Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions
Analytical footprint models that simulate the source area of scalar fluxes generally include a fundamental assumption that the fluxes originate from a horizontal, homogeneous surface. It is widely understood that this assumption is often violated in flux studies, especially for sites where there are...
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| Format: | Article |
| Language: | English |
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EDP Sciences
2023-01-01
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| Series: | E3S Web of Conferences |
| Subjects: | |
| Online Access: | https://www.e3s-conferences.org/articles/e3sconf/pdf/2023/42/e3sconf_icstce2023_04019.pdf |
| _version_ | 1797756256765607936 |
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| author | Kumari Shweta Kambhammettu BVN P |
| author_facet | Kumari Shweta Kambhammettu BVN P |
| author_sort | Kumari Shweta |
| collection | DOAJ |
| description | Analytical footprint models that simulate the source area of scalar fluxes generally include a fundamental assumption that the fluxes originate from a horizontal, homogeneous surface. It is widely understood that this assumption is often violated in flux studies, especially for sites where there are significant variations in topography, leaf area, photosynthetic pathway and underlying soil properties. An accurate interpretation of the measured flux footprint under heterogeneous canopy condition can help alleviate the problem. We evaluated the performance of analytical models (Hsieh, K&M, and Schuepp) under stable and unstable atmosheric conditions for the homoeneous canopy (Cotton- C3, zm = 3m and Sugarcane- C4, zm = 4m) and heterogeneous canopy (mixed fetch) compared to FFP model in a complex sugarcane-cotton (C3-C4) cropping system. Performance of models were evaluated using a set of three eddy covariance (EC) towers (one each capturing homogenous C3 and C4 fluxes, and a third capturing heterogeneous, mixed (C3-C4) fluxes at zm = 8m). High-quality EC fluxes that fulfil stationarity and internal turbulence tests were analyzed on the basis of daytime, unstable condition datasets. K&M model (Corr >0.75 , RMSE <0.06 , SD <0.006) performed the best in comparison to FFP model flux footprint prediction under unstable atmospheric condition in heterogeneous canopy condition with respect to Hsieh (Corr <0.6, RMSE >0.01 , SD >0.005), and Schuepp analytical model (Corr =0.2, RMSE <0.01, SD>0.2 ). Unstable atmospheric condition is further classified into four categories (neutral, near neutral unstable, unstable, and very unstable). Relative performance of the analytical models was further analyzed with experimental flux tower generated flux footprint under neutral, near neutral unstable, unstable, and very unstable atmospheric condition. FFP model performs the best in heterogeneous canopy condition under varying neutral to very unstable atmospheric condition. We make clear recommendations for future analysis of fluxes in heterogeneous crop lands under varying atmospheric stability condition. |
| first_indexed | 2024-03-12T17:58:49Z |
| format | Article |
| id | doaj.art-ce20488a061b4d108853c2add2fc3b45 |
| institution | Directory Open Access Journal |
| issn | 2267-1242 |
| language | English |
| last_indexed | 2024-03-12T17:58:49Z |
| publishDate | 2023-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | E3S Web of Conferences |
| spelling | doaj.art-ce20488a061b4d108853c2add2fc3b452023-08-02T13:18:13ZengEDP SciencesE3S Web of Conferences2267-12422023-01-014050401910.1051/e3sconf/202340504019e3sconf_icstce2023_04019Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditionsKumari Shweta0Kambhammettu BVN P1Department of Civil Engineering, Indian Institute of Technology HyderabadDepartment of Civil Engineering, Indian Institute of Technology HyderabadAnalytical footprint models that simulate the source area of scalar fluxes generally include a fundamental assumption that the fluxes originate from a horizontal, homogeneous surface. It is widely understood that this assumption is often violated in flux studies, especially for sites where there are significant variations in topography, leaf area, photosynthetic pathway and underlying soil properties. An accurate interpretation of the measured flux footprint under heterogeneous canopy condition can help alleviate the problem. We evaluated the performance of analytical models (Hsieh, K&M, and Schuepp) under stable and unstable atmosheric conditions for the homoeneous canopy (Cotton- C3, zm = 3m and Sugarcane- C4, zm = 4m) and heterogeneous canopy (mixed fetch) compared to FFP model in a complex sugarcane-cotton (C3-C4) cropping system. Performance of models were evaluated using a set of three eddy covariance (EC) towers (one each capturing homogenous C3 and C4 fluxes, and a third capturing heterogeneous, mixed (C3-C4) fluxes at zm = 8m). High-quality EC fluxes that fulfil stationarity and internal turbulence tests were analyzed on the basis of daytime, unstable condition datasets. K&M model (Corr >0.75 , RMSE <0.06 , SD <0.006) performed the best in comparison to FFP model flux footprint prediction under unstable atmospheric condition in heterogeneous canopy condition with respect to Hsieh (Corr <0.6, RMSE >0.01 , SD >0.005), and Schuepp analytical model (Corr =0.2, RMSE <0.01, SD>0.2 ). Unstable atmospheric condition is further classified into four categories (neutral, near neutral unstable, unstable, and very unstable). Relative performance of the analytical models was further analyzed with experimental flux tower generated flux footprint under neutral, near neutral unstable, unstable, and very unstable atmospheric condition. FFP model performs the best in heterogeneous canopy condition under varying neutral to very unstable atmospheric condition. We make clear recommendations for future analysis of fluxes in heterogeneous crop lands under varying atmospheric stability condition.https://www.e3s-conferences.org/articles/e3sconf/pdf/2023/42/e3sconf_icstce2023_04019.pdfflux footprintmixed fetchheterogeneous surfaceeddy covarianceparameter aggregationflux averaging |
| spellingShingle | Kumari Shweta Kambhammettu BVN P Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions E3S Web of Conferences flux footprint mixed fetch heterogeneous surface eddy covariance parameter aggregation flux averaging |
| title | Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| title_full | Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| title_fullStr | Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| title_full_unstemmed | Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| title_short | Performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| title_sort | performance of analytical footprint models in heterogeneous landscapes under varying atmospheric stability conditions |
| topic | flux footprint mixed fetch heterogeneous surface eddy covariance parameter aggregation flux averaging |
| url | https://www.e3s-conferences.org/articles/e3sconf/pdf/2023/42/e3sconf_icstce2023_04019.pdf |
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