New Transient Land Use and Land Cover Change Parameters for CLM5 and CESM2 for use in CMIP6

Transcription

1 New Transient Land Use and Land Cover Change Parameters for CLM5 and CESM2 for use in CMIP6 Dr. Peter Lawrence Project Scientist NCAR Terrestrial Science Section David Lawrence, George Hurtt and many others Slide 1 - Title

2 1. CLM5 CMIP6 New Land Surface Data Sets 1. For CLM5 and the CMIP6 climate simulations there will be new Historical and SSP - RCP land use and land cover change data sets which are currently being compiled for through the Land Use and Scenario Model Intercomparison Projects (LUMIP and ScenarioMIP). 2. The new time series include new functionality following lessons learned through CMIP5 and to include new developments in CLM5. 3. The Global Land Model (GLM) has been extended to 12 land units to better represent dynamics of agriculture and forests. The new land units include: - Primary Forest - Primary Non Forest - Secondary Forest - Secondary Non Forest - Crop C3 Annual - Crop C3 Perennial - Crop C3 Nitrogen Fixing - Crop C4 Annual - Crop C4 Perennial - Grazing Pasture - Grazing Rangeland - Urban 4. New management information for Crops and Forests is provided with transient N Fertilizer and Irrigation prescription, and new Wood Harvest Slide 2 - Outline

3 1. CMIP6 LUMIP CLM5 Land Use Harmonization (LUH2) New Resolution 0.25 grid-cell fraction New History Hyde 3.2, FAO based Landsat F/NF Multiple crop types (5) Multiple pasture types (2) Updated Forest Cover/Biomass Updated Wood harvest Updated Shifting Cultivation Extended time domain ( ) New Management Layers Agriculture Fraction of cropland irrigated Fraction of cropland flooded Fraction of cropland fertilized (industrial) Industrial Fertilizer application rates Fraction of cropland for biofuels Crop rotations Wood Harvest Fraction used for industrial products Fraction used for commercial biofuels Fraction used for fuelwood New Future Scenarios Six futures, SSP-based ~ 50x information content of CMIP5! New Transition Matrix

4 1. CMIP6 LUMIP CLM5 Land Use Harmonization (LUH2) New Resolution 0.25 grid-cell fraction New History Hyde 3.2, FAO based Landsat F/NF Multiple crop types (5) Multiple pasture types (2) Updated Forest Cover/Biomass Updated Wood harvest Updated Shifting Cultivation Extended time domain ( ) New Management Layers Agriculture Fraction of cropland irrigated Fraction of cropland flooded Fraction of cropland fertilized Industrial Fertilizer application Fraction of cropland for biofuels Crop rotations Wood Harvest Fraction industrial products Fraction commercial biofuels Fraction fuelwood New Future Scenarios Six futures, SSP-based ~ 50x information content of CMIP5!

5 2. CMIP5 Transient Land Cover in CLM 4 PFTs Method GLM 0.5 O Slide 6 PFT Mapping

6 2. CMIP6 Transient Land Cover in CLM 5 PFTs Method GLM 0.25 O Slide 6 PFT Mapping

7 Gridcell Landunit TBD HD Vegetated Lake MD Urban Glacier Crop Unirrig Irrig Unirrig Irrig Crop1 Crop1 Crop2 Crop2

8 3. CMIP6 LUMIP CLM5 1. Working with Dave Lawrence, Bill Sacks and Danica Lombardozzi developing new LUMIP CMIP6 CLM transient crop simulation capability with prescribed annual crop N fertilizer and irrigation. New landuse.timeseries files. For each year of LUMIP/CMIP6 time series specify for each grid cell: - PCT_NATVEG percent of gridcell as natural vegetation land unit - PCT_CROP percent of gridcell as crop land unit - PCT_PFT percent of natural vegetated land unit for each PFT - PCT_CFT percent of crop land unit for each CFT (irrigated/rainfed) - FERTNITRO_CFT gn/m2/yr N Fertilizer for each CFT - HARVEST_PRIMARY_FOR gc/m2/yr Wood harvest Primary Forest - HARVEST_PRIMARY_NFOR gc/m2/yr Wood harvest Primary Non Forest - HARVEST_SECONDARY_MFOR gc/m2/yr Wood harvest Second Mature For - HARVEST_SECONDARY_YFOR gc/m2/yr Wood harvest Second Young Forest - HARVEST_SECONDARY_NFOR gc/m2/yr Wood harvest Second Non Forest - UNREPRESENTED_PFT_LULCC percent of PFT unrepresented in Net LULCC - UNREPRESENTED_CFT_LULCC percent of CFT unrepresented in Net LULCC * When land ice is active then PCT_NATVEG is residual of other land units Slide 4 Land Cover Change

9 3. CMIP6 LUMIP CLM5 Annual Transitions 1. As transitions between years now occur at the Land Unit and at the PFT and CFT level we need a new protocol for dealing with conserving and transferring water, energy, carbon and nitrogen pools between each level. 2. This is done first within the Land Unit with the addition or loss of each PFT or CFT transferred between crops or natural vegetation based on the absolute grid cell fraction changes. 3. Any changes that are not met within the Land Unit are then met with the corresponding unmet changes in the PFT or CFT of the other Land Unit. Slide 4 Land Cover Change

10 4. CMIP6 Transient Land Cover in CLM 5 Land Surface Data Sets 1. Updated MODIS Land Cover, Leaf Area Index and Albedo are being used to describe Primary and Secondary Forested and Non Forested land units as well as Rangelands and Pasture. 2. Landsat Tree Cover Continuous Fields data combined with MODIS LAI are being used to specify tree, herbaceous, and bare soil fractions. This replaces the use of MODIS vegetation continuous fields data. 3. Current day Arctic Shrubs PFTs which are directly prescribed from the MODIS Land Cover have been reduced from CLM4 to make them consistent with pan arctic studies by Walker et al 2005 and Taper et al (2006) The new interpretation has around a quarter of the CLM4 arctic shrub density. 4. Reducing the shrub fraction and replacing the fraction with Arctic C3 grass to be consistent with the field studies has large impacts on Arctic climate through substantially higher albedo. In the fully coupled CESM this results in arctic cooling with impacts on sea ice extent and thickness. Slide 6 PFT Mapping

11 4. CMIP6 Transient Land Cover in CLM 5 Land Surface Data Sets 1. In CLM4, Broadleaf Deciduous Tropical (BDT) Tree PFTs were prescribed from the MODIS Vegetation Continuous Fields tree fraction and the AVHRR Continuous Fields Broadleaf and Deciduous tree data. 2. Recently Dahlin et al 2015 found that CLM4 had difficulty in simulating the BDT leaf phenology when compared to satellite LAI. While changing the phenology of BDT had some improvement in CLM4 the minimum LAI values from satellite indicated that CLM4 prescribed too much BDT in many areas. 3. For CLM5 the prescription of current day BDT tree PFTs are now guided by MODIS LAI with the BDT trees being replaced with Broadleaf Evergreen Tropical (BET) Tree PFTs Slide 6 PFT Mapping

12 4. CMIP6 CLM5 Current Day Boreal Shrub PFT Slide 4 Land Cover Change

13 4. CMIP6 CLM5 Current day Broadleaf Tropical Tree PFTs Slide 4 Land Cover Change

14 5. CMIP6 LUMIP CLM5 CLM Crop Model 1. CLM5 Crop will be used to simulate the C3/C4 irrigated/rainfed annual/perennial crops specified in GLM time series with fertilizer rates. 2. CLM5 Crop follows AgroIBIS (Kucharik & Brye, 2003) with new Tropical Crops (Badger & Dirmeyer 2014) 3. Crops simulated currently include: Temperate corn, tropical corn, cotton, rice, sugarcane, temperate soybean, tropical soybean, spring wheat (rainfed and irrigated) 4. Mapping of GLM crop information to CLM5 Crop CFTs based on closest current day crops in CLM Crop of the corresponding type from MIRCA 2000 (Portmann et al 2010) 5. Many of the current day CLM5 Crop CFTs need to be remapped to a surrogate crop if that crop is not currently simulated in the CLM5 Crop model. 6. Use UNFAO yield data along with MODIS LAI and FLUXNET GPP to build remapping table to find corresponding active CLM Crop CFT Slide 4 Land Cover Change

15 5. MIRCA 2000 Rainfed and Irrigated Crop Area Portmann et al. (2010) All Current Day Crops in Global Data PFT PFT/CFT CFT CFT CFT CFT 0. Bare Soil 14. C4 Grass 28. Winter Barley Irrigated 42. Cotton Irrigated 56. Potatoes Irrigated 70. Sunflower Irrigated 1. Needleleaf Evergreen 15. C3 Generic Crop 29. Rye 43. Datepalm 57. Pulses 71. Miscanthus Temperate Tree 2. Needleleaf Evergreen Boreal Tree 3. Needleleaf Deciduous Boreal Tree 4. Broadleaf Evergreen Tropical Tree 5. Broadleaf Evergreen Temperate Tree 6. Broadleaf Deciduous Tropical Tree 7. Broadleaf Deciduous Temperate Tree 8. Broadleaf Deciduous Boreal Tree 9. Broadleaf Evergreen Shrub 10. Broadleaf Deciduous Temperate Shrub 11. Broadleaf Deciduous Boreal Shrub 16. C3 Generic Crop Irrigated 30. Rye Irrigated 44. Datepalm Irrigated 58. Pulses Irrigated 72. Miscanthus Irrigated 17. Temperate Corn 31. Winter Rye 45. Foddergrass 59. Rapeseed 73. Switchgrass 18. Temperate Corn Irrigated 32. Winter Rye Irrigated 46. Foddergrass Irrigated 60. Rapeseed Irrigated 74. Switchgrass Irrigated 33. Cassava 47. Grapes 61. Rice 75. Tropical Corn 20. Spring Wheat Irrigated 34. Cassava Irrigated 48. Grapes Irrigated 62. Rice Irrigated 76. Tropical Corn Irrigated 21. Winter Wheat 35. Citrus 49. Groundnuts 63. Sorghum 77. Tropical Soybean 22. Winter Wheat Irrigated 36. Citrus Irrigated 50. Groundnuts Irrigated 64. Sorghum Irrigated 78. Tropical Soybean Irrigated 23. Temperate Soybean 37. Cocoa 51. Millet 65. Sugarbeet 24. Temperate Soybean Irrigated 38. Cocoa Irrigated 52. Millet Irrigated 66. Sugarbeet Irrigated 25. Barley 39. Coffee 53. Oilpalm 67. Sugarcane 12. C3 Arctic Grass 26. Barley Irrigated 40. Coffee Irrigated 54. Oilpalm Irrigated 68. Sugarcane Irrigated 13. C3 Non-Arctic Grass 27. Winter Barley 41. Cotton 55. Potatoes 69. Sunflower Slide 4 Land Cover Change

16 5. MIRCA 2000 Rainfed and Irrigated Crop Area Portmann et al. (2010) C3 Generic in Global Data (still refining) CFT CFT CFT CFT CFT 15. C3 Generic Crop 29. Rye 16. C3 Generic Crop Irrigated 30. Rye Irrigated 17. Temperate Corn 31. Winter Rye 18. Temperate Corn Irrigated 32. Winter Rye Irrigated 33. Cassava 61. Rice 34. Cassava Irrigated 62. Rice Irrigated 21. Winter Wheat 22. Winter Wheat Irrigated Slide 4 Land Cover Change 35. Citrus 23. Temperate Soybean 37. Cocoa 61. Rice 36. Citrus Irrigated 24. Temperate Soybean Irrigated 38. Cocoa Irrigated 62. Rice Irrigated 25. Barley 26. Barley Irrigated 27. Winter Barley 28. Winter Barley Irrigated 39. Coffee 61. Rice 40. Coffee Irrigated 62. Rice Irrigated 43. Datepalm 41. Cotton 44. Datepalm Irrigated 42. Cotton Irrigated 45. Foddergrass 46. Foddergrass Irrigated 47. Grapes 48. Grapes Irrigated 49. Groundnuts 61. Rice 50. Groundnuts Irrigated 62. Rice Irrigated 51. Millet 75. Tropical Corn 52. Millet Irrigated 76. Tropical Corn Irrigated 53. Oilpalm 61. Rice 54. Oilpalm Irrigated 62. Rice Irrigated 41. Cotton 55. Potatoes 42. Cotton Irrigated 56. Potatoes Irrigated 57. Pulses 58. Pulses Irrigated 59. Rapeseed 60. Rapeseed Irrigated 71. Miscanthus 17. Temperate Corn 72. Miscanthus Irrigated 18. Temperate Corn Irrigated 73. Switchgrass 17. Temperate Corn 74. Switchgrass Irrigated 18. Temperate Corn Irrigated 61. Rice 75. Tropical Corn 62. Rice Irrigated 76. Tropical Corn Irrigated 63. Sorghum 75. Tropical Corn 64. Sorghum Irrigated 76. Tropical Corn Irrigated 65. Sugarbeet 66. Sugarbeet Irrigated 67. Sugarcane 68. Sugarcane Irrigated 69. Sunflower 70. Sunflower Irrigated 77. Tropical Soybean 78. Tropical Soybean Irrigated

17 6. CMIP6 Transient Wood Harvest in CLM5 1. In CLM4 Transient Wood Harvest was prescribed as the fraction of tree PFTs to be harvested for each year. The wood harvest flux took the time step interpolated fraction of the dead stem carbon pool for trees and placed it in the 10 and 100 year product pools. Other tree carbon pools had the same fraction transferred to the litter pool. 2. In CMIP5 this implementation resulted in differences in the expected carbon wood harvest flux simulated in the GLM model and in CLM due to different carbon densities between the two models Slide 6 PFT Mapping

18 6. CMIP6 Transient Wood Harvest in CLM5 1. To overcome this inconsistency between prescribed Wood Harvest carbon flux and the intended flux from GLM we have rewritten the Wood Harvest code so that the annual flux of carbon is now prescribed in gc/m2/year. 2. In the new CLM5 code the flux is used with the carbon density found in the dead stem carbon pool of the tree PFTs. This gives a fraction of the tree PFT to be harvested that will result in a wood harvest flux that is the same as was simulated in the GLM model. 3. By calculating the wood harvest fraction in the model, the transfer of other carbon pools to the litter pool are done consistently with the CMIP6 protocol. Slide 6 PFT Mapping

19 7. CMIP6 Gross versus Net LULCC in CLM5 Shifting Cultivation Slide 4 Land Cover Change

20 7. CMIP6 Gross versus Net LULCC in CLM5 Shifting Cultivation Slide 4 Land Cover Change

21 8. Conclusions for CLM5 Land Surface Data Sets for CMIP6 1. Currently still developing new transient Land Surface Data Sets for CLM5 2. New Data Sets will allow for better prescription of both Natural and Human Managed Landscapes 3. The New Data Sets leverage new functionality in CLM 5 such as transient Crops as well as prescribed N Fertilizer and Irrigation. 4. We have addressed issues that arose through the CMIP5 process in terms of the describing current day vegetation in terms of boreal shrubs and broadleaf deciduous tropical trees. 5. We have addressed the issue of Wood Harvest dependence on carbon density by rewriting the code to work on carbon fluxes rather than tree fraction. Slide 6 PFT Mapping 6. We have a new method of dealing with Gross Transitions missed in Net LU