gold, R.M. Kamens, and J.D. Surratt. Organosulfates as Tracers for Secondary Organic Aerosol (SOA) Formation from 2-Methyl-3-Buten-2-ol (MBO) in the Atmosphere. Environmental Science & Technology, doi:10.1021/es301648z, 2012.

Zhou, L., Gierens, R., Sogachev, A., Mogensen, D., Ortega, J., Smith, J. N. et al. 2015. Contribution from biogenic organic compounds to particle growth during the 2010 BEACHON-ROCS campaign in a Colorado temperate needleleaf forest. Atmospheric Chemistry and Physics 15, 8643-8656.


The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

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