U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Hydrology and Remote Sensing Laboratory: Beltsville, MD
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Northeast Area Beltsville, Maryland (BARC) Beltsville Agricultural Research Center Hydrology and Remote Sensing Laboratory Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- People
- Research Sites
- Pesticide Volatilization
- Watershed Modeling
- Climate Change
- Soil Moisture
- Drought and ET
- HRSL Brochure

Title:   Author  item
                                            Holmes, Thomasitem
                                            Crow, Wadeitem
                                            HAIN, C - University Of Marylanditem
                                            Anderson, Martha
  Submitted to: American Geophysical Union
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 10/21/2013
                                    Publication  Date: 12/9/2013
                                    Citation: Holmes, T.R., Crow, W.T., Hain, C., Anderson, M.C. 2013. Reconciling diurnal features of thermal-andmicrowave-derived land surface temperature [abstract]. Proceedings of the Fall American Geophysical Union, December 9-13, 2013, San Francisco, CA. 2013 CDROM.Interpretive Summary:
                                Technical Abstract: Land surface temperature (T), a key ingredient for physically-based retrieval algorithms of hydrological states and fluxes, remains a poorly constrained parameter for global scale studies. The main two observational methods to remotely measure T are based on thermal infrared (TIR) observations and passive microwave observations (PMW). TIR is the most commonly used approach and the method of choice to provide standard T products for various satellite missions. It has found wide application, for example in energy balance approaches to retrieve land surface evapotranspiration. PMW-based T retrievals on the other hand are not as widely adopted for land applications; currently their principle use is in soil moisture retrieval algorithms.  

PMW and TIR technologies present two highly complementary and independent means of measuring T. PMW observations have a high tolerance to clouds but a low spatial resolution, and TIR has a high spatial resolution with temporal sampling restricted to clear skies. Furthermore, a combination of these T estimates with independent errors would inevitably reduce the overall uncertainty in estimating T. The need for improved T estimates at global scale for use in physical retrieval models of land surface parameters have motivated our work to understand the structural differences in the characteristics of the shape of the diurnal temperature cycle (DTC) as observed by PMW and TIR sensors. The ultimate goal of this work is to create a merged PMW and TIR temperature product that is spatially and diurnally continuous. 

This paper will report on recent progress in characterizing the main structural components of the DTC that explain differences in TIR and PMW estimates of T. Spatial patterns in DTC timing (phase lag with solar noon) have been calculated for TIR, PMW and compared to weather prediction estimates. Based on knowledge of DTC timing, which is relatively stable over the year, the DTC amplitude is studied in terms of spatial and temporal correlation between PMW and TIR. 

The nature of the temperature at the very surface layer of the land makes it difficult to combine temperature estimates between different methods. The skin temperature is characterized by a strong diurnal cycle that is dependant in timing and amplitude on the exact sensing depth and thermal properties of the vegetation. The results of this study present a significant step forward in reconciling the structural differences in T and thus prepare the way for a global merger of PMW and TIR T.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov