The world's most comprehensive collection of atmospheric pressure observations helping scientists reconstruct historical weather patterns and understand climate change with unprecedented precision.
Imagine being able to know exactly what the weather was like on any given day since the time of Napoleon. This isn't science fiction—it's the remarkable reality enabled by the International Surface Pressure Databank (ISPD), a global collaborative project that has assembled the world's most comprehensive collection of atmospheric pressure observations.
Data spanning from 1836 to 2015, with ongoing expansions back to 1722 4 .
Combining land stations, marine observations, and tropical cyclone data for complete global coverage.
Enables reconstruction of historical weather patterns and understanding of climate change.
The International Surface Pressure Databank is recognized as the world's most extensive collection of global surface and sea-level pressure observations. This continuously updated database spans an impressive timeframe from 1836 to 2015, with ongoing expansions that incorporate even earlier records dating back to 1722 4 .
Visualization of historical data coverage
What makes the ISPD particularly valuable is its comprehensive approach to data collection, incorporating three distinct types of pressure measurements:
From land-based weather stations across the globe, providing consistent measurements from fixed locations.
From ships and buoys scattered across the world's oceans, capturing data from the 71% of Earth covered by water.
From storm monitoring agencies, providing critical data on extreme weather events 4 .
Atmospheric pressure serves as a fundamental indicator of weather and climate patterns because it reveals how air moves and heats up across the planet. Surface pressure measurements act like fingerprints of atmospheric circulation—the large-scale movement of air that distributes heat and moisture around the globe.
These historical pressure readings are particularly valuable for climate reanalysis, a scientific process that uses assimilation techniques to recreate historical climate conditions. By incorporating actual pressure observations into sophisticated computer models, scientists can reconstruct comprehensive snapshots of past weather on a global scale 4 .
Recovering and preserving historical pressure records is no simple task. Before the digital age, weather observations were recorded in ship logs, weather diaries, and paper records that are now scattered across archives worldwide.
The ISPD initiative involves significant "data rescue" efforts to locate, image, and digitize these fragile historical documents before they are lost to decay or disposal 4 .
One remarkable aspect of this work is the inclusion of data recovered through expeditions and even citizen science projects like Oldweather.org, where volunteers help transcribe historical weather observations from digital images of original documents 4 .
Creating a unified database from millions of disparate historical observations requires sophisticated methodology and quality control. The station component of ISPDv4 represents a careful blend of numerous national and international collections, with the largest contribution coming from the International Surface Database (ISD) 4 .
The marine component primarily draws from the International Comprehensive Ocean Atmosphere Data Set (ICOADS), enhanced with additional data recovered through international cooperation. The tropical cyclone information comes mainly from the International Best Track Archive for Climate Stewardship (IBTrACS) 4 .
When central pressure estimates are unavailable from tropical cyclone records, scientists employ an empirical gradient wind equation to convert wind estimates into pressure readings, ensuring as complete a record as possible 4 .
The ultimate test and application of the ISPD is the Twentieth Century Reanalysis Project (20CRv3), which uses the databank as its primary input. This ambitious project aims to reconstruct global weather patterns dating back to the 19th century, providing researchers with a consistent, detailed timeline of planetary atmospheric behavior 4 .
Gathering historical pressure observations from various sources
Validating and standardizing the collected data
Integrating observations into climate models
Producing comprehensive historical climate reconstructions
| Component | Primary Sources | Time Span | Notable Features |
|---|---|---|---|
| Station Data | International Surface Database plus national collections | 1836-2015 | Land-based observations from fixed locations |
| Marine Data | ICOADS Version 3+ with enhancements | 1836-2015 | Ship and buoy measurements across oceans |
| Tropical Cyclone Data | IBTrACS V03r10 | 1836-2015 | Storm pressure and wind information |
One of the most crucial aspects of building the ISPD is the ongoing effort to recover and preserve historical weather records before they are lost forever. This represents perhaps the most fundamental "experiment" in historical climatology—can we reconstruct our planetary history from scattered, fragile documents?
The process begins with the Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative, which coordinates international efforts to locate and image historical weather records. Through ACRE, teams have scanned thousands of documents from archives worldwide, including the UK Met Office's extensive collection of marine weather logs 4 .
Visualization of data recovery workflow
Researchers locate historical weather records in archives worldwide, creating digital images.
Volunteers and specialists transcribe handwritten observations into digital format.
Data undergoes rigorous checks to identify and correct errors.
| Time Period | Data Density | Key Sources | Notable Gaps |
|---|---|---|---|
| Pre-1900 |
|
Ship logs, selected stations | Southern Hemisphere, oceans |
| 1900-1950 |
|
Expanding station networks, more marine data | Polar regions, wartime gaps |
| 1950-2015 |
|
Global station networks, satellites, buoys | Minimal gaps |
The success of this data recovery experiment is measured in the remarkable expansion of our historical climate record. As of version 4, the ISPD has incorporated millions of previously unavailable observations, extending our reliable climate record back well into the 19th century 3 4 . These recovered data have proven particularly valuable for understanding climate variability and change. For example, they've enabled studies of historical drought patterns across Europe, such as research examining "Drought variability and change across the Iberian Peninsula" which relied on long-term pressure observations .
Building and maintaining the International Surface Pressure Databank requires specialized tools and approaches. Below are the essential "research reagents" that make this climate time machine possible:
| Tool/Resource | Function | Significance |
|---|---|---|
| Historical Documents | Primary source of pre-20th century data | Provide otherwise irrecoverable observations from past centuries |
| ASCII Exchange Format v1.1 | Standardized data format | Ensures compatibility between diverse data sources and systems |
| ICOADS Marine Database | Repository of ocean observations | Critical for covering the 71% of Earth's surface that is ocean |
| IBTrACS Tropical Cyclone Archive | Source of storm information | Captures extreme weather events in the historical record |
| Citizen Science Platforms | Volunteer-powered data transcription | Enables large-scale digitization of historical records |
| Reanalysis Models | Physical frameworks for data integration | Test data consistency and create complete climate pictures |
Gathering from multiple international sources
Rigorous validation and error correction
Converting to unified exchange format
Merging into the comprehensive ISPD
| Version | Coverage | Notable Enhancements |
|---|---|---|
| Version 2 | 1768-2012 | Added quality control feedback records |
| Version 3 | 1755-2011 | Expanded marine and tropical cyclone data |
| Version 4 | 1836-2015 | Major expansion of station and marine data |
As impressive as the current International Surface Pressure Databank is, the work continues. Version 5 is already in development, promising even more comprehensive coverage and additional historical data 4 . Meanwhile, researchers continue to mine the existing dataset for new insights into climate variability and change.
The ISPD represents a remarkable achievement in international scientific collaboration—proof that when researchers across borders and disciplines work together, we can recover crucial pieces of our planetary history. This work doesn't just help us understand our past; it provides the essential foundation for predicting our climate future.
"Historical reanalyses that span more than a century are needed for a wide range of studies, from understanding large-scale climate trends to diagnosing the impacts of individual historical extreme events" .
Identifying long-term patterns in global climate systems
Understanding historical storms, droughts, and heatwaves
Testing and improving climate prediction models
Studying historical precipitation and drought patterns