This is the HadISDH blend 1.1.1.2020f version of the Met Office Hadley Centre Integrated Surface Dataset of Humidity (HadISDH). HadISDH-blend is a near-global gridded monthly mean surface humidity climate monitoring product. It is created from in situ observations of air temperature and dew point temperature from ships and weather stations. The observations have been quality controlled and homogenised / bias adjusted. Uncertainty estimates for observation issues and gridbox sampling are provided (see data quality statement section below). These data are provided by the Met Office Hadley Centre. This version spans 1/1/1973 to 31/12/2020.

The data are monthly gridded (5 degree by 5 degree) fields. Products are available for temperature and six humidity variables: specific humidity (q), relative humidity (RH), dew point temperature (Td), wet bulb temperature (Tw), vapour pressure (e), dew point depression (DPD).

This version extends the 1.0.0.2019f version to the end of 2020. It combines HadISDH.land.4.3.1.2020f and HadISDH.marine.1.1.0.2020f and therefore their respective update notes. Users are advised to read the update documents in the Docs section for full details.

To keep informed about updates, news and announcements follow the HadOBS team on twitter @metofficeHadOBS.

For more detailed information e.g bug fixes, routine updates and other exploratory analysis, see the HadISDH blog: http://hadisdh.blogspot.co.uk/

References:

When using the dataset in a paper please cite the following papers (see Docs for link

to the publications) and this dataset (using the "citable as" reference):

Willett, K. M., Dunn, R. J. H., Kennedy, J. J. and Berry, D. I., 2020: Development of

the HadISDH marine humidity climate monitoring dataset. Earth System Sciences Data,

12, 2853-2880, https://doi.org/10.5194/essd-12-2853-2020

Freeman, E., Woodruff, S. D., Worley, S. J., Lubker, S. J., Kent, E. C., Angel, W. E.,

Berry, D. I., Brohan, P., Eastman, R., Gates, L., Gloeden, W., Ji, Z., Lawrimore, J.,

Rayner, N. A., Rosenhagen, G. and Smith, S. R., ICOADS Release 3.0: A major update to

the historical marine climate record. International Journal of Climatology.

doi:10.1002/joc.4775.

Willett, K. M., Dunn, R. J. H., Thorne, P. W., Bell, S., de Podesta, M., Parker, D. E.,

Jones, P. D., and Williams Jr., C. N.: HadISDH land surface multi-variable humidity and

temperature record for climate monitoring, Clim. Past, 10, 1983-2006,

doi:10.5194/cp-10-1983-2014, 2014.

Dunn, R. J. H., et al. 2016: Expanding HadISD: quality-controlled, sub-daily station

data from 1931, Geoscientific Instrumentation, Methods and Data Systems, 5, 473-491.

Smith, A., N. Lott, and R. Vose, 2011: The Integrated Surface Database: Recent

Developments and Partnerships. Bulletin of the American Meteorological Society, 92,

704-708, doi:10.1175/2011BAMS3015.1

We strongly recommend that you read these papers before making use of the data, more

detail on the dataset can be found in an earlier publication:

Willett, K. M., Williams Jr., C. N., Dunn, R. J. H., Thorne, P. W., Bell, S., de

Podesta, M., Jones, P. D., and Parker D. E., 2013: HadISDH: An updated land surface

specific humidity product for climate monitoring. Climate of the Past, 9, 657-677,

doi:10.5194/cp-9-657-2013.